阅读说明：本技术 下行链路移动参考信号传送和rrm测量方法及其设备 (Downlink mobile reference signal transmission and RRM measurement method and apparatus therefor ) 是由 林烜立 廖培凯 李建樟 于 2018-01-09 设计创作，主要内容包括：本发明的方面提供一种下行链路移动参考信号传送方法。所述方法可以包含传送包含第一部分移动参考信号和附加部分移动参考信号的移动参考信号,其中所述第一部分移动参考信号包含第一移动参考信号突发,其中各所述第一移动参考信号突发与同步信号块复用,所述附加部分移动参考信号包含第二移动参考信号突发,并且所述附加部分移动参考信号被配置为传送或者不传送。通过利用本发明,可以更好地进行下行链路移动参考信号传送和无线电资源管理测量。(Aspects of the present invention provide a downlink mobile reference signal transmission method. The method can include transmitting a moving reference signal including a first portion of the moving reference signal and an additional portion of the moving reference signal, wherein the first portion of the moving reference signal includes first moving reference signal bursts, wherein each of the first moving reference signal bursts is multiplexed with a synchronization signal block, the additional portion of the moving reference signal includes a second moving reference signal burst, and the additional portion of the moving reference signal is configured to be transmitted or not transmitted. By utilizing the invention, the downlink mobile reference signal transmission and the radio resource management measurement can be better carried out.)

1. A downlink mobile reference signal transmission method, comprising:

transmitting a moving reference signal comprising a first part of the moving reference signal and an additional part of the moving reference signal,

wherein the first portion of the moving reference signal comprises one or more first moving reference signal bursts, wherein each of the one or more first moving reference signal bursts is multiplexed with a synchronization signal block, an

The additional partial moving reference signal contains one or more second moving reference signal bursts and is configured to be transmitted or not transmitted.

2. The downlink mobile reference signal transmission method of claim 1, further comprising:

in a beam scanning process, a first or second mobile reference signal burst containing a plurality of mobile reference signal symbols is transmitted over a series of beams.

3. The downlink mobile reference signal transmission method of claim 2, wherein a mobile reference signal sequence transmitted on a beam is generated based on a beam index of the beam such that the mobile reference signal sequence indicates the beam index of the beam.

4. The downlink mobile reference signal transmission method of claim 1, wherein a burst length of the one or more first or second mobile reference signal bursts is configurable.

5. The downlink mobile reference signal transmission method of claim 1, further comprising:

transmitting a mobile reference signal configuration corresponding to a serving cell or a neighboring cell of a user equipment, wherein the mobile reference signal configuration contains one or more of the following configuration parameters defining the one or more second mobile reference signal bursts transmitted from the respective cell to the user equipment:

the period of the transmission is such that,

with respect to the time offset of the synchronization signal block,

the bandwidth of the transmission is such that,

the burst duration, and

frequency domain location.

6. The downlink mobile reference signal transmission method of claim 1, further comprising:

and determining the transmission period of the mobile reference signal according to the speed of the user equipment.

7. The downlink mobile reference signal transmission method of claim 1, wherein a mobile reference signal sequence is generated based on one or more of a cell identity, a transmission reception point identity, or a transmission beam index of a serving cell transmitting the mobile reference signal.

8. The downlink mobile reference signal transmission method of claim 1, wherein a frequency domain location of the one or more first or second mobile reference signal bursts is dependent on a cell identity, a transmit receive point identity, or a transmit beam index of a serving cell transmitting the mobile reference signal.

9. The downlink mobile reference signal transmission method of claim 1, wherein the one or more first or second mobile reference signal bursts are not transmitted in a subframe or slot of a serving cell whose neighbor cells have uplink transmissions.

10. A radio resource management measurement method, comprising:

receiving, by a user equipment, a mobile reference signal configuration corresponding to a serving cell and a neighbor cell of the user equipment;

receiving mobile reference signals transmitted from the serving cell and the neighbor cells of the user equipment according to the mobile reference signal configuration,

wherein each of the moving reference signals comprises a first portion of moving reference signals comprising one or more first moving reference signal bursts, wherein each of the one or more first moving reference signal bursts is multiplexed with a synchronization signal block, and an additional portion of moving reference signals configured to transmit or not transmit; and

generating radio resource management measurement results based on the received mobile reference signals.

11. The radio resource management measurement method of claim 10, wherein one of the mobile reference signal configurations comprises one or more of the following configuration parameters, wherein the configuration parameters are used to define the one or more second mobile reference signal bursts for each cell:

the period of the transmission is such that,

with respect to the time offset of the synchronization signal block,

the bandwidth of the transmission is such that,

the burst duration, and

frequency domain location.

12. The radio resource management measurement method of claim 10, further comprising:

based on the received moving reference signals, performing one or more of the following functions:

demodulation, time synchronization tracking, frequency synchronization tracking, or channel characteristic estimation of a physical broadcast channel in a synchronization signal block burst multiplexed with the one or more first moving reference signals.

13. The radio resource management measurement method of claim 10, further comprising:

receiving the one or more first or second mobile reference signal bursts comprising a plurality of mobile reference signal symbols from a series of beams, wherein the series of beams are transmitted from the serving cell or one of the neighboring cells in a beam scanning process.

14. The radio resource management measurement method of claim 13 wherein a mobile reference signal sequence received from a beam is generated based on a beam index of the beam such that the mobile reference signal sequence indicates the beam index of the beam.

15. The radio resource management measurement method according to claim 10, wherein a moving reference signal sequence is generated based on a cell identity, a transmit receive point identity and/or a transmit beam index of the serving cell or one of the neighboring cells.

16. The radio resource management measurement method according to claim 10, wherein the frequency location of the one or more first or second mobile reference signal bursts is determined based on a cell identity, a transmit receiving point identity and/or a transmit beam index of the serving cell or one of the neighboring cells, which transmits the first or second mobile reference signal.

17. The radio resource management measurement method of claim 10, further comprising:

receiving the mobile reference signal configuration through radio resource control signaling, broadcast or multicast system information, or a combination of the radio resource control signaling and the broadcast or multicast system information.

18. The radio resource management measurement method of claim 10, wherein a transmission bandwidth of the one or more second mobile reference signal bursts is equal to or greater than a transmission bandwidth of the synchronization signal block.

19. The radio resource management measurement method of claim 10, wherein a burst length of the one or more first or second mobile reference signal bursts is greater than a burst length of a synchronization signal burst containing the synchronization signal block.

20. A radio resource management measurement method, comprising:

receiving, by a user equipment, mobile reference signals transmitted from a serving cell and neighboring cells of the user equipment, wherein each of the mobile reference signals comprises one or more first mobile reference signal bursts, wherein each of the one or more first mobile reference signal bursts is multiplexed with a synchronization signal block,

wherein a burst length of the first moving reference signal burst is greater than a burst length of a synchronization signal burst containing the synchronization signal block,

wherein each of the moving reference signals is generated based on a cell identification, a transmit receive point identification, and/or a transmit beam index of each cell corresponding to the moving reference signal; and

generating radio resource management measurement results based on the received mobile reference signals.

21. The radio resource management measurement method of claim 20, further comprising:

based on the received moving reference signals, performing one or more of the following functions:

demodulation, time synchronization tracking, frequency synchronization tracking, or channel characteristic estimation of a physical broadcast channel in a synchronization signal block burst multiplexed with the one or more first moving reference signals.

22. An apparatus for wireless communication, comprising:

a processor for performing the steps of the downlink mobile reference signal transmission or radio resource management measurement method of any of claims 1-21.

Technical Field

The present invention relates to wireless communications, and more particularly, to Downlink (DL) Reference Signal (RS) for RRM (Radio Resource Management) measurements.

Background

Work of the presently named inventors, to the extent it is provided herein in general terms, is intended to be within the context of the present disclosure, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

In a Long Term Evolution (LTE) network, a Common Reference Signal (CRS) may be transmitted in each subframe (subframe) over the full carrier bandwidth. RRM measurements may be performed based on the CRS. However, in the New Radio (NR) air interface (air interface), in order to reduce RS overhead (overhead), inter-cell interference (inter-cell interference) and User Equipment (UE) power consumption, an always-on (always-on) wideband CRS is removed. New RS designs can be introduced in the NR system for RRM measurements.

Disclosure of Invention

Aspects of the present invention provide a downlink mobile reference signal transmission method. The method can include transmitting a moving reference signal including a first portion of the moving reference signal and an additional portion of the moving reference signal, wherein the first portion of the moving reference signal includes one or more first moving reference signal bursts, wherein each of the one or more first moving reference signal bursts is multiplexed with a synchronization signal block, the additional portion of the moving reference signal includes one or more second moving reference signal bursts, and the additional portion of the moving reference signal is configured to be transmitted or not transmitted.

In an embodiment, the method may further comprise transmitting a first or second mobile reference signal burst comprising a plurality of mobile reference signal symbols on a series of beams during the beam scanning. A sequence of moving reference signals transmitted on a beam is generated based on a beam index of the beam.

In an example, a burst length of the one or more first or second mobile reference signal bursts is configurable. In an embodiment, the method may further include transmitting a mobile reference signal configuration corresponding to a serving cell or a neighboring cell of a user equipment, wherein the mobile reference signal configuration includes one or more of the following configuration parameters defining the one or more second mobile reference signal bursts transmitted from the corresponding cell of the user equipment: transmission period, time offset with respect to the synchronization signal block, transmission bandwidth, burst duration, and frequency domain location. In an example, the transmission period is determined according to a speed of the user equipment.

In an example, the mobile reference signal sequence is generated based on one or more of a cell identification, a transmit receive point identification, or a transmit beam index of a serving cell transmitting the mobile reference signal. In an example, the frequency domain location of the one or more first or second mobile reference signal bursts is dependent on a cell identification, a transmit receive point identification, or a transmit beam index of a serving cell transmitting the mobile reference signal. In an example, the one or more first or second mobile reference signal bursts are transmitted in a subframe or slot of a serving cell whose neighbor cells do not have uplink transmissions.

Aspects of the present invention provide a radio resource control connected mode radio resource management measurement method. The method may include receiving, by a user equipment, a mobile reference signal configuration corresponding to a serving cell and a neighbor cell of the user equipment; receiving mobile reference signals transmitted from the serving cell and the neighboring cells of the user equipment according to the mobile reference signal configuration, wherein each of the mobile reference signals includes a first part of the mobile reference signal and an additional part of the mobile reference signal, the first part of the mobile reference signal includes one or more first mobile reference signal bursts, wherein each of the one or more first mobile reference signal bursts is multiplexed with a synchronization signal block, the additional part of the mobile reference signal includes one or more second mobile reference signal bursts, and the additional part of the mobile reference signal is configured to be transmitted or not transmitted; and generating radio resource management measurement results based on the received mobile reference signals.

In an embodiment, the method may further include, based on the received moving reference signal, performing one or more of the following functions: demodulation of a physical broadcast channel, time and/or frequency synchronization tracking, or channel characteristic estimation in a synchronization signal block multiplexed with the one or more first moving reference signal bursts.

In an embodiment, the method may further include receiving the one or more first or second mobile reference signal bursts comprising a plurality of mobile reference signal symbols from a series of beams transmitted from the serving cell or one of the neighboring cells in a beam scanning process.

Aspects of the present invention provide a radio resource control idle mode radio resource management measurement method. The method may include receiving, by a user equipment, mobile reference signals transmitted from a serving cell and neighboring cells of the user equipment, wherein each of the mobile reference signals comprises one or more first mobile reference signal bursts, wherein each of the one or more first mobile reference signal bursts is multiplexed with a synchronization signal block, wherein each of the mobile reference signals is generated based on a cell identification, a transmit receive point identification, and/or a beam index of each cell corresponding to the mobile reference signal; and generating radio resource management measurement results based on the received mobile reference signals.

By utilizing the invention, the downlink mobile reference signal transmission and the radio resource management measurement can be better carried out.

Drawings

Various exemplary embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings, wherein like numerals denote like elements, and wherein:

fig. 1 illustrates a wireless communication network in accordance with various embodiments of the present invention.

Fig. 2 illustrates an exemplary Mobile Reference Signal (MRS) configuration according to an embodiment of the present invention.

Fig. 3 illustrates another exemplary MRS configuration according to an embodiment of the present invention.

Fig. 4 illustrates an exemplary Synchronization Signal Block (SSB) multiplexed with a first MRS burst (burst) in a Synchronization Signal (SS) region, according to an embodiment of the present invention.

Fig. 5 illustrates an exemplary second MRS burst according to an embodiment of the present invention.

Fig. 6A illustrates an exemplary first MRS burst multiplexed with an SS burst according to an embodiment of the present invention.

Fig. 6B illustrates an exemplary second MRS burst, according to an embodiment of the present invention.

Fig. 7 illustrates an exemplary Radio Resource Control (RRC) connected mode (connected mode) RRM measurement and reporting procedure in accordance with an embodiment of the present invention.

Fig. 8 illustrates an exemplary RRC idle mode (idle mode) RRM measurement procedure according to an embodiment of the present invention.

FIG. 9 illustrates an exemplary device according to some embodiments of the inventions.

Detailed Description

Fig. 1 illustrates a wireless communication network 100 in accordance with various embodiments of the present invention. The network 100 may include a plurality of Base Stations (BSs) 111-113 and UEs 161. Each BS 111-113 corresponds to cell 121-123. For example, each BS 111-113 can control a Transmission and Reception Point (TRP) to transmit a wireless signal to cover each cell 121-123. In one example, the network 100 conforms to the Fifth Generation (5G) NR communication standard developed by the third Generation Partnership Project (3rd Generation Partnership Project, 3 GPP). Accordingly, each BS 111-113 may be an implementation of a gNB as defined by the 3GPP NR air interface standard. The UE 161 may be a mobile phone, a notebook computer, a car-mounted device, and the like. UE 161 may communicate with BSs 111-113 according to the 3GPP NR air interface standard. In other examples, network 100 may operate according to other wireless communication standards.

In an example, UE 161 operates in RRC connected mode and performs RRM measurement and reporting procedures to facilitate handover over operations. For example, UE 161 is connected to BS 111, and a data or signal radio bearer may be established between UE 161 and BS 111. Thus, cell 121 is the serving cell for UE 161. While operating in connected mode, the UE 161 may monitor the Signal quality of the serving cell 121, for example, by calculating a Reference Signal Received Power (RSRP) of the RS Received from the serving cell 121. When RSRP is below a threshold (e.g., due to movement of UE 161), UE 161 may report to BS 111. In response, BS 111 may send a connected mode RRM measurement configuration to UE 161 and control UE 161 to perform RRM measurement and reporting procedures.

In particular, the connected mode RRM measurement configuration may contain the MRS configuration 141 of the serving cell 121 and the neighboring cells of the UE 161. For example, BS 111 may coordinate (coordinate) with BS 112 and 113 to determine MRS configurations for each of neighboring cells 122 and 123 and serving cell 121, and then provide MRS configuration 141 to UE 161. For example, BS 111 may communicate with BS 112 through interface 131-132 and BS 113, where interface 131-132 is similar to the X2 interface defined in the LTE standard.

Based on the connected mode RRM measurement configuration and MRS configuration 141, UE 161 may perform an RRM measurement procedure. In the RRM measurement procedure, the signal quality of a cell may be measured by calculating some measurement quantity (RSRP measurement result) based on the RS received from the cell. In an example, MRS configuration 141 may define a set of MRS configuration parameters of MRS 151 and 153 transmitted from serving cell 121 and neighbor cells 122 and 123. For example, the MRS configuration parameters of MRS 151-. For example, the UE 161 may perform inter-frequency (inter-frequency) or intra-frequency (intra-frequency) measurements accordingly and generate RSRP and/or Reference Signal Received Quality (RSRQ) measurements for the serving cell 121 and the neighboring cell 122. Subsequently, when certain conditions are met (e.g., the serving cell signal quality is below the neighbor cell signal quality for a certain time as defined by the connected mode RRM measurement configuration), UE 161 may report the RRM measurement results to BS 111. Based on the RRM measurement results received from the UE 161, the BS 111 may determine to trigger a handover procedure to handover (switch) the UE 161 to a neighboring cell.

In another example, the UE 161 operates in an RRC idle mode and performs RRM measurement and reporting procedures to facilitate cell reselection operations. For example, UE 161 is camped (camp) on BS 111 and cell 121 operates as the serving cell. UE 161 may receive an idle mode RRM measurement configuration from BS 111. For example, the idle mode RRM measurement configuration may be included in the system information broadcast from the BS 111 and received by the UE 161. Similar to the connected mode, the idle mode RRM measurement configuration may include an MRS configuration 141, where the MRS configuration 141 defines configuration parameters of MRSs 151 and 153 transmitted from the serving cell 121 and the neighboring cells 122 and 123.

UE 161 may monitor the signal quality of serving cell 121 while camped on BS 111. For example, the RRM measurement procedure may be triggered when the signal quality of the serving cell 121 is below a threshold defined by the idle mode RRM measurement configuration (due to the movement of the UE 161). The UE 161 may perform RRM measurements based on the idle mode RRM measurement configuration and the MRS configuration 141. For example, UE 161 may perform inter-frequency or intra-frequency measurements based on MRS 151-. Based on the RRM measurement results described above, the UE 161 may determine to switch from the current serving cell 121 to another neighbor cell when certain conditions (as defined in the idle mode RRM measurement configuration) are satisfied.

In an embodiment, the MRS transmitted from cells 121 and 123 may comprise a first portion and an additional portion. The first partial MRS may be a signal that is always on and may contain one or more first RS bursts. Each first RS burst may be multiplexed with the SSB during transmission. SSB refers to RE regions in an Orthogonal Frequency Division Multiplexing (OFDM) time-Frequency resource grid (resource grid), and contains Synchronization signals such as Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) in LTE or NR systems and a Physical Broadcast Channel (PBCH) carrying a Main Information Block (MIB). The SSB may be periodically broadcast from the BS and may be used by the UE in an initial access procedure to obtain DL synchronization and MIB system information.

The additional partial MRS may contain one or more second RS bursts. In particular, the transmission of the additional partial MRS may be adaptively configured to facilitate RRM measurements, e.g. configured according to the speed of the UE 161. For example, when the UE 161 moves at a low speed, the additional partial MRS may not be transmitted. Thus, the periodicity of the MRS may be decided by the transmission of the first MRS burst. In contrast, when the UE 161 moves at a high speed, an additional partial MRS may be transmitted to increase the periodicity of the MRS. Accordingly, performance of a handover operation of a high mobility UE may be improved.

Therefore, for the connected mode RRM measurement procedure described above, MRS 151-. For example, when UE 161 reports to BS 111 that the signal quality is below the threshold, BS 111 may adaptively configure MRS 151 and 153, e.g., according to the speed configuration of UE 161, by coordinating with neighboring cells 122 and 123. For example, UE 161 may report along with the speed when reporting signal quality to BS 111. BS 111 may generate MRS configuration 141 and signal MRS configuration 141 to UE 161, where MRS configuration 141 defines configuration parameters for the first partial MRS and the additional partial MRS.

In contrast, for the idle mode RRM measurement procedure described above, the idle mode RRM measurement procedure may be performed based on the first partial MRS (the additional partial MRS is not configured) received from the serving cell 121 and the neighboring cell 122 and 123. When a UE operating in idle mode moves across a cell boundary, a cell reselection decision may be determined by the UE itself, and nearby BSs may not be aware of the UE's movement. Therefore, the configuration of the (product) additional partial MRS may not be performed.

Fig. 2 illustrates an exemplary MRS configuration 200 according to an embodiment of the present invention. Fig. 2 shows an OFDM time-frequency resource region 230. Region 230 may correspond to the DL radio signal transmitted from BS 111 and 113 in the example of fig. 1. Region 230 may contain a number of subcarriers corresponding to carrier bandwidth 221 in the frequency domain and a number of subframes in the time domain. In an example, each subframe may include 1, 2, 3, or 4 slots (slots) and each slot may include 7 or 14 OFDM symbols according to a carrier parameter set (numerology) configuration of BS 111-113. The parameter set for the carrier frequency may be defined by the subcarrier spacing used by the carrier frequency. For example, different parameter sets may have subcarrier spacings of 15KHz, 30KHz, 60KHz, and so on. Different subframe structures may be defined corresponding to different parameter sets.

As shown, a series of SS regions 211 and 214 are included in region 230 and are located at the center subcarrier of carrier bandwidth 221. An SS region may be defined as an RE of a rectangular region containing one or more first MRS bursts multiplexed with one or more SSBs. The SS region may have a transmission bandwidth 224 in the frequency domain equal to the bandwidth of the contained SSBs and a time length 223 in the time domain, the time length 223 may be equal to the number of consecutive slots, where each slot contains an SSB or an MRS burst.

The MRS configuration 200 defines an MRS that includes a first portion of the MRS, where the first portion of the MRS includes a series of first MRS bursts 201 and 204. Each of the first MRS bursts 201-.

Each SS region 211-214 may comprise an SSB or a series of SSBs. The series of SSBs may be referred to as an SS burst. SSBs or SS bursts may be broadcast periodically. In the example of fig. 2, the period 222 of the SSB or SS burst transfer is 40 ms. Since each of the first MRS bursts 201-.

Fig. 3 illustrates another exemplary MRS configuration 300 according to an embodiment of the present invention. MRS configuration 300 defines an MRS that includes a first portion and an additional portion. Specifically, the first portion MRS comprises a first MRS burst 201-. In one example, each of the second bursts 301-304 has the same structure as the first burst 201-204. As shown, the MRS configured by MRS configuration 300 has a transmission period 322(20ms) that is half the transmission period (40ms) of the first MRS burst 201-.

In other examples, more than one second MRS burst may be added between two first MRS bursts so that different MRS transmission cycles may be obtained. For example, corresponding to the example of fig. 2, when 3 or 7 second MRS bursts are inserted between two first MRS bursts, then an MRS transmission period of 10ms or 5ms may be obtained.

In some examples, MRSs comprising the first MRS burst and the second MRS burst may be unevenly distributed in the time domain. Accordingly, the transmission timing of the second MRS burst may be defined using other parameters than the MRS transmission cycle. For example, a time offset (offset) may be defined with respect to a preceding first MRS burst for a second MRS burst following the preceding first MRS. Of course, for evenly distributed first and second MRS bursts, the time offset with respect to the first MRS burst may also be used as a parameter defining the timing of the subsequent second MRS burst.

Although it is assumed in the example of fig. 3 that the second MRS burst 301-. For example, first and second MRS bursts of the same MRS may have different transmission bandwidths, different burst lengths (a time interval in which the first or second MRS bursts are continued is referred to as a burst length or a burst duration), and different frequency domain positions of MRS REs in the MRS bursts.

Fig. 4 illustrates an exemplary SSB 410 multiplexed with a first MRS burst 420 in an SS region 401, according to an embodiment of the present invention. The SSB 410 may have a duration of 7 OFDM symbols (symbols) in the time domain and a bandwidth of 24 Physical Resource Blocks (PRBs) in the frequency domain. SSB 410 may carry PSS 411, SSS 412, and MIB 413 in each RE. The first MRS burst 420 is carried in REs belonging to three symbols 431-433, wherein the three symbols 431-433 are in a slot 430 comprising 14 symbols. The symbol of the RE carrying the MRS is referred to as an MRS symbol. As shown, a portion of the first MRS burst (in MRS symbols 432 and 433) is contained in SSB 410. Accordingly, the portion of the first MRS burst 420 may be used as a Demodulation Reference Signal (DMRS) for Demodulation of the PBCH (including the MIB 413) in an initial access procedure.

A scalable parameter set with subcarrier spacing scaling (scale) may be used in NR systems. Accordingly, SSBs 410 may occupy different transmission bandwidths in the frequency domain, with different durations in the time domain, depending on the parameter set configuration of the carrier carrying SSB 410. For example, for a parameter set configuration of 15KHz or 60KHz subcarrier spacing, the bandwidth of an SSB 410 occupying 24 PRBs may be 5MHz or 20MHz, respectively, and the duration of an SSB 410 lasting 7 symbols may be 0.5ms or 0.125ms, respectively.

Similarly, SS regions 401 having a time length of 14 symbols in the time domain and the same bandwidth as SSB 410 may occupy different bandwidths for different time durations for different parameter set configurations. In addition, the bandwidth of the first MRS burst 420 (equal to the bandwidth of the SSB 410 in the example of fig. 4 in terms of the number of PRBs) may also vary for different parameter set configurations.

In various examples, the first MRS burst 420 may have a different configuration. In the fig. 4 example, the first MRS burst 420 occupies three symbols, and a portion of the MRS burst 420(MRS symbol 431) is located outside of the SSB 410. In other examples, the symbol carrying the first MRS burst may be included in the SSB 410. Accordingly, the first MRS burst may have a different burst length according to the MRS configuration. For example, the burst length of the first MRS burst may be greater than the duration of an SSB or SS burst multiplexed with the MRS burst.

Note that in various examples, SSBs may have different structures. In an example, the SSB is configured to last 4 symbols in the time domain and has a format of PSS-PBCH-SSS-PBCH, where PSS and SSS are carried in the first and third symbols and PBCH is carried in the second and fourth symbols. In the frequency domain, the SSB may have a bandwidth of 24 PRBs similar to the example of fig. 4.

Fig. 5 illustrates an exemplary second MRS burst 520, according to an embodiment of the present invention. The second MRS520 may correspond to the first MRS burst 420 in the example of fig. 4 and may be configured to be transmitted along with the first MRS burst 420 to form an MRS. As shown, the second MRS520 may have the same bandwidth as the first burst 420 in terms of the number of PRBs and may be distributed over 4 MRS symbols in the time domain. In other examples, the second MRS burst 520 may be configured with a different burst length and bandwidth than the example of fig. 5 as part of the same MRS that contains the first MRS burst 420 and the second MRS burst 520. For example, to improve the accuracy of RRM measurements, the second MRS burst 520 may be configured with a wider transmission bandwidth (such as wider than 24 PRBs) and a longer burst length (such as 1ms or 2 ms).

In the RRM measurement procedure, the UE may receive a plurality of MRSs from the serving cell and a plurality of neighbor cells. Multiple MRSs may be transmitted on the same carrier frequency from multiple TRPs. In addition, a plurality of TRPs may employ beamforming (beamforming) techniques, and accordingly, the first or second MRS burst may contain RS sequences transmitted from different transmission beams of the TRP. Accordingly, in an example, to reduce interference (interference) between MRSs received from neighboring cells and a serving cell, an MRS frequency location is configured to be dependent on a cell Identification (ID), a TRP ID, and/or a transmission beam index (index). For example, for MRS transmissions from different TRPs and different transmission beams, an RE mapping pattern (mapping pattern) for mapping (map) each MRS sequence to an RE in a time-frequency grid may shift (shift) frequencies of several subcarriers in the frequency domain based on a corresponding cell ID, TRP ID, and/or transmission beam index.

In another example, to identify (identify) an MRS transmission from a different cell, TRP or transmission beam, an MRS sequence may be generated based on a cell ID, TRP ID and/or beam index. For example, for MRSs configured for a specific cell, a specific TRP, and a specific transmission beam, an initial value for generating each MRS sequence may depend on each cell ID, TRP ID, and/or transmission beam index.

In some examples, the positions of the first and second MRS bursts in the time domain are configured to be in the DL portion of a DL (DL only) or mostly DL (DL major) subframe or slot. In a subframe or slot of a predominantly DL subframe or slot type, the DL portion may occupy a longer portion of the subframe or slot than the Uplink (UL) portion.

In an example, an MRS burst may be configured to be located in a subframe or slot where a neighboring cell may not have UL transmissions. In this way, inter-cell DL and UL collisions due to dynamic Time Division multiplexing (TDD) can be avoided for DL transmission of MRS bursts.

Fig. 6A illustrates an exemplary first MRS burst 630 multiplexed with SS bursts 620, according to an embodiment of the present invention. The first MRS burst 630 comprises a series of MRSs 631 and 634 transmitted in a series of slots 611 and 614, respectively. The burst length of the first MRS burst 630 may be approximately equal to 4 slots. SS burst 620 includes a series of SSBs 621-624 that are transmitted in a series of time slots 611-614, respectively. Similarly, the burst length of SS burst 620 may last approximately 4 time slots. Although each pair of SSB and MRS in one slot 611-614 is represented by two separate rectangles, the MRS and REs of the SSBs may be mixed (mix) together as shown in the example of fig. 4.

A series of time slots 611-. For example, the TRP may continuously transmit different beams 641 and 644 toward different directions to cover the cell (this operation may be referred to as transmit beam scanning (sweep)). In addition, the transmission of the SS burst 620 and the MRS burst 630 may be repeatedly transmitted in a cycle (e.g., 40 ms). Accordingly, in the RRM measurement procedure, the UE may receive the first MRS burst 630 transmitted on the series of transmission beams 641 and 644 from the TRP. In order for the UE to distinguish (distinggush) the MRSs 631 and 634 received from a series of transmit beams, each of the MRSs 631 and 634 of the first MRS burst 630 may be generated based on the beam index of the transmit beam 641 and 644, respectively. For example, the initial values used to generate MRS 631 and 634 may be generated using the respective beam indices of one of the transmit beams 641 and 644. Accordingly, each MRS 631 and 634 may be beam specific. The beam index may be configured to the UE which may accordingly distinguish between the different transmission beams 641 and 644 based on MRS 631 and 634, e.g. using a correlation based scheme when generating RRM measurements.

In an example, the UE may also employ beamforming techniques to receive the first MRS burst 630 and the SS burst 620. For example, each MRS 631 and 634 may contain multiple MRS symbols, where each MRS symbol carries an MRS sequence. During the transmission of the time slots 611-614, the UE may generate a series of receive beams continuously towards different directions (referred to as receive beam scanning), and each receive beam may correspond to an MRS symbol in terms of transmission or reception time. By performing such a beam training process, it is possible to determine the best reception beam of the UE for reception from each TRP. In addition, in the RRM measurement procedure, RRM measurement results (such as RSRP, RSRQ, etc.) of different receive beams may be calculated to better estimate the signal quality of the neighboring cells.

Fig. 6B illustrates an exemplary second MRS burst 660 in accordance with an embodiment of the present invention. The second MRS burst 660 may be configured to transmit following the first MRS burst 630 in the example of fig. 6A to form an MRS. Similar to the fig. 6A example, the second MRS burst 660 may comprise a series of MRSs 661-664 transmitted in a series of time slots 651-654. Each MRS 661-664 or timeslot 651-654 may be transmitted on one of a series of transmit beams 671-674. Similarly, MRS 661-664 may be transmit beam specific so that the UE may distinguish between different transmit beams based on MRS 661-664 in determining signal quality.

Fig. 7 illustrates an exemplary RRC connected mode RRM measurement and reporting procedure 700 according to an embodiment of the present invention. In the process 700, the UE 701, the serving BS 702, and the set of neighbor BSs 703 communicate with each other and perform the steps of the process 700. The UE 701 operates in an RRC connected mode and is associated with the serving BS 702. In addition, the UE 701 may be located within the coverage of the neighbor BS 703. The UE 701 may be in a mobile state and process 700 may be performed to determine a suitable neighbor BS (in addition to the serving BS 702) for the UE 701 to associate with. The process may start at S710.

S710, the UE 701 reports signal quality degradation (degradation) to the serving BS 702. For example, serving BS 702 may transmit an MRS, where the MRS includes a first MRS burst. The first MRS burst may be multiplexed with the SSB and transmitted periodically. The UE 701 may receive the first MRS burst described above to monitor the signal quality of the serving BS 702. For example, RSRP measurements may be generated based on the received MRSs. Due to mobility, the UE 701 may detect signal degradation of the MRS. The UE 701 may be triggered to report to the serving cell BS 702 when the time at which the signal quality of the MRS is below the threshold reaches a preconfigured time.

At S712, the serving BS 702 coordinates with the neighbor BS703 to determine a set of MRS configurations of the serving BS 702 and the neighbor BSs. In an example, each BS 702 or 703 may control multiple TRPs to form multiple cells. The serving BS 702 may be configured with a neighbor cell list, wherein neighbor cells are associated with the neighbor BS 703. Accordingly, the serving BS 702 may be aware of the cells of the neighboring UEs 701.

In an example, due to the coordination procedure, MRS configurations for each of neighboring cells of the UE 701 and a serving cell of the UE 701 may be determined. For example, the MRS configuration of the neighboring cell may define the following configuration parameters: timing of the MRS burst (such as transmission period, time offset with respect to the SSB, etc.), transmission bandwidth, burst length of the MRS burst, etc. In addition, the MRS configuration of the neighbor cell may contain cell-related information (such as cell ID, TRP ID, transmission beam index, etc.), which is collected from the neighbor BS703 or preconfigured to the serving BS 702.

In some examples, serving BS 702 may determine some MRS configuration parameters based on the speed of movement of UE 701. For example, when the UE 701 is in low mobility, the second MRS burst may not be configured to the UE 701. When the UE 701 is in high mobility, a second MRS burst with a suitable transmission cycle may be configured. In addition, the burst length and the transmission bandwidth of the first and/or second MRS burst may also be adjusted (adjust) based on the speed of the UE 701.

At S714, the serving BS 702 may transmit an RRM measurement configuration to the UE 701 to trigger the UE 701 to perform an RRM measurement procedure. For example, the transmission of the RRM measurement configuration may be performed through RRC signaling. The RRM measurement configuration may include MRS configurations of neighboring cells and each of serving cells of the UE 701. Alternatively, the MRS configuration may be transmitted separately from the RRM measurement configuration. For example, the MRS configuration may be transmitted through RRC signaling, broadcast or multicast (multi-cast) system information, or a combination of RRC signaling and system information.

In addition, the RRM measurement configuration may contain other specifications that may be determined based on the MRS configuration, such as a measurement object (measurement object) containing a (to-be-measured) list to be measured and its operating frequency, a reporting configuration, a measurement identity, filtering to be used by RRM measurement, a measurement gap (measurement gap) for inter-frequency measurement.

At S716, the serving BS 702 transmits an MRS through the serving cell of the UE 701 according to the MRS configuration of the serving cell. At S718, the neighbor BS703 transmits an MRS through each neighbor cell of the UE 701 according to each MRS configuration of each neighbor cell. In S716 and S718, beamforming and scalable parameter sets may be employed in some neighboring cells or serving cells.

At S720, the UE 701 performs an RRM measurement procedure according to the RRM configuration and MRS configuration of the neighbor cell and serving cell of the UE 701. The RRM measurements may be performed by performing intra-frequency measurements for cells operating on the frequency of the serving cell and inter-frequency measurements for cells operating on a frequency different from the serving cell. RRM measurement results generated based on MRSs received from the serving BS 702 and the neighbor BSs 703 may contain RSRP, RSRQ, and other measurement qualities.

For example, in intra-frequency measurements, the UE 701 may acquire an MRS burst transmission opportunity (occasion) at an appropriate time based on MRS timing information. For inter-frequency measurements, the measurement gaps configured by the serving BS 702 may be used to determine measurement timing. Based on the cell ID, TRP ID and/or transmission beam index corresponding to the MRS burst, the frequency location of the MRS may be determined. Based on the transmission bandwidth and burst length of the MRS burst, REs carrying MRSs can be appropriately located. Based on the transmission beam index, RRM measurements may be associated with each transmission beam.

The obtained RRM measurement result may be reported to the serving BS 702 at S722. The reporting may be triggered by an event (event) or performed periodically, depending on the RRM configuration.

At S724, a handover decision may be determined by the serving BS 702 based on the reported RRM measurement results. Subsequently, a handover procedure may be triggered and executed. The process 700 ends after S724.

Fig. 8 illustrates an exemplary RRC idle mode RRM measurement procedure 800 according to an embodiment of the present invention. In the process 800, the UE801 performs RRM measurements based on MRSs received from the neighbor BSs 803 and the BS 802 where the UE801 is camped (camp). The BS 802 may be referred to as a camped BS 802. The UE801 operates in RRC idle mode and may be located within the coverage of the neighbor BS 803. The UE801 may be in a mobile state and the process 800 may be executed to let the UE801 reselect the BS to camp on. In particular, RRM measurements may be performed by the UE801 based on the first MRS burst contained in the received MRS. The first MRS burst may be multiplexed with the SSBs in each slot carrying the SSBs. Process 800 may begin at S810.

At S810, the UE801 may receive an RRM measurement configuration from the camped BS 802. For example, the RRM measurement configuration may be included in the system information periodically broadcast from the camped BS 802.

The RRM measurement configuration may include MRS configurations of the serving cell and the neighboring cells of the UE 801. For example, the camping BS 802 may control the operation of the serving cell of the UE801, and each neighboring BS803 may control a plurality of TRPs corresponding to the neighboring cells of the UE 801. In an example, the MRS configuration may contain a list of neighbor cells, and an operating frequency and parameter set configuration of the neighbor cells.

In addition, in an example, the MRS configuration of the neighboring cell may include timing information (including a period) of the first MRS burst (or equivalent SSB or SS burst), a burst length, a frequency domain position (RE position), and the like of each first MRS burst. In an example, the transmission bandwidth of the SSB of each neighboring cell or serving cell may be normalized to the number of PRBs (persistent). The transmission bandwidth of the first MRS burst may be determined according to SSB bandwidths.

Also, the MRS configuration may contain a cell ID, a TRP ID, and/or a transmission beam index of each neighboring cell. In some examples, the MRS sequence of a cell may be generated based on a cell ID, TRP ID, and/or transmission beam index of the cell. Thus, based on the MRS configuration, RRM measurements of MRS sequences corresponding to different cells, different TRPs or different transmission beams may be distinguished, e.g. according to a correlation-based scheme. Beam management, such as beam tracking or beam switching, may be implemented with knowledge of the signal quality of the different transmit beams for beamformed transmissions of the serving cell or neighboring cells.

In addition to the MRS configuration, the RRM measurement configuration may contain other parameters for implementing (product) RRM measurement procedures or cell reselection. In other examples, the MRS configuration may be transmitted separately from the transmission of the RRM measurement configuration.

At S812, the MRS may be transmitted from the camping BS 802 and received at the UE 801. At S814, the MRS may be transmitted from the neighbor BS803 and received at the UE 801. In some examples, for idle mode UEs 801, RRM measurements are made using only the first MRS burst multiplexed with the SSB for cell reselection purposes. Note, however, that there may be a second MRS burst transmitted from a cell associated with the camped BS 802 or the neighbor BS803, where the second MRS burst is used by other UEs operating in the RRC connected mode and performing RRM measurements.

At S816, the UE801 may perform RRM measurements based on the RRM measurement configuration and the MRS configuration received at S810. For example, RRM measurements (such as RSRP, RSRQ, etc.) of different cells, different TRPs, and/or different transmission beams may be generated based on the acquired MRS bursts.

At S818, the UE801 may make a decision to reselect a neighboring cell to camp on based on the RRM measurement result obtained at S816. For example, a cell reselection procedure may be triggered when the signal quality of the serving cell is below the signal quality of the neighboring cell and the time for which the quality difference is greater than a threshold reaches a preconfigured time. Process 800 may end after S818.

While the MRS containing the first and second MRS bursts described herein may be used for DL RRM measurements, in various examples MRS may be used for other purposes as well. In an example, since MRS (or a portion of MRS) may be mapped to REs in symbols carrying PBCH, MRS may be used for channel estimation in RRC connected mode or RRC idle mode, and the result of channel estimation may be used for coherent demodulation of PBCH in RRC connected mode or RRC idle mode. In an example, MRS described herein may be used for channel property (channel property) estimation in RRC connected mode and RRC idle mode, such as Doppler spread (Doppler spread) or delay spread (delay spread) estimation. The result of the channel characteristic estimation can be used for adaptive signal reception. For example, frequency synchronization may be performed to compensate for doppler spread, or channel equalization (channel equalization) may be performed to compensate for delay spread.

In an example, MRS described herein may be used to track time and/or frequency synchronization in RRC connected mode and RRC idle mode. Since one MRS burst may contain an RS sequence in a plurality of symbols, the performance of time and frequency tracking may be improved compared to an RS carried in one symbol within a transmission opportunity. For applications of channel characteristic estimation and time/frequency synchronization tracking, the MRS described in the present invention may be adaptively configured with periods of various transmissions for different channel conditions (conditions), which may vary with different speeds.

Fig. 9 illustrates an exemplary apparatus 900 according to some embodiments of the inventions. Device 900 may be used to implement various embodiments of the present invention. The device 900 may include a processor 910, a memory 920, and a Radio Frequency (RF) module 930. As shown in fig. 9, the above components are coupled (coupled) together. In some examples, the apparatus 900 may be used to implement a BS as described herein. Accordingly, the processor 910 may be configured to perform various functions or processes described as being performed by the BS. In other examples, device 900 may be used to implement a UE as described herein. Accordingly, the processor 910 may be configured to perform various functions or processes described as being performed by the UE.

The processor 910 may be implemented in hardware, software, or a combination thereof. In some examples, processor 910 may be implemented using an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like, which includes circuitry that may be configured to perform the various functions described herein. In an example, memory 920 may store program instructions that cause processor 910 to perform various functions. The Memory 920 may include a Read Only Memory (ROM), a Random Access Memory (RAM), a flash Memory, a hard disk drive, and the like.

The RF module 930 may receive a digital signal from the processor 910 and transmit the signal to a receiver via the antenna 940; or receives a wireless signal from a transmitter and generates a digital signal accordingly that is provided to the processor 910. The RF module 930 may include a Digital-to-Analog Converter (DAC)/Analog-to-Digital Converter (ADC), a down-Converter (frequency down Converter)/up-Converter (frequency up Converter), a filter, and an amplifier for receiving and transmitting operations. If device 900 is used to implement a BS, antenna 940 may include one or more TRPs, where each TRP includes one or more antenna elements.

The device 900 may optionally contain other components such as input and output devices, additional Central Processing Units (CPUs) or signal Processing circuits, etc. Accordingly, device 900 may perform other additional functions, such as executing applications and handling other communication protocols.

Although aspects of the present invention have been described in conjunction with specific exemplary embodiments, it is evident that many alternatives, modifications, and variations are possible. Accordingly, the described embodiments of the invention are intended to be illustrative, not restrictive. Changes may be made without departing from the scope of the invention as set forth in the claims below.