阅读说明：本技术 一种信号发送的方法及装置 (Signal sending method and device ) 是由 盛杰 张公正 于 2020-04-22 设计创作，主要内容包括：本申请提供了一种信号发送的方法及装置,该方法包括：终端在第一时刻获取包含第一正交频分复用(OFDM)循环后缀长度信息的第一配置信息之后,从所述第一配置信息获取第一OFDM循环后缀长度；并在第二时刻使用所述第一OFDM循环后缀长度与网络设备进行通信。通过在上下行通信中加入OFDM循环后缀,避免了干扰信号与期望信号存在符号间干扰而导致的子载波正交性破坏,提升了系统吞吐量。(The application provides a method and a device for sending signals, wherein the method comprises the following steps: the method comprises the steps that after a terminal acquires first configuration information containing first Orthogonal Frequency Division Multiplexing (OFDM) cyclic postfix length information at a first moment, a first OFDM cyclic postfix length is acquired from the first configuration information; and communicating with a network device at a second time instant using the first OFDM cyclic suffix length. By adding the OFDM cyclic suffix in uplink and downlink communication, the method avoids the subcarrier orthogonality damage caused by the intersymbol interference of an interference signal and a desired signal, and improves the system throughput.)

1. A method of signaling, comprising:

a terminal acquires first configuration information at a first time, wherein the first configuration information comprises length information of a first OFDM cyclic postfix;

the terminal determines the length of a first OFDM cyclic suffix according to the first configuration information;

and the terminal communicates with network equipment at a second moment by using the first OFDM cyclic postfix length, wherein the second moment is a moment after the first moment.

2. The method of claim 1,

the terminal communicates with the network device using a second OFDM cyclic suffix length before a second time instant.

3. The method of claim 2,

the second OFDM cyclic suffix length is a default configured OFDM cyclic suffix length.

4. The method according to any one of claims 1 to 3,

the length of the first OFDM cyclic postfix is determined according to one or more of inter-user interference power, user self-interference power or time advance within the coverage range of the network equipment;

wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

5. The method of claim 4, further comprising:

the terminal receives a mutual interference measurement message issued by the network equipment;

the terminal determines the transmission time delay between users and/or the mutual interference power between the users;

the time advance is determined according to the transmission time delay between the users;

the transmission delay among the users is the transmission delay between the terminal and other terminals in the network, and the mutual interference power among the users is the interference power of other terminals in the network to the terminal;

and the terminal feeds back the inter-user interference power and/or the inter-user transmission delay to the network equipment.

6. The method of claim 4, further comprising:

the terminal determines user self-interference power and feeds the user self-interference power back to the network equipment.

7. The method of any of claims 1-6, wherein the network device communicates with the terminal using the first OFDM cyclic suffix length at a second time instance, comprising:

adding a cyclic suffix meeting the length of the first OFDM cyclic suffix to each OFDM symbol when the terminal communicates with the network equipment; or

And when the terminal is communicated with the network equipment, adding a cyclic suffix meeting the length of the first OFDM cyclic suffix to part of the OFDM symbols.

8. A method of signaling, comprising:

the network device determines a first OFDM cyclic suffix length;

the network equipment sends first configuration information at a first time, wherein the first configuration information comprises length information of a first OFDM cyclic postfix;

the network device communicates with the terminal using the first OFDM cyclic suffix length at a second time instant.

9. The method of claim 8,

the network device communicates with the terminal device using a second OFDM cyclic suffix length before a second time instant.

10. The method of claim 9,

the second OFDM cyclic suffix length is a default configured OFDM cyclic suffix length.

11. The method of claim 8, wherein the network device determines a first OFDM cyclic suffix length comprising:

when a terminal accesses the network equipment for the first time, the network equipment determines the length of the first OFDM cyclic suffix; or

When an update trigger condition is satisfied, the network device determines the first OFDM cyclic suffix length.

12. The method of any of claims 8-11, wherein the network device determining the length of the first OFDM cycle suffix comprises:

the network equipment determines the length of the first OFDM cyclic suffix according to one or more of inter-user interference power, user self-interference power or time advance in a coverage range;

wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

13. The method of claim 12, further comprising:

the network equipment sends a mutual interference measurement message to a terminal, wherein the mutual interference measurement message is used for acquiring transmission delay between users and mutual interference power between the users; wherein the inter-user transmission delay is used to determine the timing advance.

14. The method of claim 12, further comprising:

the network equipment determines the transmission time delay among users according to the position information of the terminal, wherein the transmission time delay among users is used for determining the time advance; and

and determining the mutual interference power between the users according to the uplink sending power of the terminal.

15. The method of claim 12, further comprising:

and the network equipment acquires the user self-interference power from a terminal, or determines the user self-interference power according to the self-interference elimination capability of the terminal.

16. The method according to any one of claims 12 to 15,

the time advance of the mutual interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the network device and the transmission delay between the terminals, and is specifically determined according to the following formula:

Δt_i,j＝t_i+t_j-t_i,j

where Δ t_i，jRepresenting the timing advance, t, of the interfering signal relative to the desired signal_iRepresenting the transmission delay, t, between the network device and the terminal i_jRepresenting the transmission delay, t, between the network device and the terminal j_i，jRepresenting the transmission delay between the terminal i and the terminal j; the time advance of the self-interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the network device, and is specifically equal to 2t_iWherein t is_iRepresenting the transmission delay between the network device and the terminal i.

17. The method according to any one of claims 12 to 16,

the network device determines a first OFDM cyclic suffix length according to the following formula:

wherein t is_csDenotes the cyclic suffix length, t_symRepresenting OFDM symbol length, M representing the number of terminals in downlink service within the coverage area of the network equipment, N representing the number of terminals in uplink service within the coverage area of the network equipment, and P_i ^rxIndicating the desired signal power received by the downstream terminal i,represents the interference power, P, of the uplink terminal j to the downlink terminal i_i ^SIDenotes the self-interference power, Δ t, of the downlink terminal i_i，jRepresenting the timing advance of the interfering signal relative to the desired signal, 2t_iRepresenting terminal i self-interference signal phaseWith respect to the timing advance of the desired signal,n_irepresenting the white noise power of terminal i.

18. The method of any of claims 8-17, wherein the network device communicates with the terminal using the first OFDM cyclic suffix length at a first time, comprising:

adding a cyclic suffix meeting the length of the first OFDM cyclic suffix to each OFDM symbol when the network equipment communicates with the terminal; or

And when the network equipment communicates with the terminal, adding a cyclic suffix meeting the length of the first OFDM cyclic suffix to part of the OFDM symbols.

19. The method according to any of claims 8-18, wherein the network device issues the first configuration information at the first time, comprising:

the first configuration information is a statically configured OFDM cyclic suffix length, and the statically configured OFDM cyclic suffix length satisfies that signals transmitted within the coverage range of the network equipment have no intersymbol interference.

20. The method of claim 11,

the update trigger condition includes one or more of:

and the timer started after the network equipment issues the OFDM cyclic suffix length configuration is timed to be ended, or the network total interference level or the cell throughput monitored by the network equipment in real time reaches a trigger threshold value.

21. A communications apparatus, comprising:

the device comprises a processing unit, a processing unit and a processing unit, wherein the processing unit is used for acquiring first configuration information at a first time, and the first configuration information comprises first OFDM cyclic postfix length information;

the processing unit is further configured to determine a first OFDM cyclic suffix length according to the first configuration information;

and a transceiver unit, configured to communicate with a network device using the first OFDM cyclic suffix length at a second time, where the second time is a time after the first time.

22. The communication device of claim 21,

the transceiver unit is further configured to communicate with the network device using a second OFDM cyclic suffix length before a second time instant.

23. The communication device according to claim 21 or 22,

the length of the first OFDM cyclic postfix is determined by one or more of inter-user mutual interference power, user self-interference power or time advance within the coverage range of the network equipment;

wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

24. The communication device of claim 23,

the receiving and sending unit is also used for receiving mutual interference measurement information sent by the network equipment;

the processing unit is further configured to determine an inter-user transmission delay and the inter-user mutual interference power;

the time advance is determined according to the transmission time delay between the users;

the transmission delay among the users is the transmission delay between the communication device and other terminals in the network, and the mutual interference power among the users is the interference power of other terminals in the network to the communication device;

the transceiver unit is further configured to feed back the user self-interference power and/or the inter-user transmission delay to the network device.

25. The communication device of claim 23,

the processing unit is further configured to determine a user self-interference power; and

the transceiver unit is further configured to feed back the user self-interference power to the network device.

26. The apparatus according to any of claims 21-25, wherein the transceiver unit is configured to communicate with a network device using the first OFDM cyclic suffix length at a second time instance, and comprises:

when the transceiver unit is in communication with the network device, the processing unit is further configured to add a cyclic suffix satisfying the OFDM cyclic suffix length to each OFDM symbol; or

When the transceiver unit communicates with the network device, the processing unit is further configured to add a cyclic suffix satisfying the OFDM cyclic suffix length to a partial OFDM symbol.

27. A communications apparatus, comprising:

a processing unit to determine a first OFDM cyclic suffix length;

a transceiving unit, configured to send first configuration information at a first time, where the first configuration information includes length information of a first OFDM cyclic suffix;

the transceiver unit is further configured to communicate with a terminal at a second time instant using the first OFDM cyclic suffix length.

28. The communication device of claim 27,

the transceiver unit is further configured to communicate with the terminal device using a second OFDM cyclic suffix length before a second time instant.

29. The communications apparatus of claim 27, wherein the processing unit is configured to OFDM cyclic suffix length comprising:

the processing unit is used for determining the length of an OFDM cyclic suffix when a terminal accesses the communication device for the first time; or

The processing unit is configured to determine an OFDM cyclic suffix length when an update trigger condition is satisfied.

30. The communications apparatus as claimed in any of claims 27-29, wherein the processing unit is configured to determine a length of an OFDM cyclic suffix, comprising:

the processing unit is specifically configured to determine the length of the OFDM cyclic suffix according to one or more of inter-user interference power, user self-interference power, or a timing advance within a coverage range;

wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

31. The communications device of claim 30, wherein:

the receiving and sending unit is further configured to send a mutual interference measurement message to a terminal, where the mutual interference measurement message is used to obtain inter-user transmission delay and inter-user mutual interference power; wherein the inter-user transmission delay is used to calculate the timing advance.

32. The communications device of claim 30, wherein:

the processing unit is further configured to determine an inter-user transmission delay according to the location information of the terminal, where the inter-user transmission delay is used to determine the timing advance; and

and determining the mutual interference power between the users according to the uplink sending power of the terminal.

33. The communications device of claim 30, wherein:

the transceiver unit is further configured to issue a self-interference power measurement message to a terminal, where the self-interference measurement message is used to obtain the user self-interference power.

34. The communications device of claim 30, wherein:

the processing unit is further configured to obtain the user self-interference power according to a self-interference cancellation capability of the terminal.

35. The apparatus of any one of claims 30-34,

the time advance of the mutual interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the communication device and the transmission delay between the terminals, and is specifically determined according to the following formula:

Δt_i,j＝t_i+t_j-t_i,j

where Δ t_i，jRepresenting the timing advance, t, of the interfering signal relative to the desired signal_iRepresenting the transmission delay, t, between the communication device and the terminal i_jRepresenting the transmission delay, t, between the communication device and terminal j_i，jRepresenting the transmission delay between the terminal i and the terminal j;

the timing advance of the self-interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the communication device, and is specifically equal to 2t_iWherein t is_iRepresenting the transmission delay between the communication device and terminal i.

36. The apparatus of any one of claims 27-35,

the processing unit is specifically configured to determine a first OFDM cyclic suffix length according to the following formula:

wherein t is_csDenotes the cyclic suffix length, t_symM table representing OFDM symbol lengthIndicating the number of terminals in downlink service within the coverage area of the communication device, N indicating the number of terminals in uplink service within the coverage area of the communication device, P_i ^rxIndicating the desired signal power received by the downstream terminal i,represents the interference power, P, of the uplink terminal j to the downlink terminal i_i ^SIDenotes the self-interference power, Δ t, of the downlink terminal i_i，jRepresenting the timing advance of the interfering signal relative to the desired signal, 2t_iRepresenting the timing advance of the terminal i self-interference signal relative to the desired signal,n_irepresenting the white noise power of terminal i.

37. The apparatus according to any of claims 27-36, wherein the transceiver unit is configured to communicate with the terminal using the OFDM cyclic suffix length at a second time, and comprises:

when the transceiver unit communicates with the terminal, the processing unit is further configured to add a cyclic suffix satisfying the OFDM cyclic suffix length for each OFDM symbol; or

When the transceiver unit communicates with the terminal, the processing unit is further configured to add a cyclic suffix satisfying the length of the OFDM cyclic suffix to a part of the OFDM symbols.

38. The communication device of claim 29,

the update trigger condition includes one or more of:

after the receiving and sending unit issues the configuration of the length of the OFDM cyclic suffix, the timer started by the processing unit is timed to end, or the network total interference level or the cell throughput monitored by the communication device in real time reaches a trigger threshold value.

39. A communications apparatus comprising a processor coupled to a memory, the memory storing a computer program or instructions, the processor to execute the computer program or instructions in the memory such that

The method of any one of claims 1 to 7 being performed, or

The method of any one of claims 8 to 20 being performed.

40. A computer-readable storage medium, having stored therein a computer program or instructions, which when executed on a computer, causes the computer to

The method of any one of claims 1 to 7 is performed; or

The method of any of claims 8 to 20 being performed.

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for transmitting a signal.

Background

From the first generation of analog cellular mobile communication networks in the middle of the seventies of the twentieth century to the second generation of mobile communication systems represented by global system for mobile communications (GSM) and IS-95 in the middle of the eighties, to the third generation of mobile communication systems proposed by the International Telecommunications Union (ITU) in 1985, until the fourth and fifth generation of mobile communication systems in widespread use, Duplex methods are generally Frequency Division Duplex (FDD), Time Division Duplex (TDD), or a combination thereof, but these Duplex methods can only utilize one of spectrum resources and Time resources. In order to satisfy higher throughput and communication capacity in a limited frequency spectrum, researchers have proposed a simultaneous co-frequency full-duplex wireless communication technique (hereinafter, referred to as "full-duplex") by simultaneously utilizing frequency spectrum resources and time resources. Under the full-duplex communication mode, the communication equipment simultaneously transmits and receives data in a certain frequency band, and the frequency spectrum efficiency is doubled compared with the traditional duplex modes such as FDD, TDD and the like.

Meanwhile, the same-frequency full duplex technology supports the transceiving channels to simultaneously use the same frequency for communication, so that the frequency spectrum efficiency can be doubled, but the interference of the self-transmitting signal of the transmitter and the transmitting signals of other transmitters to the received signal needs to be solved. These interferences can be classified into Self-Interference (SI) and Cross-Link (CLI) by their source. Inter Symbol Interference (ISI) is caused by self-Interference signals and Inter-Interference signals in a network, and how to estimate and suppress SI and CLI so as to avoid ISI is an urgent problem to be solved.

Disclosure of Invention

The embodiment of the application provides a method and a device for sending signals in full-duplex communication, so as to avoid intersymbol interference caused by interference signals, ensure the effects of interference estimation and interference suppression, and improve the throughput of a system.

In a first aspect, an embodiment of the present application provides a method for sending a signal, including: a terminal acquires first configuration information at a first time, wherein the first configuration information comprises length information of a first OFDM cyclic postfix; the terminal acquires a first OFDM cyclic suffix length from the first configuration information; and the terminal communicates with the network equipment at a second moment by using the first OFDM cyclic postfix length, wherein the second moment is a moment after the first moment.

In the embodiment of the application, the terminal device uses the OFDM cyclic suffix length determined according to the configuration information containing the OFDM cyclic suffix length when communicating with the network device, and the cyclic suffix length is added behind the OFDM symbol in the uplink and downlink communication process, so that the inter-symbol interference caused by interference signals in the network is avoided, and the system throughput is improved.

In one possible implementation, the terminal device communicates with the network device using a second OFDM cyclic suffix length before the second time instant. Possibly, the second OFDM cyclic suffix length is the same as or different from the first OFDM cyclic suffix length.

In combination with this embodiment, it can be seen that the terminal device can communicate with the network device at the second time using an OFDM cyclic suffix length different from the OFDM cyclic suffix length used at a time before the second time (including the first time), that is, the terminal device communicates with the network device through the dynamically configured OFDM cyclic suffix length, so that the effects of interference estimation and interference suppression are improved, the interference level of the system is further reduced, and the system throughput is improved.

In a possible implementation, the second OFDM cyclic suffix length is a default configured OFDM cyclic suffix length. When the terminal device accesses the network device for the first time, the terminal device can adopt the default configured OFDM cyclic suffix length to communicate with the network device, and in the subsequent communication process, the used OFDM cyclic suffix length can be updated according to the configuration information sent by the network device.

In one possible implementation, the first OFDM cyclic suffix length is determined by one or more of inter-user interference power, user self-interference power, or timing advance within the coverage of the network device; wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

In the embodiment, the interference power and the time advance of the inter-user interference signal in the network and the interference power and the time advance of the self-interference signal of the user are considered when the length of the OFDM cyclic suffix is determined, so that the interference level in the network can be estimated more accurately, and the effectiveness of interference suppression is improved.

In one possible implementation, a terminal receives a mutual interference measurement message issued by a network device; the terminal determines the transmission time delay among users and the mutual interference power among the users; the time advance is determined according to the transmission time delay between the users; the transmission delay among the users is the transmission delay between the terminal and other terminals in the network, and the mutual interference power among the users is the interference power of other terminals in the network to the terminal; and the terminal feeds back the user self-interference power to the network equipment.

In this implementation, after receiving the mutual interference measurement message sent by the network device, the terminal measures the transmission delay between the terminal and other periodic terminals (users) and the mutual interference power between the terminals, and feeds back the measurement result to the network device, so that the network device dynamically determines the length of the OFDM cyclic suffix according to the mutual interference power between users and the transmission delay between users in the network fed back by the terminal, for suppressing the interference in the network.

In a possible implementation, a terminal receives a self-interference measurement message sent by the network device; the terminal determines user self-interference power and feeds the user self-interference power back to the network equipment.

In this possible implementation manner, after receiving the self-interference measurement message of the network device, the terminal device determines its self-interference power and feeds back the self-interference power to the network device, so that the network device determines the length of the OFDM cyclic suffix according to the self-interference power after obtaining the self-interference power of each terminal in its coverage, and the length is used to suppress interference in the network.

In one possible implementation, when the terminal communicates with the network device, a cyclic suffix satisfying the OFDM cyclic suffix length is added after each OFDM symbol; or when the terminal communicates with the network equipment, adding a cyclic suffix meeting the length of the OFDM cyclic suffix for part of the OFDM symbols.

In this possible manner, when the terminal communicates with the network device, if an OFDM cyclic suffix is added to each OFDM symbol, the effect of interference suppression can be improved, and it is ensured that no inter-symbol interference exists in the network; if an OFDM cyclic suffix is added to a part of OFDM symbols, the overhead of the OFDM cyclic suffix can be reduced while suppressing interference, and the total throughput in the network can be improved.

In a possible implementation, the first configuration information obtained by the terminal device is a statically configured OFDM cyclic suffix length, and the statically configured OFDM cyclic suffix length satisfies that a signal transmitted within a coverage area of the network device has no inter-symbol interference.

In the scene that the possible implementation mode is suitable for the network coverage area is small, the terminal equipment obtains the OFDM cyclic suffix length from the configuration information of the static configuration without receiving the information of the dynamic configuration, the signaling interaction is reduced while the condition that no intersymbol interference exists in the signal within the coverage area of the network equipment is met, and the communication efficiency is improved.

In a second aspect, an embodiment of the present application provides a signal sending method, including: the network device determines a first OFDM cyclic suffix length; the network equipment sends first configuration information at a first time, wherein the first configuration information comprises length information of a first OFDM cyclic postfix; the network device communicates with the terminal using the first OFDM cyclic suffix length at a second time instant.

In the embodiment of the application, the network device determines the length of the OFDM cyclic suffix, issues configuration information containing the length information of the OFDM cyclic suffix to the terminal device in the network, and uses the determined length of the OFDM cyclic suffix in subsequent communication with the terminal device. In the subsequent up-down communication process, the cyclic suffix determined by the network equipment is added after the OFDM symbol, so that the inter-symbol interference caused by interference signals in the network is avoided, and the system throughput is improved.

In one possible implementation, the network device communicates with the terminal device using a second OFDM cyclic suffix length before the second time instant. Possibly, the second OFDM cyclic suffix length is the same as or different from the first OFDM cyclic suffix length.

In connection with this embodiment, the network device communicates with the terminal device at a second time using the OFDM cyclic suffix length determined at the first time and communicates prior to the second time using the OFDM cyclic suffix length determined prior to the first time or configured by default (i.e., the second OFDM cyclic suffix length). The length of the OFDM cyclic suffix is determined at different moments in the communication process, and the OFDM cyclic suffix used in the uplink and downlink communication is dynamically configured, so that the effects of interference estimation and interference suppression are improved, the interference level of a system is further reduced, and the throughput of the system is improved.

In one possible implementation, the second OFDM cyclic suffix length used by the network device before the second time instant is a default configured OFDM cyclic suffix length. When the terminal equipment is accessed to the network equipment for the first time, the network equipment can adopt the default configured OFDM cyclic suffix length to communicate with the terminal equipment, and in the subsequent communication process, the network equipment can dynamically update the configuration information of the OFDM cyclic suffix length.

In one possible implementation, the network device determines the length of an OFDM cyclic suffix when the terminal first accesses the network; or determining the OFDM cyclic suffix length when the update trigger condition is satisfied. The update triggering condition comprises one or more of the following conditions: the network equipment sends OFDM cycle suffix length configuration and then starts a timer to finish timing, or the network total interference level or cell throughput monitored by the network equipment in real time reaches a trigger threshold; or take other means as an update trigger.

In the implementation manner, the network device determines and issues the length of the OFDM cyclic suffix when the terminal is accessed for the first time, and periodically or dynamically determines the length of the new OFDM cyclic suffix according to the interference level and the throughput in the cell, thereby ensuring the effectiveness of interference estimation and interference suppression.

In a possible implementation manner, the network device determines the length of the OFDM cyclic suffix according to one or more of inter-user interference power, user self-interference power, or timing advance within a coverage range; wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

In this embodiment, when determining the length of the OFDM cyclic suffix, the network device considers the interference power and the timing advance of the inter-user interference signal in the network and the interference power and the timing advance of the user self-interference signal, which can more accurately estimate the interference level in the network and improve the effectiveness of interference suppression.

In one possible implementation manner, a network device issues a mutual interference measurement message to a terminal, where the mutual interference measurement message is used to obtain transmission delay between users and mutual interference power between the users; wherein the inter-user transmission delay is used to determine the timing advance.

In the above implementation manner, the network device sends the measurement message to the terminal device to obtain the power of the inter-user interference signal and the parameters used when determining the length of the cyclic suffix, such as the time advance. The measurement message sent by the network device at least contains one or more of information such as an OFDM symbol format of the measurement signal, a Reference Signal (RS) port number, and time-frequency resources, so that the terminal device performs an approach measurement on the surrounding terminals according to the measurement message and feeds back the measurement result. By the method, the mutual interference power and the transmission delay between users in the network are acquired in real time, and the accuracy of determining the length of the OFDM cyclic suffix is improved, so that the effectiveness of interference estimation and interference suppression is ensured.

In a possible implementation manner, a network device determines an inter-user transmission delay according to location information of a terminal, where the inter-user transmission delay is used to determine the timing advance; and determining the mutual interference power between the users according to the uplink sending power of the terminal.

In the above implementation manner, the network device obtains the power of the inter-user mutual interference signal and the parameters such as the time advance for determining the length of the cyclic suffix by itself according to the parameters such as the location information of the terminal device. By the method, the inter-user interference power and the inter-user transmission delay are obtained, measurement information does not need to be sent to the user, and signaling overhead is saved.

In a possible implementation manner, the network device issues a self-interference power measurement message to the terminal, where the self-interference measurement message is used to obtain the user self-interference power.

Possibly, the self-interference measurement message sent by the network device may at least include information such as an OFDM symbol format, an RS port number, and a time-frequency resource of the measurement signal, or include a measurement enabling flag, so that the terminal device measures its own interference power after receiving the measurement message and feeds back a measurement result to the network device.

In a possible implementation manner, the network device determines the user self-interference power according to the self-interference cancellation capability of the terminal; and the self-interference elimination capability is obtained according to the UE capability reported by the terminal.

In the possible manner, the self-interference elimination capability of the terminal is included in the UE capability reported when the terminal device accesses the network device, and the network device obtains the user self-interference power according to the self-interference elimination capability without sending measurement information to the terminal device, thereby saving signaling overhead.

In a possible implementation manner, the time advance of the mutual interference signal with respect to the desired signal is obtained according to the transmission delay from the terminal to the network device and the transmission delay between the terminals, and is specifically determined according to the following formula:

Δt_i,j＝t_i+t_j-t_i,j

where Δ t_i，jRepresenting the timing advance, t, of the interfering signal relative to the desired signal_iRepresenting the transmission delay, t, between the network device and the terminal i_jRepresenting the transmission delay, t, between the network device and the terminal j_i，jRepresenting the transmission time delay between the terminal i and the terminal j;

the time advance of the self-interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the network device, and is specifically equal to 2t_iWherein t is_iRepresenting the transmission delay between the network equipment and the terminal i;

in one possible implementation, the network device uses the maximum value of the timing advance as the OFDM cyclic suffix length. When the network equipment cannot acquire the inter-user mutual interference power or the user self-interference power, the length of the OFDM cyclic suffix can be determined according to the maximum value of the time advance of the interference signal relative to the expected signal, so that the inter-symbol interference in the network is suppressed.

In one possible implementation, the network device determines the OFDM cyclic suffix length according to any one of the following formulas:

or

Wherein t is_csDenotes the cyclic suffix length, t_symIndicating the OFDM symbol length, M indicating the number of terminals in downlink traffic in the full duplex network, N indicating the number of terminals in uplink traffic in the full duplex network,indicating the desired signal power received by the downstream terminal i,represents the interference power of the uplink terminal j to the downlink terminal i,denotes the self-interference power, Δ t, of the downlink terminal i_i，jRepresenting the timing advance of the interfering signal relative to the desired signal, 2t_iRepresenting the timing advance of the terminal i self-interference signal relative to the desired signal,n_irepresenting the white noise power of terminal i.

In the implementation mode, the network equipment determines the length of the OFDM cyclic suffix according to the inter-user mutual interference power, the user self-interference power and the time advance, and considers the cyclic suffix overhead, so that the throughput of the network is improved while the inter-symbol interference is suppressed.

In one possible implementation, a network device communicating with the terminal using the OFDM cyclic suffix length includes:

when the network equipment communicates with the terminal, a cyclic suffix meeting the length of the OFDM cyclic suffix is added behind each OFDM symbol so as to improve the effect of interference suppression and ensure no inter-symbol interference in the network;

or when the network equipment communicates with the terminal, a cyclic suffix meeting the length of the OFDM cyclic suffix is added to part of OFDM symbols, so that the OFDM cyclic suffix overhead is reduced while interference is suppressed, and the network throughput is improved.

In a possible implementation manner, the first configuration information sent by the network device to the terminal device is a statically configured OFDM cyclic suffix length, and the statically configured OFDM cyclic suffix length satisfies that a signal transmitted within a coverage area of the network device has no inter-symbol interference.

In a third aspect, an embodiment of the present application provides a communication apparatus, including:

the device comprises a processing unit, a processing unit and a processing unit, wherein the processing unit is used for acquiring first configuration information at a first time, and the first configuration information comprises first OFDM cyclic postfix length information; further configured to determine a first OFDM cyclic suffix length according to the first configuration information;

and a transceiver unit, configured to communicate with a network device using the first OFDM cyclic suffix length at a second time, where the second time is a time after the first time.

The communication apparatus provided in the third aspect may be a terminal. When the terminal equipment uses the receiving and sending unit to communicate with the network equipment, the configuration information obtained by the processing unit is used for determining the length of the OFDM cyclic suffix and adding the length of the cyclic suffix to the OFDM symbol, so that the intersymbol interference caused by interference signals in the network is avoided and the system throughput is improved.

In one possible implementation, the transceiver unit is further configured to communicate with the network device using a second OFDM cyclic suffix length before the second time instant.

In a possible implementation, the transceiver unit is further configured to receive a mutual interference measurement message sent by the network device; the processing unit is further configured to determine an inter-user transmission delay and the inter-user mutual interference power; the time advance is determined according to the transmission time delay between the users; the transmission delay among the users is the transmission delay between the communication device and other terminals in the network, and the mutual interference power among the users is the interference power of other terminals in the network to the communication device; the transceiving unit is further configured to feed back the user self-interference power and/or the inter-user transmission delay to the network device.

In a possible implementation, the transceiver unit is further configured to receive a self-interference measurement message sent by the network device; the processing unit is also used for user self-interference power; and the transceiving unit is further configured to feed back the user self-interference power to the network device.

In one possible implementation, the transceiver unit is configured to communicate with a network device using the first OFDM cyclic suffix length at a second time instant, and includes: when the transceiving unit communicates with the network device, the processing unit is further configured to add a cyclic suffix satisfying the length of the OFDM cyclic suffix to each OFDM symbol; or when the transceiver unit communicates with the network device, the processing unit is further configured to add a cyclic suffix satisfying the length of the OFDM cyclic suffix to a part of the OFDM symbols.

In a fourth aspect, an embodiment of the present application provides a communication apparatus, including:

a processing unit to determine a first OFDM cyclic suffix length;

a transceiving unit, configured to send first configuration information at a first time, where the first configuration information includes length information of a first OFDM cyclic suffix;

the transceiver unit is further configured to communicate with the terminal using the first OFDM cyclic suffix length at a second time instant.

The communication apparatus provided in the fourth aspect may be a network device. The processing unit of the network equipment determines the length of the OFDM cyclic suffix, transmits configuration information containing the information of the length of the OFDM cyclic suffix to the terminal equipment in the network through the transceiving unit, and uses the determined length of the OFDM cyclic suffix in subsequent communication with the terminal equipment. In the subsequent up-down communication process, the cyclic suffix determined by the processing unit is added after the OFDM symbol, so that the inter-symbol interference caused by interference signals in the network is avoided, and the system throughput is improved.

In one possible implementation, the transceiver unit is further configured to communicate with the terminal device using a second OFDM cyclic suffix length before the second time instant.

In one possible implementation, the processing unit is for an OFDM cyclic suffix length, comprising: the processing unit is used for determining the length of an OFDM cyclic suffix when the terminal accesses the communication device for the first time; or the processing unit is used for determining the length of the OFDM cyclic suffix when the updating triggering condition is met;

the update triggering condition comprises one or more of the following conditions: after the receiving and sending unit issues the configuration of the OFDM cyclic suffix length, the timer started by the processing unit is timed to end, or the network overall interference level or the cell throughput monitored by the communication device in real time reaches the trigger threshold.

In one possible implementation, the processing unit is configured to determine a length of an OFDM cyclic suffix, and includes: the processing unit is specifically configured to determine the length of the OFDM cyclic suffix according to one or more of inter-user interference power, user self-interference power, or a timing advance within a coverage range; wherein the timing advance comprises a timing advance of the mutual interference signal relative to the desired signal and/or a timing advance of the self-interference signal relative to the desired signal.

In one possible implementation, the transceiver unit is further configured to issue a mutual interference measurement message to the terminal, where the mutual interference measurement message is used to obtain inter-user transmission delay and inter-user mutual interference power; wherein the inter-user transmission delay is used to determine the timing advance.

In one possible implementation, the processing unit is further configured to determine an inter-user transmission delay according to the location information of the terminal, where the inter-user transmission delay is used to determine the timing advance; and determining the mutual interference power between the users according to the uplink sending power of the terminal.

In a possible implementation, the transceiver unit is further configured to send a self-interference power measurement message to the terminal, where the self-interference measurement message is used to obtain the user self-interference power.

In a possible implementation, the processing unit is further configured to determine the user self-interference power according to a self-interference cancellation capability of the terminal.

In a possible implementation, the processing unit is further configured to use a maximum value of the timing advance as an OFDM cyclic suffix length.

In one possible implementation, the time advance of the mutual interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the communication device and the transmission delay between the terminals, and is specifically determined according to the following formula:

Δt_i,j＝t_i+t_j-t_i,j

where Δ t_i，jRepresenting the timing advance, t, of the interfering signal relative to the desired signal_iRepresenting the transmission delay, t, between the communication device and the terminal i_jRepresenting the transmission delay, t, between the communication device and terminal j_i，jRepresenting the transmission delay between the terminal i and the terminal j;

the time advance of the self-interference signal relative to the desired signal is obtained according to the transmission delay from the terminal to the communication device, and is specifically equal to 2t_iWherein t is_iRepresenting the transmission delay between the communication device and terminal i.

In one possible implementation, the processing unit is specifically configured to determine the first OFDM cyclic suffix length according to the following formula:

wherein t is_csDenotes the cyclic suffix length, t_symIndicating the OFDM symbol length, M indicating the number of terminals in downlink traffic within the coverage area of the communication device, N indicating the number of terminals in uplink traffic within the coverage area of the communication device,indicating the desired signal power received by the downstream terminal i,represents the interference power of the uplink terminal j to the downlink terminal i,denotes the self-interference power, Δ t, of the downlink terminal i_i，jRepresenting the timing advance of the interfering signal relative to the desired signal, 2t_iRepresenting the timing advance of the terminal i self-interference signal relative to the desired signal,n_irepresenting the white noise power of terminal i.

In one possible implementation, the transceiver unit is configured to communicate with the terminal using the OFDM cyclic suffix length at the second time instant, and includes: when the transceiver unit communicates with the terminal, the processing unit is further configured to add a cyclic suffix satisfying the OFDM cyclic suffix length for each OFDM symbol; or when the transceiver unit communicates with the terminal, the processing unit is further configured to add a cyclic suffix satisfying the OFDM cyclic suffix length to a part of the OFDM symbols.

In a fifth aspect, there is provided a communication device comprising a processor coupled to a memory, the memory being configured to store computer programs or instructions, and the processor being configured to execute the computer programs or instructions in the memory, such that the method provided by the first aspect and any possible implementation thereof is performed.

Possibly, the memory coupled to the processor may be located outside the communication device or may be integrated with the processor.

In one possible implementation, the communication device further comprises a transceiver for implementing the transceiving function of the communication device.

In a sixth aspect, there is provided a communication device comprising a processor coupled to a memory, the memory being configured to store a computer program or instructions, and the processor being configured to execute the computer program or instructions in the memory, such that the method provided by the second aspect and any possible implementation thereof is performed.

Possibly, the memory coupled to the processor may be located outside the communication device or may be integrated with the processor.

In one possible implementation, the communication device further comprises a transceiver for implementing the transceiving function of the communication device.

In a seventh aspect, a communication apparatus is provided, including: input interface, logic circuit and output interface. The logic circuitry is configured to perform the method provided by the first aspect and any possible implementation thereof or to perform the method provided by the second aspect and any possible implementation thereof.

In an eighth aspect, a computer-readable storage medium is provided, in which a computer program or instructions are stored, which, when executed on a computer, cause the method provided by the first aspect and any possible implementation manner thereof or the second aspect and any possible implementation manner thereof to be performed.

A ninth aspect provides a computer program product for causing a method provided by the first aspect and any possible implementation manner thereof or the second aspect and any possible implementation manner thereof to be performed when the computer program product is executed by a computer.

A tenth aspect provides a chip comprising a processor, the processor being configured to invoke and execute a computer program from a memory to perform the method of the first aspect and any possible implementation manner thereof or to perform the method of the second aspect and any possible implementation manner thereof.

Drawings

Fig. 1 is a schematic diagram of different full duplex systems.

Fig. 2 is a diagram illustrating interference in a simultaneous co-frequency full duplex system.

Fig. 3 is a timing relationship diagram of a user equipment and a network device during full duplex communication.

Fig. 4 is a schematic timing relationship diagram of a user equipment after adding a cyclic suffix according to an embodiment of the present application.

Fig. 5 is a schematic view of an application scenario of full-duplex communication according to an embodiment of the present application.

Fig. 6 is an interaction schematic diagram of a signal sending method according to an embodiment of the present application.

Fig. 7 is a flowchart illustrating a signal sending method according to an embodiment of the present application.

Fig. 8 is a flowchart illustrating a signal sending method according to an embodiment of the present application.

Fig. 9 is an interaction diagram of a signal transmission method according to an embodiment of the present application.

Fig. 10 is a schematic diagram of an OFDM symbol structure according to an embodiment of the present application.

Fig. 11a is a schematic diagram of an OFDM symbol structure according to an embodiment of the present application.

Fig. 11b is a schematic diagram of an OFDM symbol structure according to an embodiment of the present application.

Fig. 12a is a schematic structural diagram of a frequency domain signal and a time domain signal according to an embodiment of the present application.

Fig. 12b is a schematic structural diagram of a frequency domain signal and a time domain signal according to an embodiment of the present application.

Fig. 13 is a schematic diagram of a communication device according to an embodiment of the present application.

Fig. 14 is a schematic diagram of a communication device according to an embodiment of the present application.

Fig. 15 is a schematic diagram of a communication device according to an embodiment of the present application.

Detailed Description

The embodiment of the application provides a method and a device for signal transmission, so as to avoid intersymbol interference caused by interference signals, ensure the effects of interference estimation and interference suppression, and improve the throughput of a system. The method and the device are conceived according to the same application, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated details are not repeated.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.

The terms "first" and "second," and the like, in the description and in the claims of the embodiments of the present application are used for distinguishing between different objects and not for describing a particular order of the objects. For example, the first target object and the second target object, etc. are specific sequences for distinguishing different target objects, rather than describing target objects.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

In the description of the embodiments of the present application, the meaning of "a plurality" means two or more unless otherwise specified. For example, a plurality of processing units refers to two or more processing units; the plurality of systems refers to two or more systems.

In the embodiment of the present application, the "uplink" may refer to a signal transmission direction for signal reception for the wireless access device and a signal transmission direction for signal transmission for the terminal; "downlink" may refer to a signal transmission direction for signal transmission to the wireless access device and a signal transmission direction for signal reception to the terminal; "uplink user" means a user in uplink service, that is, a terminal that transmits an uplink signal to a wireless access device; "downlink user" means a user in downlink service, that is, a terminal receiving a downlink signal from a wireless access device; of course, other modifications and alternatives based on this should fall within the scope of the present application.

It should be noted that "first time" and "second time" in the embodiments of the present application relate to a concept of a radio frame. For example, the first time and the second time are the same time, and represent that the first time and the second time indicate the same time-frequency resource, that is, indicate the same subframe number in the same system frame number, and do not necessarily represent that the first time and the second time are the same time in absolute time. For example, the network device issues configuration information to the terminal device at a first time, the terminal obtains the configuration information at the first time, the configuration information is indicated to be carried in a radio frame with a system frame number of 11 and a subframe number of 5 by the network device, and the user device receives the radio frame with the system frame number of 11 and the subframe number of 5 and obtains the configuration information from the radio frame.

According to the technical solution in the embodiment of the present application, applicable communication systems include but are not limited to: the system comprises a Narrow-Band Internet of Things system (English: Narrow Band-Internet of Things, NB-IoT for short), a Long-Term Evolution system (Long Term Evolution, LTE for short), and three application scenarios of a 5G mobile communication system: enhanced Mobile Broadband (eMBB), Ultra-high reliable and Low-delay Communication (URLLC), Massive Machine Type Communication (mMTC), or 6G.

Various embodiments relate to a terminal. A terminal may refer to a User Equipment (UE), an access terminal, a subscriber unit (subscriber unit), a subscriber station, a mobile station (mobile station), a remote station, a remote terminal, a mobile device, a User Terminal (TE), a terminal, a wireless communication device, a User agent, or a User Equipment. The access terminal may be a cellular phone (cellular phone), a cordless phone (cordless phone), a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a tablet computer (pad), a handheld device with a Wireless communication function, a computing device, or other processing devices connected to a Wireless modem, a vehicle-mounted device, a wearable device, a 5G network, or a terminal device in a network after 5G, etc.; with the development of wireless Communication technology, all the devices that can access a Communication system, can communicate with a network side of the Communication system, or communicate with other objects through the Communication system may be terminals in the embodiments of the present application, such as terminals in intelligent transportation and automobiles, home devices in smart homes, power meter reading instruments in smart grids, voltage monitoring instruments, environment monitoring instruments, video monitoring instruments in smart security networks, cash registers, Machine Type Communication (MTC) terminals, and the like, which are not limited in the present application.

Various embodiments of the present application also relate to a network device. The network device may be a device for communicating with the terminal device, and for example, may be a Base Station (BTS) in a GSM system or a CDMA system, a Base Station (NB) in a WCDMA system, an evolved Node B (eNB or eNodeB) in an LTE system, a next generation Base Station (gNB) in a 5G system, a Transmission and Reception Point (TRP), a relay Node, an Access Point (AP), or a network device such as a relay Station, an access point, a vehicle-mounted device, a wearable device, and a network-side device in a future network system, which is not limited in this application.

The network device of the embodiment of the present application may be a network device of a cell, and may be a base station in a cell level sense or a network device having a function similar to the base station. The network device may be a network device that provides wireless access and communication services for mobile or fixed terminal devices within a cell.

To facilitate an understanding of the embodiments of the present application, a brief description of full duplex communication is provided below.

In a communication system, the duplexing method is usually frequency division duplexing FDD, time division duplexing TDD or a combination of both, however, the above duplexing methods can only utilize one of spectrum resources and time resources. Meanwhile, the co-frequency co-time full duplex (CCFD) wireless communication technology (hereinafter referred to as "full duplex") utilizes both frequency spectrum resources and time resources. Under the full-duplex communication mode, the communication equipment simultaneously transmits and receives data in a certain frequency band, and the frequency spectrum efficiency is doubled compared with the traditional duplex modes such as FDD, TDD and the like. Fig. 1 shows a schematic diagram of different duplexing modes, where (a) is a TDD system in which uplink and downlink are distinguished by using different time slots, for example: the sending signal and the receiving signal of the node 1 are transmitted on different time resources, and the node 2 is the same; (b) and (c) FDD systems, where the uplink and downlink are distinguished by using different frequency spectrums, for example: the sending signal and the receiving signal of the node 1 are transmitted on different frequency spectrum resources, and the node 2 is the same; (d) for the CCFD system, the transmit signal and the receive signal of node 1 are transmitted on the same time domain resource and frequency domain resource, and node 2 is the same.

The full-duplex technology supports the transceiving paths to simultaneously use the same frequency for communication, so that the frequency efficiency is doubled. However, in a full-duplex system, devices simultaneously transmit and receive at the same frequency, and a receiving antenna receives a transmission signal from the device, that is, self-interference SI. Because the transmitting and receiving antennas of the same equipment are very close to each other or even the same antenna, the strength of the self-interference signal is far higher than that of the useful signal, which can cause the saturation of devices in a receiver and cause the loss of the useful signal; in addition, the receiving antenna also receives the transmitted signal from other nearby devices, namely the mutual interference CLI. Fig. 2 shows a schematic diagram of interference in a full duplex system. As shown in fig. 2, the network device receives a signal and is interfered by a transmission signal of the base station, that is, self-interference of the network device; when receiving a signal, a terminal receives interference generated by a transmission signal of the terminal, that is, self-interference of the terminal, and also receives interference generated by transmission signals of other terminals nearby, that is, mutual interference between terminals.

In addition, the interference signal and the expected signal received by the terminal are asynchronous in time due to the different distances between the terminal and the base station. Inter-user mutual interference signals, user self-interference signals, and non-synchronization of the interference signals and the desired signal will cause inter-symbol interference.

Fig. 3 is a timing relationship between a network device and different terminals in a full duplex system. In the network device of fig. 3, terminal 1 and terminal 2 are both in full duplex mode.

For ease of understanding, a brief description of synchronization in a communication system is first presented: in the prior art, synchronization is a basic requirement of cellular mobile communication systems, especially in LTE and 5G systems based on Orthogonal Frequency Division Multiplexing (OFDM): the non-synchronization causes severe Inter Symbol Interference (ISI) and Inter Carrier Interference (ICI). In a conventional cellular mobile communication system, downlink signals of terminals in a cell are all sent by network equipment during downlink transmission, so that the downlink signals can be synchronized. In the uplink transmission process, the network device receives uplink signals sent by different terminals, and since the distances between the terminals and the network device may be different, and based on the difference of the propagation times of the signals, the arrival times of the uplink signals at the network device may be different. In order to realize uplink synchronization (that is, the time of the uplink signal of the same time slot reaching the base station is the same), a timing advance mechanism is adopted, that is, different terminals send in advance by a certain amount of time according to the distance between the different terminals and the network equipment, so as to ensure that the time of each terminal reaching the network equipment is consistent.

In addition, in order to combat the multipath effect caused by the complex wireless propagation environment, the orthogonality of OFDM is ensured by a Cyclic Prefix (CP) added in front of the OFDM symbol, and the length of the CP (which refers to the length of the symbol occupied by the CP) is usually related to the maximum transmission delay of multipath.

Taking fig. 3 as an example, the network device sends downlink data to the terminal 1, and the data is received by the terminal 1 after propagation delay of t 1; the uplink signal of the terminal 1 is sent at t1 earlier than the reference time, so as to ensure that the uplink signal of the terminal 1 is aligned with the uplink signal receiving window of the network device; similarly, the network device sends downlink data to the terminal 2, and the data is received by the terminal 2 after propagation delay of t 2; the uplink signal of the terminal 2 is sent at an earlier time t2 than the reference time, so as to ensure that the uplink signal of the terminal 1 is aligned with the uplink signal receiving window of the network device; all the data transmission is performed on the same frequency domain resource.

As shown in fig. 3, the downlink receiving window of the terminal 1 includes a desired downlink signal, and also includes a residual uplink transmission signal after the terminal 1 self-interference is eliminated, and a signal that an uplink transmission signal of the terminal 2 reaches the terminal 1 after a propagation delay t. If the terminals can measure these Interference signals, Interference Rejection Combining (IRC) can be used to suppress the Interference. However, since the interference signal in the receiving window of the useful signal may contain the signal of the next OFDM symbol period, the result of the interference estimation is subject to severe inter-symbol interference ISI, thereby affecting the performance of interference suppression. For example, the downlink receiving window of terminal 1 in fig. 3 includes a self-interference signal spanning two OFDM symbol periods and a mutual interference signal spanning two OFDM symbol periods.

According to the method, the Cyclic Suffix (CS) with configurable length is added behind the existing OFDM symbol, so that the useful signal receiving window of the terminal equipment in the full-duplex system only contains the interference signal in one OFDM symbol period, the subcarrier orthogonality damage caused by ISI of the interference signal is avoided, and the effects of interference estimation and interference suppression are ensured.

Taking fig. 4 as an example, fig. 4 is a timing relationship between a network device and different terminals in a full-duplex system after adding a cyclic suffix. After the cyclic suffix is added, one OFDM symbol period consists of the cyclic prefix CP, the OFDM symbol and the cyclic suffix CS. Similar to fig. 3, the network device sends downlink data to the terminal 1, and the data is received by the terminal 1 after the propagation delay of t 1; the uplink signal of the terminal 1 is sent at an earlier time t1 than the reference time; similarly, the network device sends downlink data to the terminal 2, and the data is received by the terminal 2 after propagation delay of t 2; the uplink signal of the terminal 2 is sent at an earlier time t2 than the reference time; the uplink signal of the terminal 2 reaches the terminal 1 through propagation delay; all the data transmission is performed on the same frequency domain resource.

The downlink receiving window of the terminal 1 includes an expected downlink signal, and also includes a residual uplink transmitting signal after the terminal 1 self-interference is eliminated and a signal that the terminal 2 uplink transmitting signal reaches the terminal 1 after the propagation delay t. Unlike fig. 3, after adding a cyclic suffix with variable length, the interference signal existing in the downlink receiving window of terminal 1 can be prevented from including the signal of the next OFDM symbol period, thereby preventing the existence of ISI.

The technical solution of the embodiment of the present application is described in detail below.

Fig. 5 is a diagram of an application scenario according to an embodiment of the present application. The network device provides communication service for the terminal device, and the terminal can be a full-duplex terminal or a half-duplex terminal. The network equipment communicates with the terminal in the half-duplex mode in a half-duplex mode; the network device communicates with the terminal in full duplex mode. The terminal in this embodiment of the present application may be any one or more of the foregoing terminals, and the network device may be any one of the foregoing network devices, which is not limited in this application.

Referring to fig. 6, fig. 6 is an interaction schematic diagram of a signal transmission method provided in the embodiment of the present application.

S601, the network equipment determines the length of the cyclic suffix.

It should be noted that the network device determines the cyclic suffix length in S601.

In a possible implementation, the network device configures the same cyclic suffix length for all uplink and downlink terminals in the cell, and the network device may send the cyclic suffix configuration information to the terminals in the cell by broadcasting. In the implementation mode, the network equipment uniformly adjusts the length of the cyclic suffix of the users in the cell, and the implementation complexity is low.

In a possible implementation, the network device configures different cyclic suffix lengths for different users in the cell, or groups the users in the cell and allocates different cyclic suffix lengths for the users in different groups.

Step S601 is an optional step, and in a possible implementation, the network device and the terminal device communicate with each other by using a default configured cyclic suffix length, in which case, step S601 does not need to be executed.

Illustratively, the network device determines a first OFDM cyclic suffix length.

In one possible implementation, the network device determines the first OFDM cyclic suffix length t according to one or more of a self-interference power of terminals, a mutual interference power between terminals, and a timing advance of a self-interference signal or a mutual interference signal with respect to a desired signal within a full-duplex network_cs。

In one possible implementation, the network device determines the OFDM cyclic suffix length also taking into account the cyclic suffix overhead. As shown in fig. 4, after adding the cyclic suffix CS, one OFDM symbol period is composed of the cyclic prefix CP, the OFDM symbol, and the cyclic suffix CS. The length of the cyclic suffix CS will affect the OFDM symbol duration (i.e. the DATA part time in fig. 4) or the OFDM symbol period and thus may affect the number of OFDM symbols in a slot. Thus, the network device determines the length of the first OFDM cyclic suffix taking into account the overhead incurred by the cyclic suffix length.

The method by which the network device determines the length of the OFDM cyclic suffix will be described in detail below.

S602, the network equipment sends configuration information to the terminal; and the terminal receives the configuration information issued by the network equipment. The configuration information includes OFDM cyclic suffix length information.

Step S602 is an optional step, and when the network device and the terminal device communicate with each other by using the default configured cyclic suffix length, the step need not be executed.

For example, the network device sends configuration information to the terminal at a first time, where the configuration information includes first OFDM cyclic postfix length information.

It should be noted that the configuration information may be notified to the terminal through signaling.

In a possible implementation, the network device sends the configuration information to the terminal through Radio Resource Control (RRC).

In a possible implementation, the network device sends the configuration information to the terminals in the cell in a broadcast manner.

In one possible implementation, the network device sends the configuration Information to the terminal through a System Information Bit (SIB).

Possibly, the configuration information may indicate an index, the index corresponding to an entry, the entry indicating a cyclic suffix configuration value;

possibly, the configuration information may also indicate specific configuration values;

possibly, the configuration information may also indicate a cyclic suffix adjustment value,

and after receiving the adjustment value, the terminal accumulates the adjustment value on the basis of the last cyclic suffix configuration value to obtain the current cyclic suffix configuration value, wherein the adjustment value can be a positive number or a negative number.

It should be noted that the network device may also send the configuration information to the terminal device through other signaling or other manners, which is not limited in this application.

In one possible implementation, when a terminal first accesses a network device, the network device issues the configuration information; in one possible implementation, the network device issues the configuration information when the update trigger condition is satisfied.

S603, the terminal equipment acquires configuration information, wherein the configuration information comprises OFDM cyclic suffix length information.

For example, the terminal device obtains the configuration information at a first time.

In one possible implementation, the configuration information is OFDM cyclic suffix length configuration information of a default configuration of the network device and the terminal.

In one possible implementation, the configuration information is the configuration information sent by the network device at the first time in S602. For example, the network device carries the configuration information in the radio frame with the system frame number of 10 and the subframe number of 2, and the terminal device obtains the configuration information from the radio frame with the system frame number of 10 and the subframe number of 2.

S604, the terminal communicates with the network equipment.

The terminal device communicates with the network device, including the terminal device communicating with the network device using the OFDM cyclic suffix length.

Illustratively, the terminal device communicates with the network device at the second time instant using the first OFDM cyclic suffix length. Prior to the second time instant, the terminal device communicates with the network device using a second OFDM cyclic suffix length. Wherein the second time is a time after the first time.

In one possible implementation, the first OFDM cyclic suffix length is a default configured cyclic suffix length; possibly, the length of the second OFDM cyclic suffix is also the length of the default configuration, i.e. the length of the first OFDM cyclic suffix is the same as the length of the second OFDM cyclic suffix;

in a possible implementation, the length of the first OFDM cyclic suffix is the length of the first OFDM cyclic suffix included in the configuration information sent by the network device to the terminal device in step S602. Possibly, the second OFDM cyclic suffix length is an OFDM cyclic suffix length included in the configuration information sent by the network device to the terminal device before the first time. The length of the first OFDM cyclic suffix may be the same as or different from the length of the second OFDM cyclic suffix, and the present application is not limited thereto.

In S604, the network device and the terminal communicate using the new cyclic suffix length. Specifically, the cyclic suffix is included in an OFDM symbol period of the uplink and downlink transmission signal in a communication process between the network device and the terminal, and a cyclic suffix length (i.e., a cyclic suffix duration) of the cyclic suffix may be determined by cyclic suffix length configuration information issued by the network device.

In one possible implementation, when the network device and the terminal communicate using a new cyclic suffix, a cyclic suffix is added to each OFDM symbol that satisfies the OFDM cyclic suffix length. For example, fig. 10 is a diagram of an OFDM signal structure after adding a cyclic suffix to each OFDM symbol. As shown in fig. 10, each OFDM symbol period contains a cyclic prefix CP, an OFDM symbol (DATA) carrying DATA, and a cyclic suffix CS.

In one possible implementation, when the network device and the terminal communicate using a new cyclic suffix, a cyclic suffix is added to a portion of the OFDM symbol that satisfies the OFDM cyclic suffix length.

It should be noted that, when adding a cyclic suffix to a part of OFDM symbols, the symbol to which the cyclic suffix is added may be a symbol carrying a specific signal, or may be a designated symbol negotiated by a network device and a terminal, which is not limited in this application. The appointed symbols negotiated by the possible network equipment and the terminal can be symbols with higher requirement on the error rate, the interference is reduced by adding a cyclic suffix to the symbols, and the decoding accuracy of the receiving end is improved. For example, FIG. 11a is a block diagram of a possible OFDM signal structure after adding a cyclic suffix to a portion of the OFDM symbols. As shown in fig. 11a, the first OFDM symbol period is composed of a cyclic prefix CP and OFDM symbols; the second OFDM symbol period is then formed by the cyclic prefix CP, the OFDM symbol and the cyclic suffix CS. In fig. 11, the second OFDM symbol period is used to carry an interference measurement pilot (measurement pilot), and the terminal may measure information such as interference of other current users and propagation delay between users through the measurement pilot.

It is possible to periodically configure when a cyclic suffix is added to a partial OFDM. The network device and the terminal device negotiate a period for adding the OFDM cyclic suffix, or the network device specifies the period for adding the OFDM cyclic suffix through broadcasting and the like. For example, FIG. 11b is a block diagram of a possible OFDM signal structure after adding a cyclic suffix to a portion of the OFDM symbols. As shown in fig. 11b, a cyclic suffix is added to the OFDM symbols after every 2 OFDM periods, i.e. the first OFDM symbol period and the fourth OFDM symbol period are composed of a cyclic prefix CP, an OFDM symbol and a cyclic suffix CS, while the second OFDM symbol period and the third OFDM symbol period are composed of a cyclic prefix CP and an OFDM symbol.

By adding a cyclic suffix CS to a portion of an OFDM symbol, the overhead of the cyclic suffix can be reduced while suppressing inter-symbol interference ISI.

In the above embodiment, the terminal device obtains the OFDM cyclic suffix length configuration information, and performs communication using the OFDM cyclic suffix length in subsequent communication between the terminal and the network device, thereby reducing inter-symbol interference caused by self-interference of the full-duplex terminal and mutual interference between terminals in the full-duplex network, and improving throughput of the system.

However, as new terminals continuously access, leave or initiate uplink and downlink services in the cells under the network equipment, the interference power in the cells and the transmission delay between the terminals also change correspondingly, so the network equipment will re-determine the length of the cyclic suffix according to the requirements and update the configuration information of the length of the cyclic suffix.

Referring to fig. 7, fig. 7 is a flowchart illustrating a network device updating a length of a cyclic suffix.

S701, the network equipment judges whether the updating triggering condition is met.

In one possible implementation, the update trigger condition is a timing trigger. For example, after issuing the configuration information of the length of the cyclic suffix, the network device starts a timer, and when the timer is over, the base station updates the length of the cyclic suffix; or the network equipment updates the length of the cyclic suffix according to the measurement period of the user; or the cyclic suffix length is updated periodically by the network device in other ways, and the application is not limited thereto.

In one possible implementation, the update trigger condition is an event trigger. For example, the network device monitors real-time interference levels and/or cell throughputs within the network, and when an overall interference level or cell throughput triggers an adjustment threshold, the network device updates the cyclic suffix length.

S702 to S705: when the update triggering condition is met, the network equipment determines the length of the new cyclic suffix and issues updated configuration information of the length of the cyclic suffix, the feedback of correctly acquiring the length information sent by the terminal is received, and the network equipment and the terminal communicate by using the updated length of the new cyclic suffix. The details of steps S702 and S703 refer to S601 to S602 in fig. 6, and the details of step S704 refer to S604 in fig. 6, which are not described herein again.

In this embodiment, the network device determines a new cyclic suffix length by judging the update trigger condition and updates the cyclic suffix length configuration information sent to the terminal, thereby ensuring the effectiveness of interference estimation and interference suppression.

The network device determining the cyclic suffix length (S601, S702) is described in detail below.

For convenience of describing the embodiment of the present application, it is assumed that M terminals (users) are in downlink service and N terminals (users) are in uplink service in a coverage area of the network device, that is, the number of downlink users and the number of uplink users in the coverage area of the network device are M and N. If the terminal is a full-duplex terminal (full-duplex user), the terminal belongs to both uplink and downlink users. The user index of the downlink user is denoted by i, the user index of the uplink user is denoted by j,representing the interference power of the uplink user j to the downlink user i,and the residual interference power of the downlink user i receiving the uplink signal of the downlink user i, namely the self-interference power of the downlink user i. t is t_i，t_jRespectively representing the transmission delays, t, of the network devices to user i and user j_i,jRepresenting the transmission delay from user j to user i.Indicating the desired signal power received by the downlink user i.Indicating the uplink user j transmit signal power.

It should be noted that, if the terminal is a half-duplex terminal (half-duplex user), the self-interference power of the terminal is 0; if the terminal is a full-duplex terminal, the self-interference power of the terminal is related to the sending signal and the self-interference elimination capability of the terminal.

In one embodiment provided by the present application, a network device determines an OFDM cyclic postfix length according to inter-user interference power, user self-interference power, and a time advance within its coverage.

Referring to fig. 8, fig. 8 is a flow chart illustrating a network device determining an OFDM cyclic suffix length.

S801, obtaining transmission time delay t between users by network equipment_i,jInter-user interference powerAnd user self-interference power

In a possible implementation, the network device sends the mutual interference measurement message to the terminal to obtain the transmission delay t between users_i,jAnd inter-user interference power

As shown in fig. 9, in S901, the network device issues a measurement message to the terminal to instruct the terminal to measure other terminals around the terminal, and the terminal receives the measurement message sent by the network device. The measurement message at least contains one or more of information such as OFDM symbol format of the measurement signal, Reference Signal (RS) port number and time frequency resource. Wherein the OFDM symbol format of the measurement signal comprises a Cyclic Prefix (CP) length, a Cyclic Suffix (CS) length, and a data symbol length.

In S902, the terminal performs measurement and feeds back a measurement result to the network device, and the network device receives the measurement result sent by the terminal. Terminal measuring mutual interference power using measurement signalAnd inter-user transmission delay t_i,jWherein the measurement signal may be an uplink signal used in a normal service flow of the terminal, such as a sounding reference signal (english): sounding Reference Signal, abbreviation: SRS), demodulation reference signal (english: modulation Reference Signal, abbreviated as: DMRS), etc.; or may be a signal used within a certain measurement time specified by the network device, which is not limited in this application. The terminal feeds back a measurement result to the network equipment, wherein the measurement result at least comprises information such as Reference Signal Receiving Power (RSRP) corresponding to an RS port of a measurement Signal, transmission delay and the like; the measurement result may also include the angle of arrival corresponding to the RS port of the measurement signal and the antenna configuration information of the terminal itself, such as an omnidirectional antenna, a directional or polarization angle, and so on.

In one possible implementation, the terminal device may periodically measure other terminals in the network, obtain interference power of the other devices to the terminal and transmission delay from the other devices to the terminal, and send a measurement result to the network device. In this implementation, the measurement signal and/or time-frequency resource configured at the initial access of the network device or configured by default may be used to perform the measurement of the mutual interference power.

In a possible implementation, the network device calculates the transmission delay t between the users using the calculation parameters_i,jAnd inter-user interference powerFor example, the network device obtains the geographical location information of each terminal (user) in its coverage area, and calculates the spatial distance and propagation delay t between users according to the location of each terminal_i,j. The network equipment can also obtain the uplink transmission power of each terminal in the coverage area, and further utilizes a path loss model to calculate the inter-user interference power of an uplink signal reaching other terminals according to the spatial distance between users and the uplink transmission power of each terminal

In a possible implementation, the network device issues a measurement message to the terminal to obtain the self-interference power of the userIt is possible that the network device sends a self-interference measurement message to the full-duplex user in the terminal. The network device sends a self-interference measurement message to the terminal to indicate the terminal to measure the residual interference power of the uplink signal of the terminal, namely the self-interference power of the terminal, and the terminal receives the self-interference measurement message sent by the network device. Similar to the mutual interference measurement message issued by the network device, the self-interference measurement message issued by the network device may at least include information such as an OFDM symbol format, an RS port number, and time-frequency resources of the measurement signal; it should be noted that, since the uplink transmission signal of the terminal is known to the terminal, the network device does not need to inform detailed measurement content, and the self-interference measurement message sent by the network device may only include a measurement enabling flag, where the measurement enabling flag is used to indicate whether the terminal performs measurement based on a certain measurement signal. The terminal measures self-interference power of the terminal and feeds back a measurement result to the network equipment, wherein the measurement feedback result comprises information of the self-interference power of the terminal. The measurement signal used by the terminal to measure the self-interference power may be an uplink signal used in a normal service flow of the terminal, such as SRS, DMRS; or may be a signal used within a certain measurement time specified by the network device, which is not limited in this application.

In one possible implementation, the terminal device may measure its self-interference power and periodically send the self-interference power of the terminal to the network deviceThe measurement signal used by the terminal to measure the self-interference power may be an uplink signal used in a normal service flow of the terminal.

It should be noted that, when the terminal is in the half-duplex mode, the downlink signal of the terminal is only interfered by the uplink signals of other users, and is not interfered by the signal sent by the terminal itself, and at this time, the self-interference power of the terminal is 0.

In a possible implementation, the network device eliminates the capability according to the self-interference of the terminalCalculating the user self-interference power of the terminalSpecifically, when the terminal accesses the network, the network device obtains the self-interference cancellation capability of the terminal. For example, the terminal takes the self-interference cancellation capability as the UE capability (sub-item of UE capability). The self-interference cancellation capability of each terminal may be statically stored by category. As shown in table 1, the user may be divided into 6 bins, each corresponding to a different elimination capability. Index 0 indicates that the terminal is a half-duplex user, the full-duplex mode is not supported, and the residual self-interference power is 0. The network device may obtain the self-interference cancellation capability of each terminal in a table look-up manner, and calculate the residual self-interference power of the terminal according to the transmission signal power of the terminal and the self-interference cancellation capability. Specifically, the network device subtracts the result of the self-interference cancellation capability from the transmit signal power as the residual self-interference power of the user.

Table 1 self-interference cancellation capability table

User category indexing	Self-interference cancellation capability
		0	0dB
1	70dB
		2	80dB
3	90dB
		4	100dB
5	110dB

For example, a UE-fullbduplexclass field may be added to the BandNR sub-entry in the radio frequency parameters (RF parameters) information element in the UE capability of the standard TS 38.331, and the value of the field may be fd0, fd1, fd2, fd3, fd4, or fd5, which respectively indicate the self-interference cancellation capabilities corresponding to indexes 0 to 5 in table 1. Specific examples are as follows, where the black italic part is the proposed new ue-fullbilxclass field:

s802, the network equipment calculates the time advance of the interference signal relative to the expected signal.

The network device calculates the timing advance of the mutual interference signal relative to the desired signal and the timing advance of the self-interference signal relative to the desired signal respectively.

The time advance of the mutual interference signal relative to the expected signal is determined by the transmission time delay between users, specifically, the delta t is determined according to the following formula_i，j＝t_i+t_j-t_i，jWherein t is_i，t_jRespectively representing the transmission delays, t, of the network devices to user i and user j_i，jRepresenting the transmission delay, Δ t, from user j to user i_i，jThe time advance of the time when the transmission signal of the uplink user j reaches the downlink user i is compared with the time when the expected signal sent by the network equipment to the downlink user i reaches the downlink user i, that is, the time advance of the mutual interference signal relative to the expected signal。

The timing advance of the self-interference signal relative to the desired signal is determined by the transmission delay from the network device to the terminal, specifically Δ t_i＝2t_i，Δt_iAnd the time advance represents the time advance of the uplink signal of the user i relative to the downlink signal expected signal of the user i, namely the time advance of the self-interference signal relative to the expected signal.

S803, the network equipment determines the length of the OFDM cyclic suffix.

And the network equipment determines the length of the OFDM cyclic suffix according to the transmission delay among the users, the mutual interference power among the users and the self-interference power of the users. Specifically, the network device performs scheduling according to at least one of the following principles, and determines the OFDM cyclic suffix length: the overall interference level within the network covered by the network device is minimal, or the overall throughput is maximal, or the throughput of a certain user is maximal, or the throughput of certain users is maximal, etc.

In the above embodiment, the network device obtains the inter-user mutual interference power, the user self-interference power, and the time advance of the interference signal relative to the desired signal by indicating a user measurement method or a method of calculating according to the calculation parameter, and determines the length of the OFDM cyclic suffix according to the parameter and a specific principle, so that when the network device and the terminal communicate by using the length of the OFDM cyclic suffix, the interference level in the network can be reduced, and the throughput of the system can be improved.

In some cases, the network device cannot obtain the inter-user interference power and/or the user self-interference power by a method of indicating user measurement or calculating according to a calculation parameter, or the network device needs to accurately measure the interference condition in the network.

In one embodiment provided herein, a network device determines an OFDM cyclic suffix length based on a timing advance of an interfering signal relative to a desired signal. Wherein the timing advance of the interference signal relative to the desired signal comprises the timing advance of the inter-user mutual interference signal relative to the desired signal and the timing advance of the user self-interference signal relative to the desired signal.

In one possible implementation, the network device rootThe OFDM cyclic suffix length is determined according to a maximum value of a timing advance of the interfering signal relative to the desired signal. OFDM cyclic suffix length t_csSpecifically, the formula is as follows:

t_cs＝max(Δt_i，j，2t_i)，0≤i≤N-1，0≤j≤M-1

Δt_i，jthe time lead representing the time lead of the time when the sending signal of the uplink user j reaches the downlink user i compared with the time when the expected signal sent by the network equipment to the downlink user i reaches the downlink user i, namely the time lead of the mutual interference signal of the user j to the user i relative to the expected signal; 2t of_iAnd the time lead representing the time lead of the time when the uplink signal of the user i reaches the downlink signal receiving window of the user i compared with the time when the expected signal sent to the user i by the network equipment reaches the downlink signal receiving window of the user i, namely the time lead of the self-interference signal of the user i relative to the expected signal. N denotes the number of terminals (users) in the network in the uplink traffic, and M denotes the number of terminals (users) in the network in the downlink traffic.

And according to the maximum value of the time advance of the interference signal relative to the expected signal as the length of the cyclic suffix, the uplink and downlink signals between the network equipment and each terminal in the system have no intersymbol interference.

In one possible implementation, when the interference suffered by users in the network mainly originates from self-interference and the network device does not consider or can not acquire the self-interference power, the network device determines the length of the OFDM cyclic suffix according to the maximum value of the time advance of the self-interference signal relative to the expected signal. OFDM cyclic suffix length t_csSpecifically, the formula is as follows:

t_cs＝max(2t_i)，0≤1≤N-1

2t_ithe time lead representing the time lead of the time when the uplink signal of the user i reaches the downlink signal receiving window of the user i is compared with the time when the expected signal sent to the user i by the network equipment reaches the downlink signal receiving window of the user i, namely the time lead of the self-interference signal of the user i relative to the expected signal; n represents the number of terminals (users) in the network in uplink traffic

In a possible implementation, when the interference suffered by users in the network mainly comes from the inter-user mutual interference and the network device does not consider or cannot obtain the inter-user mutual interference power, for example, most terminals in the network are in a half-duplex mode, the network device determines the length of the OFDM cyclic suffix according to the maximum value of the time advance of the inter-user mutual interference signal relative to the desired signal. OFDM cyclic suffix length t_csSpecifically, the formula is as follows:

t_cs＝max(Δt_i，j)，0≤i≤N-1，0≤j≤M-1

Δt_i，jthe time lead representing the time lead of the time when the sending signal of the uplink user j reaches the downlink user i compared with the time when the expected signal sent by the network equipment to the downlink user i reaches the downlink user i, namely the time lead of the mutual interference signal of the user j to the user i relative to the expected signal; n denotes the number of terminals (users) in the network in the uplink traffic, and M denotes the number of terminals (users) in the network in the downlink traffic.

It is noted that, in each possible implementation manner of this embodiment, the network device obtains Δ t_i，jAnd/or 2t_iThe method can refer to the contents described in S801 and S802 above, and the details are not repeated here.

After the cyclic suffix is added after the OFDM symbol, the transmittable resources in the network are reduced, namely certain cyclic suffix overhead exists. For example, after adding a cyclic suffix, the OFDM symbol period will become longer, or the OFDM symbol duration or cyclic prefix duration within one OFDM symbol period will become shorter, and so on.

In one embodiment provided herein, the network device determines the length of the cyclic suffix taking into account the cyclic suffix overhead. Specifically, the network device compromises self-interference power, mutual interference power and cyclic postfix overhead which need to be suppressed when determining the cyclic postfix length.

In one possible implementation, when the network device determines the cyclic suffix, the fraction of the length of the cyclic suffix of the OFDM symbol in the entire OFDM symbol period is reduced as much as possible, i.e., the fraction of the duration of the OFDM symbol in the OFDM symbol period is increased, while satisfying the interference suppression requirement.

The cyclic suffix length t can be determined, for example, using the following formula_cs：

For example, t can also be determined using the following formula_cs：

In the above two formulae, t_symIndicating the OFDM symbol length, M indicating the number of terminals in downlink traffic in the full duplex network, N indicating the number of terminals in uplink traffic in the full duplex network,indicating the desired signal power received by the downstream terminal i,represents the interference power of the uplink terminal j to the downlink terminal i,denotes the self-interference power, Δ t, of the downlink terminal i_i，jRepresenting the timing advance of the interfering signal relative to the desired signal, 2t_iRepresenting the timing advance of the terminal i self-interference signal relative to the desired signal,n_irepresenting the white noise power of terminal i.

In one possible implementation, when the interference suffered by the user in the network mainly originates from the self-interference signal, the network device determines the length of the OFDM cyclic suffix according to the self-interference power of the user in the network and the time advance of the self-interference signal of the user relative to the desired signal. For example, the following formula can be used to calculateOFDM cyclic suffix length t_cs：

For example, t can also be determined using the following formula_cs：

In the above two formulae, t_symIndicating the OFDM symbol length, M indicating the number of terminals in downlink traffic in a full duplex network,indicating the desired signal power received by the downstream terminal i,represents the self-interference power of the downlink terminal i, 2t_iRepresenting the timing advance of the terminal i self-interference signal relative to the desired signal,n_irepresenting the white noise power of terminal i.

In one possible implementation, when the interference experienced by the users in the network mainly originates from the mutual interference signal, for example, when most of the terminals in the network are in the half-duplex mode, the network device determines the cyclic postfix length according to the mutual interference power between the users in the network and the time advance OFDM of the mutual interference signal between the users relative to the desired signal. For example, the following formula may be used to calculate the OFDM cyclic suffix length t_cs：

For example, t can also be determined using the following formula_cs：

In the above two formulae, t_symIndicating the OFDM symbol length, M indicating the number of terminals in downlink traffic in the full duplex network, N indicating the number of terminals in uplink traffic in the full duplex network,indicating the desired signal power received by the downstream terminal i,represents the interference power of the uplink terminal j to the downlink terminal i, delta t_i，jRepresenting the timing advance, n, of the interfering signal relative to the desired signal_iRepresenting the white noise power of terminal i.

It should be noted that, in each possible implementation of this embodiment, the parameters used by the network device to obtain and determine the length of the OFDM cyclic suffix may refer to the contents described in S801 and S802, and are not described herein again.

In the above embodiment, when the network device determines the length of the cyclic suffix, in addition to the self-interference power of the users, the mutual interference power between the users, and the timing advance of the interference signal relative to the desired signal, the overhead caused by the length of the cyclic suffix is also considered, so that the total throughput of the network is improved while interference suppression is realized.

When the multipath time delay expansion, the mutual interference time lead between users and the self-interference time lead in the full-duplex network are related to the coverage of the network. When the coverage is smaller, the multipath time delay spread, the inter-user mutual interference time lead and the self-interference time lead in the full-duplex network are smaller. Therefore, under the scene that the full-duplex network coverage is small, the intersymbol interference ISI can be eliminated on the basis of not increasing extra overhead, and the network equipment does not need to dynamically adjust the length of the OFDM cyclic postfix.

In one embodiment provided herein, a network device statically configures an OFDM cyclic suffix length. The embodiment is suitable for scenes with small full-duplex network coverage, such as rooms or buildings.

In one possible implementation, the network device uses the maximum value of the timing advance of the interference signal relative to the desired signal in its coverage area as the static configuration value of the OFDM cyclic postfix length, so that there is no ISI in the coverage area. Taking the scenario with a subcarrier spacing of 15k as an example, the OFDM cyclic suffix length can be statically configured by table 2 below.

Table 215 k subcarrier spacing OFDM cyclic suffix static configuration table

Configuration index	0	1	2	3	4
						Number of symbols	14	14	14	14	14
OFDM symbol duration (us)	66.667	66.667	66.667	66.667	66.667
						CP duration (us)	4.355	4.021	3.688	2.688	1.355
CS duration (us)	0.333	0.667	1.000	2.000	3.333
						Coverage (m)	50	100	150	300	500

The cyclic postfix length (CS duration) configured in table 2 may satisfy the ISI free from inter-symbol interference for upstream and downstream communications at a corresponding coverage range at 15k subcarrier spacing. For example, when the coverage radius is 100m, the maximum value of the timing advance of the interference signal relative to the desired signal isMicrosecond, when the cyclic suffix length CS is greater than or equal to 0.667us, it can ensure no intersymbol interference ISI in the network under the coverage, where the OFDM symbol duration is 66.667us, and the cyclic prefix CP length is 4.021us, the length of the cyclic suffix CS is 0.667us, and the OFDM period is 71.355 us; when the coverage radius is 150m, and the length of the cyclic suffix CS is 1us, ISI-free in the network of the coverage area can be guaranteed, where the OFDM symbol duration is 66.667us, the cyclic prefix CP length is 3.688us, the length of the cyclic suffix CS is 1us, and the OFDM period is 71.355 us.

In the possible implementation, because the coverage area is small, and the multipath delay spread is also small, the network device can use a part of the CP length of the cyclic prefix for the CS length of the cyclic suffix without changing the OFDM symbol duration and the OFDM period, thereby ensuring that no inter-symbol interference exists in the coverage area of the network device.

In one possible implementation, the configuration may be reported to the user as a static configuration via a Master Information Block (MIB) when the user accesses the configuration.

In a possible implementation, the configuration may also be implicitly notified to the user by a cell Identity (ID), for example, after the user acquires the cell ID in the initial access process, the cell ID or a remainder obtained by modulo a certain value of the cell ID is used as an index of the static configuration, and the application is not limited.

It should be noted that the static configuration information sent by the network device to the terminal device may be index information, where the index information is used to indicate a configuration value of the OFDM cyclic suffix length, and after receiving the static configuration information, the terminal device obtains the corresponding OFDM cyclic suffix length according to the index information; the static configuration information sent by the network device to the terminal may be a specific configuration value, and the terminal device determines the length of the OFDM cyclic suffix according to the configuration value sent by the network device.

In the above embodiment, in a scenario where the network coverage is small, the network device issues the statically configured cyclic suffix length to the network device, and on the basis of not increasing additional overhead, it is ensured that there is no ISI.

In one embodiment provided by the present application, when a network device dynamically configures a cyclic suffix length according to different interference levels, the cyclic suffix length is set as a configuration item in advance. The configuration item corresponds to a range of cyclic suffix durations. The network device dynamically determines the length of the cyclic suffix by the method described in the above embodiments, and determines the configuration item to which the determined length of the cyclic suffix belongs. And when the network equipment issues configuration information to the terminal equipment, sending a configuration index corresponding to the configuration item to which the determined length of the cyclic suffix belongs, and after the terminal equipment receives the configuration information, acquiring the corresponding length of the OFDM cyclic suffix according to the configuration index, wherein the length of the OFDM cyclic suffix is the maximum value of the duration of the cyclic suffix corresponding to the configuration index.

Taking the scenario with a subcarrier spacing of 15k as an example, the OFDM cyclic suffix length can be dynamically configured by table 3 below.

Table 315 k subcarrier spacing OFDM cyclic suffix dynamic configuration table

Configuration index	0	1	2	3
					Number of symbols	14	12	10	8
OFDM symbol duration (us)	66.667	66.667	66.667	66.667
					CP duration (us)	1.355	4.688	4.688	4.688
CS duration (us)	3.407	11.979	28.646	53.646
					CS duration Range (us)	0～3.407	3.407～11.979	11.979～28.646	11.979～53.646
Coverage (m)	0～511	511～1796.85	1796.85～4,296.9	1796.85～8,046.9

For example, when the configuration index is 1, the terminal device adds a cyclic suffix length of 11.979us after the OFDM symbol, the cyclic suffix length corresponding to a cyclic suffix length in the range of 3.407us to 11.979us determined by the network device.

In a possible implementation, the configuration information may be notified to the user through an RRC message, or may be notified to the user through other information, which is not limited in the present application.

In the above embodiment, the length of the cyclic suffix dynamically determined by the network device is used as the configuration item, the network device sends the configuration index corresponding to the configuration item when issuing the configuration information of the cyclic suffix to the terminal device, and the terminal device obtains the length of the cyclic suffix according to the configuration index.

The method for configuring the cyclic suffix for the OFDM symbol provided in the embodiment of the present application is also applicable to a scene in which a full-duplex frequency band and a half-duplex frequency band are adjacent to each other. As shown in fig. 12a and 12b, the desired Downlink Signal received by the user can be divided into a half-duplex frequency band and a full-duplex frequency band in the frequency domain, wherein the half-duplex frequency band is used for transmitting Control messages such as Synchronization signals and PBCH blocks (SSB), Physical Downlink Control Channels (PDCCH). In addition, the user also receives uplink interference signals of other users, and because the interference signals and the desired signal are asynchronous, the interference signals generate inter-carrier interference ICI due to inter-symbol interference ISI in a receiving window of the desired signal, thereby affecting reliability of control message transmission.

In one possible implementation, as shown in fig. 12a, when there is no OFDM cyclic suffix proposed in the embodiment of the present application in the OFDM period, a guard band needs to be added between the half-duplex band and the full-duplex band to protect the control signal from ICI. Wherein the bandwidth of the guard band is related to the interference power level.

In one possible implementation, as shown in fig. 12b, the subcarrier orthogonality of the interfering signal is not destroyed by adding a cyclic suffix after the OFDM symbol, so that the interfering signal is free of ICI due to ISI within the reception window of the desired signal, depending on the current interference situation. When the possible realization is adopted, an extra guard band is not needed to be added between half-duplex and full-duplex transmission frequency bands, and the network throughput is improved.

In the embodiments provided in the present application, the method provided in the embodiments of the present application is introduced from the perspective of interaction between a terminal and a network device. In order to implement the functions in the method provided by the embodiments of the present application, the terminal and/or the network device may include a hardware structure and/or a software module, and the functions are implemented in the form of a hardware structure, a software module, or a hardware structure and a software module. Whether any of the above-described functions is implemented as a hardware structure, a software module, or a hardware structure plus a software module depends upon the particular application and design constraints imposed on the technical solution.

Fig. 13 is a schematic diagram of a communication apparatus 1300. The communication apparatus 1300 includes a processing unit 1301 and a transmitting/receiving unit 1302.

In a possible implementation, the apparatus 1300 may be the terminal device in the above method embodiment, or an apparatus (e.g., a chip, or a system of chips, or a circuit) in the terminal device, or an apparatus capable of being used with the terminal device.

When the communication apparatus 1300 is a terminal device, the processing unit 1301 is configured to obtain configuration information, where the configuration information includes OFDM cyclic suffix length information; the OFDM cyclic suffix length is determined according to the acquired configuration information; the transceiving unit 1302 is configured to communicate with a network device using an OFDM cyclic suffix length.

The specific implementation manner of the operation performed by each unit may refer to the specific implementation manner of the operation performed by the terminal device in the foregoing method embodiment, and details are not described here again.

In a possible implementation, the apparatus 1300 may be a network device in the above method embodiment, or an apparatus (e.g., a chip, or a system of chips, or a circuit) in the network device, or an apparatus capable of being used with the terminal device.

When communications apparatus 1300 is a network device, processing unit 1301 is configured to determine an OFDM cyclic suffix length; the transceiving unit 1302 is configured to issue first configuration information to the terminal, where the configuration information includes OFDM cyclic suffix length information and is further configured to communicate with the terminal using the OFDM cyclic suffix length.

The specific implementation manner of the operation performed by each unit may refer to the specific implementation manner of the operation performed by the terminal device in the foregoing method embodiment, and details are not described here again.

Fig. 14 shows a schematic structure of a communication apparatus 1400. The communication apparatus 1400 may be configured to implement the method corresponding to the network device or the method corresponding to the terminal described in the foregoing method embodiment, which is specifically referred to the description in the foregoing method embodiment.

The communication device 1400 may comprise one or more processors 1401, which processors 1401 may also be referred to as processing units and may implement certain control functions. The processor 1401 may be a general purpose processor, a special purpose processor, or the like.

In an optional implementation, the processor 1401 may also store instructions 1403, which can be executed by the processor, so that the communication apparatus 1400 performs the method corresponding to the terminal or the network device described in the above method embodiment.

In yet another possible implementation, the communication device 1400 may include circuitry that may implement the functionality of transmitting or receiving or communicating in the foregoing method embodiments.

Optionally, the communication device 1400 may include one or more memories 1402 coupled to a processor 1401, on which instructions 1404 or intermediate data are stored, the instructions 1404 being executable on the processor to cause the communication device 1400 to perform the methods described in the method embodiments above. Optionally, other related data may also be stored in the memory. Optionally, instructions and/or data may also be stored in the processor. The processor and the memory may be provided separately or may be integrated together.

Optionally, the communication device 1400 may further include a transceiver 1405.

The processor 1401 may be referred to as a processing unit. The transceiver 1405 may be referred to as a transceiver unit, a transceiver, a transceiving circuit, a transceiver, or the like, and is used for implementing transceiving functions of the communication apparatus.

If the communication apparatus is used to implement operations corresponding to a terminal device, for example, the transceiver 1405 may receive configuration information sent by a network device, and the transceiver 1405 may further perform other corresponding communication functions; processor 1401 can obtain configuration information and determine an OFDM cyclic suffix length based on the obtained configuration information. The specific processing manner of each component can be referred to the related description of the previous embodiment.

If the communication apparatus is used to implement operations corresponding to network devices, for example, the transceiver 1405 may issue configuration information containing OFDM cyclic suffix length information to the terminal device, and the transceiver 1405 may further perform other corresponding communication functions; processor 1401 can determine an OFDM cyclic suffix length. The specific processing manner of each component can be referred to the related description of the previous embodiment.

The functions implemented by the processing unit 1301 in fig. 13 may be implemented by the processor 1401, and the functions implemented by the transceiving unit 1302 may be implemented by the transceiver 1405.

The processor 1401 described herein may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present application, such as: one or more Digital Signal Processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs).

The memory 1402 described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM). For example, RAM can be used as external cache memory. By way of example and not limitation, RAM may include the following forms: static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and direct bus RAM (DR RAM). Alternatively, the memory may be integrated in the terminal device or the network device, or the memory may not be integrated in the terminal device or the network device, and the memory may be provided externally. The details are not limited herein.

Alternatively, the communication means may be a stand-alone device or may be part of a larger device. For example, the device may be: a stand-alone integrated circuit IC, or chip, or system-on-chip or subsystem; a set of one or more ICs, which optionally may also include storage components for storing data and/or instructions; an ASIC, such as a modem (MSM); a module that may be embedded within other devices; receivers, terminals, cellular telephones, wireless devices, handsets, mobile units, network devices, and the like.

Fig. 15 shows an apparatus 1500 provided in this embodiment of the present application, which may be used to execute the method performed by the terminal or the network device, where the apparatus 1500 may be a communication device or a chip in the communication device. As shown in fig. 15, the apparatus 1500 includes: at least one input interface (input (s))1501, logic 1502, and at least one output interface (output (s)) 1503. Alternatively, the logic circuit 1502 may be a chip or other integrated circuit that can implement the method of the present application.

The logic circuit 1502 may implement the methods performed by the terminal or the network device in the various embodiments described above;

the input interface 1501 is used for receiving data; the output interface 1503 is used to transmit data. For example, when the apparatus 1500 is a terminal, the input interface 1501 can be used to receive configuration information sent by a network device; the input interface 1501 and the output interface 1503 may also be used to communicate with network devices using OFDM cyclic suffix length. When the apparatus 1500 is a network device, the output interface 1503 is configured to issue configuration information to a terminal device, and the input interface and the output interface may also be configured to communicate with the terminal device using an OFDM cyclic suffix length.

The functions of the input interface 1501, the logic circuit 1502, or the output interface 1503 can refer to methods executed by the terminal or the network device in the above embodiments, and are not described herein again.

When the communication device is a chip applied to a terminal device, the terminal device chip implements the functions of the terminal device in the above method embodiment. The terminal device chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal device, wherein the information is sent to the terminal device by the network device; or, the terminal device chip sends information to other modules (such as a radio frequency module or an antenna) in the terminal device, where the information is sent by the terminal device to the network device.

When the communication device is a chip applied to a network device, the network device chip implements the functions of the network device in the above method embodiments. The network device chip receives information from other modules (such as a radio frequency module or an antenna) in the network device, wherein the information is sent to the network device by the terminal device; alternatively, the network device chip sends information to other modules (such as a radio frequency module or an antenna) in the network device, and the information is sent by the network device to the terminal device.

Based on the same concept as the method embodiments, embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program causes the computer to perform operations performed by a terminal or a network device in any one of the possible implementations of the method embodiments and the method embodiments.

Based on the same concept as the method embodiments described above, the present application also provides a computer program product, which may include instructions that, when invoked by a computer, may cause the computer to implement the operations performed by the terminal or the network device in any one of the possible implementations of the method embodiments, the method embodiments described above.

Based on the same concept as the method embodiments described above, the present application also provides a chip or a chip system, which may include a processor. The chip may further include or be coupled with a memory (or a storage module) and/or a transceiver (or a communication module), where the transceiver (or the communication module) may be used to support the chip for wired and/or wireless communication, and the memory (or the storage module) may be used to store a program that is called by the processor to implement the operations performed by the terminal or the network device in any of the possible implementations of the above-described method embodiments and method embodiments. The chip system may include the above chip, and may also include the above chip and other discrete devices, such as a memory (or storage module) and/or a transceiver (or communication module).

Based on the same conception as the method embodiment, the application also provides a communication system which can comprise the terminal and/or the network equipment. The communication system may be used to implement the operations performed by the terminal or the network device in any of the possible implementations of the method embodiments, method embodiments described above. Illustratively, the communication system may have a structure as shown in fig. 5.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The above description is only a few specific embodiments of the present application, but the scope of the present application is not limited thereto, and those skilled in the art can make further changes and modifications to the embodiments within the technical scope of the present disclosure. It is therefore intended that the following appended claims be interpreted as including the foregoing embodiments and all such alterations and modifications as fall within the scope of the application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.