阅读说明：本技术 一种中间前导码指示、接收方法及装置 (Method and device for indicating and receiving middle lead code ) 是由 于健 希米·西隆 根纳季·特所迪克 奥德·里德里 亚龙·本·阿里 多伦·埃兹里 淦明 于 2017-08-31 设计创作，主要内容包括：本申请公开了一种中间前导码指示、接收方法及装置。该方法中,第一设备获取第二设备处理中间前导码的能力信息,所述能力信息包括所述第二设备对多普勒模式的支持信息。所述第一设备将中间前导码指示信息发送给所述第二设备,所述中间前导码指示信息由前导码中的HE-SIG-A中的B21和B22比特携带,所述B21和B22比特的值为3,其中,所述B21和B22比特的值为0,1或2的可能基于所述第二设备对多普勒模式的支持信息被禁止。(The application discloses a method and a device for indicating and receiving a middle lead code. In the method, a first device acquires capability information of a second device for processing a middle preamble, wherein the capability information includes Doppler mode support information of the second device. The first device sends middle preamble indication information to the second device, wherein the middle preamble indication information is carried by B21 and B22 bits in HE-SIG-A in a preamble, the B21 and B22 bits have a value of 3, and the B21 and B22 bits have a value of 0, and the possibility of 1 or 2 being prohibited based on the second device support information for Doppler mode.)

1. A method for indicating an inter-preamble, comprising:

the method comprises the steps that a first device obtains capability information of a second device for processing a middle lead code, wherein the capability information comprises Doppler mode supporting information of the second device;

the first device sends middle preamble indication information to the second device, wherein the middle preamble indication information is carried by B21 and B22 bits in HE-SIG-A in a preamble, the B21 and B22 bits have a value of 3, and the B21 and B22 bits have a value of 0, and the possibility of 1 or 2 being prohibited based on the second device support information for Doppler mode.

2. The method of claim 1, wherein a value of 3 for the B21 and B22 bits indicates:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s; or

The HE-LTF symbol is 4 basic symbol duration except for the GI part, and GI is 3.2 mu s.

3. An intermediate preamble receiving method, comprising:

the second device sends the capability information of the second device for processing the middle lead code to the first device, wherein the capability information comprises the Doppler mode support information of the second device;

the second device receives the intermediate preamble indication information transmitted by the first device, wherein the intermediate preamble indication information is carried by B21 and B22 bits in HE-SIG-A in a preamble, the B21 and B22 bits have a value of 3, and the B21 and B22 bits have a value of 0, and the possible suppression of 1 or 2 is based on the second device support information for Doppler mode;

and the second equipment receives the intermediate preamble according to the indication information.

4. The method of claim 3, wherein a value of 3 for the B21 and B22 bits indicates:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s; or

The HE-LTF symbol is 4 basic symbol duration except for the GI part, and GI is 3.2 mu s.

5. An apparatus, characterized in that the apparatus, as a first apparatus, comprises:

a unit for acquiring capability information of a second device for processing a middle lead code, wherein the capability information comprises Doppler mode support information of the second device;

transmitting intermediate preamble indication information to the second device, the intermediate preamble indication information being carried by B21 and B22 bits in the HE-SIG-a in the preamble, the B21 and B22 bits having a value of 3, wherein the B21 and B22 bits having a value of 0, 1 or 2 are disabled, possibly based on the second device support information for the doppler mode.

6. The apparatus of claim 5, wherein a value of 3 for the B21 and B22 bits indicates:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s; or

The HE-LTF symbol is 4 basic symbol duration except for the GI part, and GI is 3.2 mu s.

7. An apparatus, characterized in that the apparatus, as a second apparatus, comprises:

a unit for sending capability information of the second device for processing the middle preamble to the first device, wherein the capability information comprises the support information of the second device for the Doppler mode;

a unit for receiving the intermediate preamble indication information transmitted by the first device and receiving an intermediate preamble according to the indication information, the intermediate preamble indication information being carried by B21 and B22 bits in HE-SIG-a in a preamble, the B21 and B22 bits having a value of 3, wherein the B21 and B22 bits having a value of 0, 1 or 2 may be disabled based on the second device's support information for doppler mode.

8. The apparatus of claim 7, wherein a value of 3 for the B21 and B22 bits indicates:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s; or

The HE-LTF symbol is 4 basic symbol duration except for the GI part, and GI is 3.2 mu s.

Technical Field

The present application relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for indicating and receiving an intermediate preamble.

Background

In high efficiency wireless local area network communication, data transmission between devices can be performed with a data unit structure as shown in table 1. As shown in table 1, the data unit contains a legacy preamble. The legacy preamble includes a legacy short training field (L-STF), a legacy long training field (L-LTF), and a legacy signaling (L-SIG) field. Following the legacy preamble, a repeated legacy signaling (repeated L-SIG) field; a high efficiency signaling field A (HE-SIG-A), a high efficiency Short Training field (HE-STF), and a high efficiency Long Training field (HE-LTF). The HE-LTF field is used for channel estimation, and may contain one or more HE-LTF symbols for channel estimation over multiple Space Time Streams (STS). Then follows a Data (Data) section, which is used to carry Media Access Control (MAC) frames. Finally, a Packet Extension (PE) is used to help the receiving device get more processing time.

TABLE 1

Wireless Local Area Network (WLAN) systems typically consider a scenario in which a device is relatively stationary, i.e., assuming that the channel does not change significantly over a period of time. Therefore, after the device receiving the data performs channel estimation according to the HE-LTF field, the device decodes the data field by using the result of the channel estimation according to the HE-LTF field, assuming that the channel state of the subsequent data field is the same as the channel state when the HE-LTF field is received.

In some scenarios where doppler phenomenon occurs due to device movement or other device movement in the surrounding environment, the channel may change with time, so it is proposed to insert a midamble (midamble) in the data symbols, so that the receiving device can perform channel estimation again according to the midamble, so as to avoid decoding error of the receiving device.

However, in the doppler scenario, various information about the middle preamble is not clearly defined, and how to indicate and receive the middle preamble is a problem to be solved.

Disclosure of Invention

The application provides a method and a device for indicating and receiving an intermediate lead code, which are used for realizing that a second device can correctly decode received data symbols according to the intermediate lead code sent by a first device.

In a first aspect, the present application provides a method for indicating an intermediate preamble, including:

the first device sends the middle lead code indication information to the second device, wherein the time length of one HE-LTF symbol contained in the middle lead code indicated by the middle lead code indication information is one of the HE-LTF symbol time length sets.

In the method, the duration of the middle preamble indicated by the middle preamble indication information is one of the preset middle preamble duration sets, but cannot indicate durations outside the middle preamble duration set, so that the duration of the middle preamble to be transmitted subsequently meets the requirement of the middle preamble.

In one possible implementation manner, the HE-LTF symbol duration set includes one or any combination of the following:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 1.6 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 3.2 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 1.6 mu s;

the HE-LTF symbol is 2 basic symbol duration except for the GI part, and GI is 3.2 mu s.

In a second aspect, an intermediate preamble receiving method provided in an embodiment of the present application includes:

the second device receives middle lead code indication information sent by the first device, wherein the time length of a high-efficiency long training field HE-LTF symbol contained in the middle lead code indicated by the middle lead code indication information is one of a HE-LTF symbol time length set.

In one possible implementation, the HE-LTF symbol duration set includes one or a combination of the following:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 1.6 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 3.2 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 1.6 mu s;

the HE-LTF symbol is 2 basic symbol duration except for the GI part, and GI is 3.2 mu s.

In a third aspect, the present application provides a method for indicating an intermediate preamble, including:

the method comprises the steps that a first device sends middle lead code indication information to a second device, wherein the time length of a middle lead code indicated by the middle lead code indication information is larger than or equal to a threshold value, and the threshold value is related to the processing capacity of the second device.

In the method, the first device sends the middle preamble indication information to the second device, so that the second device can receive the middle preamble according to the indication information, and in addition, as the duration of the middle preamble increases, the duration for processing the middle preamble does not significantly increase, and therefore, the duration of the middle preamble is greater than or equal to the threshold, which helps to avoid the situation that the second device cannot correctly decode the data symbols according to the middle preamble due to limited processing capability after receiving the middle preamble.

In a possible implementation manner, the indication information of the middle preamble includes: indication information used for indicating the number of HE-LTF symbols contained in the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; multiplying the time length of the HE-LTF symbol by the number of the HE-LTF symbols, wherein the time length is greater than or equal to the preset threshold value; alternatively, the first and second electrodes may be,

the indication information of the duration of the middle preamble includes: indication information used for indicating the number of space-time streams used by the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; and the time length of the HE-LTF symbol is multiplied by the number of the HE-LTF symbols corresponding to the number of the space-time streams, and the time length is greater than or equal to the preset threshold value.

The time length of the middle lead code is the sum of the time lengths of one HE-LTF and one GI multiplied by the number of HE-LTF symbols; in addition, in some cases, the indication information of the middle preamble may also not directly give the number of HE-LTF symbols, but carry the number of space-time streams in the indication information, and since there is a correspondence between the number of space-time streams and the number of HE-LTF symbols, the second device may determine the number of HE-LTF symbols corresponding to the number of space-time streams, and then further determine the duration of the middle preamble.

In a possible implementation manner, the indication information of the middle preamble at least includes indication information for indicating a duration of a GI part and a duration of a GI in one HE-LTF symbol; the duration of the GI part in the one HE-LTF symbol is 2 basic symbol durations or 4 basic symbol durations.

One basic symbol duration is 3.2 mus and the minimum duration of the guard interval is 0.8 mus. Therefore, if the duration of the HE-LTF symbol included in the intermediate preamble, divided by the GI part, is 2 basic symbol durations or 4 basic symbol durations, the sum of the durations of one HE-LTF symbol is at least 7.2 μ s or 13.6 μ s, that is, the duration of the intermediate preamble is at least 7.2 μ s or 13.6 μ s, which can satisfy the duration required by most devices to process the intermediate preamble.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

The HE-LTF fields in the intermediate preamble and the preamble can be used for channel estimation, however, the intermediate preamble is transmitted by being inserted into the middle of the data symbols, so that the device receiving data needs to perform channel estimation according to the intermediate preamble after demodulating the data symbols before the intermediate preamble, and the above process needs to be completed before completely receiving the next data symbol of the intermediate preamble, so that the intermediate preamble has more requirements on the duration. Because the two requirements on the time length are different, different indication information indications can be used for indicating different time lengths respectively, which is beneficial to saving signaling overhead.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate one of at least three preset intermediate preamble periods.

In the above manner, at least four periods of the intermediate preamble are provided for the intermediate preamble, so as to meet the requirements of the doppler effect on channel estimation in different scenarios. For example, a longer period may be used when the device is moving at a slower speed and the channel changes more rapidly on a high speed train, and a shorter period may be used.

In one possible implementation, the sending, by the first device, the middle preamble indication information to the second device includes: the method comprises the steps that a first device sends the period of a middle preamble and/or indication information used for indicating the duration of one HE-LTF symbol to a second device through a reserved entry in a Spatial Reuse Parameter (SRP) field; or, the first device sends indication information indicating the duration of one HE-LTF symbol to the second device through reserved bits.

Since some reserved bits or some reserved entries exist in one data frame, the reserved bits or reserved entries are used for sending the middle preamble indication information, and the existing frame structure can be fully utilized.

In a possible implementation manner, before the first device sends the intermediate preamble indication information to the second device, the method further includes: the first equipment acquires the capability information of the second equipment for processing the middle lead code; the first device determines the threshold value according to the capability information.

Different devices have different processing capacities, some devices have high processing speed or can perform parallel processing, the time length of the middle lead code is not required to be high, some devices have low processing speed or cannot perform parallel processing, the time length of the middle lead code is required to be high, the first device determines the threshold value according to the processing capacity of the second device, and therefore decoding errors caused by untimely processing of the second device are effectively avoided.

In a possible implementation manner, after the first device sends the middle preamble indication information to the second device, the method further includes: the first equipment sends the middle lead code to the second equipment, the middle lead code is obtained by filling the content contained in the appointed middle lead code, and the duration of the filled middle lead code is more than or equal to the threshold value.

The content of the intermediate preamble is predetermined, and the second device performs channel estimation according to the received intermediate preamble and the known content of the intermediate preamble. In the method, the content of the pre-agreed intermediate preamble code is padded, so that the duration of the padded intermediate preamble code is greater than or equal to the threshold. The content and the location of the padding may be predetermined, or may be notified to the second device by the middle preamble indication information.

In a fourth aspect, an embodiment of the present application provides an intermediate preamble receiving method, including:

the method comprises the steps that a second device receives middle lead code indication information sent by a first device, wherein the time length of a middle lead code indicated by the middle lead code indication information is larger than or equal to a threshold value, and the threshold value is related to the processing capacity of the second device.

Further, the second device receives an intermediate preamble according to the intermediate preamble indication information.

In a possible implementation manner, before the second device receives the middle preamble indication information sent by the first device, the method further includes: the second device sends, to the first device, capability information of the second device to process an intermediate preamble.

In a possible implementation manner, the indication information of the middle preamble includes: indication information used for indicating the number of HE-LTF symbols contained in the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; multiplying the time length of the HE-LTF symbol by the number of the HE-LTF symbols, wherein the time length is greater than or equal to the preset threshold value; or, the indication information of the duration of the middle preamble includes: indication information used for indicating the number of space-time streams used by the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; and the time length of the HE-LTF symbol is multiplied by the number of the HE-LTF symbols corresponding to the number of the space-time streams, and the time length is greater than or equal to the preset threshold value.

In a possible implementation manner, the indication information of the middle preamble at least includes indication information for indicating a duration of a GI part and a duration of a GI in one HE-LTF symbol; the duration of the GI part in the one HE-LTF symbol is 2 basic symbol durations or 4 basic symbol durations.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate that one of at least four intermediate preamble periods is preset.

In a possible implementation manner, the receiving, by the second device, the middle preamble indication information sent by the first device includes: the second equipment receives the period of the middle lead code and/or the indication information used for indicating the duration of one HE-LTF symbol through a reserved entry in the SRP field; or, the second device receives the indication information of the duration of one HE-LTF symbol through the reserved bits.

In a possible implementation manner, after the second device receives the middle preamble indication information sent by the first device, the method further includes: and the second equipment receives an intermediate lead code according to the intermediate lead code indication information, wherein the intermediate lead code is obtained by filling the content contained in the appointed intermediate lead code, and the duration of the filled intermediate lead code is more than or equal to the threshold.

In a fifth aspect, an embodiment of the present application provides a method for indicating an intermediate preamble, including: the method comprises the steps that first equipment obtains the capability information of second equipment for processing the middle lead code; the first equipment sends the middle lead code indication information to the second equipment, and the duration of the middle lead code indicated by the middle lead code indication information is determined according to the capability information of the second equipment.

In the method, the first device determines the intermediate preamble indication information according to the capability information of the second device for processing the intermediate preamble, which helps to avoid that the second device is too late to correctly decode the data symbols according to the intermediate preamble due to limited processing capability after receiving the intermediate preamble.

In one possible implementation, the capability information includes at least one of the following information:

a minimum duration of the intermediate preamble code that the second device can support;

information on whether the second device can support a single user and/or a Doppler mode under a single-user extended range;

information on whether the second device can support a doppler mode under multiple users;

the maximum space-time stream number occupied by the middle lead code which can be supported by the second equipment;

the maximum number of subcarriers occupied by the middle lead code which can be supported by the second equipment;

and the second device can support information of a modulation and coding strategy MCS when the middle lead code occupies L subcarriers and K space-time streams, wherein L and K are integers greater than or equal to 1.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate one of at least three preset intermediate preamble periods.

In one possible implementation, the sending, by the first device, the middle preamble indication information to the second device includes: the first equipment sends the period of the middle preamble and/or the indication information used for indicating the duration of one HE-LTF symbol to the second equipment through a reserved entry in an SRP field; or, the first device sends indication information indicating the duration of one HE-LTF symbol to the second device through reserved bits.

In a possible implementation manner, after the first device sends the middle preamble indication information to the second device, the method further includes: the first equipment sends the middle lead code to the second equipment, the middle lead code is obtained by filling the content contained in the appointed middle lead code, and the duration of the filled middle lead code is more than or equal to the threshold value.

In a sixth aspect, an embodiment of the present application provides an intermediate preamble receiving method, including:

the second equipment sends the capability information of the second equipment for processing the middle lead code to the first equipment; the second device receives the middle lead code indication information sent by the first device, wherein the duration of the middle lead code indicated by the middle lead code indication information is determined according to the capability information of the second device; and the second equipment receives the intermediate preamble according to the indication information.

In one possible implementation, the capability information includes one or a combination of the following:

a minimum duration of the intermediate preamble code that the second device can support;

information on whether the second device can support a single user and/or a Doppler mode under a single-user extended range;

information on whether the second device can support a doppler mode under multiple users;

the maximum space-time stream number occupied by the middle lead code which can be supported by the second equipment;

the maximum number of subcarriers occupied by the middle lead code which can be supported by the second equipment;

and the second device can support information of a modulation and coding strategy MCS when the middle lead code occupies L subcarriers and K space-time streams, wherein L and K are integers greater than or equal to 1.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate one of at least three preset intermediate preamble periods.

In a possible implementation manner, the second device receives, through a reserved entry in the SRP field, a period of the middle preamble and/or indication information for indicating a duration of one HE-LTF symbol; or, the second device receives the indication information of the duration of one HE-LTF symbol through the reserved bits.

The first device sends the middle preamble indication information to the second device, and the method comprises the following steps: the first equipment sends the period of the middle preamble and/or the indication information used for indicating the duration of one HE-LTF symbol to the second equipment through a reserved entry in an SRP field; or, the first device sends indication information indicating the duration of one HE-LTF symbol to the second device through reserved bits.

In a possible implementation manner, after the second device receives the intermediate preamble indication information sent by the first device, the method further includes: and receiving an intermediate lead code sent by the first device, wherein the intermediate lead code is obtained by filling the content contained in the appointed intermediate lead code, and the duration of the filled intermediate lead code is greater than or equal to the threshold.

In a seventh aspect, an embodiment of the present application provides a method for indicating an intermediate preamble, including: the method includes that a first device sends middle preamble indication information to a second device, wherein the middle preamble indication information is not the same information as indication information of an HE-LTF field in a preamble sent by the first device to the second device.

The HE-LTF field in the preamble and the middle preamble can be flexibly indicated through the method.

In a possible implementation manner, the duration of the HE-LTF symbol included in the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF symbol included in the HE-LTF field indicated by the indication information of the HE-LTF field.

Optionally, the HE-LTF field in the preamble may use a HE-LTF symbol with a shorter duration, and indicate that the middle preamble uses a HE-LTF symbol with a larger duration.

Optionally, HE-LTF symbols with a larger duration may be used for an HE-LTF field in the preamble, or HE-LTF symbols with a larger number may be used for initialization of channel estimation, and HE-LTF symbols with a shorter duration or HE-LTF symbols with a smaller number may be used for the middle preamble, and the data receiving device performs comprehensive analysis on the channel estimation result obtained according to the middle preamble and the initial channel estimation result to ensure accuracy of channel estimation and help to reduce signaling overhead of the middle preamble.

In an eighth aspect, an embodiment of the present application provides an intermediate preamble receiving method, including: the second equipment receives the middle lead code indication information sent by the first equipment, and the middle lead code indication information is not the same information as the indication information of a high-efficiency long training sequence HE-LTF field sent by the first equipment to the second equipment; and the second equipment receives the intermediate preamble according to the indication information.

In a possible implementation manner, the duration of the HE-LTF symbol included in the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF symbol included in the HE-LTF field indicated by the indication information of the HE-LTF field.

In a ninth aspect, an embodiment of the present application provides a method for indicating an intermediate preamble, including: the method comprises the steps that a first device sends middle lead code indication information to a second device, wherein the middle lead code indication information is used for indicating the second device to decode the (X + 1) th to (X + M) th data symbols after a middle lead code according to the middle lead code after the second device receives the middle lead code; the M represents that the first equipment sends an intermediate lead code every time M data symbols are sent, and X is an integer which is predetermined or is more than or equal to 1 and is determined according to the capability of the second equipment for processing the intermediate lead code.

In the method, the intermediate preamble is transmitted according to the transmission position indicated by the intermediate preamble indication information, so that a buffering time can be provided for the data receiving device to perform channel estimation, which helps to avoid the situation that the receiving device cannot correctly decode the data symbols according to the intermediate preamble due to limited processing capability after receiving the intermediate preamble.

In a tenth aspect, an embodiment of the present application provides an intermediate preamble receiving method, including: the second device receives the intermediate preamble; the second equipment carries out channel estimation according to the middle lead code; the second equipment decodes the data symbols from the (X + 1) th to the (X + M) th after the middle lead code according to the channel estimation result; the M represents that the second device receives an intermediate preamble every time the second device receives M data symbols, and X is an integer which is predetermined or is greater than or equal to 1 and is determined according to the capability of the second device for processing the intermediate preamble.

In an eleventh aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a first apparatus, and includes a processing unit and a sending unit, where the processing unit and the sending unit may execute corresponding functions in the method example described in the first aspect, where reference is specifically made to detailed description in the method example, and details are not repeated here.

In a twelfth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a second apparatus, and includes a receiving unit and a processing unit, where the receiving unit and the processing unit may execute corresponding functions in the method example described in the second aspect, and refer to detailed descriptions in the method example, which are not described herein again.

In a thirteenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a first apparatus, and includes a processing unit and a sending unit, where the processing unit and the sending unit may execute corresponding functions in the method example described in the third aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a fourteenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a second apparatus, and includes a receiving unit and a processing unit, where the receiving unit and the processing unit may execute corresponding functions in the method example described in the fourth aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a fifteenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a first apparatus, and includes a processing unit and a sending unit, where these units may perform corresponding functions in the method example described in the fifth aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a sixteenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a second apparatus, and includes a sending unit and a receiving unit, where these units may perform corresponding functions in the method example described in the sixth aspect, where reference is specifically made to detailed description in the method example, and details are not repeated here.

In a seventeenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a first apparatus, and includes a processing unit and a sending unit, where these units may perform corresponding functions in the method example described in the seventh aspect, where reference is specifically made to the detailed description in the method example, and details are not repeated here.

In an eighteenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a second apparatus, and includes a receiving unit and a processing unit, where these units may perform corresponding functions in the method example described in the above eighth aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a nineteenth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a first apparatus, and includes a processing unit and a sending unit, where the processing unit and the sending unit may execute corresponding functions in the method example described in the third aspect, where reference is specifically made to detailed description in the method example, and details are not repeated here.

In a twentieth aspect, an embodiment of the present application provides an apparatus, where the apparatus serves as a second apparatus, and includes a receiving unit and a processing unit, where these units may perform corresponding functions in the method example described in the fourth aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a twenty-first aspect, this application further provides a computer storage medium storing a software program, which when read and executed by one or more processors can implement the method described in any one of the first to tenth aspects.

Drawings

Fig. 1 is a schematic diagram of processing an intermediate preamble according to an embodiment of the present application;

fig. 2 is a schematic view of an application scenario provided in an embodiment of the present application;

fig. 3 is a schematic diagram of an intermediate preamble indication and reception flow provided in an embodiment of the present application;

FIG. 4 is a schematic diagram of capability information provided by an embodiment of the present application;

fig. 5 is a schematic diagram of middle preamble padding provided in an embodiment of the present application;

fig. 6 is a schematic diagram of a middle preamble transmission position according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of an apparatus according to an embodiment of the present disclosure;

fig. 8 is a second schematic structural diagram of an apparatus according to an embodiment of the present application;

fig. 9 is a third schematic structural diagram of an apparatus according to an embodiment of the present application;

FIG. 10 is a fourth schematic structural view of an apparatus according to an embodiment of the present disclosure;

fig. 11 is a fifth schematic structural diagram of an apparatus according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings.

In some wireless local area network scenarios, a device that sends data and a device that receives data may be in a state of relative motion, and a doppler effect generated by the relative motion may cause a change in a channel state during data transmission, and if a channel estimation result obtained according to an HE-LTF field in a preamble is used, decoding a data symbol received when the channel state has changed significantly may cause a decoding error.

In order to solve the above problem, an intermediate preamble (intermediate preamble) may be inserted in the data field every M data symbols, so that the receiving device may perform channel estimation again according to the intermediate preamble and decode subsequently received data symbols according to a new channel estimation result.

Specifically, the HE-SIG-a field may contain information indicating whether the doppler mode is employed. In the on-doppler mode, the data cell structure may be as shown in table 2.

TABLE 2

Wherein the intermediate preamble is generally identical to the HE-LTF field content in the preamble.

Taking a specific scenario as an example, the HE-SIG-a field indicates: when the Doppler mode is adopted, the data unit uses a space-time stream, the number of HE-LTF symbols contained in the HE-LTF field in the preamble and the number of HE-LTF symbols contained in the middle preamble are both 1, and one HE-LTF symbol comprises: a Guard Interval (GI) of 0.8 μ s, and a non-GI part of one base symbol duration (one base symbol duration is 3.2 μ s, which may be denoted by 1 ×).

As shown in fig. 1, after receiving the intermediate preamble, the receiving device needs to perform Fast Fourier Transform (FFT), channel estimation (channel estimation) and preprocessing (such as preparation for mimo correlation) according to the HE-LTF field; after receiving Data-0, demodulating Data-0 according to the channel estimation result; after Data-1 is received, Data-1 is demodulated according to the channel estimation result.

After a Data symbol Data-1 of duration 4X (12.8 μ s), it usually takes about 4X (12.8 μ s) time to demodulate Data-1; after receiving the intermediate preamble with a short duration, the receiving device further needs to perform Fast Fourier Transform (FFT), channel estimation, and preprocessing (preparation work like mimo correlation) according to the received intermediate preamble. The flow of demodulating Data-1 and performing channel estimation by the receiving equipment needs to be completed before the time of completely receiving Data-2, so as to ensure correct demodulation of Data-2, that is, the receiving equipment needs to complete demodulating Data-1 and performing channel estimation within the sum of the time length of the middle preamble and Data-2. However, for a receiving device with poor processing capability, it is likely that the receiving device will not finish the channel estimation and preprocessing after demodulating Data-1 within the sum of the durations of the intermediate preamble and Data-2, and as shown in fig. 1, the channel estimation and preprocessing is finished some time after receiving Data-2, which may cause errors in the demodulation of Data-2.

In order to solve the above problem, the present application provides an intermediate preamble indication method, so as to enable a receiving device to correctly decode received data symbols according to an intermediate preamble sent by a first device.

The devices described in the embodiments of the present application include, but are not limited to, a communication server, a router, a switch, a bridge, a computer, a mobile phone, an Access Point (AP), a Station (STA), and the like. The communication system can be specifically vehicle-mounted communication equipment, a train relay communication module, a railway side AP, a communication base station and the like.

The embodiment of the application can be applied to the application scenario shown in fig. 2, and is used for communication between an AP and an STA, communication between an AP and an AP, or communication between an STA and an STA. Of course, the application scenario of the embodiment of the present application is not limited to the scenario shown in fig. 2.

When the doppler mode is turned on, the indication information of the middle preamble is usually transmitted before the middle preamble is transmitted, and the indication information at least includes information indicating the duration of the middle preamble and/or information indicating the period of the middle preamble.

Since the inter-preamble is typically identical in content to the HE-LTF field in the preamble, in some embodiments, the inter-preamble and the HE-LTF field in the preamble may use the same duration indication information.

Wherein the information indicating the duration of the middle preamble may further include: indication information used for indicating the number of HE-LTF symbols contained in the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; or, indication information for indicating the number of space-time streams used by the middle preamble, and indication information for indicating one HE-LTF symbol.

Specifically, one HE-LTF symbol includes a GI part for avoiding interference between symbols and a non-GI part for FFT, channel estimation, and pre-processing.

In particular, the duration T of the middle preamble_MidambleCan be obtained according to equation (1).

T_Midamble＝N_HE-LTF×(T_HE-LTF+T_GI) (1)

Wherein N is_HE-LTFIndicates the number of HE-LTF symbols, T, contained in the intermediate preamble_HE-LTFDenotes the duration of the GI part of one HE-LTF symbol, T_GIIndicating the duration of one GI.

In addition, when the type of data to be transmitted is a high efficiency single user physical layer protocol data unit (HE SU PPDU) or a high efficiency extended distance single user physical layer protocol data unit (HE SU PPDU), N is not separately indicated_HE-LTFHowever, there is a correspondence relationship between the number of space-time streams used by the intermediate preamble and the number of HE-LTF symbols included in the intermediate preamble as shown in equation (2).

Therefore, the duration of the middle preamble can also be determined according to formula (2), the number of space-time streams used by the middle preamble, and the duration of one GI in one HE-LTF symbol, except for the duration of the GI part.

In a specific embodiment, when the type of the transmitted data is HE SU PPDU or HE ER SU PPDU, the indication information of the intermediate preamble may be included in the HE-SIG-a field, as shown in table 3.

TABLE 3

In another embodiment, when the type of the transmitted data is a high efficiency multi-user physical layer protocol data unit (HE MU PPDU), the indication information of the middle preamble may be included in the HE-SIG-a field, as shown in table 4.

TABLE 4

In yet another embodiment, for the case of transmitting a physical layer protocol data unit (PPDU) based on a trigger frame (TB), the indication information for indicating the number of HE-LTF symbols included in the middle preamble and the indication information for indicating the duration of one HE-LTF symbol excluding the GI portion and the duration of one GI may be similar to when the data type is the HE MU PPDU. But differs in that indication information of the intermediate preamble is carried in a trigger frame transmitted by the access point to the station, for example, fields for setting the number of HE-LTF symbols and the period of the intermediate preamble in a common domain. When data transmission is needed subsequently, whether the AP sends a data frame to the STA or the STA sends a data frame to the AP, the intermediate preamble is sent according to the indication information about the intermediate preamble in the trigger frame.

And indication information (for example, denoted by GI + LTF) of one HE-LTF symbol except for the duration of the GI part and the duration of one GI may also be carried in the HE-SIG-a field in the preamble or in the trigger frame. Specifically, the duration of one HE-LTF symbol excluding the GI part may be 1X (3.2 μ s), 2X (6.4 μ s), 4X (12.8 μ s), and the duration of one GI may be 0.8 μ s, 1.6 μ s, 3.2 μ s, so that there are various combinations of durations of one HE-LTF symbol excluding the GI part and one GI, for example, as shown in table 5.

TABLE 5

Based on the above tables 4 and 6, it can be obtained that, when the data type of the transmission is HE SU PPDU or HE ER SU PPDU, the duration of the middle preamble can be as shown in table 6.

TABLE 6

Based on the above tables 4 and 5, it can be obtained that, when the transmitted data type is HE MU PPDU, the duration of the middle preamble can be as shown in table 7.

TABLE 7

Based on the above tables 4 and 5, it can be obtained that the duration of the middle preamble for the case of TB PPDU can be as shown in table 8.

TABLE 8

As described above, since the device receiving the data may have poor processing capability, if the duration of the intermediate preamble is short, the device receiving the data may not have time to complete channel estimation according to the intermediate preamble, thereby causing errors in decoding the data symbols after the intermediate preamble. Therefore, in a possible implementation manner, a threshold may be set for the duration of the middle preamble, that is, the duration of the middle preamble indicated by the indication information of the middle preamble is greater than or equal to the threshold, so as to avoid decoding errors. Specifically, it can be as shown in formula (3).

T_Midamble＝N_HE-LTF×(T_HE-LTF+T_GI)≥T_m (3)

Wherein, T_mRepresenting a threshold value.

As the duration of the middle preamble increases, the duration of processing the middle preamble does not correspondingly increase according to the proportion of the increase of the duration of the middle preamble, for example, if the duration of the middle preamble increases to 4 times of the original duration, the duration of processing the middle preamble is less than 4 times of the original processing duration. Therefore, the minimum threshold is set for the duration of the intermediate preamble, which helps to avoid that a device receiving data is too late to correctly decode data symbols according to the intermediate preamble due to limited processing capability after receiving the intermediate preamble.

Specifically, when data transmission is performed based on the HE SU PPDU, the HE ER SU PPDU, or the HE MU PPDU, the flow of indicating and receiving the intermediate preamble may be as shown in fig. 3:

step 301, the sending device sends middle preamble indication information to the receiving device, where the middle preamble indication information indicates that the duration of the middle preamble is greater than or equal to the threshold.

When determining to turn on the doppler mode, the sending device may determine the duration of the middle preamble according to the threshold described in the above embodiment, and carry the indication information of the duration of the middle preamble in the HE-SIG-a to send to the device receiving the data. Further, the sending device generates a middle preamble according to the duration indicated by the indication information and sends the middle preamble to the device for receiving data.

Step 302, the receiving device receives the middle preamble according to the duration of the middle preamble indicated by the middle preamble indication information.

Specifically, the receiving device receives the intermediate preamble according to the duration indicated by the intermediate preamble indication information in the HE-SIG-a. Further, the receiving device performs channel estimation and preprocessing according to the received middle preamble only when the duration of the middle preamble is greater than or equal to the threshold, and demodulates the data symbols after the middle preamble according to the channel estimation result.

When data transmission is performed based on the TB PPDU, a device transmitting the middle preamble indication channel may be an access point. When the access point determines to turn on the doppler mode, the access point may determine the duration of the middle preamble according to the threshold in the above embodiment, and send the indication information of the duration of the middle preamble to the station by carrying the indication information in the trigger frame.

The station determines the duration of the middle preamble according to the received middle preamble indication information, and when performing data transmission with the access point or other stations, the station may generate the middle preamble according to the duration indicated by the middle preamble indication information and send the middle preamble to the access point or other stations, or receive the middle preamble sent by the access point or sent by other stations according to the middle preamble indication information and demodulate data symbols after the middle preamble according to a channel estimation result.

In a particular embodiment, the threshold T_mCan be pre-agreed, e.g., a threshold T specifying the duration of the intermediate preamble in the communication protocol_mThe duration of the intermediate preamble transmitted by the device that transmits data needs to be greater than or equal to a threshold (or just greater than the threshold); the threshold may be determined by a researcher by statistically analyzing the time of processing the intermediate preamble by a large number of devices in advance and according to the analysis result. For example, the threshold may be 7.2. mu.s (2X HE-LTF + 0.8. mu.s GI), 14.4. mu.s (2X HE-LTF +0.8us GI)), 8. mu.s (2X HE-LTF + 1.6. mu.s GI, or 2X (1X HE-LTF + 0.8. mu.s GI)).

In another embodiment, the capability information of the device receiving the data for processing the intermediate preamble may be obtained in advance, and the threshold T may be determined according to the capability information_m. Optionally, the STA may report capability information of the STA for processing the intermediate preamble when accessing the AP, and further, the AP may also send the capability information of the AP to the STA, so that the STA and the AP can send the intermediate preamble according to the processing capability of the device receiving the data when performing data transmission and needing to start the doppler mode, thereby avoiding a situation that a data symbol after the intermediate preamble is decoded incorrectly due to that the receiving device does not have to finish channel estimation according to the intermediate preamble. Optionally for communication between STAsFor example, if STA1 transmits data to STA2 and the current environment needs to use doppler mode, STA1 may obtain the capability information of STA2 before transmitting data and determine the corresponding threshold according to the capability information of STA2, and then STA1 transmits data according to the capability information of STA2, and the duration of the middle preamble transmitted between data symbols is greater than or equal to the threshold. Further, acquiring capability information may also be performed bi-directionally, i.e., both STA1 and STA2 transmit their own capability information to each other.

Specifically, when data transmission is performed based on the HE SU PPDU, the HE ER SU PPDU, or the HE MU PPDU, the device that transmits the middle preamble indication information may be a device that transmits data. When determining to start the doppler mode, the sending device may determine information such as a duration of the middle preamble according to the obtained capability information of the receiving device, carry indication information of the duration of the middle preamble in the HE-SIG-a to send to the device receiving data, and generate the middle preamble according to the duration indicated by the indication information to send to the device receiving data.

The data receiving device may send capability information of processing the intermediate preamble to the sending device in advance, receive the intermediate preamble according to a duration indicated by the intermediate preamble indication information in the HE-SIG-a sent by the sending device, perform channel estimation and preprocessing according to the received intermediate preamble, and demodulate data symbols after the intermediate preamble according to a channel estimation result.

When data transmission is performed based on the TB PPDU, a device transmitting the middle preamble indication channel may be an access point. When the access point determines to turn on the doppler mode, the access point may determine information such as the duration of the middle preamble according to the capability information of the station for processing the middle preamble, and carry the indication information of the duration of the middle preamble in the trigger frame to send to the station.

The station determines the duration of the middle preamble according to the received middle preamble indication information, and when performing data transmission with the access point or other stations, the station may generate the middle preamble according to the duration indicated by the middle preamble indication information and send the middle preamble to the access point or other stations, or receive the middle preamble sent by the access point or sent by other stations according to the middle preamble indication information and demodulate data symbols after the middle preamble according to a channel estimation result.

Optionally, the capability information of the device receiving the data to process the intermediate preamble may include a minimum threshold of a duration of the intermediate preamble that the device can process, and then the device transmitting the data or the AP transmitting the trigger frame may determine the duration of the intermediate preamble indicated in the indication information of the transmitted intermediate preamble according to the minimum threshold.

Since the duration and complexity of processing the intermediate preamble code are related to the configuration of the intermediate preamble code, in some embodiments, the acquired capability information of the device for receiving data to process the intermediate preamble code may further include configuration information of the intermediate preamble code that can be supported by the receiving device. For example, the duration of processing the midamble code, the number of Resource Units (RUs) occupied by the midamble code (i.e., the number of occupied subcarriers), and the number of space-time streams (N)_sts) Modulation and Coding Scheme (MCS), if RU number, N_stsAnd any two configuration parameters in the MCS are unchanged, and if the other configuration parameter is increased, the required processing time length is correspondingly increased, otherwise, the required processing time length is correspondingly reduced. Therefore, the capability information of the device receiving the data may include one or a combination of the following information:

the maximum number of RUs that can be supported;

maximum N that can be supported_sts；

When the middle lead code occupies L RUs and K N_stsAnd the information of the supported MCS, wherein L and K are integers which are more than or equal to 1.

Further, the capability information of the receiving device may include both the minimum threshold and the configuration information of the intermediate preamble, where the minimum threshold represents a threshold that can satisfy the processing capability of the receiving device regardless of the configuration information of the intermediate preamble. And the device for determining the indication information of the middle preamble code can directly determine the minimum thresholdThe value determines the duration of the corresponding middle preamble for the receiving device, and may also determine the configuration of the corresponding middle preamble according to the configuration information of the middle preamble that can be supported without considering the minimum threshold according to the specific application requirements, so that the transmitting receiving device can process the middle preamble in time without affecting the demodulation of the subsequent data symbols. For example, if the number of RUs, N, of the middle preamble configuration_stsThe MCS enables the receiving device to process normally without considering the duration of the middle preamble, and thus the receiving device can process timely even if the middle preamble only containing one 1X DE-LTF is adopted, and if the configured middle preamble has the configured number of RUs and N_stsAnd the MCS ensures that the receiving device cannot guarantee normal processing without considering the middle preamble duration, so the minimum threshold of the middle preamble duration needs to be considered.

In addition, the capability information may further include information that the receiving device supports the doppler mode. For example, 2 bits may be included in the capability information, where 1 bit is used to indicate whether to support the doppler mode under HE SU PPDU or HE ER SU PPDU, and another 1 bit is used to indicate whether to support the doppler mode under MU PPDU or TB PPDU; or, the capability information may include 4 bits, where 1 bit is used to indicate whether to support receiving data in the doppler mode under the HE SU PPDU or the HE ER SU PPDU, 1 bit is used to indicate whether to support receiving data in the doppler mode under the HE MU PPDU or the TB PPDU, and 1 bit is used to indicate whether to support receiving data in the doppler mode under the MU PPDU or the TB PPDU; or, the HE SU PPDU can be used as a group separately, the HE ER SU PPDU, the MU PPDU and the TB PPDU are divided into a group, or 4 bits can be adopted to respectively indicate whether the two groups support receiving and transmitting in the doppler mode; alternatively, since the complexity of receiving the doppler pattern may be different in different data packets, the performance may be affected when data of one STA needs to be carried on more symbols in multi-user transmission (i.e. HE MU PPDU or TB PPDU), and thus needs to be indicated separately.

In a specific embodiment, the capability information sent by the data receiving device may be as shown in fig. 4, and includes: an information element identifier indicating that the information is for indicating information related to a capability of processing the inter-preamble; a length indicating a length of the information; threshold value T_MIf the duration of the middle preamble is greater than or equal to the threshold, the data receiving device can process normally; the SU/ER SU Doppler mode indicates whether the device supports the SU/ER SU based Doppler mode, and further, the device can also include whether the device supports the reception and transmission in the SU/ER SU based Doppler mode; the MU/TB Doppler mode indicates whether the equipment supports the MU/TB based Doppler mode, and further, whether the equipment supports receiving and transmitting in the MU/TB based Doppler mode can be further included; the number of the space-time streams represents the maximum number of the space-time streams occupied by the middle lead code which can be processed by the equipment; the number of RUs represents the maximum number of RUs occupied by the middle preamble which can be processed by the equipment; when N is present_sts＝N1、N_RURU1, the maximum value of MCS that the device can support; …, respectively; when N is present_sts＝N_k、N_RU＝RU_kThe maximum value of MCS that the device can support.

In a possible implementation manner, the duration of the GI part in each HE-LTF symbol included in the intermediate preamble indicated in the indication information of the intermediate preamble may also be limited, for example, the duration of the GI part in one HE-LTF symbol in the intermediate preamble may be limited to 2X or 4X, so as to satisfy the duration required by most devices to process the intermediate preamble. As shown in tables 6 to 8, when the duration of the GI part in one HE-LTF symbol is 2X or 4X (i.e., the GI + LTF duration field is 1, 2, or 3), the corresponding middle preamble duration is greater than or equal to 7.2 μ s; alternatively, the duration of the GI part in one HE-LTF symbol in the middle preamble may be limited to only 4X, and as shown in tables 6 to 8, when the duration of the GI part in one HE-LTF symbol is 4X (i.e., when the GI + LTF duration field is 3), the duration of the corresponding middle preamble is equal to or greater than 13.6 μ s.

In one possible implementation manner, the duration of the middle preamble indicated by the middle preamble indication information is one of the set of durations of the middle preambles.

Optionally, the set of intermediate preamble durations includes only one or any combination of the following:

the duration of a part except the GI part in the HE-LTF symbol is 4X, and the GI is 0.8 mu s;

the duration of a part except the GI part in the HE-LTF symbol is 4X, and the GI is 1.6 mu s;

the duration of a part except the GI part in the HE-LTF symbol is 4X, and the GI is 3.2 mu s;

the duration of a part except the GI part in the HE-LTF symbol is 2X, and the GI is 0.8 mu s;

the duration of a part except the GI part in the HE-LTF symbol is 2X, and the GI is 1.6 mu s;

the length of the HE-LTF symbol except for the GI part is 2X, and the GI is 3.2 mu s.

Further, the data receiving device performs channel estimation and preprocessing according to the received intermediate preamble only when the duration of one high efficiency long training field HE-LTF symbol included in the intermediate preamble is one of available sets.

In a specific embodiment, when the data type of the transmission is HE SU PPDU or HE ER SU PPDU, the fields for GI + LTF carried in HE-SIG-a in the preamble may be as shown in table 9.

TABLE 9

In a specific embodiment, when the data type of the transmission is HE MU PPDU, the fields for GI + LTF carried in HE-SIG-a in the preamble may be as shown in table 10.

Watch 10

In a specific embodiment, for the case of TB PPDU, the fields for GI + LTF carried in the trigger frame may be as shown in table 11.

TABLE 11

Optionally, the threshold described in any of the above embodiments may be valid only when the number of space-time streams occupied by the midamble is greater than or equal to 2, that is, if the number of space-time streams occupied by the midamble is 1, it may be not considered whether the duration of the midamble is greater than or equal to the threshold. Because the complexity of the equipment for receiving data in processing the middle lead code is lower when the number of the space-time streams occupied by the middle lead code is 1, even if the time length of the middle lead code is shorter, the receiving equipment can still finish the process of channel estimation according to the middle lead code in time; when the number of the space-time streams occupied by the middle lead code is greater than or equal to 2, the complexity of the receiving device in processing the middle lead code is increased, and the threshold value of the middle lead code needs to be set to ensure that the receiving device can smoothly complete channel estimation according to the middle lead code without affecting decoding of the data symbols after the middle lead code.

Specifically, the duration of the middle preamble may be as shown in equation (4).

T_Midamble＝N_HE-LTF×(T_HE-LTF+T_GI)≥T_M,N_sts≥2 (4)

In a specific embodiment, when the null stream data is greater than or equal to 2, the duration of dividing the GI part in one HE-LTF symbol should be 4X; alternatively, when the space-time stream data is 2 or more, the duration of dividing the GI part in one HE-LTF symbol should be 2X or 4X.

In the on-doppler mode, since the middle preamble is usually the same as the HE-LTF field in the preamble, the middle preamble and the HE-LTF field in the preamble may use the same duration indication information. However, in some scenarios, the content of the HE-LTF field in the intermediate preamble and the preamble may not be the same, or the duration of the intermediate preamble may need to be increased due to the requirement of the receiving device for different durations of the intermediate preamble and the HE-LTF field in the preamble, and therefore, in one possible implementation, the duration of the HE-LTF field in the intermediate preamble and the preamble may also be indicated by different indication information.

Specifically, when data transmission is performed based on the HE SU PPDU, the HE ER SU PPDU, or the HE MU PPDU, the device that transmits the middle preamble indication information may be a device that transmits data. When determining to turn on the doppler mode, the transmitting device may respectively determine indication information of an HE-LTF field in the preamble and indication information of the middle preamble, and carry the indication information to the device receiving data in the HE-SIG-a, and generate the middle preamble according to the information of the middle preamble indicated by the indication information, and transmit the middle preamble to the device receiving data.

The data receiving equipment respectively receives the indication information of the HE-LTF field in the lead code and the indication information of the middle lead code, respectively determines the relevant information of the HE-LTF field in the lead code and the relevant information of the middle lead code, receives the HE-LTF field and the middle lead code in the lead code according to the relevant information, carries out channel estimation and preprocessing according to the HE-LTF field in the received lead code and the middle lead code, and demodulates the data symbols after the middle lead code according to the channel estimation result.

When data transmission is performed based on the TB PPDU, a device transmitting the middle preamble indication channel may be an access point. When the access point determines to turn on the doppler mode, the access point may respectively determine the indication information of the HE-LTF field in the preamble and the indication information of the middle preamble, and the indication information is carried in a trigger frame and sent to the station.

The station respectively determines the information of the preamble and the information of the middle preamble after receiving the indication information of the HE-LTF field and the indication information of the middle preamble in the preamble, and can generate the preamble and the middle preamble according to the preamble information and the information of the middle preamble and send the preamble and the middle preamble to the access point or other stations when performing data transmission with the access point or other stations.

Optionally, the duration of the GI part and the duration of one GI in one HE-LTF symbol included in the HE-LTF field in the intermediate preamble and the preamble are indicated by different indication information.

In order not to increase signaling overhead, the inter-preamble information may be indicated by some reserved bits or reserved entries (entries) in the data frame.

For example, there are some reservation entries in the SRP field in the field by HE-SIG-a, as shown in table 12.

TABLE 12

Value	Description of the invention
		0	Disabling spatial multiplexing parameter based SR transmission
1-12	Reservation
		13	Restricting SR transmissions
14	Delayed SR transmission
		15	Overlapping basic service set-packet identification with non-SR set disabled

The SR field has 4 bits, and 16 entries may be provided, as shown in table 10, where entries with SR values of 1-12 are reserved, so that part or all of the 12 reserved entries may be used to indicate the duration of each HE-LTF symbol except the GI part and/or the duration of each GI in the HE-LTF fields in the intermediate preamble and the preamble, for example, the reserved entries in the SR field are defined as shown in table 13.

Watch 13

In other embodiments, the duration of each GI included in the HE-LTF fields in the intermediate preamble and the preamble may also be the same, which only indicates the duration of each HE-LTF symbol except for the GI part included in the HE-LTF fields in the intermediate preamble and the preamble, respectively, that is, the entry in table 11 only corresponds to the duration of each HE-LTF symbol except for the GI part being 1X, 2X, or 4X.

In addition, in addition to indicating the duration of the GI part and/or the duration of the GI in one HE-LTF symbol included in the middle preamble by using the reserved entry existing in the SRP field, the duration of one HE-LTF symbol included in the middle preamble and/or the duration of one GI may also be indicated by using the reserved bit existing in the HE-SIG-a field or the trigger frame. For example, when the transmitted data is HE SU PPDU or HE ER SU PPDU; 2 reserved bits exist in an HE-SIG-A field, and 1 reserved bit exists in the HE-SIG-A field when the transmitted data is an HE MU PPDU; there are some Reserved bits in the trigger frame, where part of the Reserved bits is called HE-SIG-a Reserved, since this part of the reservation corresponds to the Reserved bits in the HE-SIG-a field in the subsequent transmission data frame.

In a specific embodiment, the definition shown in table 14 may be performed on 1 reserved bit present in the HE-SIG-a field or the trigger frame in the data frame.

TABLE 14

As shown in table 12, only the duration of one HE-LTF symbol included in the middle preamble except for the GI part is defined, and the duration of one GI included in the middle preamble is the same as the duration of the GI in the preamble. In addition, since these reserved bits are usually set to default values or set to 1 in the prior art, the use of setting 1 in table 12 indicates that the duration is the same as the duration of the HE-LTF field in the intermediate preamble and the preamble, so as to facilitate the identification of the receiving device, and of course, the corresponding meanings of 0 and 1 may be interchanged, which is not limited in this application.

In another specific embodiment, the definition shown in table 15 may be further performed on 2 reserved bits existing in the HE-SIG-a field or the trigger frame in the data frame.

Watch 15

Because the duration information of the HE-LTF fields in the middle lead code and the lead code is respectively indicated, the limitation on the duration of the middle lead code does not affect the HE-LTF fields in the lead code, namely the HE-LTF fields in the lead code can use the GI part or the GI part of the HE-LTF symbols with shorter duration or the GI with shorter duration, and the HE-LTF symbols with larger duration or the GI part or the GI with larger duration, which is indicated by the middle lead code, thereby being beneficial to saving the signaling overhead of the lead code. Or, because the duration information of the HE-LTF fields in the middle preamble and the preamble is respectively indicated, the HE-LTF field in the preamble may adopt GI part divided from HE-LTF symbols with a larger duration or GI with a longer duration or adopt a larger number of HE-LTF symbols to achieve the purpose of more accurate initialization of channel estimation, and the HE-LTF symbols with a shorter duration except GI part or adopt a smaller number of HE-LTF symbols in the middle preamble, the data receiving device performs weighted average on the channel estimation result obtained according to the middle preamble and the initial channel estimation result to ensure the accuracy of channel estimation and help to reduce the signaling overhead of the middle preamble.

In addition, in order to realize that the duration of the middle lead code can meet the requirement of the data receiving equipment on the duration of the middle lead code, the middle lead code which does not meet the duration can be filled, so that the duration of the filled middle lead code meets the processing requirement. Specifically, the intermediate preamble is padded, which may be by copying the original intermediate preamble, for example, the original intermediate preamble includes a GI-divided part and 1 GI with a duration of 0.8 μ s in 1 HE-LTF symbol with a duration of 2X, and the padded intermediate preamble includes a GI-divided part and 2 GIs with a duration of 0.8 μ s in 2 HE-LTF symbols with a duration of 2X; or some irrelevant bits can be added at a specified position according to the specification of the communication protocol to achieve the effect of increasing the duration of the middle preamble, or indication information for indicating the starting position of the useful information in the middle preamble can be added in the indication information of the middle preamble, so that the data receiving device can acquire the useful information from the padded middle preamble for channel estimation.

In a specific embodiment, whether the intermediate preamble is padded or not may be indicated by a reserved bit or a reserved entry as described above. The duration of the padded middle preamble is N times of the duration of the original middle preamble, where N is a value greater than 1, and N may be 2, 3, or 4, for example. Optionally, the value of N may be specified in a standard, and may also be notified to the data receiving device through the indication information of the intermediate preamble.

Taking N equal to 2 as an example, the padded middle preamble can be as shown in fig. 5. Wherein, a case shown in fig. 5 represents a padded intermediate preamble obtained by copying an original intermediate preamble, and b case shown in fig. 5 represents a padded intermediate preamble obtained by adding irrelevant bits to the original intermediate preamble, and the padding position is before useful information; the case c shown in fig. 5 shows the padded intermediate preamble obtained by adding the irrelevant bits to the original intermediate preamble, and the padding position is after the useful information.

Correspondingly, the data receiving equipment determines that the data sending equipment copies the original intermediate lead code according to the indication information of the intermediate lead code, so that the data receiving equipment can delete the repeated information according to the standard regulation or the indication information of the intermediate lead code after receiving the filled intermediate lead code, and carry out channel estimation according to the deleted intermediate lead code; or the data receiving equipment determines that the data sending equipment adds irrelevant bits to the original intermediate lead code according to the indication information of the intermediate lead code, and then the data receiving equipment screens out useful information and carries out channel estimation according to standard regulation or the indication information of the intermediate lead code after receiving the filled intermediate lead code.

Two transmission periods of the intermediate preamble are provided in the current standard, which are represented by 1 bit, and as shown in table 3 and table 4, one intermediate preamble can be transmitted every 10 or 20 data symbols. The transmission periods of the two intermediate preambles can cope with the doppler effect when the device moves at a slow speed, however, for the device moves at a fast speed, for example, on a train running at a high speed, the channel state changes very rapidly due to the more severe doppler effect, and the channel estimation result needs to be updated in a shorter period to realize correct decoding of the data symbols.

In order to solve the above problem, in one possible implementation manner, the transmission period of the intermediate preamble is represented by a plurality of bits, so as to implement providing a plurality of transmission periods of the intermediate preamble, so as to meet the requirements of different degrees of doppler effect on channel estimation. Optionally, the period field in the indication information of the intermediate preamble occupies at least two bits, and is used for indicating one of at least three preset intermediate preamble periods.

In particular, as previously described, there are some reserved bits or reserved entries in the HE-SIG-a field or trigger frame, which can be utilized to implement a transmission period that provides more intervening preambles.

In a specific embodiment, a reserved bit may be used in combination with a bit originally used to indicate a transmission period of the intermediate preamble, as shown in table 16.

TABLE 16

In another specific embodiment, the transmission period of the middle preamble may also be indicated by a reserved entry in the SRP field, as shown in table 17.

TABLE 17

Value	Transmission period of intermediate preamble
		5	2 data symbols
6	5 data symbols
		7	10 data symbols
8	20 data symbols

Alternatively, the bits originally used for indicating the transmission period of the intermediate preamble may be reserved, and the reserved entry in the SRP field may be used to indicate the transmission period of the intermediate preamble, which is not illustrated here.

In addition, the reserved entries in the HE-SIG-a field can be utilized for the purpose of providing various transmission periods of the intermediate preamble.

In another embodimentThe transmission period of the middle preamble can also be according to MCS, N_stsAnd the determination of parameters related to the time duration required for processing the intermediate preamble.

For example, the transmission period of the intermediate preamble may be determined by bits originally used to indicate the transmission period of the intermediate preamble and the MCS configuration together, as shown in table 18.

Watch 18

For another example, the period of the intermediate preamble may be determined by the bit and N originally used to indicate the transmission period of the intermediate preamble_stsThe configuration is determined collectively as shown in table 19.

Watch 19

In addition, if the period of the intermediate preamble is small, the processing capability requirement on the data receiving device is relatively high, and the data receiving device may not support the small period of the intermediate preamble. Further, the capability information of the data receiving apparatus for processing the intermediate preamble may further include information on whether the extended intermediate preamble period is supported.

It should be understood that the 4 alternative intermediate preamble transmission periods provided in the above embodiments are merely examples, and the number of symbols included in one period and the number of optional periods are not limited in the present application.

Any of the above embodiments can be independently applied to a scenario in which the middle preamble needs to be sent when the doppler effect is turned on, and the above embodiments can also be combined arbitrarily to meet different requirements for the middle preamble in different scenarios.

When data transmission is performed based on the HE SU PPDU, the HE ER SU PPDU or the HE MU PPDU, a device that sends the middle preamble indication information may be a device that sends data, and when the sending device determines to turn on the doppler mode, the sending device may determine the middle preamble indication information according to the middle preamble information described in any of the embodiments above, for example, information such as the number of HE-LTF symbols included in the middle preamble, the number of space-time streams, a duration of one HE-LTF symbol, a middle preamble period, and the like, and carry the indication information in the HE-SIG-a to send to a device that receives data, and generate the middle preamble according to the indication of the indication information to send to the device that receives data.

And the data receiving equipment receives the intermediate lead code according to the intermediate lead code indication information in the HE-SIG-A, performs channel estimation and preprocessing according to the received intermediate lead code, and demodulates the data symbols after the intermediate lead code according to the channel estimation result.

When data transmission is performed based on the TB PPDU, a device transmitting the middle preamble indication channel may be an access point. When the access point determines to turn on the doppler mode, the access point may determine the middle preamble indication information according to the middle preamble information described in any of the above embodiments, and send the indication information to the station by carrying the indication information in the trigger frame.

After receiving the intermediate preamble indication information, the station performs data transmission with the access point or another station, may generate an intermediate preamble according to the intermediate preamble indication information and transmit the intermediate preamble to the access point or another station, or may receive the intermediate preamble transmitted by the access point or another station according to the intermediate preamble indication information and demodulate data symbols after the intermediate preamble according to a channel estimation result.

In order to solve the problem that the channel estimation process according to the middle lead code is not completed in time and data decoding is wrong due to limited capacity of the data receiving equipment, the embodiment of the application also provides a method for solving the problem by changing the sending position of the middle lead code without prolonging the time length of the middle lead code.

Taking the period of the middle preamble as 10 Data symbols as an example, the Data receiving device performs channel estimation according to the HE-LTF field in the preamble, demodulates Data _1 to Data _10 according to the channel estimation result, receives the middle preamble and performs channel estimation again, demodulates Data _11 to Data _20 according to the channel estimation result, and repeats the above process if there are more Data symbols, which is not described herein again. If the duration of the intermediate preamble is short, the Data receiving apparatus may not have time to obtain the channel estimation result from the intermediate preamble, and demodulation of Data symbols of Data _11 or more may be erroneous.

Accordingly, embodiments of the present application provide a method to solve the above problems. In the method, the indication information of the intermediate preamble is used to indicate that, in the kepler mode, after the intermediate preamble is received, channel estimation is performed according to the intermediate preamble, and the data symbols from the (X + 1) th to the (X + M) th after the intermediate preamble are demodulated according to the channel result. Where M denotes a period of the intermediate preamble, and X is an integer of 1 or more, which is specified by a standard or determined according to a capability of the receiving device to process the intermediate preamble. If the value of X is not specified by the standard, the data receiving device may be indicated by the reserved bit or the reserved entry.

Still taking the period of the intermediate preamble as 10 Data symbols, X is equal to 2 as an example, as shown in fig. 6, the Data sending device first sends Data _1 to Data _8, then sends the intermediate preamble, then sends Data _9 to Data _18, sends the intermediate preamble again, then sends Data _19 to Data _20, and if there are more Data symbols, the above process is repeatedly executed, and details are not repeated here.

And the Data receiving equipment carries out channel estimation according to the HE-LTF field in the preamble to obtain a channel estimation result 1, and carries out channel estimation on Data _1 to Data _8 according to the channel estimation result 1. Then, channel estimation is performed again according to the received intermediate preamble and channel estimation result 2 is obtained, and even if the channel estimation process is not completed before Data _9 is received, demodulation of Data _9 is not affected, because demodulation of Data _9 and Data _10 is performed according to channel estimation result 1, and then Data _11 to Data _18 are demodulated according to channel estimation result 2. The intermediate preamble is received again to perform channel estimation again and obtain a channel estimation result 3, while demodulation of Data _19 and Data _20 is still performed according to the channel estimation result 2, and then Data _21 and the like are demodulated according to the channel estimation result 3.

Still taking the example that the period of the intermediate preamble is 10 Data symbols and X is equal to 2, in some embodiments, if the Data receiving device completes the channel estimation process of the intermediate preamble before receiving Data _10, the Data receiving device may also demodulate Data _10 according to the newly obtained channel estimation result, so as to fully utilize the newly obtained channel estimation result, and ensure the correctness of Data demodulation.

In some embodiments, the method for changing the transmission position of the middle preamble can be combined with the aforementioned embodiments that provide various middle preamble periods to meet the requirements of the channel estimation by the doppler effect of different degrees.

Due to the fact that the sending position of the middle lead code is changed, buffering time is provided for channel estimation of the data receiving device, and the situation that the receiving device cannot correctly decode data symbols according to the middle lead code due to limited processing capacity after receiving the middle lead code is avoided.

Based on the same technical concept, the embodiment of the present application further provides an apparatus, which can be used as a first apparatus to implement the above method embodiment. Referring to fig. 7, the apparatus includes:

a processing unit 701, configured to determine middle preamble indication information, where a duration of a high efficiency long training field HE-LTF symbol included in a middle preamble indicated by the middle preamble indication information is one of available sets;

a sending unit 702, configured to send the middle preamble indication information to the second device.

In one possible implementation, the available set includes one or any combination of the following:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 1.6 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 3.2 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 1.6 mu s;

the HE-LTF symbol is 2 basic symbol duration except for the GI part, and GI is 3.2 mu s.

Based on the same technical concept, the embodiment of the present application further provides a device, which can be used as a second device to implement the above method embodiment. Referring to fig. 8, the apparatus includes:

a receiving unit 801, configured to receive intermediate preamble indication information sent by a first device;

a processing unit 802, configured to perform channel estimation according to the received intermediate preamble only when a duration of one high efficiency long training field HE-LTF symbol included in the intermediate preamble indicated by the intermediate preamble indication information is one of available sets.

In one possible implementation, the available set includes one or any combination of the following:

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 1.6 mu s;

the GI part of the HE-LTF symbol is divided into 4 basic symbol durations, and the GI is 3.2 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 0.8 mu s;

the GI part of the HE-LTF symbol is 2 basic symbol durations, and the GI is 1.6 mu s;

the HE-LTF symbol is 2 basic symbol duration except for the GI part, and GI is 3.2 mu s.

Based on the same technical concept, the embodiment of the present application further provides an apparatus, which can be used as a first apparatus to implement the above method embodiment. The apparatus comprises:

a processing unit, configured to determine middle preamble indication information, where a duration of a middle preamble indicated by the middle preamble indication information is greater than or equal to a threshold, where the threshold is related to a processing capability of the second device;

a sending unit, configured to send the middle preamble indication information to the second device.

The connection between the processing unit and the transmitting unit is similar to that shown in fig. 7.

In a possible implementation manner, the indication information of the middle preamble includes: indication information used for indicating the number of HE-LTF symbols contained in the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; multiplying the time length of the HE-LTF symbol by the number of the HE-LTF symbols, wherein the time length is greater than or equal to the preset threshold value; or, the indication information of the duration of the middle preamble includes: indication information used for indicating the number of space-time streams used by the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; and the time length of the HE-LTF symbol is multiplied by the number of the HE-LTF symbols corresponding to the number of the space-time streams, and the time length is greater than or equal to the preset threshold value.

In a possible implementation manner, the indication information of the middle preamble at least includes indication information for indicating a duration of a GI part and a duration of a GI in one HE-LTF symbol; the duration of the GI part in the one HE-LTF symbol is 2 basic symbol durations or 4 basic symbol durations.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate one of at least three preset intermediate preamble periods.

In a possible implementation manner, the sending unit is specifically configured to: sending the period of the middle preamble and/or indication information for indicating the duration of one HE-LTF symbol to a second device through a reserved entry in an SRP field; or, the indication information for indicating the duration of one HE-LTF symbol is transmitted to the second device through the reserved bits.

In one possible implementation, the processing unit is further configured to: acquiring the capability information of the second equipment for processing the middle lead code; and determining the threshold value according to the capability information.

In a possible implementation manner, after sending the middle preamble indication information to the second device, the sending unit is further configured to: and sending the middle lead code to second equipment, wherein the middle lead code is obtained by filling the content contained in the appointed middle lead code, and the duration of the filled middle lead code is more than or equal to the threshold.

Based on the same technical concept, the embodiment of the present application further provides a device, which can be used as a second device to implement the above method embodiment. The apparatus comprises:

a receiving unit, configured to receive the middle preamble indication information sent by the first device.

Further, the receiving unit is further configured to receive an intermediate preamble according to the indication information.

A processing unit, configured to perform channel estimation according to the received intermediate preamble only when a duration of the intermediate preamble indicated by the intermediate preamble indication information is greater than or equal to a threshold, where the threshold is related to a processing capability of the second device.

The connection between the processing unit and the transmitting unit is similar to that shown in fig. 8.

In a possible implementation manner, the apparatus further includes a sending unit, configured to: before the receiving unit receives the middle preamble indication information sent by the first device, the capability information of the second device for processing the middle preamble is sent to the first device.

In a possible implementation manner, the indication information of the middle preamble includes: indication information used for indicating the number of HE-LTF symbols contained in the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; multiplying the time length of the HE-LTF symbol by the number of the HE-LTF symbols, wherein the time length is greater than or equal to the preset threshold value; or, the indication information of the duration of the middle preamble includes: indication information used for indicating the number of space-time streams used by the middle preamble and indication information used for indicating the duration of one HE-LTF symbol; and the time length of the HE-LTF symbol is multiplied by the number of the HE-LTF symbols corresponding to the number of the space-time streams, and the time length is greater than or equal to the preset threshold value.

In a possible implementation manner, the indication information of the middle preamble at least includes indication information for indicating a duration of a GI part and a duration of a GI in one HE-LTF symbol; the duration of the GI part in the one HE-LTF symbol is 2 basic symbol durations or 4 basic symbol durations.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate that one of at least four intermediate preamble periods is preset.

In a possible implementation manner, the receiving unit is specifically configured to: receiving the period of the middle preamble and/or indication information for indicating the duration of one HE-LTF symbol through a reserved entry in the SRP field; or, receiving indication information of a duration of one HE-LTF symbol through reserved bits.

In a possible implementation manner, the receiving unit receives an intermediate preamble according to the intermediate preamble indication information, where the intermediate preamble is obtained by filling contents included in an agreed intermediate preamble, and a duration of the filled intermediate preamble is greater than or equal to the threshold.

Based on the same technical concept, the embodiment of the present application further provides an apparatus, which can be used as a first apparatus to implement the above method embodiment. The apparatus comprises:

the processing unit is used for acquiring the capability information of the second equipment for processing the middle lead code and determining the indication information of the middle lead code according to the capability information;

and a transmitting unit which transmits the intermediate preamble indication information to the second device.

The connection between the processing unit and the transmitting unit is similar to that shown in fig. 7.

In one possible implementation, the capability information includes at least one of the following information:

a minimum duration of the intermediate preamble code that the second device can support;

information on whether the second device can support a single user and/or a Doppler mode under a single-user extended range;

information on whether the second device can support a doppler mode under multiple users;

the maximum space-time stream number occupied by the middle lead code which can be supported by the second equipment;

the maximum number of subcarriers occupied by the middle lead code which can be supported by the second equipment;

and the second device can support information of a modulation and coding strategy MCS when the middle lead code occupies L subcarriers and K space-time streams, wherein L and K are integers greater than or equal to 1.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate one of at least three preset intermediate preamble periods.

In a possible implementation manner, the sending unit is specifically configured to: sending the period of the middle preamble and/or indication information for indicating the duration of one HE-LTF symbol to a second device through a reserved entry in an SRP field; or, the indication information for indicating the duration of one HE-LTF symbol is transmitted to the second device through the reserved bits.

In a possible implementation manner, the sending unit is further configured to: the first equipment sends the middle lead code to the second equipment, the middle lead code is obtained by filling the content contained in the appointed middle lead code, and the duration of the filled middle lead code is more than or equal to the threshold value.

Based on the same technical concept, the embodiment of the present application further provides a device, which can be used as a second device to implement the above method embodiment. Referring to fig. 9, which is a schematic structural diagram of the apparatus, as shown in the figure, the apparatus includes:

a sending unit 901, configured to send, to a first device, capability information of the second device to process the intermediate preamble;

a receiving unit 902, configured to receive the middle preamble indication information sent by the first device, where a duration of a middle preamble indicated by the middle preamble indication information is determined according to capability information of the second device; and receiving the intermediate preamble according to the indication information.

In one possible implementation, the capability information includes one or a combination of the following:

a minimum duration of the intermediate preamble code that the second device can support;

information on whether the second device can support a single user and/or a Doppler mode under a single-user extended range;

information on whether the second device can support a doppler mode under multiple users;

the maximum space-time stream number occupied by the middle lead code which can be supported by the second equipment;

the maximum number of subcarriers occupied by the middle lead code which can be supported by the second equipment;

and the second device can support information of a modulation and coding strategy MCS when the middle lead code occupies L subcarriers and K space-time streams, wherein L and K are integers greater than or equal to 1.

In one possible implementation manner, the indication information of the intermediate preamble is different from the indication information determined by the first device to indicate the HE-LTF field in the preamble.

Further, the duration of the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF field indicated by the indication information of the HE-LTF field.

In a possible implementation manner, the indication information of the intermediate preamble includes a period field of the intermediate preamble, where the period field occupies at least two bits and is used to indicate one of at least three preset intermediate preamble periods.

In a possible implementation manner, the receiving unit is specifically configured to: sending the period of the middle preamble and/or indication information for indicating the duration of one HE-LTF symbol to a second device through a reserved entry in an SRP field; or, the first device sends indication information indicating the duration of one HE-LTF symbol to the second device through reserved bits.

In a possible implementation manner, after the second device receives the intermediate preamble indication information sent by the first device, the method further includes: and receiving an intermediate lead code sent by the first device, wherein the intermediate lead code is obtained by filling the content contained in the appointed intermediate lead code, and the duration of the filled intermediate lead code is greater than or equal to the threshold.

Based on the same technical concept, the embodiment of the present application further provides an apparatus, which can be used as a first apparatus to implement the above method embodiment. The apparatus comprises:

a processing unit which determines the middle lead code indication information;

a sending unit, configured to send middle preamble indication information to a second device, where the middle preamble indication information is not the same information as indication information of an HE-LTF field in a preamble sent by the first device to the second device.

The connection between the processing unit and the transmitting unit is similar to that shown in fig. 7.

In a possible implementation manner, the duration of the HE-LTF symbol included in the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF symbol included in the HE-LTF field indicated by the indication information of the HE-LTF field.

Optionally, the HE-LTF field in the preamble may use a HE-LTF symbol with a shorter duration, and indicate that the middle preamble uses a HE-LTF symbol with a larger duration.

Optionally, HE-LTF symbols with a larger duration may be used for an HE-LTF field in the preamble, or HE-LTF symbols with a larger number may be used for initialization of channel estimation, and HE-LTF symbols with a shorter duration or HE-LTF symbols with a smaller number may be used for the middle preamble, and the data receiving device performs comprehensive analysis on the channel estimation result obtained according to the middle preamble and the initial channel estimation result to ensure accuracy of channel estimation and help to reduce signaling overhead of the middle preamble.

Based on the same technical concept, the embodiment of the present application further provides a device, which can be used as a second device to implement the above method embodiment. The apparatus comprises:

a receiving unit, configured to receive the middle preamble indication information sent by a first device, where the middle preamble indication information is not the same information as indication information of a high efficiency long training field HE-LTF sent by the first device to a second device; receiving an intermediate lead code according to the indication information;

and the processing unit is used for processing according to the received intermediate preamble.

The connection between the processing unit and the transmitting unit is similar to that shown in fig. 8.

In a possible implementation manner, the duration of the HE-LTF symbol included in the middle preamble indicated by the middle preamble indication information is different from the duration of the HE-LTF symbol included in the HE-LTF field indicated by the indication information of the HE-LTF field.

Based on the same technical concept, the embodiment of the present application further provides an apparatus, which can be used as a first apparatus to implement the above method embodiment. The apparatus comprises:

a processing unit, configured to determine intermediate preamble indication information, where the intermediate preamble indication information is used to indicate that, after receiving an intermediate preamble, the second device decodes, according to the intermediate preamble, data symbols from the (X + 1) th to the (X + M) th data symbols after the intermediate preamble; the M represents that the first equipment sends an intermediate lead code every time when sending M data symbols, and X is an integer which is predetermined or is more than or equal to 1 and determined according to the capability of the second equipment for processing the intermediate lead code;

a sending unit, configured to send the middle preamble indication information to the second device.

The connection between the processing unit and the transmitting unit is similar to that shown in fig. 7.

Based on the same technical concept, the embodiment of the present application further provides a device, which can be used as a second device to implement the above method embodiment. The apparatus comprises:

a receiving unit configured to receive an intermediate preamble;

a processing unit, configured to perform channel estimation according to the intermediate preamble; decoding the data symbols from the (X + 1) th to the (X + M) th after the middle lead code according to the channel estimation result; the M represents that the second device receives an intermediate preamble every time the second device receives M data symbols, and X is an integer which is predetermined or is greater than or equal to 1 and is determined according to the capability of the second device for processing the intermediate preamble.

The connection between the receiving unit and the processing unit is similar to that shown in fig. 8.

Based on the same technical concept, the embodiment of the present application further provides an apparatus, which can be used as a first apparatus to implement the above method embodiment. A schematic structural diagram of the apparatus may be as shown in fig. 10, including: a processor 1001, a transceiver 1002.

The processor 1001 may perform the method steps performed by the first device in any of the above method embodiments via the transceiver 1002.

Based on the same technical concept, the embodiment of the present application further provides a device, which can be used as a second device to implement the above method embodiment. A schematic structural diagram of the apparatus may be as shown in fig. 11, including: a processor 1101, a transceiver 1102.

The processor 1101 may perform the method steps performed by the second device in any of the above method embodiments through the transceiver 1102.

Embodiments of the present application also provide a computer storage medium, in which a software program is stored, and the software program can implement the method described in any one of the first aspect to the tenth aspect when read and executed by one or more processors.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, magnetic storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. 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.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the scope of the application. Thus, to the extent that such modifications and variations of the present application fall within the scope of the claims of the present application, it is intended that the present application also encompass such modifications and variations.