Method and apparatus for enhancing SRS

Abstract

In accordance with an embodiment, a UE receives, from a network device, a configuration of sounding reference signal (SRS) resources including eight antenna ports, a transmission comb configuration of the SRS resources, and a cyclic shift (CS) configuration of the SRS resources. The transmission comb is configured to indicate a comb value K. And K is one of 2, 4 or 8. The transmission comb configuration is also used to indicate a configured comb offset (k). K is an integer between 0 and K-1. The CS configuration is configured to indicate a CS location. And the UE maps each port of the eight antenna ports to a corresponding resource element (RE) on a corresponding CS (Circuit Switching) and a corresponding frequency domain, and the UE maps each port of the eight antenna ports to a corresponding resource element (RE) on the corresponding CS and the frequency domain. Within the SRS transmission bandwidth, the corresponding REs are a subset of the plurality of REs and are located per K REs, and there is one offset based on the configured comb offset (k). And the UE sends the SRS by using the eight antenna ports according to the mapping.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims U.S. Provisional Application No. 63 / 485,394, filed on February 16, 2023, entitled “Methods and Apparatus for Advanced SRS Configurations and Operations,” U.S. Provisional Application No. 63 / 422,738, filed on November 4, 2022, entitled “Methods and Apparatus for Enhancements of SRS Interference Randomization in Frequency / Code Domains,” U.S. Provisional Application No. 63 / 411,472, filed on September 29, 2022, entitled “Methods and Apparatus for Enhancements of SRS Interference Randomization,” and U.S. Provisional Application No. 63 / 411,472, filed on September 29, 2022, entitled “Methods and Apparatus for Enhancements of SRS Interference Randomization,” and U.S. Provisional Application No. 63 / 411,472, filed on August 11, 2022, entitled “Methods and Apparatus for Enhancements of SRS Interference Randomization.” The disclosure of which is incorporated herein by reference as if reproduced in its entirety. Technical Field

[0003] The present disclosure relates generally to wireless communications and, in particular embodiments, to methods and apparatus for resource configuration. Background Art

[0004] A sounding reference signal (SRS) is a reference signal sent by user equipment (UE) in the uplink to enable uplink channel estimation over a wide bandwidth. Therefore, the network may be able to communicate with the UE based on the uplink channel estimation. In addition, due to the channel reciprocity between uplink and downlink in time division duplex (TDD) communication systems, the network can use SRS to perform dynamic scheduling. In other words, the network can use channel-dependent scheduling. In this case, time-frequency resources are dynamically scheduled, taking into account different traffic priorities and quality of service requirements. Typically, the UE monitors several physical downlink control channels (PDCCH) to obtain scheduling decisions, which are indicated to the UE by the network. When a valid PDCCH is detected, the UE receives (or sends) data according to the scheduling decision. Summary of the invention

[0005] The disclosed embodiments describe methods and apparatus for resource hopping, thereby generally achieving technical advantages.

[0006] According to an embodiment, a network device configures a first sounding reference signal (SRS) resource. The first SRS resource is associated with a first transmission parameter defined on a value set. The network device configures the first transmission parameter for the first SRS resource to jump on a first value subset of the value set. The network device receives a first SRS on the first SRS resource. The first SRS causes the first transmission parameter to jump according to the first value subset.

[0007] In some embodiments, the value set includes a second value subset for resource hopping of a second SRS resource. The network device may configure the second SRS resource. The second SRS resource may be associated with a second transmission parameter defined on the value set. The network device may configure the second transmission parameter for the second SRS resource to hop on the second value subset of the value set. The network device may receive a second SRS on the second SRS resource. The second SRS causes the second transmission parameter to hop according to the second value subset. The first SRS resource and the second SRS resource may at least partially overlap in the time domain or the frequency domain.

[0008] In some embodiments, the resource hopping may include a cyclic shift (CS) hopping. The first value subset may be a first subset of a CS value set used for the CS hopping. The second value subset may be a second subset of the CS value set used for the CS hopping.

[0009] In some embodiments, the resource hopping may include a comb offset hopping. The first value subset may be a first subset of a comb offset value set for the comb offset hopping. The second value subset may be a second subset of the comb offset value set for the comb offset hopping. The first value subset may include a first comb offset value, and the second value subset may include a second comb offset value.

[0010] In some embodiments, the first SRS resource may be configured for a first user equipment (UE). The second SRS resource may be configured for a second UE different from the first UE.

[0011] In some embodiments, the resource hopping may include a CS hopping.The first subset of values ​​may be a first subset of a CS value set used for the CS hopping.

[0012] In some embodiments, the resource hopping may include a comb offset hopping.The first subset of values ​​may be a first subset of a set of comb offset values ​​for the comb offset hopping.

[0013] In some embodiments, the first value subset of the first SRS can jump on the first value subset on multiple SRS transmission occasions according to an SRS hopping randomization identifier (identifier, ID), a pseudo-random integer sequence on the multiple SRS transmission occasions, a configured first resource value, the number of values ​​in the first value subset and a time domain index of the multiple SRS transmission occasions.

[0014] In some embodiments, the first SRS resource may be configured with multiple ports. The multiple ports may perform hopping according to the same pseudo-random integer sequence on the multiple SRS transmission opportunities. In each of the multiple SRS transmission opportunities, the multiple ports may all use the same pseudo-random integer value.

[0015] In some embodiments, the time domain index may be based on a system frame number (SFN), a time slot number within the SFN, and an orthogonal frequency-division multiplexing (OFDM) symbol index within a time slot.

[0016] In some embodiments, the first number of values ​​in the first subset may be 1, or the second number of values ​​in the second subset may be 1.

[0017] According to an embodiment, a UE receives a first resource configuration from a network device. The first resource configuration is used to configure a first sounding reference signal (SRS) resource. The first SRS resource is associated with a first transmission parameter defined on a value set. The UE receives a first hopping configuration of the first SRS resource from the network device. The first hopping configuration is used to configure the first transmission parameter to hop on a first value subset of the value set. The UE sends a first SRS to the network device on the first SRS resource. The first SRS causes the first transmission parameter to hop according to the first value subset.

[0018] In some embodiments, the UE may receive a second resource configuration from the network device. The second resource configuration may be used to configure the second SRS resource. The second SRS resource may be associated with a second transmission parameter defined on the value set. The UE may receive a second hopping configuration of the second SRS resource from the network device. The second resource configuration is used to configure the second transmission parameter to hop on a second value subset of the value set. The UE may send a second SRS to the network device on the second SRS resource. The second SRS may cause the second transmission parameter to hop according to the second value subset. The first SRS resource and the second SRS resource may at least partially overlap in the time domain or the frequency domain.

[0019] In some embodiments, the resource hopping may include a cyclic shift (CS) hopping. The first value subset may be a first subset of a CS value set used for the CS hopping. The second value subset may be a second subset of the CS value set used for the CS hopping.

[0020] In some embodiments, the resource hopping may include a comb offset hopping. The first value subset may be a first subset of a comb offset value set for the comb offset hopping. The second value subset may be a second subset of the comb offset value set for the comb offset hopping. The first value subset may include a first comb offset value, and the second value subset may include a second comb offset value.

[0021] In some embodiments, the resource hopping may include a CS hopping.The first subset of values ​​may be a first subset of a CS value set used for the CS hopping.

[0022] In some embodiments, the resource hopping may include a comb offset hopping.The first subset of values ​​may be a first subset of a set of comb offset values ​​for the comb offset hopping.

[0023] In some embodiments, the first value subset of the first SRS can jump on the first value subset on multiple SRS transmission occasions according to an SRS hopping randomization identifier (identifier, ID), a pseudo-random integer sequence on the multiple SRS transmission occasions, a configured first resource value, the number of values ​​in the first value subset and a time domain index of the multiple SRS transmission occasions.

[0024] In some embodiments, the first SRS resource may be configured with multiple ports. The multiple ports may perform hopping according to the same pseudo-random integer sequence on the multiple SRS transmission opportunities. In each of the multiple SRS transmission opportunities, the multiple ports may all use the same pseudo-random integer value.

[0025] In some embodiments, the time domain index may be based on a system frame number (SFN), a time slot number within the SFN, and an orthogonal frequency-division multiplexing (OFDM) symbol index within a time slot.

[0026] In some embodiments, the first number of values ​​in the first subset may be 1, or the second number of values ​​in the second subset may be 1.

[0027] According to an embodiment, a UE receives a configuration of a sounding reference signal (SRS) resource including 8 antenna ports, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource from a network device. The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a configured comb offset (k). k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. The UE maps each of the 8 antenna ports to a corresponding CS and a corresponding resource element (RE) in the frequency domain. The corresponding RE is a subset of multiple REs, located on every K REs within the SRS transmission bandwidth, and has an offset based on the configured comb offset (k). The UE sends an SRS to the network device using the 8 antenna ports according to the mapping.

[0028] In some embodiments, the corresponding RE may be located in an orthogonal frequency division multiplexing (OFDM) symbol.

[0029] In some embodiments, the usage of the SRS resources may be set to "codebook" or "antenna switching".

[0030] In some embodiments, the comb value K may be 2. The UE may map the 8 antenna ports to every K REs using the configured comb offset (k) within the SRS transmission bandwidth. Alternatively, within the SRS transmission bandwidth, the UE may map the first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port of the 8 antenna ports to every K REs using the configured comb offset (k), and map the second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port of the 8 antenna ports to every K REs using the comb offset (k+1) modulo K.

[0031] In some embodiments, the comb tooth value K may be 4. Within the SRS transmission bandwidth, the UE may use the configured comb tooth offset (k) to map the first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port of the eight antenna ports to every K REs, and use the comb tooth offset (k+2) modulo K to map the second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port of the eight antenna ports to every K REs.

[0032] In some embodiments, the comb tooth value K may be 8. The UE may use the configured comb tooth offset (k) to map the first antenna port and the fifth antenna port among the 8 antenna ports to every K REs, use the first comb tooth offset (k+2) modulo K to map the second antenna port and the sixth antenna port among the 8 antenna ports to every K REs, use the second comb tooth offset (k+4) modulo K to map the third antenna port and the seventh antenna port among the 8 antenna ports to every K REs, and use the third comb tooth offset (k+6) modulo K to map the fourth antenna port and the eighth antenna port among the 8 antenna ports to every K REs.

[0033] According to an embodiment, a UE receives a configuration of a sounding reference signal (SRS) resource including 8 antenna ports and a time division multiplexing (TDM) parameter, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource from a network device. The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a comb offset k. k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. The SRS resource is mapped to m consecutive orthogonal frequency division multiplexing (OFDM) symbols in the same time slot. m is greater than or equal to 1. The UE maps each of the m consecutive OFDM symbols to a corresponding subset of the 8 antenna ports according to m and s. s is determined according to the TDM parameters and is the number of subsets of the 8 antenna ports. The UE sends an SRS to the network device using the 8 antenna ports according to the mapping.

[0034] In some embodiments, the UE may map an i-th subset of 8 / s antenna ports among the 8 antenna ports to every s OFDM symbols among the m consecutive OFDM symbols, starting from the i-th OFDM symbol among the m consecutive OFDM symbols, where i is 1 to s.

[0035] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same comb offset allocation and the same CS position.

[0036] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same physical resource block (PRB) allocation.

[0037] In some embodiments, the SRS transmission on the m consecutive OFDM symbols may be periodic, semi-static or aperiodic. The SRS transmission may be based on an SRS counter determined by s*R. R is a repetition factor configured for the SRS resource.

[0038] In some embodiments, m may be a multiple of s.

[0039] According to an embodiment, a network device sends a configuration of a sounding reference signal (SRS) resource including 8 antenna ports, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource to a user equipment (UE). The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a configured comb offset (k). k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. Each of the 8 antenna ports is mapped to a corresponding CS and a corresponding resource element (RE) in the frequency domain. The corresponding RE is a subset of multiple REs, located on every K REs within the SRS transmission bandwidth, and has an offset based on the configured comb offset (k). The network device receives an SRS from the UE.

[0040] In some embodiments, the corresponding RE may be located in an orthogonal frequency division multiplexing (OFDM) symbol.

[0041] In some embodiments, the usage of the SRS resources may be set to "codebook" or "antenna switching".

[0042] In some embodiments, the comb value K is 2, and the 8 antenna ports can be mapped to every K REs using the configured comb offset (k) within the SRS transmission bandwidth. Alternatively, within the SRS transmission bandwidth, the first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port among the 8 antenna ports can be mapped to every K REs using the configured comb offset (k), and the second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port among the 8 antenna ports can be mapped to every K REs using the comb offset (k+1) modulo K.

[0043] In some embodiments, the comb value K is 4. The first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port among the 8 antenna ports can be mapped to every K REs using the configured comb offset (k). The second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port among the 8 antenna ports can be mapped to every K REs using the comb offset (k+2) modulo K within the SRS transmission bandwidth.

[0044] In some embodiments, the comb value K is 8. The first antenna port and the fifth antenna port among the 8 antenna ports can be mapped to each K RE using the configured comb offset (k). The second antenna port and the sixth antenna port among the 8 antenna ports can be mapped to each K RE using the first comb offset (k+2) modulo K. The third antenna port and the seventh antenna port among the 8 antenna ports can be mapped to each K RE using the second comb offset (k+4) modulo K. The fourth antenna port and the eighth antenna port among the 8 antenna ports can be mapped to each K RE using the third comb offset (k+6) modulo K.

[0045] According to an embodiment, a network device sends a configuration of a sounding reference signal (SRS) resource including 8 antenna ports and time division multiplexing (TDM) parameters, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource to a user equipment (UE). The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a comb offset k. k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. The SRS resource is mapped to m consecutive orthogonal frequency division multiplexing (OFDM) symbols in the same time slot. m is greater than or equal to 1. Each of the m consecutive OFDM symbols is mapped to a corresponding subset of the 8 antenna ports according to m and s. s is determined according to the TDM parameters and is the number of subsets of the 8 antenna ports. The network device receives an SRS from the UE.

[0046] In some embodiments, the UE may map an i-th subset of 8 / s antenna ports among the 8 antenna ports to every s OFDM symbols among the m consecutive OFDM symbols, starting from the i-th OFDM symbol among the m consecutive OFDM symbols, where i is 1 to s.

[0047] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same comb offset allocation and the same CS position.

[0048] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same physical resource block (PRB) allocation.

[0049] In some embodiments, the SRS transmission on the m consecutive OFDM symbols may be periodic, semi-static or aperiodic. The SRS transmission may be based on an SRS counter determined by s*R. R is a repetition factor configured for the SRS resource.

[0050] In some embodiments, m may be a multiple of s.

[0051] In some embodiments, m may be one of 2, 4, 8, 10, 12, or 14. s may be 2. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The structure and use of the disclosed embodiments will be discussed in detail below. It should be understood that in order to more fully understand the present disclosure and its advantages, reference is made to the following description in conjunction with the accompanying drawings, in which:

[0053] Figure 1 An exemplary communication system provided by some embodiments is shown;

[0054] Figure 2 An exemplary communication system provided by some embodiments is shown;

[0055] Figure 3 An example of RE / PRB skipping within one hop is shown;

[0056] Figure 4A An example of hopping regarding SRS orthogonality and SRS collision is shown;

[0057] Figure 4B An example of a transition on SRS orthogonality is shown;

[0058] Figure 4C An exemplary effect of complementary CS hopping is shown;

[0059] Figure 5A and Figure 5B The TRP common SRS method and TRP specific SRS method provided by some embodiments are shown;

[0060] Figure 6 An exemplary communication system is shown;

[0061] Fig. 7A and Figure 7B Exemplary devices that can implement the methods and guidance provided by the present disclosure are shown;

[0062] Figure 8 A block diagram of a computing system provided by some embodiments that can be used to implement the devices and methods disclosed herein is shown;

[0063] Fig. 9The use of carrier aggregation (CA) provided by some embodiments is shown;

[0064] Fig. 10A shows exemplary physical layer channels and signals provided by some embodiments;

[0065] Fig. 10B Some embodiments provide for multiplexing signals / channels for more than one PDSCH;

[0066] Fig. 10C An example of a non-zero power (NZP) CSI-RS for channel estimation and interference measurement provided by some embodiments is shown;

[0067] Fig.11A A flowchart of a method performed by a network device provided by some embodiments is shown;

[0068] Fig. 11B A flowchart of a method performed by a UE provided in some embodiments is shown;

[0069] Fig. 11C A flowchart of a method performed by a UE provided in some embodiments is shown;

[0070] Fig.11D A flowchart of a method performed by a UE provided in some embodiments is shown;

[0071] Fig.11E A flowchart of a method performed by a network device provided by some embodiments is shown;

[0072] Fig.11F A flowchart of a method performed by a network device provided by some embodiments is shown;

[0073] Fig. 12A The CDF of the path loss difference is shown;

[0074] Fig. 12B The channel estimation performance under received power imbalance and orthogonal / non-orthogonal SRS is shown;

[0075] Fig.13 The SRS performance when the same SRS sequence (cyclic shift interval is 1 or 2) or different SRS sequences (cyclic shift interval is 0 or 2) are shown;

[0076] Fig.14 The SRS performance of the SRS port through CDM is shown when the CDL-C 300ns channel and the cyclic shift interval is 1, 2 or 3;

[0077] Fig.15The SRS performance for orthogonal ports, fully colliding ports, and partial collisions with weaker interfering ports is shown;

[0078] Fig.16 The SRS performance of cyclic shift hopping of the SRS port through CDM in the CDL-C 300ns channel is shown;

[0079] Fig.17 The SRS performance of cyclic shift hopping of the weaker interfering port is shown;

[0080] Fig.18 Performance evaluation of one UE using CS 0 and performance evaluation of another UE using CS 1 / f are shown.

[0081] Unless otherwise indicated, corresponding numerals and symbols in the different figures generally refer to corresponding parts. These figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0082] The making and use of the disclosed embodiments will be discussed in detail below. However, it should be understood that the concepts disclosed herein can be embodied in a variety of specific contexts, and the specific embodiments discussed herein are merely illustrative and are not intended to limit the scope of the claims. In addition, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0083] The configuration of SRS related parameters (e.g., SRS transmission port, SRS transmission bandwidth, SRS resource set, transmission comb and cyclic shift, etc.) of the SRS to be transmitted in the uplink is semi-static in nature and can be provided through high-layer signaling such as radio resource control (RRC) signaling. A more dynamic technique is needed to indicate such configuration to better associate SRS parameters (e.g., SRS transmission bandwidth and / or port) with physical data shared channel (PDSCH) parameters. In addition, the association between downlink reference signals such as channel state information reference signal (CSI-RS) or demodulation reference signal (DMRS) and uplink SRS should be communicated to the UE to accurately reflect the interference situation and perform optimal beamforming. Therefore, there is a need for an apparatus and method for transmitting control information that accurately indicates a more dynamic configuration (e.g., not semi-static) of the above parameters, for example, a portion of the transmission bandwidth required to transmit a subset of SRS resource sets using a subset of transmission ports associated with a specific set of downlink reference signals (thereby implicitly indicating the transmission comb and cyclic shift). The transmission of control information can be closely linked to the actual data transmission. The transmitted SRS can be a periodic SRS configured by layer 3 RRC configuration signaling (e.g., periodic SRS (P-SRS or PSRS)), a semi-static SRS activated / deactivated by a layer 2 medium access control (MAC) control element (CE), or an aperiodic SRS indicated by layer 1 downlink control information (DCI) in a PDCCH (i.e., an aperiodic SRS (A-SRS, AP-SRS, A SRS, or AP SRS)).

[0084] Figure 1An exemplary communication system 100 provided by an embodiment is shown. The communication system 100 includes an access node 110 having a coverage area 101. The access node 110 serves user equipment (UE), for example, UE 120. In a first operating mode, communications to and from the UE pass through the access node 110 having the coverage area 101. The access node 110 is connected to a backhaul network 115 in order to connect to the Internet and perform operations and management, etc. In a second operating mode, communications to and from the UE do not pass through the access node 110, however, the access node 110 typically allocates resources for communication to the UE when certain conditions are met. Communications between a pair of UEs 120 may use a sidelink connection (shown as two separate unidirectional connections 125). In Figure 1 In the embodiment, the sidelink communication is performed between two UEs operating in the coverage area 101. However, the sidelink communication can generally be performed in the following situations: both UEs 120 are outside the coverage area 101; both UEs are inside the coverage area 101; or one UE is inside the coverage area 101 and the other UE is outside the coverage area 101. The communication between the UE and the access node pair is performed through a unidirectional communication link, wherein the communication link between the UE and the access node is called an uplink 130, and the communication link between the access node and the UE is called a downlink 135.

[0085] Access nodes may also be generally referred to as NodeB, evolved NodeB (eNB), next generation (NG) base station (NG NodeB, gNB), master eNB (MeNB), secondary eNB (SeNB), master gNB (MgNB), secondary gNB (SgNB), network controller, control node, base station, access point, transmission point (TP), transmission-reception point (TRP), cell, carrier, macro cell, femto cell, pico cell, etc., and UE may also be generally referred to as mobile station, mobile phone, terminal, user, subscriber, site, etc. The access node can provide wireless access according to one or more wireless communication protocols, such as third generation partnership project (3GPP) long term evolution (LTE), advanced LTE (LTE-A), 5G, 5G LTE, 5G NR, future communication system, high speed packet access (HSPA), IEEE 802.11 series standards such as 802.11a / b / g / n / ac / ad / ax / ay / be, etc.

[0086] A cell may include one or more bandwidth parts (BWP) of UL or DL ​​allocated to a UE. Each BWP may have its own BWP-specific parameter set (numerology) and configuration, for example, the bandwidth of the BWP. It should be noted that for the UE, it is not necessary for all BWPs to be activated at the same time. A cell may correspond to one carrier, and in some cases, may also correspond to multiple carriers. Typically, a cell (e.g., a primary cell (PCell) or a secondary cell (SCell)) is a component carrier (e.g., a primary component carrier (PCC) or a secondary CC (SCC)). For some cells, each cell may include multiple UL carriers, one carrier may be referred to as a UL carrier with an associated DL or a non-supplementary UL (non-SUL or simply UL) carrier, while other carriers are referred to as supplementary UL (SUL) carriers without associated DL. A cell, or carrier, can be configured with a time slot or subframe format including DL symbols and UL symbols, and the cell or carrier can be regarded as operating in time division duplex (TDD) mode. Generally speaking, for non-paired spectrum, the cell or carrier is in TDD mode, and for paired spectrum, the cell or carrier is in frequency division duplex (FDD) mode. The transmission time interval (TTI) generally corresponds to a subframe (in LTE) or a time slot (in NR). The access node can provide wireless access according to one or more wireless communication protocols, such as long term evolution (LTE), advanced LTE (LTEadvanced, LTE-A), 5G, 5G LTE, 5GNR, future 5G NR versions, future communication systems, high speed packet access (HSPA), Wi-Fi802.11a / b / g / n / ac, etc. For simplicity, Figure 1 Only one access node and two UEs are shown in FIG. However, it can be understood that the communication system may adopt multiple access nodes (or base stations) capable of communicating with multiple UEs.

[0087] In standard antenna element-to-element channel estimation, the channel between two devices is estimated by having the first device send a known signal to the second device on a known time or frequency domain resource. The signal received by the second device can be expressed as:

[0088] y=Hx+n (1)

[0089] Wherein, y is the signal received by the second device, x is a known signal (which may be a reference signal, a pilot or a pilot signal), H is a channel model or response, and n is noise (interference for some communication channels). Since the second device knows x, the second device can determine or estimate H based on y.

[0090] It should be noted that the concepts of antenna, antenna element, and antenna port are generally interchangeable, but in some specific scenarios, they may represent different but related entities. For example, a transmit (Tx) antenna port can be composed of multiple antenna elements or antennas (or virtualized), and the receiver only sees this one Tx antenna port, but not each of the multiple antenna elements or antennas. For example, virtualization can be achieved through beamforming.

[0091] Figure 2 An exemplary communication system 200 is shown and a mathematical representation of signals transmitted in the communication system is provided. The communication system 200 includes an access node 205 communicating with a UE 210. Figure 2 As shown, access node 205 uses transmit filter v and UE 210 uses receive filter w. Both access node 205 and UE 210 use linear precoding or combining. Assume H is the N of the multiple-input multiple-output (MIMO) system. rx ×N tx Matrix, that is, there exists N tx transmit antennas and N rx N receiving antennas. tx The transmit filter v of dimension ×Ns enables the transmitter to precode or beamform the transmit signal, where Ns is the number of transmitted layers, streams, symbols, pilots, messages, or known sequences. The receive filter w in a multi-antenna system has dimension N rx ×Ns, represents the merging matrix. It should be noted that the above description is for the transmission from the access node 205 to the UE 210, that is, the downlink transmission. The transmission can also be carried out in the opposite direction (uplink transmission), in which case the channel matrix becomes H H , which is the Hermitian matrix of the channel model H, w can be regarded as a transmit filter, and v can be regarded as a receive filter. The w used for transmission and the w used for reception can be the same or different, and the same is true for v.

[0092] The downlink (or forward) channel 215 between the access node 205 and the UE 210 has a channel model or response H, and the uplink (or backward or reverse) channel 220 between the UE 210 and the access node 205 has a channel model or response H. H , which is the Hermitian matrix of the channel model H. Although Figure 2 Only one access node and one UE are described, but this is not limited to this case. The access node can serve multiple UEs on different time-frequency resources (e.g., frequency division multiplexing (FDM)-TDM, as in a typical cellular system), or serve multiple UEs on the same time-frequency resources (e.g., multi-user (MU)-MIMO, in which multiple UEs are paired together and each UE is precoded separately). There is intra-cell interference between paired UEs. In addition, there may be multiple access nodes in the network, some of which can collaboratively serve UE 210 through joint transmission (joint transmission, JT) mode (e.g., coherent joint transmission (CJT), non-coherent joint transmission (NCJT), coordinated multi-point transmission, etc.), dynamic point switching mode, etc. Some other access nodes may not serve UE 210, and the transmission of these access nodes to other UEs will cause inter-cell interference to UE 210. The scenario considered and analyzed herein is a scenario of multiple access nodes and multiple UEs, in which the access nodes cooperatively serve the UEs and use MU-MIMO, and the exemplary embodiments of bidirectional training are applicable to such a scenario.

[0093] The purpose of UE sending SRS includes the acquisition of downlink (DL) channel state information (CSI) (by using "antenna switching" to support DL CJT / NCJT / single TRP transmission) and uplink (UL) CSI (by using "codebook" or "noncodebook"), and sometimes also includes timing advance (TA) / UL PC adjustment. (In some optional embodiments, beam management can also be included in frequency range 2 (FR2), but not applicable to FR1). In general, the UE may need to send SRS to each TRP serving the UE. Considering the limited UL time slots / orthogonal frequency-division multiplexing (OFDM) symbols in time division duplex (TDD) networks, this will lead to serious SRS interference problems (if some SRS are not orthogonal) and / or SRS capacity problems (if some SRS are orthogonal). Therefore, one of the goals is to manage cross-SRS interference between TRPs through SRS capacity enhancement and / or reduce the interference impact through interference randomization.

[0094] The protocol in RAN1#109-e records many potential SRS enhancements. Some of these enhancements have been proposed or discussed in earlier 3GPP documents, including some enhancements in the Rel-18 RAN plenary discussion and some enhancements in the Rel-17 enhancements regarding SRS flexibility, coverage, and capacity in Rel-17 further enhanced MIMO (FeMIMO). This disclosure will discuss the potential enhancements in the protocol one by one.

[0095] Before discussing the details, a general issue may be discussed first. Some potential enhancements are aimed at achieving SRS interference randomization, and if not designed / implemented properly, the existing orthogonality between different SRS may be lost due to randomization. For example, SRS1 and SRS2 are orthogonal according to the current mechanism (e.g., code division multiplexed (CDMed) or frequency division multiplexed (FDMed)), but if additional code domain randomization and / or frequency domain randomization is adopted, they may conflict on some resources. In the present disclosure, such conflicts can be avoided by appropriate design (e.g., hopping in the same manner) and / or appropriate implementation (e.g., gNB coordination). That is, enhancements to SRS interference randomization should not prevent the gNB from configuring orthogonal SRS. These enhancements are further described in detail below.

[0096] Depending on the design / implementation, some SRS interference randomization enhancement schemes may cause collision / loss of orthogonality of originally orthogonal SRSs multiplexed via FDM / CDM.

[0097] In some embodiments, the enhancement scheme for SRS interference randomization does not prevent the gNB from configuring orthogonal SRS.

[0098] Randomized frequency domain resource mapping for SRS transmission has been proposed, and some examples are documented in the protocol (eg, further enhancements to frequency hopping (FH), comb hopping).

[0099] SRS FH has been defined in Rel-15 and enhanced in Rel-17 through RB-based partial frequency sounding (RPFS). Some exemplary enhancements are discussed below, and further enhancements to FH based on RPFS will be described in the RPFS section of this disclosure.

[0100] SRS FH can be based on including C SRS , B SRS , b hop 、n shift and n RRC The FH design may be very sophisticated, and in some embodiments, it is recommended to only add FH enhancements based on the existing FH mode without changing the existing parameters / equations / modes. For example, it may not be desirable to change the N-based FH design by changing the number of PRBs in a hop. b Value or m SRS,bHowever, it is possible to consider adding more rows to Table 6.4.1.4.3-1 (SRS bandwidth configuration) of TS 38.211 to support more N b value, you can also consider the existing m SRS,b The value reduces the number of physical RBs (PRBs) or resource elements (REs).

[0101] Table 6.4.1.4.3-1 in TS 38.211 (SRS bandwidth configuration, including C SRS , B SRS 、m SRS,b 、N b ) More rows can be added so that at the same maximum detection bandwidth m SRS,0 Under, support more N b values, and the gNB can select from these values ​​to obtain better randomization results. For example, when m SRS,0 =40, there is only one row, so there is only one N1 value (N1=2), but when C SRS >63, more rows can be added for the maximum detection bandwidth to support N1 = {4, 5, 10}, etc., and new N2 and N3 values ​​can be defined accordingly. Similarly, when N b >3, more columns can be added to the right side of the table, mainly to correspond to the new rows added. Existing definitions of parameters and equations do not need to be changed.

[0102] The extended table 6.4.1.4.3-1 is fully backward compatible, relatively simple, and easy to support through the existing signaling and operating framework.

[0103] Some REs or PRBs can be skipped within the current detection bandwidth of one hop, and the skipping method can be different on different hops to improve the degree of randomization. To prevent the peak-to-average power ratio (PAPR) from increasing, the skipped REs can be evenly distributed in frequency (basically using new comb values; described below) or located on the edge of the FH bandwidth, while the skipped PRBs should be located on the edge of the FH bandwidth. For example, in one hop, the gNB can instruct the UE to skip x PRBs at the bottom edge, and in the next hop, the gNB can instruct the UE to skip y PRBs at the top edge and y PRBs at the bottom edge, and so on. The gNB can also instruct the UE to skip half of the PRBs, and so on, which is similar to the RPFS described later in the RPFS section.

[0104] The implication of RE / PRB skipping is that SRS-based channel estimation cannot assume the existence of a uniform pattern in the time / frequency domain (ie, at some times, according to the previous mechanism, SRS samples are not available on some REs carrying SRS). Figure 3 An example of RE / PRB skipping within a hop is shown (taking three transmission opportunities 302, 304 and 306 as an example), showing that SRS samples are not available on some REs in some transmission opportunities. This skipping may affect the design and performance of the channel estimation filter. However, since the bandwidth per hop is narrowed due to RE / PRB skipping, the SRS power of each RE can be increased to compensate for the performance loss. In addition, due to RE / PRB skipping, the SRS sequence will become shorter, which may have a certain impact on the orthogonality of code domain resources and can be further studied. When skipping SRS on some RE / PRBs, the SRS sequence can still use a partial sequence according to the previous mechanism instead of using a shorter sequence, which can help multiplex with SRS that may overlap with the SRS.

[0105] Comb hopping has been proposed before. This disclosure describes enhancements to comb hopping and comb offset hopping.

[0106] Comb hopping may refer to using a comb tooth (e.g., 2) at the first SRS transmission opportunity of the SRS resource, and using a different comb tooth (e.g., 8) at the second SRS transmission opportunity. In this way, over time, SRS interference appears on some REs in some OFDM symbols, but does not appear continuously in all SRS OFDM symbols, thereby achieving (pseudo) randomization in the frequency domain.

[0107] To support comb hopping, a comb hopping sequence (e.g., {2, 4, 8, 2, 4, 8, ...}) can be defined. An existing pseudo-random sequence including integer values ​​can be reused in the following way: for example, for each integer value in the sequence, a 2 mod(x ,3)+1 to transform.

[0108] In order to ensure that the SRS transmissions via CDM still maintain orthogonality, it may be necessary to configure the same comb hopping sequence for the SRS via CDM. Other methods can also be used to maintain CDM orthogonality when performing comb hopping.

[0109] Similar to pseudo-random RE / PRB skipping within a hop, when comb hopping is performed, the receiver performing channel estimation based on SRS cannot assume the existence of a uniform pattern in the time / frequency domain (i.e., at some times, SRS samples are not available on some REs). This may affect the channel estimation filter design and performance.

[0110] The comb offset hopping may refer to using a comb offset (e.g., 0) at the first SRS transmission timing of the SRS resource and using a different comb offset (e.g., 1) at the second SRS transmission timing. In this way, over time, the SRS interference changes from K TC Move between REs (K TC are the configured transmission comb teeth), thereby achieving (pseudo) randomization in the frequency domain.

[0111] To achieve this, a comb offset hopping sequence can be used. For SRS resources configured for positioning purposes (using IESRS-PosResource), a comb offset hopping sequence can be used. (See the following table in TS 38.211, which defines the offset of the comb offset jump for positioning SRS resources ) enables comb offset hopping over multiple OFDM symbols within a timeslot, but this mechanism does not apply to SRS resources that are not configured for positioning purposes.

[0112]

[0113]

[0114] This exemplary mechanism may be standardized and / or configured for SRS resources that are not configured for positioning purposes. However, if supported, the gNB may enable this exemplary mechanism with careful planning between multiple multiplexed SRS transmissions to avoid collisions of SRS on the same REs in some OFDM symbols. For example, some 2-symbol 4-port SRS may be multiplexed with 4-symbol 4-port SRS that overlap on the last 2 OFDM symbols in a slot according to FDM with different comb offsets. Thus, when the 2-symbol 4-port SRS hops using the pattern {0,2} and the 4-symbol 4-port SRS hops using the pattern {0,2,1,3}, these SRS may sometimes occupy the same comb offset on some OFDM symbols, resulting in collisions and strong interference. The gNB may foresee such collisions and the gNB may configure parameters appropriately to prevent collisions (e.g., SRS occupy the same OFDM symbol and PRB), but with some loss of configuration flexibility. One design to avoid this technical problem could be to assign the hopping sequence backward in time in the OFDM symbol, since most SRS occupy the last few OFDM symbols within a slot. Alternatively, the offset value sequence could be based on the absolute symbol position, which is common to all UEs. Alternatively, the gNB could configure some skip pattern to the same pseudo-random sequence so that different SRS are aligned with their offsets.

[0115] Similarly, a comb offset hopping sequence may also be defined between multiple time slots. More details and several embodiments are provided below.

[0116] a. Hopping pattern (e.g., pseudo-random sequence, time domain granularity of hopping)

[0117] The hopping pattern of the additional comb offset values ​​(in addition to the comb offset value combOffset configured by RRC) can be based on the comb offset hopping sequence This sequence can reuse 12 OFDM symbols and a positioning SRS hopping sequence of comb 4 (e.g., {0,2,1,3,0,2,1,3,0,2,1,3}), as shown in Table 6.4.1.4.3-2 of TS 38.211. A limitation of this approach is that more OFDM symbol allocations are supported than those in the table, e.g. It can be 10 or 14. Therefore, some generalization may be needed (e.g., the sequence can be obtained by truncating a longer sequence (preferably if applicable) or cyclically extending a shorter sequence). For example, for 10 OFDM symbols, truncating the sequence of 12 OFDM symbols will result in {0,2,1,3,0,2,1,3,0,2}; for 14 OFDM symbols, cyclically extending the sequence of 12 OFDM symbols will result in {0,2,1,3,0,2,1,3,0,2,1,3,0,2}. Another limitation is that the hopping pattern is limited to within a time slot and not between time slots.

[0118] Another way to define the hopping pattern is to reuse the widely adopted binary pseudo-random sequence c(i). This approach can be used if more OFDM symbol allocations are supported, and can cover intra-slot hopping and / or inter-slot hopping. Denote the system frame number (SFN) of the radio frame as n f , the time slot index in the wireless frame is represented as The OFDM symbol index in the time slot is represented as l, the SRS starting symbol index in the time slot is represented as l0, and the SRS symbol index relative to the starting symbol is represented as l'. is expressed as the number of time slots in a radio frame, and It is expressed as the number of OFDM symbols in a time slot. The equation for determining the starting position of the SRS frequency domain without hopping (traditional behavior) is The equation for determining the SRS frequency domain starting position in the presence of hopping will have an additional term (e.g., ),in, is the additional comb offset value. For example, if the comb offset needs to jump between 2 values, then The c(i) sequence can also support switching between more values. For example, for M values, the offset can be (or ). M values ​​may be used for comb 2 (M=2), comb 4 (M=4), and comb 8 (M=8), or for comb offset hopping with a subset configured for hopping restrictions (e.g., comb 8 with a subset of [1,5,6], M=3). In addition, if SFNn0 is a reinitialization instance and the current SFN is n f , then in the above formula, we can use Go to replace If every n I Each radio frame needs to be reinitialized once, and the current SFN is n f , then in the above formula, we can use These formulas can also be applied to the cyclic shift hopping described below. If the non-periodic SRS is expected to have greater randomness, the SRS counter n SRS can be used as a parameter in c(i), but this may lead to occasional conflicts with other SRS.

[0119] b. Time domain parameters and / or behaviors (e.g., slot index, symbol index, reinitialization behavior)

[0120] If only intra-slot hopping needs to be supported, only the symbol index l′ is required, which is similar to the case of positioning SRS.

[0121] If it is necessary to support intra-slot hopping and inter-slot hopping, then the slot index, symbol index, and possibly the SRS counter may be used.

[0122] In the existing sequence / group hopping using a pseudo-random sequence c(i), the pseudo-random sequence may be used at the beginning of each radio frame Initialize at the beginning of each radio frame. This can be reused for comb offset hopping. Reinitialization at the beginning of each radio frame helps ensure that the newly multiplexed SRS can be aligned with the existing multiplexed SRS in terms of c(i) values, so that these SRS can remain orthogonal over time. Therefore, reinitialization can be maintained, but can be extended to be initialized at the beginning of the radio frame based on the system frame number (SFN).

[0123] c. Network configuration ID for UE specific initialization

[0124] SRS sequence identifier By SRS-Resource IE (in this case, ) or SRS-PosResource-r16 IE (in this case, ). This is already used to determine the SRS sequence and UE-specific initialization for sequence / group hopping and can be reused here. Alternatively, another ID for comb offset hopping can also be introduced to achieve greater flexibility and randomness, so that SRS inside and outside the CJT transmission area can be jumped / behaved in different ways even if they happen to be assigned the same sequence / sequenceId.

[0125] d. How to determine the comb offset value for each SRS port in an SRS resource through parameters for an SRS transmission timing

[0126] For different SRS ports in one SRS resource, they can be associated with the same additional comb offset value at each transmission to avoid collision on the same comb offset (ie, RE) and the same cyclic shift (at least corresponding to comb 8) and reduce complexity. The additional comb offset value at each transmission can be determined by the above method (e.g., according to the positioning SRS method or according to the c(i) sequence with a network configuration ID for UE-specific initialization).

[0127] e. Potential issues with multiplexing with legacy UEs if comb offset hopping is enabled

[0128] When legacy UEs and new UEs with comb offset hopping enabled are multiplexed on the same PRBs and OFDM symbols, the new UE may hop to the comb offset assigned to the legacy UE, resulting in a conflict. This situation should be avoided (e.g., by performing FDM on different PRBs or implementing TDM by the gNB). It is also possible to perform FDM on different REs of the same PRB by excluding some comb offset values ​​for comb offset hopping. For example, if a legacy UE occupies comb offset 0 on a PRB shared with the new UE, the new UE should not hop to comb offset 0, but only to comb offsets 1, 2, and 3 configured via RRC. Use This can then be easily achieved by mapping to the set of additional allowed comb offset values.

[0129] In any case, when one SRS port uses comb offset hopping, it should not completely collide with another SRS port using the same cyclic shift of the same UE or different UE through FDM by hopping to the same comb offset (i.e. RE), because this will cause severe interference between the orthogonal SRS ports, rendering both ports unusable. Therefore, if comb offset hopping is enabled for a set of SRS ports that use the same cyclic shift and occupy overlapping time-frequency resources, these SRS ports should be configured with the same hopping pattern, the same ID for comb offset hopping, the same reinitialization, and the same time domain behavior and resource allocation (unless the hopping pattern is designed to depend only on the frame / time slot / OFDM symbol position and not on UE-specific parameters). For any SRS port that may transmit on the same RE, they need to be CDMed, that is, they need to have the same SRS sequence but different cyclic shift values.

[0130] f. Applicable to periodic / semi-static / aperiodic SRS

[0131] The comb offset hopping should be applicable to periodic / semi-persistent / aperiodic SRS. The above hopping pattern design depends on the OFDM symbol position within the time slot / radio frame, which ensures that any SRS multiplexed in an orthogonal manner remains orthogonal, regardless of whether the SRS transmission is periodic (P) / semi-persistent (SP) / aperiodic (AP) SRS transmission. Therefore, in order to enhance the SRS interference randomization advantage, it is desirable to apply the comb offset hopping / cyclic shift hopping to the use of AP / P / SP SRS and all SRS.

[0132] In general, several randomized frequency domain resource mapping enhancements for SRS transmission can be considered. The limitation of these enhancements may be that they need to ensure that potential conflicts may occur when SRS transmission occupies some REs that are not allocated according to traditional standards. Although potential conflicts can be avoided with proper gNB implementation, the complexity may be higher and the configuration flexibility may be reduced. Another aspect that needs to be studied is the uneven time / frequency domain SRS samples caused by hopping and randomization, which may affect SRS-based channel estimation.

[0133] For randomized frequency domain resource mapping for SRS transmission, the present disclosure describes adding more rows / columns in Table 6.4.1.4.3-1 (SRS bandwidth configuration) in TS 38.211; performing pseudo-random RE / PRB skipping within one hop, and its potential impact due to uneven time / frequency domain SRS samples and potential impact on the minimum SRS sequence length; comb tooth hopping using comb tooth values ​​according to a pseudo-random sequence, and its potential impact on multiple multiplexed SRSs and potential impact due to uneven time / frequency domain SRS samples; performing comb tooth offset hopping based on a comb tooth offset value obtained according to a pseudo-random sequence, and its potential impact on multiple multiplexed SRSs; randomized code domain resource mapping for SRS transmission.

[0134] Randomized code-domain resource mapping for SRS transmission has been proposed before, and the protocol documents some examples (eg, cyclic shift hopping / randomization, sequence hopping / randomization, sequence per hop in a long SRS sequence).

[0135] In existing standards, the mapping between one or more SRS ports and one or more cyclic shifts is fixed and cannot be changed unless the SRS is reconfigured by RRC. Therefore, once two SRSs using one or more identical cyclic shifts collide on one OFDM symbol, these SRSs may collide on other OFDM symbols. In order to improve the randomization of interference between different SRSs sent by different UEs, cyclic shift hopping / randomization can be used.

[0136] To enable cyclic shift randomization / hopping over time, a pseudo-random sequence can be used to introduce one or more additional offsets of one or more current cyclic shifts. When multiple ports in an SRS resource multiplex an RE with different cyclic shifts, current designs provide suitable spacing between these ports (usually spreading them evenly, for example, a 2-port SRS can use cyclic shifts 0 and 4). If a common additional offset is applied to all ports, this spacing can be maintained, which simplifies the design.

[0137] For SRS orthogonalized by CDM, with the same sequence and occupying the same OFDM symbol and PRB, these SRS should be configured with the same cyclic shift hopping sequence, so that these SRS hop in the same way to maintain CDM orthogonality. In other words, all ports / UEs passing through CDM should hop in a pre-coordinated manner to avoid conflicts. One possible approach is that the hopping pattern can be a function of the sequence ID, for example, changing the configured cyclic shift value α0 to ( α 0+(d l+n)s)mod D, where s can be the SRS sequence ID (ranging from 0 to 1023), {d l} is a pseudo-random integer sequence over multiple SRS transmission opportunities, n may be an additional value indicated by the network for further randomization between different cells using a possibly identical sequence, l is the index of the SRS transmission opportunity, and D is the maximum cyclic shift. These SRSs may occupy the same OFDM symbol; otherwise, over time, these SRSs may use different cyclic shift offsets on one OFDM symbol, thereby colliding. Alternatively, the gNB may configure a skip pattern to the same pseudo-random sequence so that different SRSs are aligned with their cyclic shift offsets.

[0138] SRS-based channel estimation for TDD CJT can be enhanced. One direction is to mitigate the negative impact of cross-SRS interference through various randomization / hopping schemes (including CS hopping or randomization). However, CS hopping or randomization may inadvertently cause two SRSs to hop on the same CS value, causing severe interference and rendering the SRS unusable. Therefore, it is desirable to provide a design for CS hopping or randomization so that the SRSs do not collide on the same CS value. Figure 4A An example of hopping with respect to SRS orthogonality and SRS collision is shown. The straight arrow represents the current CS value, while the curved arrow represents the CS hopping from one CS value to the next CS value. When the SRS of UE 2 hops to CS 0, a complete collision occurs.

[0139] Some embodiments take 8 CSs in the present disclosure as an example, which corresponds to SRS comb 2. Other numbers of CSs are also applicable. The design is to be used by the gNB to configure and trigger the UE's SRS, the UE's setting of SRS parameters and corresponding transmission operations, and the gNB's reception and processing of SRS according to the SRS parameters.

[0140] The cyclic shift configuration space includes {0, 1, ..., 6, 7}, and the cyclic shift values ​​are allocated to 0, 7, 6 ..., 2, 1 in a cyclic manner according to existing standard specifications.

[0141] To resolve the CS conflict issue, the gNB configures SRS CS hopping on a subset of CS values. Over time, the UE generates SRS CS values ​​based on the configured subset of CS values, so that the generated CS values ​​do not conflict with the CS value already used by another SRS. For example, in the traditional SRS, the first SRS port is configured with a cyclic shift value of α0.

[0142] In one embodiment of unrestricted CS hopping, the first SRS port is configured with a cyclic shift value of α0, but l =(α0+(dl +n)s)modD to jump, where s is the SRS sequence ID, {d l} is a pseudo-random integer sequence over multiple SRS transmission opportunities, n may be an additional value indicated by the network, l is the index of the SRS transmission opportunity, and D is the maximum cyclic shift.

[0143] In one embodiment of performing CS hopping only on a subset of CS values, first, the first SRS port is configured with a cyclic shift value of α0 and also configured with m possible hopping values ​​(e.g., Figure 4B Then, the first port jumps to the i-th hopping value in the l-th SRS transmission opportunity, where i = α l mod m. Thus, for regular CS hopping, the UE generates a pseudo-random integer sequence and then applies mod 8 (for the example of up to 8 CS values) to obtain its CS value. In this restriction, the UE applies mod 3 (for example) and uses the result to select a CS value from the 3 configured values. The parameters used to generate the pseudo-random sequence are known to both the gNB and the UE, so both the gNB and the UE know which CS value or values ​​to use.

[0144] Restricting the CS hopping prevents complete collisions caused by pseudo-randomized CS hopping, which can result in poor performance. This may be necessary to support CS hopping.

[0145] Other embodiments are described below.

[0146] In one embodiment, each port may be individually configured with a subset of hopping values. Alternatively, all ports in an SRS resource (for codebook / antenna switching) or an SRS resource set (for non-codebook) hop on the configured subset of hopping values.

[0147] In another embodiment, the number of hopping values ​​may be 1 (ie, each port is configured with one CS value). This embodiment may also cover non-hopping situations.

[0148] In yet another embodiment (fractional CS hopping), the hopping value subset may include fractions, e.g., [0, 4 / 3, 5, 7 / 8]. This fraction may further help randomize interference since it does not completely conflict with integer CS values. This also effectively increases the maximum number of CS values. In the above example of [0, 4 / 3, 5, 5 / 6], the gNB may determine the minimum CS interval required for each port multiplexed via CDM based on the delay spread information of each port, and if the delay spread of the port is small, a fractional CS value with a suitable interval with the neighboring ports of the port may be determined and configured to the UE. The fractional CS value is not necessarily associated with CS hopping. In some embodiments, the gNB may configure a fractional CS value for the SRS port of the UE.

[0149] In another embodiment (fractional CS offset), the CS value can be offset by a number, which can be a fraction, which is added to any CS value obtained by the UE according to network signaling and / or calculated using network provided parameters. For example, an offset of 1 / 2 can be configured so that the SRS jumps according to 3, 7, 2, 7, 2, 2, 3, 7, 3... to 3.5, 7.5, 2.5, 7.5, 2.5, 2.5, 3.5, 7.5, 3.5... (i.e., an offset of 1 / 2 is added to any obtained CS value). Integer CS offsets can also be used (for example, at multiple SRS transmission opportunities, CS0 will jump to CS1, CS2... CS7, CS0...). SRS ports passing through CDM can be configured with the same offset so that they can randomize the interference caused to other SRS.

[0150] In yet another embodiment (complementary CS hopping), if a port has a CS value α, and the number of maximum CS values ​​is n, the port hops between α and n-α, which creates a complementary CS hopping pattern (ie, inverted CS assignment).

[0151] When all ports perform the same complementary CS hopping in the case of long delay spread, the interfering port becomes the interfered port and the interfered port becomes the interfering port, thus averaging the SINR and performance of each port. Figure 4C An example is shown where port 1 of UE 1 causes interference to port 2 of UE 2 due to a longer channel response in the delay domain associated with port 1. When the cyclic shift is reversed, the interfering port / interfered port are interchanged, resulting in an interference randomization / averaging effect. Although the figure shows the case where the channel response of a port is longer and extends to the channel samples of another port, the same exemplary design can be used for the case where the channel delay of a port is longer (i.e., shifted to the right) and extends to the channel samples of another port.

[0152] In another embodiment (combined CS hopping), the CS offset and the CS hopping on the CS value subset can be combined, so that all ports passing through CDM will be offset left and right, and on this basis, some ports will have additional hopping patterns. That is, for each SRS transmission opportunity, an offset value will be added to the configured CS value subset.

[0153] In another embodiment, CS hopping can be combined with non-uniform CS allocation. For example, for comb 2 and 2-port SRS, the new mapping can be [CS0, CS4] instead of the traditional cyclic shift mapping [CS0, CS2]. Regions CS0 to CS3 can be regarded as the region where the SRS with longer channel delay is located. Within this region, the ports in the SRS resources can be evenly distributed. Then, for these 2 ports, they can be configured with subsets {CS0, CS1} and {CS2, CS3} respectively for cyclic shift hopping; that is, while achieving interference randomization, these ports still hop within the specified long delay region. This situation can be called intra-region hopping (that is, each SRS resource is configured with a region, and the hopping is performed within the region). In another embodiment, each SRS resource is configured in one of several regions, and the hopping is performed across different regions, which can be called inter-region hopping. In general, depending on the network configuration, intra-region hopping and cross-region hopping can be supported. A region can be a plurality of consecutive cyclic shifts (including wraparound, e.g., cyclic shifts 0 and 7 under comb tooth 2), which can be configured to an SRS resource to determine the cyclic shift position of a port in the SRS resource. For example, if regions CS0 to CS3 are configured to a 2-port SRS resource using comb tooth 2 and α0 is configured to 0, and if the ports are configured uniformly within the region, the two ports are mapped to CS0 and CS2, rather than CS0 and CS4. For another example, if regions CS0 to CS3 are configured to a 2-port SRS resource using comb tooth 2 and α0 is configured to 0, and if the ports are configured non-uniformly within the region, the two ports can be mapped to CS0 and CS1, which is useful when the port has a short delay / delay spread. Other examples combining non-uniform mapping and hopping are also applicable and can be configured by the network as required for implementation.

[0154] In some embodiments, complementary CS hopping and CS offset may be combined.

[0155] In another embodiment, for cyclic shift hopping, the delay domain granularity can be finer than the cyclic shift allocation in the existing standard. For example, for comb tooth 2, there are currently 8 cyclic shifts on RE, and 8 equally spaced cyclic shift points in the delay domain (also referred to as the cyclic shift domain, code domain, cyclic shift configuration space, etc.), and ports are assigned to these cyclic shift points (with or without hopping). If the port can hop between 8K equally spaced points in the delay domain (factor K>1), greater randomness can be achieved. One or more potential values ​​of K can be determined. The larger K is, the greater the randomization advantage, but as the cyclic shift interval becomes narrower, the larger K is, the smaller the randomization advantage is, and the complexity may also increase. A reasonable value may be K=2. For comb tooth 2, since the cyclic shift interval is relatively large compared to comb teeth 4 and 8, K=3 or even K=4 can be used. Then, for the cyclic shift value, in, Each time SRS is transmitted, Randomly selected from .

[0156] 5G NR has supported sequence hopping and sequence group hopping since Rel-15 (6.4.1.4.2 in TS 38.211). The sequence number v can change between different SRS transmission opportunities, roughly speaking, it is initialized with parameter s (SRS sequence ID) and jumps according to a predefined pseudo-random sequence c(i). The generated SRS sequence group number u can jump between 30 values, and the SRS sequence number v can jump between {0,1}. Sequence hopping and sequence group hopping can be enabled as only sequence hopping or only sequence group hopping, but not both.

[0157] Therefore, sequence-level hopping / randomization has been standardized. While it may be straightforward to introduce more hopping patterns for sequence hopping or sequence group hopping (e.g., introducing new parameters or new pseudo-random sequences), it is unclear how much additional gain can be achieved since the current sequence numbers or sequence group numbers are already sufficiently (pseudo-)randomized by s and c(i). A low-complexity enhancement scheme based on existing designs may be to enable sequence hopping and sequence group hopping for the same SRS resources, which improves the level of randomization. That is, if groupOrSequenceHopping specifies both sequence hopping and group hopping, then both sequence hopping and group hopping should be used, where the sequence hopping part follows the hopping rules in sequence hopping only, and the group hopping part follows the hopping rules in group hopping only, i.e.

[0158]

[0159] where the pseudo-random sequence c(i) is defined in Section 5.2.1 and shall be used at the beginning of each radio frame Initialize.

[0160] Some other details and several embodiments of cyclic shift hopping / randomization are provided below. Comb offset hopping and cyclic shift hopping have a lot in common, and most of the exemplary designs provided for one of the hoppings can be applied to the other hopping. Therefore, unless otherwise specified, the embodiments described for one of the hoppings can also be used for the other hopping. Although some embodiments take comb teeth 8 or a maximum cyclic shift of 8 as an example, other comb teeth (e.g., comb teeth 2, comb teeth 4) or maximum cyclic shift numbers are also applicable. Some other embodiments in the present application are described using cyclic shift hopping (including a subset configured for hopping restrictions) as an example, but these embodiments can also be applied to comb offset hopping (including a subset configured for hopping restrictions).

[0161] The hopping pattern may include a pseudo-random sequence, a time domain granularity of the hopping, etc. The hopping pattern of the cyclic shift offset value (based on the cyclic shift value calculated according to the cyclic shift value cyclicShift configured by RRC) can be based on the cyclic shift hopping sequence by reusing the widely adopted pseudo-random sequence c(i). Therefore, the equation for determining the SRS cyclic shift will have an additional term, for example, is the cyclic shift offset value. For example, if the cyclic shift needs to jump between 2 values, then It is also possible to support hopping between more values ​​according to the c(i) sequence. For example, for M values, the offset can be If the aperiodic SRS is expected to have greater randomness, the SRS counter n SRS can be used as a parameter in c(i), but this may lead to occasional conflicts with other SRS.

[0162] For cyclic shift hopping, the delay domain granularity can also be finer than the cyclic shift allocation in the existing standard. For example, for comb tooth 2, there are 8 cyclic shifts on RE, and 8 equally spaced cyclic shift points in the delay domain, and ports are assigned to these cyclic shift points (with or without hopping). If the port can hop between 8K equally spaced points (factor K>1) in the delay domain, greater randomness can be achieved. This is similar to the fractional cyclic shift provided in this application in a sense, but the difference is that for each of the 8 cyclic shift points, not all K sub-sampling points can be fully configured with SRS ports using different fractional cyclic shifts, but only one of the sub-sampling points is occupied at a time. That is, when performing finer granularity cyclic shift hopping, the gNB expects that only one port can occupy any of the K sub-sampling points around each of the 8 cyclic shift points at each transmission.

[0163] The time domain parameters and / or characteristics may include time slot index, symbol index, reinitialization characteristics, etc. When designing the time domain characteristics of the hopping, one of the factors that needs to be considered is the multiplexing orthogonality between multiple SRSs. For SRSs multiplexed according to CDM and / or FDM with different comb offsets, regardless of whether these SRSs are configured with the same or different periods, the same or different numbers of OFDM symbols, the same or different repetition factors, whether they are discarded (for example, due to conflicts), and whether they are triggered non-periodically, these SRSs should remain orthogonal when the hopping is enabled. Taking all these possibilities into account, the present disclosure provides exemplary techniques in which the hopping is related to the frame / time slot / OFDM symbol structure but is independent of any UE-specific configuration / characteristic. For example, based on the OFDM symbol index l and the time slot index within the radio frame The hopping of can be used as the time domain parameter of the hopping, which is similar to the existing sequence hopping / group hopping. This covers intra-time slot hopping and / or inter-time slot hopping. System frame number (SFN) n f It can also be included if the multiplexed SRS resources have the same dependency on SFN, and the multiplexing orthogonality is still maintained.

[0164] The slot index, symbol index and possibly SRS counter can be used for cyclic shift hopping and / or comb offset hopping. In the existing sequence / group hopping using pseudo-random sequence c(i), the pseudo-random sequence should be used at the beginning of each radio frame. Initialize. This can be reused for cyclic shift hopping. Reinitialization at the start of each radio frame helps ensure that the newly multiplexed SRS can be aligned with the existing multiplexed SRS in terms of c(i) values, so that these SRS can remain orthogonal over time. Therefore, the reinitialization can be maintained, but can be extended to be initialized at the start of the radio frame based on the SFN. This is because reinitialization in each radio frame means that the same pattern will appear for every radio frame (20ms), thus limiting the randomization effect. To achieve patterns longer than the radio frame, the UE can initialize at the start of the radio frame based on the SFN (for example, if SFN 0 is set as the time for reinitialization, all hops are aligned to SFN 0, which means that the hopping pattern will only repeat after 1024 radio frames). It is also possible to align to another SFN value, which may need to be known by both the gNB and the UE (for example, through standardization, through RRC configuration, etc.). If the reinitialization / alignment SFN is t, then the additional offset equation can be modified to Among them, n f is the current SFN. It is also possible to reinitialize multiple times between SFN 0 and SFN 1023 (for example, every n I Once for every n radio frames). I The reinitialization is performed once every radio frame (starting from SFN0), and the current SFN is n f , then in the above formula, we can use the term Right now

[0165] The network configuration ID can be used for UE-specific initialization. When determining the network configuration ID for hopping initialization, one of the factors to be considered is still the multiplexing orthogonality between multiple SRSs. The multiplexed SRSs can be configured with the same initialization ID so that these SRSs will not conflict on the same time-frequency resources due to pseudo-random hopping. This may mean that UE-specific IDs such as C-RNTI are not suitable, and even cell IDs are not suitable, unless it is in the scenario of intra-cell CJT, but this scenario has great limitations. Therefore, the present disclosure provides a method that only considers the SRS sequence identifier Or exemplary technology of new ID.

[0166] SRS sequence identifier By SRS-Resource IE (in this case, ) or SRS-PosResource-r16 IE (in this case, ) is given by the high-level parameter sequenceId in . This is already used to determine the SRS sequence and the UE-specific initialization for sequence / group hopping, and can be reused here. However, a possible disadvantage is that all hopping patterns are completely correlated with each other. As an extreme example, suppose the underlying pseudo-random sequence has a stretch of continuous zeros, then any hopping method will not actually hop on the corresponding OFDM symbol, which may be undesirable. Furthermore, if two cells happen to use the same SRS sequence for their UEs, the UE's SRS is likely to hop in the same way, resulting in a lack of sufficient interference randomization.

[0167] Alternatively, another ID for cyclic shift hopping can also be introduced to achieve greater flexibility and randomness, so that SRS inside and outside the CJT transmission area can be jumped / performed in different ways even if they happen to be assigned the same sequence / sequenceId. If both comb offset hopping and cyclic shift hopping are supported, one dedicated ID for comb offset hopping and another dedicated ID for cyclic shift hopping can be supported to achieve better interference randomization.

[0168] In order to determine the cyclic shift value for each SRS port in the SRS resource for the SRS transmission opportunity by the parameter, for different SRS ports in the SRS resource, for simplicity, the SRS port can be associated with the same cyclic shift offset value at each transmission, which also avoids conflicts. The cyclic shift offset value at each transmission can be determined by the above method (e.g., according to the c(i) sequence with the network configuration ID for UE-specific initialization).

[0169] If comb offset hopping is enabled, there are potential issues with multiplexing with legacy UEs. When a legacy UE and a new UE with cyclic shift hopping enabled are multiplexed on the same REs, the new UE may hop to the cyclic shift assigned to the legacy UE, resulting in a conflict. This conflict issue can be avoided (for example, by performing FDM on different PRBs / REs or implementing TDM by the gNB). Code division multiplexing (CDM) can also be performed on the same REs by excluding some cyclic shift values ​​for cyclic shift hopping. For example, if a legacy UE occupies cyclic shift 0 on an RE shared with a new UE, the new UE may not hop to cyclic shift 0, but only to cyclic shifts 1 to 7 configured via RRC. Use This can then be easily achieved by mapping to the set of allowed cyclic shift offset values.

[0170] For SRS orthogonalized by CDM, with the same sequence and occupying the same OFDM symbol and PRB / RE, if cyclic shift hopping is enabled, these SRS should be configured with the same cyclic shift hopping sequence, so that these SRS are hopped in the same way to maintain CDM orthogonality. In other words, if cyclic shift hopping is enabled, all ports / UEs passing through CDM should hop in a pre-coordinated manner to avoid conflicts.

[0171] In any case, when an SRS port uses cyclic shift hopping / randomization, it should not completely conflict with another SRS port over CDM using the same cyclic shift of the same UE or different UE, because this will cause severe interference between the orthogonal SRS ports, rendering both ports unusable. Therefore, these SRS ports over CDM should be configured with the same SRS sequence, the same hopping pattern, the same ID for cyclic shift hopping, the same reinitialization, and the same time domain characteristics and resource allocation (unless the hopping pattern is designed to depend only on the frame / time slot / OFDM symbol position and not on UE specific parameters). The difference between these SRS ports may be the network configured cyclic shift value (i.e. the cyclic shift value when cyclic shift hopping is disabled).

[0172] The cyclic shift hopping can be applicable to periodic / semi-static / aperiodic SRS.

[0173] Here, comb offset hopping and cyclic shift hopping are compared. Regarding the granularity of hopping, for comb offset hopping, in the case of comb 2, SRS can hop at most 2 values, in the case of comb 4, SRS can hop at most 4 values, and in the case of comb 8, SRS can hop at most 8 values. For cyclic shift hopping, if the additional delay domain hopping granularity is not supported, SRS can hop at most 8 values ​​in the case of comb 2, in the case of comb 4, SRS can hop at most 12 values, and in the case of comb 8, SRS can hop at most 6 values. If additional delay domain hopping granularity is supported (factor K>1), SRS can hop at K times more values ​​as described above.

[0174] Regarding multiplexing restrictions, comb offset hopping causes an SRS port to transmit according to multiple comb offset values. However, for each comb offset value, the SRS port should still be orthogonal to any other SRS port through CDM. For example, if an SRS port using comb 8 performs 8 hops on all 8 comb offsets, then all SRS ports on all these REs may have to have the same SRS sequence. This may be a restriction. Cyclic shift hopping does not have such restrictions because it is only performed on the same frequency domain resources.

[0175] Therefore, in general, the hopping granularity of comb offset hopping may be coarser than that of cyclic shift hopping, and the multiplexing restrictions are more. If only one of the hopping is supported, cyclic shift hopping can be used. However, a better approach may be to support both hopping at the same time, thereby providing the network with more SRS interference randomization options. Note that when both hopping are supported, although both hopping can be enabled on the same time-frequency resources to obtain the maximum advantage of interference randomization, in practice, it may be easier to configure the two hopping on non-overlapping time-frequency resources to avoid complex interactions between them. If both hopping are supported, the initialization ID for the hopping method can be configured separately for the two hopping. In any case, it may be necessary to ensure that all SRS on overlapping time / frequency resources adopt the same hopping pattern, and the only difference is the comb offset and / or cyclic shift of the initial configuration of these SRS. Joint hopping in the frequency code domain can also be supported. That is, the comb offset and cyclic shift configured for the joint hopping constitute a two-dimensional resource grid and hop from one grid point to another using a pseudo-random sequence. To avoid collisions within the two-dimensional resource grid due to pseudo-random hopping, all SRS ports configured to hop on the resource grid may use the same hopping / offset pattern, which may limit the additional randomization benefit (if any) compared to separate comb offset hopping and cyclic shift hopping. For simplicity, some embodiments may employ separate hopping.

[0176] For the comb offset hopping of SRS and the randomized code domain resource mapping for SRS transmission through cyclic shift hopping, for each SRS port, the hopping pattern can be intra-slot hopping / inter-slot hopping based on a pseudo-random sequence (e.g., c(i)), and for cyclic shift hopping, the delay domain granularity can be based on the existing cyclic shift or K times the existing cyclic shift. The hopping can be based on the slot index and the symbol index, and reinitialized at the beginning of each radio frame or a radio frame according to the system frame number (SFN). Comb offset hopping / cyclic shift hopping can be supported for new network configuration IDs for UE-specific initialization. When multiplexing with legacy UEs, one or more comb offsets and one or more cyclic shifts used by legacy UEs may not be used for comb offset hopping / cyclic shift hopping. Comb offset hopping / cyclic shift hopping can be applicable to periodic / semi-static / non-periodic SRS.

[0177] To support hopping only on a subset of comb offset values, the following operations may be performed. First, the network configures M possible hopping values ​​(e.g., for comb 8, the subset configured for comb offset hopping of SRS resources is S = [1, 5], i.e., S(0) = 1 and S(1) = 5). In this case, It can be 1 or 5, M = 2. Secondly, the UE performs comb offset hopping on one or more associated SRS ports in the SRS resources in the subset. This equation can ensure that the reused ports will not conflict (i.e., through For example, Alternatively, the above operation may be as follows: First, the network configures M possible hopping values ​​(for example, for comb tooth 8, the subset configured for the comb tooth offset hopping of the SRS resource is S = [1, 5], that is, S (0) = 1, S (1) = 5). In this case, It can be 1 or 5, M = 2. Application Comb offset hopping is performed on one or more associated SRS ports in the SRS resources in the subset. The additional offset (i.e., hopping pattern) is applied to all ports (all ports). i ) are universal. The design and equations for cyclic shift hopping are similar.

[0178] If a port needs to transition between more than 2 values, the binary c(i) sequence may require more operations to generate more than 2 values. For M values ​​in the subset S, the above binary function Can be extended to For example, S can be [1, 5, 6], so M = 3, and the above formula generates a random value of 0, 1, or 2 at each SRS transmission. Then, according to S(0) = 1, S(1) = 5, and S(2) = 6, the additional offset of the hop is The value of is 1, 5 or 6.

[0179] A subset is configured using a new RRC parameter, which includes one or more integer values ​​for the hopping offset. The new RRC parameter includes a list of values ​​in the comb offset / cyclic shift set of the SRS resource. The ordering of the elements in the subset can be designed differently. One method is that the configured subset always includes elements arranged in order from small to large or from large to small, for example, S = {1,5,6}. In one embodiment, the elements are not necessarily sorted in order from small to large or from large to small. The configured subset of comb offset values ​​is ordered, and the UE follows the ordering for mapping. For example, S can be [1,5,6] or [5,1,6], etc., and even if the elements are the same after sorting, they may bring different characteristics. These elements can be unique and different from each other, or they can be the same elements in the subset (for example, S can be [5,1,6,1], and the jumps must use the order given by the subset, that is, S(0) = 5, S(1) = 1, S(2) = 6, S(3) = 1; it can also be [5,1,1,6], etc.). In the latter case, M can be greater than or equal to K TC or However, to limit complexity / overhead, the comb offset hopping or cyclic shift hopping can be limited to K TC or

[0180] In one embodiment, the new RRC parameter for subset configuration includes a bitmap of comb offset / cyclic shift sets. For example, in the case of comb 8, the RRC parameter combOffsetHoppingSubset can be configured by an 8-bit bitmap {0,1,0,0,0,1,1,0}. That is, S = {1,5,6}, S(0) = 1, S(1) = 5, S(2) = 6. The number of elements in S is at most K TC or The elements in a subset are unique and distinct from each other (ie, no duplicates are possible).

[0181] In one embodiment, a subset of the SRS resource is explicitly configured by the traditional parameters cyclicShift and combOffset for cyclic shift hopping and comb offset hopping, respectively. In this case, a new RRC parameter is indicated to enable a hopping subset, and the subset has the same cyclicShift and combOffset values ​​for all SRS ports in the SRS resource. For example, if the SRS resource includes 4 ports, and ports {0,1,2,3} use cyclic shifts {1,3,5,7} respectively, then when the hopping subset is enabled, ports {0,1,2,3} hop on {1,3,5,7}, but not on any other cyclic shift. The RRC signaling overhead and complexity are lower, but the interference randomization advantage may be limited.

[0182] In order to take into account all cases of SRS cyclic shift hopping and comb offset hopping, the following hopping pattern equation can be used. Assume F is SFN, N = 128, S{n} is the (n+1)th element in the set S, then:

[0183] For comb offset transitions, Wherein, if R=1 or the SRS resource is configured with combOffsetHoppingWithRepetition=Per-symbol, then l=l0+l′, or if the SRS resource is configured with combOffsetHoppingWithRepetition=Per-R-Repetition, then l is the OFDM symbol index of the first symbol in the R repetitions;

[0184] If combOffsetHoppingSubset is not configured, S={0,1,…,K TC -1}; otherwise, determine S according to combOffsetHoppingSubset; M = |S|; or

[0185] For cyclic shift transitions, Where, l = l0 + l'; if cyclicShiftHoppingSubset is not configured, then Otherwise, S is determined according to cyclicShiftHoppingSubset; if cyclicShiftHoppingFinerGranularity is not configured, K=1; otherwise, K is determined according to cyclicShiftHoppingFinerGranularity; M=K|S|.

[0186] In one embodiment, the configured comb offset value subset is ordered, and the UE follows the ordering to perform mapping. For example, S can be [1,5,6] or [5,1,6], etc. Even if the elements are the same after ordering, they may bring different characteristics. It can also be the same element in the subset (for example, S can be [5,1,6,1] or [5,1,1,6], etc.).

[0187] For each hop sequence in the long SRS sequence, according to the same base sequence length N ZC (which is a prime number) is the same base sequence that differs only in the cyclic shift The generated SRS are orthogonal at any integer multiple of 12 SRS subcarriers, except that the SRS are usually non-orthogonal. Therefore, when a shorter SRS is multiplexed with a longer SRS, the SRS are usually non-orthogonal. This may cause some problems or limitations. For example, SRS1 is configured with FH and multiplexed with SRS2, SRS1 and SRS2 span multiple hops of PRBs, and the two are not orthogonal to each other; SRS1 is configured with RPFS and multiplexed with SRS2, SRS1 and SRS2 span multiple partially detected PRBs, and the two are not orthogonal to each other.

[0188] These technical problems can be solved by using the same base sequence length N for different SRS ZC The same base sequence To solve this problem, even in the SRS transmission opportunity, due to FH and / or RPFS, the SRS sequence length is longer than N. ZC Then, as long as the overlapping subcarriers are an integer multiple of 12, the SRSs on the overlapping parts are mutually orthogonal. An exemplary technical solution to achieve this is that for FH, the parameter N of the SRS sequence ZC is based on Rather than Generated, and for RPFS, the parameter N of the SRS sequence ZC is based on (for FH) or (for non-FH) instead of In other words, the per-hop sequence or RPFS SRS sequence is extracted from the long SRS sequence.

[0189] One possible problem with this approach is the increase in PAPR. The present disclosure may further discuss the trade-off between higher multiplexing capacity and increased PAPR.

[0190] In some embodiments, for randomized code domain resource mapping for SRS transmission, the present disclosure discusses cyclic shift hopping / randomization based on a pseudo-random sequence to obtain an additional cyclic shift offset value and its potential impact on multiplexing multiple SRSs; combining SRS sequence hopping and sequence group hopping; extracting SRS sequences from long SRS sequences in frequency hopping and / or RPFS and its impact on PAPR.

[0191] Randomized transmission of SRS has been proposed before, for example, pseudo-random muting of SRS transmission for periodic SRS and semi-static SRS. For PSRS or SP SRS, the interference generated by this technique is usually predictable in the time domain, and randomization can be introduced to improve SRS performance. A binary pseudo-random sequence can be introduced, where each bit corresponds to a potential SRS transmission opportunity (before randomization is applied), and SRS is transmitted only when the bit is 1. If more randomness is desired, the pseudo-random sequence can also include some fractional values ​​(between 0 and 1), and only some PRBs are actually detected in the SRS transmission opportunity.

[0192] A possible disadvantage of randomized SRS transmission is that SRS-based channel estimation cannot assume the existence of a uniform pattern in the time / frequency domain (i.e., at some point, SRS samples are not available on some REs. This may affect the channel estimation filter design and performance.

[0193] In some embodiments, for SRS randomized transmission, the present disclosure discusses skipping some SRS transmission opportunities or some PRBs of some SRS transmission opportunities according to a pseudo-random sequence and its potential impact due to non-uniformity of SRS samples in the time domain.

[0194] Some enhancements have been proposed regarding power control of each TRP and / or power control of multiple TRPs by one SRS.

[0195] As described below regarding the path loss difference of TRP common SRS, in the scenario of TRP common SRS, where there is an SRS sent by the UE and used by multiple TRPs for channel estimation, the path loss between the UE and the TRP may differ greatly, which will cause the SRS receive power imbalance of the TRP receiver. In actual scenarios, it is likely that a path loss difference of at least 6dB to 10dB needs to be processed. The path loss difference will cause the receive power imbalance. For example, if there is a 10dB path loss difference, if the TRP common SRS transmission power is set according to the path loss of one TRP, the total receive power imbalance in one TRP may reach about 10dB, or if the TRP common SRS transmission power is set according to the path loss value of two TRPs (for example, according to the average value of the path loss value), the total receive power imbalance dispersed in the two TRPs may reach about 10dB. As to which situation can improve the overall CJT performance, further study is needed.

[0196] However, if it is desired to adjust the SRS transmit power, the standard already provides considerable flexibility. For example, if the gNB wants the SRS to be sent at higher / lower power with a fixed difference, a different P0 can be set. If the gNB wants to change the sensitivity of the SRS transmit power to path loss, the gNB can change the α value. If the gNB wants to change the SRS transmit power in one or more occasions, a TPC command can be sent with each change of power up to –1dB to 3dB.

[0197] If a standardized method is required, there are several embodiments, as described below. It should be noted that the existing SRS power is calculated as follows: P = P0 + α1·PL1 + 10log 10 BW+h, where for simplicity, the maximum value P is not used here and below. cMAX to truncate, but it should be understood that such truncation is considered whenever the power reaches the maximum value. Alpha, PL RS, and closed-loop power control adjustment states are configured for SRS resource sets, and these configurations apply to all SRS resources in the set. This applies to transmissions to one TRP that transmits PL RS. When there are multiple TRPs, it may be necessary to configure multiple SRS resource sets, each corresponding to one TRP, unless the gNB determines that one SRS is sufficient to cover multiple TRPs under TDD CJT. Therefore, in general, M power control processes for M (M≥1) SRS resource sets are required, where each of the M SRS resource sets corresponds to one TRP in the M TRPs. Each of the M power control processes is based on a different UL power control parameter set (P0, alpha, and closed-loop state) associated with a different DL path loss RS. This technical solution may have some disadvantages. First, according to current standards, the number of SRS resource sets is usually at most 2, which may not be enough to support TDDC JT. Increasing the number of SRS resource sets is not a scalable technical solution because it will increase the SRS overhead several times and increase the standard complexity. Secondly, the SRS transmission and the near-far problem of each TRP may cause serious SRS interference. Some embodiments of the present disclosure may not adopt this technical solution.

[0198] In one embodiment, for an SRS resource set, all SRS resources in the SRS resource set use the same power control process, wherein the power control process is based on a P ovalue and a closed-loop state, and are jointly based on more than one DL path loss RS and / or more than one alpha. In other words, for multiple TRPs under TDD CJT, there can still be only one SRS resource set, which may include one or more SRS resources, and the resource set is associated with a power control parameter set applicable to all SRS resources. Each transmission opportunity of any SRS resource in the resource set is for multiple TRPs. In this way, for this embodiment, for the case of 2 TRPs, the SRS power can be P=P0+(α1·PL1+α2·PL2) / 2+10log 10 BW+h,P=P0+(α1+α2)·PL / 2+10log 10 BW+h or P=P0+α·(PL1+PL2) / 2+10log 10 BW+h, where the first power needs to be configured with 2 alphas and 2 path loss RSs, each alpha and each RS is associated with a TRP respectively; the second power is configured with 2 alphas and 1 path loss RS, each alpha is associated with a TRP respectively; the third power is configured with 1 alpha and 2 path loss RSs, each RS is associated with a TRP respectively. The first power seems to better consider the path loss difference of different TRPs and the requirements for fractional power control, so it can be utilized. For more TRPs, this embodiment can be extended to n DL path loss RSs and / or n alphas. All SRS resources in the SRS resource set configured with N DL path loss RSs and N alphas use the same power control process, and the power control is based on

[0199] In another embodiment, for an SRS resource set, a subset of SRS resources in the SRS resource set uses more than one power control process, wherein each power control process is based on a different UL power control parameter set (Po, alpha, and closed-loop state) associated with a different DL path loss RS. In other words, for multiple TRPs under TDD CJT, there can still be only one SRS resource set including multiple SRS resources, one or more SRS resources are associated with a UL power control parameter set (Po, alpha, and closed-loop state) associated with a DL path loss RS, and one or more other SRS resources are associated with different UL power control parameter sets (Po, alpha, and closed-loop state) associated with different DL path loss RS. Different transmission timings of the SRS resource set can be oriented to different TRPs. Thus, for this embodiment, the SRS power of TRP 1 (i.e., subset 1 of the SRS resources) can be P1=P 0,1 +α1·PL1+10log 10BW+h1, and the SRS power of TRP 2 (i.e., subset 2 of SRS resources) can be P2=P 0,2 +α2·PL2+10log 10 BW+h2. For more TRPs, this embodiment can be extended to n power control parameter sets (Po, alpha and closed-loop state), each parameter set corresponding to one TRP. Since in the current standard, all SRS resources in an SRS resource set share the same power control parameter setting, in order to ensure the smooth implementation of this embodiment, the standard needs to be changed so that an SRS resource set can be associated with multiple power control parameter settings, and each SRS resource needs to be associated with one of them. Since the actual number of SRS resource configurations or SRS transmissions is not reduced (essentially, multiple SRS resource sets are aggregated into one), this embodiment may not be used. This exemplary scheme solves the technical problem of limited SRS resource sets by reducing SRS overhead / transmission / interference while still covering multiple TRPs, but more SRS resources may need to be configured within the SRS resource set.

[0200] In another embodiment, for one SRS resource set, there are more than one power control process and one or more SRS resources. Each SRS resource in the SRS resource set is associated with a power control process. The power control processes are based on different UL power control parameter sets (Po, alpha, and closed-loop state) associated with different DL path loss RSs. In other words, for multiple TRPs under TDD CJT, there can still be only one SRS resource set including one or more SRS resources, all SRS resources are associated with a first UL power control parameter set (Po, alpha, closed-loop state) associated with a first DL path loss RS, and one or more of the same SRS resources are also associated with a second UL power control parameter set (Po, alpha, and closed-loop state) associated with a second DL path loss RS. Different transmission opportunities for the same SRS resource can be oriented to different TRPs. In this way, for this embodiment, the SRS power of TRP 1 for the SRS resource can be P1=P 0,1 +α1·PL1+10log 10 BW+h1, and the SRS power of TRP 2 for the same SRS resource can be P2=P 0,2 +α2·PL2+10log 10BW+h2. For more TRPs, this embodiment can be extended to n power control parameter sets (Po, alpha and closed-loop state), each parameter set corresponding to one TRP. Since in the current standard, all SRS resources in an SRS resource set share the same power control parameter settings, in order to ensure the smooth implementation of this embodiment, it is necessary to change the standard so that an SRS resource set can be associated with multiple power control parameter settings, and each SRS resource may need to be associated with all settings. This exemplary scheme solves the problem of limited SRS resource sets and resources by reducing SRS overhead / transmission / interference while still covering multiple TRPs, but each SRS transmission may be received by a TRP with lower power accuracy. Since the actual number of SRS resource configurations or SRS transmissions is reduced, this embodiment may be more advantageous than the previous embodiment.

[0201] This can also be extended to include a third power control process of a third SRS resource in the SRS resource set, where the third power control process and the third SRS resource are for both TRP1 and TRP2, wherein P 1,2 =P0+(α1·PL1+α2·PL2) / 2+10log 10 BW+h. Whether a specific SRS transmission is for TRP1 or TRP2 or both is pre-configured by the network and known to the UE, and / or indicated in the MAC CE / DCI so that the UE knows to apply the correct power control for each transmission. In general, for the exemplary technology, a resource set is associated with m power control processes, where each of the m power control processes is configured with a UL power control parameter set (Po, alpha, and closed-loop state), but is configured with one or more DL path loss RSs. The timing of the SRS resource set can be for different subsets of a total of M TRPs, where M≥m (i.e., each of the m power control processes is for a subset of the M TRPs). For example, when transmitting to TRP 1 (i.e., the transmission is a TRP-specific transmission under TRP-specific power control), the SRS power can be P1=P 0,1 +α1·PL1+10log 10 BW+h1; when transmitting to both TRP 2 and TRP 3 (ie, the transmission is a TRP common transmission under TRP common power control), the SRS power can be P 2&3 =P 0,2&3 +(α2·PL2+α3·PL3) / 2+10log 10 BW+h 2&3. In summary, there are m (m≥1) power control processes for the SRS resource set, wherein each power control process is configured with a P0 value and a closed-loop state, and these power control processes are jointly based on n (n≥1) DL path loss RSs and / or n alphas, wherein n under different power control processes may be different. Depending on the power control process used, the transmission timing of the SRS resources may be directed to N (i.e., one or more) TRPs. Which TRPs are more suitable for TRP-specific transmissions and which TRPs are more suitable for TRP-common transmissions may be determined by the network implementation. This embodiment also solves the problem of limited SRS resource sets by still covering multiple TRPs without increasing the number of SRS resource sets. This embodiment combines the above two embodiments according to the network configuration, but may slightly increase the complexity. This embodiment may be more advantageous than the previous three embodiments.

[0202] When one or more SRS resources in an SRS resource set are configured with m>1 power control processes and one or more resources and resource sets are periodic or semi-static, these power control processes can be applied alternately to transmissions (i.e., for the first time slot in which the resource is to be transmitted, the first power control process is applied, for the second time slot in which the resource is to be transmitted, the second power control process is applied, and so on). Alternatively, each resource can be configured with more than one set of period and time slot offsets, each set corresponding to a power control process. For non-periodic SRS resources, the DCI bit field can be used to indicate which power control processes need to be applied for the associated non-periodic SRS transmission.

[0203] An enhancement scheme for SRS time domain (TD) orthogonal cover code (OCC) is proposed and documented. In TD OCC, the same SRS on 2 or more adjacent OFDM symbols uses superimposed orthogonal codes, for example, {+1,+1}, {+1,–1}, etc.

[0204] The potential advantage of SRS TD OCC is that SRS can be transmitted on more OFDM symbols while being orthogonally multiplexed with other SRS, and then transmitted at the desired power on each of the multiple OFDM symbols (whereas if TD OCC is not used, SRS will be "silent" on some of the multiple OFDM symbols). In addition, compared to SRS repetition, TDOCC can effectively average the different interferences that SRS experiences on different OFDM symbols, so it can work well with SRS interference randomization.

[0205] SRS TD OCC may need to solve some technical issues. Unlike CSI-RS or DMRS using OCC, SRS uses cyclic shift to multiplex with other SRS. If SRS TD OCC is to be supported, a method combining cyclic shift and TD OCC is required. In addition, since SRS received power imbalance may occur in some CJT scenarios, the multiplexed SRS using TDOCC may have different received power levels, and the impact on SRS performance may require further study.

[0206] For multi-port SRS, if the channel delay is long due to reasons such as TRP common SRS transmission (since the TA value may not be adjusted based on some of the TRPs in the TRP and the propagation delay in the DL reference timing and UL SRS transmission), the cyclic shifts allocated to SRS on each OFDM symbol used by TD OCC can be spaced out by allocating or configuring multiple ports on the same cyclic shift, which helps in efficient utilization of code domain resources (depending on several factors, such as configuration of SRS ports to cyclic shifts, knowledge of channel delay on the network side, etc.). This is also useful if the channel delay spread of some SRS ports is long, in which case the gNB, which is aware of the delay spread, can configure the SRS ports on fewer cyclic shifts (by allocating multiple ports on the same cyclic shift using TD OCC) so that the ports with longer delay spread overlap, leaving more resources for other SRS transmissions. The disadvantages of TD OCC relative to SRS repetition include: if the SRS transmission on one OFDM symbol is discarded, the SRS transmission using TD OCC may not be used. In this case, in order to reduce power and interference, the SRS on other OFDM symbols covered by one OCC can be discarded.

[0207] Increasing the maximum cyclic shift amount has been previously proposed and documented, including multiplying a mask sequence by the legacy SRS sequence to effectively increase the maximum cyclic shift.

[0208] In TS 38.211, the following maximum number of cyclic shifts are supported:

[0209]

[0210] One way to increase SRS capacity is to allow a larger maximum number of cyclic shifts to be specified. For example, the maximum number under comb 2 can be increased to 12 or 16, the maximum number under comb 4 can be increased to 16, and the maximum number under comb 8 can be increased to 12. To avoid loss of orthogonality, the increased maximum number may only apply to FR1, and in scenarios with short delay spread, such as small cells and / or indoor scenarios, it will be determined by the gNB. In general, RAN1 can further study the feasibility and potential applicable scenarios of increasing the maximum number of cyclic shifts.

[0211] If the maximum number of cyclic shifts under the comb teeth is increased, then in some cases, the SRS with the increased maximum number should not be multiplexed on the same RE with other SRS with the legacy maximum number to avoid loss of orthogonality between them. For example, if the maximum value is increased from 8 to 12, and if the legacy SRS and the new SRS are multiplexed on the same RE, the spacing between them can be as small as 1 / 24 of the total spacing instead of 1 / 12 of the total spacing. This may also be a disadvantage of this potential enhancement. To avoid this technical issue, the gNB may not multiplex the legacy SRS and the new SRS on the same RE, or the gNB must avoid configuring certain cyclic shifts for SRS that are too close to each other, and the maximum number can be increased to a multiple of the legacy maximum number.

[0212] In addition, the minimum SRS sequence length under each comb tooth may need further study. This is for further study. Fractional cyclic shifts can be used while still maintaining orthogonality.

[0213] This disclosure discusses increasing the maximum number of cyclic shifts to 12 or 16, including feasibility and potential applicable scenarios, multiplexing with legacy SRS, and the impact on the minimum SRS sequence length.

[0214] Another potential solution for SRS capacity enhancement is to increase the number of SRS comb teeth, for example, to comb tooth 12, without reducing the cyclic shift of each comb tooth offset. For comb tooth 12, if the number of cyclic shifts per comb tooth offset can be greater than 4, for example, 6 or 8 or more, the SRS capacity can be increased on the PRB using comb tooth 12. This is feasible for channels with shorter delay spread (e.g., CDL-C 30ns).

[0215] For precoded SRS for DL ​​CSI acquisition, in the existing standards, the SRS for DL ​​CSI acquisition using "antenna switching" is not precoded, which is similar to the SRS for UL CSI acquisition using "codebook". Therefore, for 4-port SRS using "antenna switching", it needs to consume 4 times the time domain / frequency domain / code domain resources of 1-port SRS. However, in CJT transmission using many paired UEs, the UE may only need to support 1 or 2 layers. Therefore, if precoded SRS for DL ​​CSI acquisition is supported, the UE may only need to detect 1 or 2 layers on 1 or 2 precoding ports, which can significantly reduce SRS overhead and increase SRS capacity. If 8 (or even more than 8) Tx SRS are supported, the overhead may be reduced more significantly.

[0216] In order to support precoded SRS for DL ​​CSI acquisition, precoded SRS has been supported since Rel-15. That is, the SRS used for UL CSI acquisition in a "non-codebook" manner is precoded. Therefore, the potential standard support for precoded SRS for DL ​​CSI acquisition is very similar to the potential standard support for NCB SRS. Therefore, it is expected that the basic standard impact of supporting precoded SRS for DL ​​CSI acquisition is limited. In order to limit the standard impact and implementation complexity of the potential enhancement of precoded SRS for DL ​​CSI, the present disclosure can only focus on the basic standard impact of UEs that already support "non-codebook" when using precoded SRS to acquire DL CSI. For these UEs that support "non-codebook", they already have the ability to calibrate the transmit antenna for beamforming purposes. In addition, since the UE supports TDD, their transmit antennas and receive antennas have also been calibrated to ensure that channel reciprocity remains good. Combining these two aspects, UEs supporting “non-codebook” and TDD should be able to support precoded SRS for DL ​​CSI acquisition, if any additional UE antenna calibration determined by RAN1 / RAN4 is still required, the standards and implementation efforts to support additional UE antenna calibration may be quite limited.

[0217] In one embodiment, for precoded SRS for DL ​​CSI acquisition, it is studied whether the standardized mechanism of NCBSRS can be largely reused.

[0218] Enhanced signaling for flexible SRS transmission (eg, dynamic updating of SRS parameters) has been proposed previously.

[0219] In the existing standardized mechanisms, most SRS parameters are specified through RRC configuration signaling, which can be quite slow and inflexible. For example, most of the time / frequency / code domain parameters for SRS transmission are RRC-based, so even with various hopping / randomization schemes, SRS transmission follows a fairly deterministic pattern, so SRS interference may not be sufficiently random. Therefore, if necessary, MAC CE and DCI can be enhanced to increase the flexibility of SRS parameter allocation, and the gNB can dynamically determine the best SRS transmission parameters to use, and communicate this decision to the UE through MAC CE or DCI.

[0220] In the existing DCI design, the following is conveyed for AP SRS transmission: up to 3 bits of SRS request, up to 2 bits of SRS available offset indication, and up to 2 bits of SRS TPC command. This does not provide enough flexibility for the gNB to control AP SRS transmission, so the pattern and randomness of AP SRS transmission are limited.

[0221] To address this issue, the gNB can indicate more parameters in the DCI. The DCI may include frequency domain parameters such as the sounding bandwidth and comb teeth, code domain parameters such as the sequence identifier and cyclic shift, and some randomization parameters such as the indicator of the pseudo-randomization sequence that the UE is to use for the SRS as described above. This is likely to increase the DCI overhead, so designs such as GC-DCI or other methods to reduce the DCI overhead should be considered. For example, to avoid large DCI overhead, a typical approach is to use MAC CE to activate / deactivate / update some parameter sets, and then rely on DCI to indicate further selection based on the MAC CE. This is similar to the method of updating the CSI request trigger state list through MAC CE and then using up to 6 bits in DCI to select the CSI request trigger state. Another method to reduce DCI overhead is described below.

[0222] Compared with various SRS transmissions using a predetermined pseudo-randomization scheme, data transmission is inherently more random. An exemplary method to significantly improve SRS interference randomness and capacity is to rely more on AP SRS transmissions on demand and reduce P / SP SRS transmissions once data packets arrive, and the AP SRS parameters can be based in part on the associated data transmission parameters. For example, the PUSCH / PDSCH FDRA is determined based on multiple factors such as traffic load, channel and interference variations, and scheduler algorithms, so the allocated bandwidth and PRB location have a lot of randomness. Then, the AP SRS can be used to obtain CSI for data transmission, so the data transmission parameters of SRS can be reused, for example, using PUSCH / PDSCH FDRA to determine the SRS frequency domain resource location. Then, through appropriate DCI design, the SRS indication can be embedded in the PUSCH / PDSCH scheduling DCI while only adding limited DCI overhead. Due to the randomness of the data transmission PRB location, the PRB location of the SRS transmission will also become a little unpredictable, and the impact on the SRS-based channel estimation needs further study.

[0223] P / SP SRS does not have enough randomness after configuration / activation. To improve flexibility and randomness, DCI or MAC CE can be used to dynamically change / update some parameters of P / SP SRS transmission. For example, the configured cyclic shift value α0 can be updated at regular intervals via DCI / MAC, the SRS sequence ID can be updated at regular intervals via DCI / MAC, and so on. As mentioned above, the change of parameters may need to be sent not only to one UE, but also to multiple UEs that multiplex SRS with each other. Therefore, group common DCI / MAC update signaling can be provided to reduce signaling overhead.

[0224] In one embodiment, in order to enhance the signaling for flexible SRS transmission, the present disclosure discusses AP SRS indicating SRS parameters in DCI and its impact on DCI overhead; SRS parameters based on data transmission parameters and its impact on channel estimation; P / SP SRS in which DCI / MAC changes some parameters and its impact on DCI overhead.

[0225] One or more of the following SRS parameters may be dynamically updated.

[0226] For frequency domain parameters (e.g., BW changes, comb changes, and / or hopping position changes), there is no mechanism in existing standards to dynamically update SRS frequency domain parameters, unless different trigger states in the SRS request are used to indicate different frequency domain parameters, which is very limited. Therefore, the resulting SRS transmission has limited patterns and randomness, even for non-periodic SRS transmissions. Therefore, improving SRS frequency domain flexibility may be critical for SRS capacity enhancement and interference randomization.

[0227] Parameters related to SRS frequency domain resource allocation can be indicated by the gNB in ​​MAC CE and / or DCI. However, SRS frequency domain resource allocation may involve a large number of value selections, which may incur a large overhead. Therefore, designs such as GC-DCI or other methods to reduce overhead should be considered. For example, in order to avoid large DCI overhead, a typical method is to use MAC CE to activate / deactivate / update some parameter sets, and then rely on DCI to indicate further selections based on MAC CE, that is, 3-step indication. This is similar to the method of updating the CSI request trigger state list through MAC CE and then using up to 6 bits in DCI to select the CSI request trigger state.

[0228] One embodiment is to dynamically change the starting RB position of RPFS by a parameter dynamically selected from a pre-configured parameter set. This also helps to randomize cross-SRS interference in the frequency domain. If this is to be supported, dynamic update signaling should be sent to a group of UEs that are multiplexed for transmission to avoid conflicts between them, and should be updated simultaneously. In order to achieve synchronous updates for multiple UEs at the same time, a group common DCI can be designed and used.

[0229] For code domain parameters (e.g., cyclic shift / SRS sequence), similar to SRS frequency domain parameters, there is no mechanism in the existing standards to dynamically update SRS code domain parameters. Therefore, even if SRS cyclic shift hopping based on pseudo-random sequences is considered, there is no method to change the code domain parameters fast enough on demand. Therefore, improving SRS code domain flexibility may be crucial for SRS capacity enhancement and interference randomization.

[0230] Parameters related to SRS code domain resource allocation can be indicated by the gNB in ​​the MAC CE and / or DCI. For example, two different SRS sequences can be configured for an SRS resource (through two different SRS sequenceIds), and the MAC CE and / or DCI can dynamically select one of them. However, when an SRS resource changes its sequence, the SRS resources of the same UE or other UEs that perform CDM with the SRS resource also need to change their sequences synchronously to avoid conflicts in this transmission or future transmissions. One potential design is to configure the same sequenceId to the SRS resources of multiple UEs that undergo CDM, and use GC-DCI to dynamically update the sequences of the SRS resources of these UEs. This update can be applied to P / SP / AP SRS.

[0231] A similar approach can be used to dynamically change the cyclic shift via GC-DCI. However, if the cyclic shift change affects only one UE, then GC-DCI is not required and UE-specific DCI can be used. For example, if the gNB detects a persistent conflict for one cyclic shift, the gNB can inform the UE to use a different cyclic shift.

[0232] Partial sounding is a useful technique that enables more SRS to be multiplexed. In Rel-17, RB-based partial frequency sounding (RPFS) was introduced. Partial frequency sounding extensions have been proposed before, such as larger partial frequency sounding factors, enhanced starting RB position hopping, and bandwidth reduction except for the last RB. SRs Other bandwidths (corresponding to b, where b hop <b<B SRS ) on partial frequency hopping.

[0233] In Rel-17, partial detection factors PF = 2 and 4 are supported. For Rel-18, other PF factors can help alleviate the SRS capacity shortage problem. Considering the current SRS design, additional PF factors, such as 3, 6, 8 or 12, can be considered, which is usually an extension of the Rel-17 mechanism and can significantly increase the SRS capacity.

[0234] Partial probing may require the UE to spend a longer time to complete the bandwidth probing. To address this issue, the gNB may decide to enable partial probing with a larger PF factor only when the frequency / time selectivity is not too severe. In addition, with partial probing, the transmit power per RE can be increased, which may offset the negative impact of the larger PF factor.

[0235] Another problem with RPFS is that in some cases, after reducing the detection bandwidth, the SRS sequence length will become very short, for example, less than the maximum cyclic shift number. This requires further study. In addition, if the Rel-17 agreement on sequence length is still maintained, the larger PF factor may not be applicable to a certain sequence length.

[0236] When RPFS is configured, the UE may expect the length of the SRS sequence to be a multiple of 6.

[0237] In summary, increasing the PF factor can be an effective way to significantly reduce cross-SRS interference by increasing SRS capacity, so that more SRS can be multiplexed in an orthogonal manner, but there are also some disadvantages and some issues that need further study. However, whether to use the enhancement scheme for a specific scenario can be decided by the gNB, that is, the gNB will only use this enhancement scheme if it believes that the enhancement scheme is suitable and beneficial for the scenario.

[0238] For frequency hopping with RPFS, starting RB position hopping can be supported across different legacy FH ​​cycles. However, for SRS within the same FH cycle, for example, when repetition factor R>1, additional starting RB position hopping was discussed but not supported. Considering the need to improve interference randomization, Rel-18 may further discuss partial detection starting RB position hopping within one FH cycle.

[0239] In order to support the starting RB position jump within an FH cycle, it should be noted that the frequency domain starting position The definition is as follows:

[0240]

[0241] in,

[0242]

[0243] The starting RB position jump in different FH cycles is defined. In order to achieve the starting RB position jump in one FH cycle, one more item can be added to the equation, for example,

[0244]

[0245] k FH Depends only on the SRS counter n SRS, and select from a predefined pseudo-random sequence (e.g., {0,2,1,3}). With this simple change, each time an SRS is transmitted, the SRS counter is incremented by 1, and accordingly, the next number in the pseudo-random sequence is selected and added to the SRS starting position value. This achieves the starting RB position hopping within one FH cycle. The same equation can also be applied to the case without FH, so even if FH is not enabled, some additional randomness can be achieved if this scheme is adopted.

[0246] This scheme helps to increase the interference randomization advantage, but the generated SRS samples in the time domain / frequency domain may be quite non-uniform at this time, which may increase the complexity of channel estimation or affect the channel estimation performance.

[0247] In Rel-17, the RB position hopping sequence based on partial frequency detection of RBs is introduced. Specifically, for P F =2, k hopping ={0,1}, for P F =4, k hopping ={0,2,1,3}. These hopping sequences help to randomize the SRS frequency position, but the number of sequences is very limited. In Rel-18, more hopping sequences can be considered to achieve a larger interference randomization gain.

[0248] For example, for P F =2, you can add k hopping = {1,0} as an option configured by the gNB, which can be configured with multiplexed RPFS SRS so that they always occupy different PRBs. F =4, you can also add k hopping = {0,1,2,3}, and this option can be multiplexed with other RPFS SRS in all transmissions through FDM. F =8, then k hopping ={0,4,2,6,1,5,3,7} (this is the existing pseudo-random sequence), and can also support k hopping ={0,1,2,3,4,5,6,7}.

[0249] Typically, if RPFS is enabled, in order to avoid conflicts among SRSs multiplexed on potentially overlapping time / frequency / code resources, the gNB may need to configure all these SRSs to have the same PF factor and the same hopping sequence. This requires additional coordination work by the gNB.

[0250] In one embodiment, for partial frequency detection extension, the present disclosure discusses a larger partial frequency detection factor and its potential impact due to uneven time-frequency / frequency domain SRS samples and its impact on the minimum sequence length; partial detection starting RB position hopping within an FH period based on a pseudo-random sequence and its potential impact due to uneven time-domain / frequency domain SRS samples and its potential impact on multiplexing of multiple SRSs; a new sequence for partial detection starting RB position hopping and its potential impact due to uneven time-domain / frequency domain SRS samples and its potential impact on multiplexing of multiple SRSs.

[0251] Some enhancement schemes are proposed regarding the configuration of enhanced SRS transmission to achieve more efficient SRS parameter allocation (eg, configuring v (sequence index within a group) of each SRS resource, configuring the cyclic shift of each SRS port in each SRS resource).

[0252] For consistency with TS 38.211 (excerpt below), v is called a "sequence number" rather than a "sequence index":

[0253]

[0254] In the current standard, v is set to 0 unless sequence hopping is configured for the long SRS sequence of an SRS resource, in which case v hops between 0 and 1 in a pseudo-random manner. For long SRS sequences of SRS resources without sequence hopping, if the gNB is able to set v to 1 in some cases, the randomness of the generated SRS interference can be improved.

[0255] This approach seems easy to support, but requires that all SRSs that pass through CDM are configured with the same v to maintain orthogonality between these SRSs. In addition, the effect of randomization may not be as obvious as sequence hopping, that is, the gNB can configure sequence hopping for each SRS resource to achieve greater randomness.

[0256] In the current standard, when multiple SRS ports are configured for an SRS resource, only one cyclic shift value α0 is configured for the first port (corresponding to the cyclicShift value configured as ), the cyclic shifts for the other ports are calculated according to equations that depend on α0 and the port index.

[0257] For all 2-port SRS and some 4-port SRS, only one comb offset is used, and the cyclic shift is uniformly extended within the maximum cyclic shift of the comb offset, that is, the ports are separated as much as possible in the cyclic shift domain. In these cases, it is hoped to keep the current design unchanged, otherwise some ports will get closer and closer in the cyclic shift domain.

[0258] For some 4-port SRS, two comb offsets are used, and the cyclic shift of the two comb offsets is still determined by only one value (i.e., α0). This seems to have considerable limitations. For example, in some cases, for any comb offset, the ports are not separated as much as possible in the cyclic shift domain. For another example, in some cases, ports on different comb offsets use the same cyclic shift value, thereby increasing the PAPR of the SRS transmission. These technical problems can be solved by introducing the ability to configure cyclic shifts for each SRS port in each SRS resource. More specifically, when an SRS resource uses multiple comb offsets, a cyclic shift value should be configured for each comb offset. Then, for each comb offset, the ports can be separated as much as possible according to the configured cyclic shift value. In any case, the potential impact of configuring cyclic shifts for each SRS port on PAPR can be further studied, and the minimum interval on the cyclic shift of the SRS resource may need to be limited.

[0259] In one embodiment, in order to enhance the configuration of SRS transmissions to achieve more efficient SRS parameter allocation, the effectiveness of configuring v (sequence number within the group) of each SRS resource relative to the sequence hopping of each SRS resource is studied. The present disclosure discusses configuring the cyclic shift of each SRS port in each SRS resource for at least SRS using more than one comb offset and its potential impact on PAPR, as well as potential restrictions on the minimum spacing on the cyclic shift of the SRS resources.

[0260] However, in some cases, it may be desirable to allocate the cyclic shifts of the SRS resources non-equidistantly. For example, if the channel delay of a certain SRS is very different from the channel delay of another SRS, the ports of these SRSs can be assigned to the same cyclic shift point in the cyclic shift space instead of mixing their cyclic shifts together. In this way, this configuration can better adapt to different channel delays. In addition, if the delay spread of the SRS resource is short, the cyclic shifts of the ports do not have to be too far apart; instead, they can be close to each other, leaving more room for SRS with longer delay spread. On the other hand, in order to ensure that the above two examples are well implemented, the network needs to know the delay / delay spread, but with this knowledge, the network may use other implementation-based methods to achieve similar effects. For example, in some cases, ports on different comb offsets use the same cyclic shift value, which may increase the PAPR of SRS transmission in some cases. These problems can be solved by introducing the ability to configure cyclic shifts for each SRS port in each SRS resource. This capability may also be required for 8Tx SRS configurations. More specifically, when an SRS resource uses multiple comb offsets, a cyclic shift value should be configured for each comb offset.In general, in some cases, it may be beneficial to configure a cyclic shift for each SRS port in each SRS resource.

[0261] Some enhancement schemes regarding enhanced SRS transmission based on additional parameters are proposed (eg, SRS resource mapping based on network provided parameters (eg, configurable indexes) or a basic parameter set (eg, slot indexes)).

[0262] Using network-provided parameters to randomize SRS transmission parameters has been widely used in current standards. For example, the SRS sequence identifier is provided by the SRS-Resource IE (in this case, or SRS-PosResource-r16IE (in this case, The network-provided parameter given by the high-level parameter sequenceId in is the configuration index. This identifier is used as an initial value (seed) in many cases. For example, for SRS sequence hopping or SRS sequence group hopping, a pseudo-random sequence c(i) is used and used at the beginning of each radio frame. Initialize.

[0263] The same approach can be applied to some of the enhancements discussed above to improve the randomization effect. For example, when determining a pseudo-random sequence for an enhancement, a network-provided parameter (reusing an SRS sequence identifier or a new parameter) can be used to select a value (e.g., an initial value) from the sequence. At least the following enhancements can be associated with this approach: further enhanced frequency hopping (e.g., pseudo-random RE / PRB skipping within a hop); comb hopping; comb offset hopping; cyclic shift hopping / randomization; sequence hopping / randomization; randomized transmission of SRS; RPFS start RB position hopping enhancement scheme, including SRS interference randomization by partial detection start RB position hopping within one FH period; new sequence for partial detection start RB position hopping.

[0264] The use of system parameters (e.g., slot index) to randomize SRS transmission parameters has been widely used in current standards. For example, many SRS transmission parameters are reinitialized at the beginning of each radio frame. Another example is that many SRS transmission parameters depend on the number of OFDM symbols in the SRS resource, which is usually expressed as As l′ changes, the SRS transmission parameters also change.

[0265] The same approach can be applied to some of the enhancements discussed above to improve the randomization effect. For example, time slot indexes, PRB indexes, PUSCH RBG indexes, etc. can be further added to provide additional randomness. At least the following enhancements can be associated with this approach: further enhanced frequency hopping (e.g., pseudo-random RE / PRB skipping within a hop); comb hopping; comb offset hopping; cyclic shift hopping / randomization; sequence hopping / randomization; randomized transmission of SRS; RPFS start RB position hopping enhancement scheme, including SRS interference randomization through partial detection start RB position hopping within one FH period; new sequence for partial detection start RB position hopping.

[0266] In more detail, in order to make the enhancement scheme described in this subsection applicable to orthogonal SRS (the orthogonality of these orthogonal SRS is maintained by additional resource randomization introduced by network-provided parameters or system parameters), SRS may need to be assigned with the same or carefully selected network-provided parameters or system parameters and use the same randomization enhancement scheme. For example, if SRS1 and SRS2 differ only in frequency domain resources (i.e., FDM is performed), but may occupy the same time domain / code domain resources, then when SRS1 uses additional frequency domain randomization / hopping and the resulting SRS1 frequency domain resources may overlap with SRS2, the gNB may also need to configure the same frequency domain randomization / hopping to SRS2, and the randomization parameters may be selected to be the same value (so that SRS1 and SRS2 can be jumped in the same way) or some related values ​​to ensure that SRS1 and SRS2 always occupy orthogonal frequency domain resources. To this end, SRS1 and SRS2 must sometimes be configured with the same time domain resources, that is, certain network coordination is required.

[0267] If SRS1 and SRS2 differ only in code domain resources (i.e., CDM is performed through different cyclic shifts), but may occupy the same time domain / frequency domain resources, then when SRS1 uses additional code domain randomization / hopping and the resulting SRS1 frequency domain resources may overlap with SRS2, the gNB may also need to configure the same code domain randomization / hopping to SRS2, and the randomization parameters can be selected to be the same value (so that SRS1 and SRS2 can be jumped in the same way) or some related values ​​to ensure that SRS1 and SRS2 always occupy orthogonal code domain resources. For this reason, SRS1 and SRS2 must sometimes be configured with the same time domain resources, that is, certain network coordination is required.

[0268] In one embodiment, for resource mapping for SRS transmission based on network-provided parameters or system parameters, the present disclosure discusses at least some potential enhanced schemes in which the network updates the SRS sequence identifier to achieve SRS hopping / randomization; and utilizes system parameters such as OFDM symbol / time slot / radio frame index to achieve at least some potential enhanced schemes for SRS hopping / randomization.

[0269] Many technical enhancements have been described above, and there are more that have been proposed or may be proposed. In this disclosure, many of these technical enhancements can be used for standard support, but some enhancements require additional research on possible problems. These problems and associated potential enhancements are summarized as follows:

[0270] The uneven SRS sample pattern in the time / frequency domain and its impact on SRS-based channel estimation can be studied in the following aspects: pseudo-random RE / PRB skipping within one hop; comb-tooth hopping; randomized transmission of SRS; SRS parameters based on data transmission parameters; partial detection start RB position hopping within one FH period; new sequence for partial detection start RB position hopping.

[0271] The potential increase in PAPR can be studied for: each hop sequence in a long SRS sequence; configuring cyclic shift for each SRS port in each SRS resource.

[0272] Additional coordination between multiplexed SRSs to ensure orthogonality can be studied in the following aspects: comb tooth hopping; comb tooth offset hopping; cyclic shift hopping; configuring v (intra-group sequence number) for each SRS resource; partial detection start RB position hopping within an FH period; new sequence for partial detection start RB position hopping.

[0273] The impact on the minimum SRS sequence length can be studied for the following aspects: pseudo-random RE / PRB skipping within a hop; increasing the maximum number of cyclic shifts; and larger partial frequency detection factors.

[0274] The impact on signaling overhead can be studied in the following aspects: APSRS indicating SRS parameters in DCI; P / SP SRS where DCI / MAC changes some parameters.

[0275] In one embodiment, for the TDD CJT SRS enhancement scheme, the following issues of the related enhancement scheme can be studied: the non-uniformity of the SRS sample pattern in the time domain / frequency domain and its impact on SRS-based channel estimation; the potential increase in PAPR; the need for additional coordination between multiplexed SRSs to ensure orthogonality; the impact on the minimum SRS sequence length; and the impact on signaling overhead.

[0276] To support TDD CJT, WID and RAN1#109-e protocols provide some assumptions and requirements, focusing on obtaining SRS-based CSI for TDD CJT. The following article analyzes the SRS scenario of TDD CJT, taking these assumptions and requirements into account.

[0277] This article provides some preliminary analysis of two different methods of sending SRS for CJT, namely TRP common SRS and TRP specific SRS. Figure 5A and Figure 5B shown.

[0278] exist Figure 5A and Figure 5B, 2 TRPs serving 2 UEs are shown. UE 501 is served by TRP 511 and sends SRS 521 targeted at TRP 511 (i.e., the transmit power of SRS 521 is set according to the propagation channel between UE 501 and TRP 511, and SRS 521 is received by TRP 511 at a desired power level).

[0279] UE 502 is a CJT UE served by TRP 511 and TRP 512. UE 502 transmits at least SRS 522 targeting TRP 512, i.e., the power of SRS 522 is set according to the propagation channel between UE 502 and TRP 512, and SRS 522 is received by TRP 512 at a desired power level.

[0280] exist Figure 5A , UE 502 sends a TRP common SRS (i.e., SRS 522). SRS 522 is targeted to TRP 512, but can also be received by TRP 511 through cross-TRP link 532. Based on SRS 522, TRP 511 estimates the channel between UE 502 and TRP 511 and performs at least DL CJT using the acquired CSI. SRS 522 can be received by TRP 511 at a power level different from the power level of SRS 521. The received power imbalance is due to the fact that SRS 522 is not targeted to TRP 511 (i.e., the power of SRS 522 is not set according to the propagation channel between UE 502 and TRP 511).

[0281] Advantages of TRP common SRS include reduced SRS overhead, thereby reducing overall cross-SRS interference.

[0282] However, possible disadvantages may include that SRS 522 is strongly interfered due to the non-negligible received power imbalance of TRP 511. This may cause difficulties in performing channel estimation of UE 501 and UE 502, especially when SRS 521 and SRS 522 are non-orthogonal and SRS 522 received by TRP 511 through cross-TRP link 532 is weak. The channel estimation performance depends largely on whether SRS 521 and SRS 522 are orthogonal (which depends on the SRS capacity) and how many dB SRS 522 is weaker than SRS 521 at the receiving end; see preliminary study below. In addition to implementation-based methods (e.g., network coordination of UE's SRS transmissions), potential solutions may also be to increase SRS capacity (to support more orthogonal SRS) and improve SRS interference randomization (to avoid persistent high interference).

[0283] exist Figure 5BIn the embodiment, UE 502 sends a TRP-specific SRS (i.e., SRS 522) to TRP 512 at a certain time, and also sends SRS 523 to TRP 511 at a different time (i.e., TDM is performed). SRS 523 targets TRP 511 (i.e., the power of SRS 523 is set according to the propagation channel between UE 502 and TRP 511, and SRS 523 is received by TRP 511 at a desired power level). Based on SRS 523, TRP 511 estimates the channel between UE 502 and TRP 511 and performs at least DL CJT using the acquired CSI.

[0284] SRS 522 can still be received by TRP 511 through the cross-TRP link, similar to SRS 522 in the TRP common SRS case. That is, SRS 522 may still cause interference to SRS 521. However, TRP 511 does not need to perform channel estimation based on SRS 522.

[0285] Advantages of TRP-specific SRS include eliminating the receive power imbalance of TRP 511, which can improve the channel estimation performance between UE 502 and TRP 511, thereby improving the DL CJT performance of UE 502.

[0286] Disadvantages include increased SRS overhead and therefore increased cross-SRS interference. A potential solution could be to increase SRS capacity.

[0287] As described above, in the scenario of TRP common SRS, where there is an SRS sent by a UE and used by multiple TRPs for channel estimation, the path loss between the UE and the TRP may differ greatly, which will cause the SRS receive power of the TRP receiver to be unbalanced. The power imbalance value is related to the path loss difference. The present disclosure provides some preliminary numerical studies below, which show that if only a 3dB path loss difference is allowed, approximately 28% of UEs can be served by 2 TRPs, approximately 5% of UEs can be served by 3 TRPs, and only approximately 1% of UEs can be served by 4 TRPs. In general, the higher the percentage of UEs that can be served by 2, 3, or 4 TRPs, the better the CJT performance. Therefore, allowing only a 3dB path loss difference is quite limited and high CJT performance cannot be achieved. In actual scenarios, it is likely that a path loss difference of at least 6dB to 10dB will need to be processed. Path loss differences can lead to receive power imbalance. For example, if there is a 10dB path loss difference, the total received power imbalance (in one TRP or distributed across two TRPs) may reach approximately 10dB.

[0288] For the TDD CJT SRS enhancement scheme, TRP common SRS can reduce SRS overhead, but the channel estimation of weak links may deteriorate, especially when SRS is non-orthogonal. Potential technical solutions include increasing SRS capacity and improving SRS interference randomization.

[0289] TRP-specific SRS may lead to increased SRS overhead and interference. Potential technical solutions include increasing SRS capacity.

[0290] For the TDD CJT SRS enhancement solution, a path loss difference of at least 6dB to 10dB needs to be handled in actual scenarios.

[0291] Non-orthogonal SRS will lead to significant performance degradation, especially for weaker SRS.

[0292] Orthogonal SRS generally has good performance, with slightly worse performance for weaker signals (if the signal is x dB weaker, the performance will drop by approximately x dB).

[0293] SRS enhancement schemes for 8Tx have been discussed. Regarding 8Tx SRS, the agenda item 9.1.3.1 being worked on concurrently in RAN1 covers “Increasing the number of orthogonal DMRS ports; including increasing orthogonal DMRS ports for UL / DL MU-MIMO and UL SU-MIMO for 8Tx”, and agenda item 9.1.4.2 covers “SRI / TPMI enhancement schemes to enable 8Tx UL transmission; supporting up to 4 layers or more per UE in UL towards CPE / FWA / vehicle / industrial equipment.” Some decisions regarding 8Tx SRS may be related to other agenda items, so some coordination between the various agenda items may be needed to ensure consistency, or the current agenda item may need to consider some results of other agenda items. In any case, the 8Tx SRS enhancement schemes being considered in the current agenda item should be flexible / general enough to have the potential to be consistent with the possible results of the related agenda items.

[0294] In this disclosure, the 8Tx SRS enhancement scheme is discussed in the case of using codebook (CB), non-codebook (NCB) and antenna switching (AS), and the maximum number of SRS resource sets, whether 8 ports are supported in one or more resources, whether 8 ports are supported in one or more OFDM symbols, etc. are described. First, the existing design is reviewed. Then, it is analyzed which parts can be easily extended to 8Tx SRS, and which other parts may need to be updated / modified / further studied (FFS) to adapt to 8Tx SRS.

[0295] Regarding the number of ports in the SRS resource, existing standards specify some restrictions on 1 / 2 / 4Tx SRS.

[0296]

[0297]

[0298] Table 1 summarizes the existing design of the number of ports per SRS resource for up to 4Tx SRS:

[0299] Table 1 Existing designs of the number of ports per SRS resource with up to 4Tx SRS

[0300] CB NCB AS using nTnR nrofSRS-Ports, i.e. 1, 2, 4 1 nrofSRS-Ports, i.e. 1, 2, 4

[0301] As shown above, the NCB always provides one port for the SRS resource, since each (virtualized) port corresponds to one UL transport layer. This design can be reused for 8Tx SRS for the NCB, which is reflected in the protocol. For CB and AS, n TxSRS supports n ports in one SRS resource, where n=1, 2, 4. This design can still be reused for 8Tx SRS, that is, 8-port SRS resources can be supported in Rel-18. Although 8Tx SRS can also be supported by 2 SRS resources, and each resource has 4 ports (if necessary, it can be discussed further), the baseline solution should be to support 8-port SRS resources.

[0302] In one embodiment, for 8Tx SRS, for the number of ports in the SRS resources, the NCB may support 1 port in each SRS resource, or the CB / AS may support 8 ports in the SRS resources.

[0303] Regarding the number of SRS resources in each SRS resource set for 8Tx SRS, the existing standards stipulate some restrictions for 1 / 2 / 4Tx SRS.

[0304]

[0305] Table 2 summarizes existing designs for the number of SRS resources in each SRS resource set including n ports, where n=1, 2, 4.

[0306] Table 2 includes existing designs of the number of SRS resources in each SRS resource set of n ports, where n=1, 2, 4

[0307]

[0308]

[0309] For CBs using up to 4 ports, each SRS resource set can be configured to include a maximum of 2 SRS resources in addition to "fullpowerMode2". In case the CB supports 8Tx SRS, the same maximum value can be reused, that is, if "fullpowerMode2" is not configured, 8Tx SRS should still support a maximum of 2 SRS resources per SRS resource set. However, if "fullpowerMode2" is configured, the maximum number of SRS resources in each SRS resource set used for 8Tx SRS may depend on the UE capabilities / implementation, as the SRS resources may be related to a certain specific design of the UE Tx chain, PA architecture and / or panel. Further studies may be needed, taking into account the results of the relevant agenda items.

[0310] For NCBs using up to 4 layers, the existing design includes up to 4 SRS resources in each SRS resource set. The same principle can still be reused to support up to 8 layers, that is, in Rel-18, for NCBs, the maximum number of SRS resources in each SRS resource set can be modified from 4 to 8.

[0311] For AS using nTnR, the existing design is that each SRS resource set includes 1 SRS resource. This can still be reused for 8Tx SRS.

[0312] In one embodiment, for 8Tx SRS, for the maximum number of SRS resources in each SRS resource set, the CB without "fullpowerMode2" supports at least 2, the CB with "fullpowerMode2" is for further study (FFS), the NCB supports at least 8, and the AS supports at least 1.

[0313] In the existing design, for a UE supporting n Tx SRS, the UE can simultaneously detect n ports (in 1 SRS resource or in n SRS resources), that is, n ports can be detected in 1 OFDM symbol. This can be extended to 8Tx SRS, so that with the support of appropriate design, the UE should be able to detect all 8 ports in 1 OFDM symbol. Some preliminary considerations related to this are discussed below.

[0314] According to the current standard, all n ports (n=1, 2, 4) for n Tx SRS will be detected on the RB at the same time:

[0315] For CB / AS, n ports are configured in 1 SRS resource, and resource mapping ensures that all n ports occupy the same RB at the same time. These ports are multiplexed by cyclic shift and use 1 comb offset (corresponding to 1Tx, 2Tx, and in some cases 4Tx) or 2 comb offsets (corresponding to 4Tx in some cases).

[0316] For NCB, n ports are configured in n SRS resources in a resource set as follows. These ports can be multiplexed by cyclic shift and / or comb offset.

[0317]

[0318] In most cases, it is simple to multiplex 8 ports on the same OFDM symbol and the same RB. For example, when using comb 2, 1 comb offset configured with 8 different cyclic shifts or 2 comb offsets configured with 4 different cyclic shifts can be used. When using comb 4, 2 comb offsets configured with 4 different cyclic shifts can be used, or even 4 comb offsets configured with 2 different cyclic shifts can be used. On the other hand, the 8 ports of comb 2 or comb 4 can be distributed over multiple consecutive OFDM symbols. It can also be achieved by existing mechanisms.

[0319] However, when using comb 8, up to 6 cyclic shifts are supported and further details may need to be discussed.

[0320] Some ports on different comb offsets must use the same cyclic shift. This can increase PAPR (depending on the UE transmitter architecture). Although the 4 ports using comb 8 in the current standard have the same PAPR problem, it remains to be discussed whether Rel-18 will adopt this approach.

[0321] In Rel-18, the maximum number of cyclic shifts under comb 8 may be increased, so that the 8 ports can use different cyclic shifts. Some advantages and disadvantages of this approach have been discussed above.

[0322] The 8 ports can be spread over N consecutive OFDM symbols, with a subset of the ports being detected on each OFDM symbol. However, if N=2, then 4 ports need to be detected on each OFDM symbol using comb 8, and the CB / AS still has a PAPR problem based on the existing Rel-17 design. (This problem may not exist for NCB, depending on the gNB's configuration of the cyclic shift for each port / resource). If N=4 or 8, there is no such PAPR problem, but the latency may not be ideal.

[0323] It is further possible to implement 8Tx SRS using comb 8. The standard may also consider supporting 8 ports over multiple OFDM symbols by TDM and / or TD-OCC means (simple repetition over multiple OFDM symbols is allowed, but is different from the concept considered here).

[0324] When 8 ports are TDMed over multiple OFDM symbols, the network may be required to configure multiple OFDM symbols in one slot (which may affect multiplexing with other UL transmissions) or spread the OFDM symbols across different slots (which may create phase alignment issues and may increase the time to complete probing of all 8 ports).

[0325] The advantages of 8 ports via TDM include that in some cases, each port can use higher transmit power for sounding, thereby improving channel estimation performance. However, if the UE is already using full power transmission for all its PAs when configuring 1 OFDM symbol for 8 ports, spreading the ports over different OFDM symbols will not result in an increase in power per port.

[0326] In any case, the network knows the advantages and disadvantages of 8 ports via TDM, and the network can decide whether there is enough advantage to use these ports. In this regard, 8 ports via TDM can be supported.

[0327] When 8 ports are spread over N OFDM symbols, these N OFDM symbols should be adjacent in one slot, and N can be 2 or 4. In the case of N=8, the distance between ports is a bit far, so it is not recommended. Each port can still have the same PRB allocation.

[0328] In addition to TDM, TD OCC can also be used to transmit 8-port SRS over multiple OFDM symbols. Compared to simple repetition, TD OCC allows more ports to be transmitted over the same number of time / frequency resources. The same restrictions on N should also apply to TD OCC over N OFDM symbols, and on each OFDM symbol, all 8 ports should be transmitted to reduce the delay in acquiring the channel for these 8 ports.

[0329] At least one or more 8-port SRS resources with the usage mode of "codebook", "non-codebook" or "antenna switching" for transmission on multiple OFDM symbols are supported, wherein different ports are mapped to N different OFDM symbols (N=2 or 4, n different OFDM symbols are continuous in 1 time slot).

[0330] At least one or more 8-port SRS resources with the usage mode of "codebook", "non-codebook" or "antenna switching" transmitted on multiple OFDM symbols are supported, wherein the port is mapped to N different OFDM symbols according to TD-OCC (N=2 or 4, n different OFDM symbols are continuous in 1 time slot; 1 / 2 / 4-port SRS TD OCC can also be supported).

[0331] In one embodiment, at least 8Tx SRS on 1 OFDM symbol using comb 2 and comb 4 can be supported (eg, 8Tx SRS using comb 8 is for further study (FFS); 8Tx SRS on more than 1 OFDM symbol is for further study (FFS)).

[0332] Maximum number of SRS resource sets for 8Tx SRS

[0333] Regarding the maximum number of SRS resource sets for 8Tx SRS, existing standards may have some restrictions on 1 / 2 / 4Tx SRS.

[0334]

[0335] Table 3A summarizes existing designs for the number of SRSs including n ports, where n=1, 2, 4.

[0336] Table 3A includes the existing designs of the number of SRS resource sets for n ports, where n=1, 2, 4

[0337]

[0338]

[0339] As shown above, each UE typically supports up to 2 SRS resource sets in each usage mode of CB, NCB, and AS using nTnR. This is usually related to up to 2 TRPs to which the UE may send SRS. Therefore, in a sense, each SRS resource set can correspond to one TRP. Note that for an AS using nTmR (where n and m are different), 3 or 4 AP SRS resource sets can be configured, in which case different AP SRS resource sets do not correspond to different TRPs.

[0340] The same design can be extended to the case where CB / NCB / AS supports 8Tx SRS. Although in principle the number of SRS resource sets for 8Tx SRS can be increased, for example, by combining 2 SRS resource sets for 8Tx SRS (while maintaining M-TRP support), this may require additional design to indicate the relationship between different SRS resource sets. Therefore, it is recommended not to change the maximum number of SRS resource sets for 8Tx SRS.

[0341] In one embodiment, the existing design of the maximum number of SRS resource sets for 8Tx SRS can be reused (ie, without any changes). Summary of important SRS parameters under n ports, n=1, 2, 4, 8

[0342] Table 3B summarizes the above discussion on some important SRS parameters for SRS under n ports (n=1, 2, 4, 8), including the number of ports in each SRS resource, the number of SRS resources in each SRS resource set, the number of OFDM symbols used to detect all n ports, and the maximum number of SRS resource sets. As shown in Table 3B, most of these parameters for 8Tx SRS can be set according to the principles of existing mechanisms (except for several cases marked in italics in the table, which are for further study (FFS)).

[0343] Table 3B Important SRS parameters for n ports, where n = 1, 2, 4, 8 Italic text requires further study (FFS); all other contents are based on existing design principles. (FPM2 = fullpowerMode2)

[0344]

[0345] For the usage modes CB / NCB / AS, 8Tx SRS supports legacy values ​​and legacy schemes (repetition, FH, RPFS). The present disclosure describes in detail the comb and cyclic shift design of 8Tx SRS for legacy schemes based on one or more OFDM symbols (repetition, frequency hopping, partial sounding or a combination thereof) in the following paragraphs.

[0346] The comb / comb offset design of 8Tx SRS and the cyclic shift design of 8Tx SRS are closely related. Changing one of the designs may change the other. Therefore, one approach is to consider the two designs together in a coupled manner, but the disadvantage is that there may be many combinations to consider. Therefore, a step-by-step approach is taken. First, some high-level guidelines / considerations are provided, and then the comb offset can be determined, based on which the cyclic shift is determined.

[0347] Normally, the comb offsets and cyclic shifts assigned to SRS resources are equally spaced. However, non-equidistant cyclic shifts may be useful in some cases. For example, 8 ports in an SRS resource can be configured on a comb offset of comb 4, allowing up to 12 cyclic shifts. For another example, 8 ports can be configured on 3 comb offsets, which are respectively configured with 3, 3, and 2 ports. These situations are very atypical, and they can form a lot of combinations. The present disclosure first focuses on the equidistant situation, and then discusses the non-equidistant situation.

[0348] Comb Teeth and Comb Teeth Offsets: For comb 2, the 8 ports can be placed in 1 comb offset (8 cyclic shifts per comb offset) or 2 comb offsets (e.g., 4 cyclic shifts per comb offset). Both approaches are feasible and have their own advantages. The exemplary techniques in this disclosure support both approaches. For comb 4, if the comb offsets of the 8 ports are equidistant, 2 or 4 comb offsets can also be used. Both approaches are feasible and have their own advantages. The exemplary techniques in this disclosure support both approaches. For comb 8, if the comb offsets and cyclic shifts of the 8 ports are equidistant, 4 or 8 comb offsets can also be used. Both approaches are feasible and have their own advantages. The exemplary techniques in this disclosure support both approaches.

[0349] In some embodiments, for an 8-port SRS resource in an SRS resource set whose usage mode is "codebook" or "antenna switching", in order to equidistantly configure one or more comb tooth offsets and cyclic shifts, the following situations can be supported: 1 or 2 comb tooth offsets for comb tooth 2; 2 or 4 comb tooth offsets for comb tooth 4; 4 or 8 comb tooth offsets for comb tooth 8.

[0350] Cyclic shift: For equidistant cyclic shift, if there is no restriction on which ports can perform CDM on the same comb offset, there can still be many combinations. For example, in ports {1000,…,1007}, ports 1000 and 1001, or ports 1000 and 1002, or ports 1000 and 1004, etc. can perform CDM on one RE. There may even be hardware / PA-related considerations for which ports should perform CDM / FDM. To reduce complexity, some embodiments may configure cyclic shifts for ports in only one of two sorting methods. That is, for the eight ports 1000 to 1007, the rectangular grid consists of C comb offsets (i.e., C rows) arranged in ascending order and 8 / C cyclic shifts (i.e., 8 / C columns) on each comb offset. Sorting method 1 first allocates the eight ports to a row in ascending order, and then allocates them between C rows in ascending order. Sorting method 2 first allocates the 8 ports to a column in ascending order, and then allocates them between columns 8 / C.

[0351] The disclosure below describes how the cyclic shift positions are distributed among C comb offsets. For example, 8 ports can be evenly interleaved between 2 comb offsets of comb 2 (where n_CS^max=8): comb offset 0 is configured with {CS0, CS2, CS4, CS6}; comb offset 1 is configured with {CS1, CS3, CS5, CS7}.

[0352] However, the distribution between comb offsets may not always be uniform. For example, for 2 comb offsets of comb 4 (where n_CS^max=12) (see Tables 4 and 5): comb offset 0 is configured with {CS0, CS3, CS6, CS9}; comb offset 2 is configured with {CS1, CS4, CS7, CS10} or {CS2, CS5, CS8, CS11}.

[0353] In addition, when using comb 8 (where n_CS^max=6), the distribution between comb offsets cannot be uniform, and some ports on different comb offsets must use the same cyclic shift. One example (see also Table 6) is as follows: comb offset 0 is configured with {CS0, CS3}; comb offset 2 is configured with {CS1, CS4}; comb offset 4 is configured with {CS2, CS5}; comb offset 6 is configured with {CS0, CS3}.

[0354] Considering all the possible examples above, it may be desirable to provide sufficient flexibility in the standard and leave room for network configuration. The network can configure C cyclic shift positions for C comb offsets, that is, each comb offset corresponds to a cyclic shift position, and at each comb offset, the ports are evenly distributed according to the configured cyclic shift positions, which is similar to the traditional design.

[0355] In some embodiments, for an 8-port SRS resource in an SRS resource set whose usage mode is "codebook" or "antenna switching", when the rectangular grid is composed of C comb tooth offsets (i.e., C rows) arranged in order from small to large and 8 / C cyclic shifts (i.e., 8 / C columns) on each comb tooth offset, the first cyclic shift position on the comb tooth offset is configured by the network, and the other cyclic shift positions are evenly distributed on the comb tooth offset. The 8 ports 1000 to 1007 can be allocated in order from small to large according to the following two sorting methods: sorting method 1 (first allocated to a row, and then allocated between C rows in order from small to large); sorting method 2 (first allocated to a column, and then allocated between 8 / C columns).

[0356] If only one sorting method is supported for simplicity, sorting method 2 may be more advantageous because it is more consistent with existing multi-comb offset designs.

[0357] In one embodiment, the 8 / C cyclic shifts on each comb offset are aligned between C comb offsets, which may increase the PAPR if the 8 ports are transmitted by less than C PAs. To avoid an increase in PAPR, the 8 / C cyclic shifts can be staggered on half or all of the comb offsets. The staggering on all comb offsets is similar to the 4 ports using comb 4 and 2 comb offsets. For example, for comb 4, 4 ports use CS{0,3,6,9} on comb offset 0, and the other 4 ports use CS{1,4,7,10} on comb offset 2. For another example, for comb 4, 2 ports use CS{0,6} on comb offset 0, 2 ports use CS{3,9} on comb offset 1, 2 ports use CS{0,6} on comb offset 2, and 2 ports use CS{3,9} on comb offset 3. For another example, for comb tooth 4, 2 ports use CS{0,6} at comb tooth offset 0, 2 ports use CS{1,7} at comb tooth offset 1, 2 ports use CS{3,9} at comb tooth offset 2, and 2 ports use CS{4,10} at comb tooth offset 3.

[0358] To illustrate the proposal, in Table 4, the ordering mode 1 of comb teeth 4 and the configured cyclic shift positions {CS0, CS1} are shown (i.e., the α0 of the first comb tooth offset is 0, and the α0 of the second comb tooth offset is 1). In Table 5, the ordering mode 2 of comb teeth 4 and the configured cyclic shift positions {CS0, CS2} are shown, i.e., the α0 of the first comb tooth offset is 0, and the α0 of the second comb tooth offset is 2. In Table 6, the ordering mode 2 of comb teeth 8 and the configured cyclic shift positions {CS0, CS1, CS2, CS0} are shown, i.e., the α0 of the comb tooth offsets are 0, 1, 2, and 0, respectively. For comb teeth 2, there is no need to configure multiple cyclic shift positions unless more flexibility is required.

[0359] Table 4 Cyclic shift mapping for comb tooth 4 sorting mode 1 and configured cyclic shift position {CS0, CS1}

[0360] CS0 CS1 CS2 CS3 CS4 CS5 CS6 CS7 CS8 CS9 CS10 CS11 RE0 1000 1001 1002 1003 RE2 1004 1005 1006 1007

[0361] Table 5 Cyclic shift mapping for comb 4 sorting mode 2 and configured cyclic shift position {CS0, CS2}

[0362] CS0 CS1 CS2 CS3 CS4 CS5 CS6 CS7 CS8 CS9 CS10 CS11 RE0 1000 1002 1004 1006 RE2 1001 1003 1005 1007

[0363] Table 6 Cyclic shift mapping for comb tooth 8 sorting mode 2 and configured cyclic shift positions {CS0, CS1, CS2, CS0}

[0364] CS0 CS1 CS2 CS3 CS4 CS5 RE0 1000 1004 RE2 1001 1005 RE4 1002 1006 RE6 1003 1007

[0365] for 8 antenna ports By p i =1000+i. For comb tooth 2, that is, K TC =2, the specific implementation is as follows. The configured cyclic shift Used according to and Generates the cyclic shift position, where is the maximum number of cyclic shifts. If p i ∈{1001,1003,1005,1007} ​​and Then the frequency domain starting position term is otherwise,

[0366] for and comb tooth 4, i.e. K TC =4, the specific implementation is as follows. For J comb tooth offsets, a total of J∈{2,4} configured cyclic shifts Used according to and Generates the cyclic shift position, where when When j = 0, When j=1, and so on. The frequency domain starting position items of these ports are These equations can be extended to comb offsets for 8 and 4 configurations.

[0367] Finally, non-equidistant cyclic shifts and comb offsets can be supported. For 8-port SRS resources in the SRS resource set with the usage mode of "codebook" or "antenna switching", non-equidistant configurations of one or more comb offsets and / or cyclic shifts can be supported. The 8 ports in the SRS resource (even n>8, i.e. more than 8 ports in future versions) can be distributed from 1 to K TC Comb offsets, at each comb offset, 1 or more (up to n or the maximum number of CSs in that comb offset) cyclic shifts can be allocated. The number of comb offsets configured with ports can be 3, 5, etc., and does not have to be divisible by n or K. TC , the intervals of the comb tooth offsets do not have to be equal. The intervals of the ports on each comb tooth offset do not have to be equal, and different comb tooth offsets can allocate different numbers of ports to SRS resources. The cyclic shift can be configured per port or per comb tooth offset.

[0368] When 8 ports are configured with m OFDM symbols, these m OFDM symbols can be adjacent in one time slot, and m is 2, 4, 8, 10, 12, or 14. It should be noted here that m should not be interpreted as the TDM splitting factor, because the TDM scheme can still be enabled with repetition, frequency hopping, and / or RPFS. To distinguish, the TDM splitting factor is represented as s, which should be 2 or 4, and s=8 can also be supported. In addition, for simplicity, m should also be divisible by s.

[0369] On each of the m OFDM symbols, there should be exactly 8 / s ports. Whether or not frequency hopping is enabled, the ports for TDM on s consecutive OFDM symbols should be different but have the same PRB / comb offset allocation. For example, for ports {1000,…,1007} ​​for TDM when s=2, the first symbol can have ports {1000,1001,1004,1005}, the second symbol can have ports {1002,1003,1006,1007}, and on each symbol, 4 ports are allocated to physical resources and cyclic shift positions according to the traditional 4-port SRS mechanism. This consideration is based on coherent port groups. For the codebook design of 8Tx partially coherent UE configured with 8-port SRS resources, when Ng = 2, two coherent groups {0, 1, 4, 5} and {2, 3, 6, 7} can be configured; when Ng = 4, four coherent groups {0, 4}, {1, 5}, {2, 6} and {3, 7} can be configured. Therefore, to maintain consistency, if applicable, the port mapping within the set of s OFDM symbols can be split according to the coherent group.

[0370] Several detailed example designs include:

[0371] The ports can be split into {1000, 1002, 1004, 1006} and {1001, 1003, 1005, 1007} ​​or other combinations at different comb offsets. Whether different splitting methods are substantive may depend on the UE implementation. For simplicity, it can be split only once, for example, {1000, ..., 1003} and {1004, ..., 1007}. If necessary, more splitting can be supported. In general, the sorting method can be similar to the content discussed for comb offset and cyclic shift mapping sorting methods, and up to 2 sorting methods can be supported, namely, first mapping 8 / s consecutive ports to one OFDM symbol and then moving on to the next OFDM symbol, or first mapping s consecutive ports to s OFDM symbols and then mapping the next s consecutive ports to s OFDM symbols.

[0372] To map ports on an OFDM symbol to cyclic shift positions, the port indices can be remapped to reuse the traditional 4-port equation. For example, {1001, 1003, 1005, 1007} ​​can be remapped to {1000', 1001', 1002', 1003'} and use a 4-port cyclic shift mapping. This can be done by the equation To achieve this, for 8 ports, p i =1000+i,p i 'To be used in the existing cyclic shift equation as the equation in 3GPP TS 38.211 p i .

[0373] If repetition, frequency hopping and / or RPFS are also enabled, the 8 ports should transmit as a whole on consecutive OFDM symbols. For example, for a configuration with s=2 and 2 repetitions, there are ports {1000,…,1007} ​​in m=4 OFDM symbols. On 4 adjacent OFDM symbols, the transmissions should be {1000,…,1003}, {1004,…,1007}, {1000,…,1003}, {1004,…,1007}. In other words, repetition or hopping should be performed after all 8 ports have completed detection as a whole. Other orderings are possible, namely {1000,…,1003}, {1000,…,1003}, {1004,…,1007}, {1004,…,1007}, but the time domain diversity of each port is slightly worse. If the repetition factor is R, it may be advantageous to make m divisible by s*R. 3GPP TS 38.211 and 3GPP TS 38.214 include The existing equation will change to in, Here is m. For example, for periodic or semi-static SRS, Change to For aperiodic SRS, Change to

[0374] Table 7 8-port SRS resources with 4 repetitions on 8 OFDM symbols and TDM split factor 2

[0375]

[0376] In some embodiments, for 8-port SRS resources in the SRS resource set with a usage mode of "codebook" or "antenna switching" (configured with a TDM partitioning factor s≥1 and a resource mapping of m≥2 OFDM symbols), m=2, 4, 8, 10, 12, 14 and s=1, 2, 4 can be supported, where m is a multiple of s. These 8 ports are scattered over s adjacent OFDM symbols, and each symbol has p=8 / s different ports. On each OFDM symbol, the resource mapping reuses the existing p-port mapping, where ports {1000,…,1000+p–1} are on the first symbol, {1000+p,…,1000+2p–1} are on the second symbol, and so on, and these ports are remapped to {1000',…,(1000+p-1)'} on each symbol to achieve cyclic shift mapping. When s=1, TDM is not enabled.

[0377] An exemplary method includes: a user equipment (UE) receives control information of a first sounding reference signal (SRS) resource, wherein the control information is used to at least indicate a first frequency resource in a carrier, a frequency domain shift parameter, a partial sounding factor (PF) value, and a frequency domain offset value; the UE sends a first SRS resource on a first portion of frequency sounding resources within a first frequency resource in the carrier according to the control information, wherein a resource starting physical resource block (PRB) of the first frequency resource is based on the frequency domain shift parameter, a bandwidth of the first portion of frequency sounding resources is based at least on the PF value and the bandwidth of the first frequency resource, and a partial frequency sounding resource starting PRB of the first portion of frequency sounding resources is based at least on a resource starting PRB of the first frequency resource and a frequency domain offset value.

[0378] SRS may collide with other transmissions and thus may be dropped. The existing baseline approach to SRS collision handling is to drop SRS transmissions on a per-symbol basis. This works well for SRS resources that are not TDMed. However, for SRS ports that are TDMed, if transmissions within a group of {1,2,…,s} are dropped on an OFDM symbol, the remaining SRS transmissions in the group may not be useful to the gNB, especially when one or more of the dropped ports are in a coherent group with one or more other ports. In addition, for subsequent PUSCH transmissions that rely on SRS resources that are codebook-based, it may be unclear what the SRI refers to when some ports in the SRS resource are dropped while other ports transmit.

[0379] To solve these technical problems, one approach is to discard all transmissions when discarding any transmission in the group {1,2,…,s}. If higher "precision" is desired, the UE can discard all transmissions when discarding any transmission in the coherent group of ports with the usage mode set to "codebook", and different coherent groups can decide to discard independently.

[0380] More complex optimizations can also be considered. In fact, when SRS repetition is configured, dropping on one OFDM symbol does not affect the gNB's ability to estimate the channel for each port. As long as a complete set of 8 ports can be transmitted in the m OFDM symbols configured for SRS resources within a time slot, there is no need to drop the entire group {1,2,…,s}. In addition, the UE can swap the transmission of some ports based on the dropping decision, which helps to keep all 8 ports being sounded. The gNB and UE are aware of the dropping and swapping, so there is no problem of the network and UE being "out of sync". However, this approach is much more complicated and may not be favored by UE / network vendors.

[0381] Proposal 7: For 8-port SRS resources with the usage mode of "codebook" or "antenna switching" and TDM factor s=2 in the SRS resource set, when s subsets of ports are mapped to m≥2 OFDM symbols in the time slot according to the pattern {{1,2,…,s},…,{1,2,…,s}} (a total of m / s groups {1,2,…,s}), and when SRS transmission on a subset of s OFDM symbols in the group {1,2,…,s} is discarded:

[0382] If m / s=1, the UE drops SRS transmission on the remaining OFDM symbols in the group {1, 2, ..., s}.

[0383] If m / s>1, the UE transmits SRS on the remaining m OFDM symbols if the complete set of 8 ports can be transmitted on the OFDM symbols not affected by the drop; otherwise, the UE drops SRS transmission on all m OFDM symbols.

[0384] If comb offset hopping is configured for SRS resources under TDM, when multiple groups {1,2,…,s} are transmitted in a timeslot, the hopping pattern between groups can follow the configuration combOffsetHoppingWithRepetition=Per-R-Repetition or CombOffsetHoppingWithRepetition=Per-symbol. Within each group {1,2,…,s}, there can be hopping and no hopping. With hopping, multiplexing with other SRS can be achieved more easily, but without hopping, UE / gNB characteristics can be simplified. There are several options.

[0385] Option 1: The time domain characteristics of the cyclic shift hopping and / or comb offset hopping depend on the OFDM symbol index l' of each symbol.

[0386] Option 2: If HoppingWithRepetition=Per-R-Repetition (or the first symbol among s OFDM symbols), the time domain characteristics of the cyclic shift hopping and / or comb offset hopping depend on the OFDM symbol index l' of the first symbol among m OFDM symbols.

[0387] Option 3: Cyclic shift hopping and comb offset hopping of 8-port SRS are not supported.

[0388] For a given SRS resource, the UE is configured with a repetition factor R∈{1,2,4} or R∈{1,2,3,4,5,6,7,8,10,12,14} through the high-level parameter resourceMapping in SRS-Resource, where R≤N s / s, if the high-level parameters related to s are configured, s=2; otherwise, s=1. When frequency hopping is not configured in the SRS resource in each time slot, comb offset hopping is not configured and s=1 (R=N s ), the antenna ports in the SRS resources in each time slot are in all N s When frequency hopping is not configured in the SRS resource in each time slot, and comb offset hopping is not configured and s=2 (R=N s / s), according to Section 6.4.1.4.2 of [TS 38.211], the antenna ports {1000, 1001, 1004, 1005} in the SRS resources within each time slot are in N s The antenna ports {1000, 1002, 1004, 1006} in the SRS resources in each time slot are mapped in half of the N symbols. s The other half of the symbols are mapped to the same subcarrier set in the same PRB set. When frequency hopping is not configured in the SRS resources in each time slot, but comb offset hopping is configured and s=1 (R=N s ), according to Section 6.4.1.4.3 of [TS 38.211], the antenna ports in the SRS resources within each time slot are in all N s When frequency hopping is configured in the SRS resources within each time slot but without repetition (R=1), the SRS hopping parameter B defined in Section 6.4.1.4 of [4, TS 38.211] SRS , C SRS and bhop , the antenna ports in the SRS resources in each time slot are mapped to different subcarrier sets in each OFDM symbol, where it is assumed that different subcarrier sets have the same transmission comb value. When frequency hopping and repetition (N s ≥4, R ≥ 2), the antenna ports in the SRS resources in each time slot are mapped to the same set of subcarriers in each set of sR adjacent OFDM symbols. The frequency hopping on the set is based on the SRS hopping parameter B SRS , C SRS and b hop , where N s Should be divisible by R.

[0389] For operation in FR1 using shared spectrum channel access, the UE does not expect multiple hops of SRS resource transmission to be in different RB sets.

[0390] The UE may be configured with N timeslot hopping within the bandwidth portion. s =2, 4, 8, 10, 12 or 14 adjacent symbols of aperiodic SRS resources, where when frequency hopping is configured and R = 1, the full hopping bandwidth will be in N s The UE can be configured with N subbands that perform intra-slot frequency hopping within the bandwidth portion. s ≥4 adjacent symbols of aperiodic SRS resources, where when frequency hopping is configured and R≥2, N s ≥R,N s When it is divisible by sR, the full hopping bandwidth will be within sR adjacent OFDM symbols. If comb offset hopping is not configured, the antenna ports in the SRS resource are mapped to the same subcarrier set in each set of sR adjacent OFDM symbols in the resource.

[0391] The UE may be configured with N timeslot hopping within a bandwidth portion. s = 1 The UE may be configured with N symbols for intra-slot hopping and inter-slot hopping within the bandwidth part. s = 2, 4, 8, 10, 12 or 14 symbols of periodic or semi-static SRS resources, where the SRS resources occupy one or more identical symbol positions in each time slot. s ≥4, when frequency hopping is configured and R ≥ 2, the antenna ports in the SRS resource are all in the sR adjacent OFDM symbols in the resource in each time slot. The N sets are mapped to different subcarrier sets to support intra-slot hopping and inter-slot hopping. s It should be divisible by sR. The antenna ports in the SRS resource are mapped to the same set of subcarriers in each set of sR adjacent OFDM symbols in the resource in each time slot. s =sR, when frequency hopping is configured, if comb offset hopping is not configured, inter-slot frequency hopping is supported by mapping the antenna ports in the SRS resources to the same set of subcarriers in R adjacent OFDM symbols in the resources within each slot.

[0392] Figure 6 An exemplary communication system 600 is shown. In general, the system 600 enables multiple wireless or wired users to send and receive data and other content. The system 600 can implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

[0393] In this example, the communication system 600 includes electronic devices (ED) 610a to 610c, radio access networks (RAN) 620a and 620b, a core network 630, a public switched telephone network (PSTN) 640, the Internet 650, and other networks 660. Figure 6 A certain number of these components or units are shown, but any number of these components or units may be included in system 600 .

[0394] EDs 610a to 610c are used to operate or communicate in the system 600. For example, EDs 610a to 610c are used to send or receive through a wireless communication channel or a wired communication channel. Each ED 610a to 610c represents any suitable end-user device and may include (or may be referred to as): user equipment / device (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular phone, personal digital assistant (PDA), smart phone, laptop, computer, touch pad, wireless sensor or consumer electronic device.

[0395] Here, the RAN 620a and 620b include base stations 670a and 670b, respectively. The base stations 670a and 670b are used to wirelessly connect to one or more EDs in ED610a to 610c so as to access the core network 630, PSTN 640, Internet 650 or other networks 660. For example, the base stations 670a and 670b may include (or may be) one or more of several well-known devices, such as a base transceiver station (BTS), Node-B (NodeB), evolved NodeB (eNodeB), next generation (NG) base station (NG NodeB, gNB), home base station, home eNodeB, site controller, access point (AP) or wireless router. ED 610a to 610c are used to connect and communicate with the Internet 650, and can access the core network 630, PSTN 640 or other networks 660.

[0396] exist Figure 6 In the illustrated embodiment, base station 670a is part of RAN 620a, which may include other base stations, units and / or devices. Similarly, base station 670b is part of RAN 620b, which may include other base stations, units or devices. Base stations 670a and 670b both send or receive wireless signals within a specific geographic area or region (sometimes referred to as a "cell"). In some embodiments, multiple-input multiple-output (MIMO) technology may be used so that multiple transceivers are used for each cell.

[0397] Base stations 670a and 670b communicate with one or more of EDs 610a-610c using wireless communication links over one or more air interfaces 690. Air interfaces 690 may utilize any suitable radio access technology.

[0398] It is contemplated that the system 600 may use multi-channel access functionality, including the schemes described above. In an embodiment, the base station and ED implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and wireless protocols may also be used.

[0399] RAN 620a and 620b communicate with core network 630 to provide voice, data, applications, voice over Internet Protocol (VoIP) or other services to ED 610a to 610c. It is understood that RAN 620a and 620b or core network 630 can communicate directly or indirectly with one or more other RANs (not shown). Core network 630 can also be used as a gateway access for other networks (e.g., PSTN 640, Internet 650, and other networks 660). In addition, some or all of ED 610a to 610c may include functions for communicating with different wireless networks through different wireless links using different wireless technologies or protocols. Instead of wireless communication (or in addition to wireless communication), ED can also communicate with a service provider or switch (not shown) and communicate with Internet 650 through a wired communication channel.

[0400] Although Figure 6 An example of a communication system is shown, but the Figure 6 For example, communication system 600 may include any number of EDs, base stations, networks, or other components in any suitable configuration.

[0401] Fig. 7A and Figure 7B An exemplary device that can implement the methods and guidance provided by the present disclosure is shown. Specifically, Fig. 7A An exemplary ED 710 is shown, Figure 7B An exemplary base station 770 is shown. These components may be used in system 600 or any other suitable system.

[0402] like Fig. 7AAs shown, ED 710 includes at least one processing unit 700. Processing unit 700 implements various processing operations of ED 710. For example, processing unit 700 can perform signal encoding, data processing, power control, input / output processing, or any other function that enables ED 710 to operate in system 600. Processing unit 700 also supports the methods and instructions described in detail above. Each processing unit 700 includes any suitable processing device or computing device for performing one or more operations. For example, each processing unit 700 may include a microprocessor, a microcontroller, a digital signal processor, a field programmable gate array, or an application-specific integrated circuit.

[0403] ED 710 also includes at least one transceiver 702. Transceiver 702 is used to modulate data or other content so as to be transmitted through at least one antenna or network interface controller (NIC) 704. Transceiver 702 is also used to demodulate data or other content received through at least one antenna 704. Each transceiver 702 includes any suitable structure for generating a signal for wireless transmission or wired transmission or for processing a signal received wirelessly or wired. Each antenna 704 includes any suitable structure for sending or receiving a wireless signal or a wired signal. One or more transceivers 702 can be used in ED 710, and one or more antennas 704 can be used in ED 710. Although transceiver 702 is shown as a separate functional unit, transceiver 702 can also be implemented using at least one transmitter and at least one separate receiver.

[0404] ED 710 also includes one or more input / output devices 706 or interfaces (e.g., a wired interface to the Internet 650). Input / output devices 706 support interaction with users or other devices in a network (network communication). Each input / output device 706 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

[0405] In addition, the ED 710 includes at least one memory 708. The memory 708 stores instructions and data used, generated, or collected by the ED 710. For example, the memory 708 can store software instructions or firmware instructions executed by one or more processing units 700 and data for reducing or eliminating interference in input signals. Each memory 708 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Any suitable type of memory can be used, for example, random access memory (RAM), read only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) card, etc.

[0406] like Figure 7B As shown, the base station 770 includes at least one processing unit 750, at least one transceiver 752 including the functions of a transmitter and a receiver, one or more antennas 756, at least one memory 758, and one or more input / output devices or interfaces 766. A scheduler as understood by those skilled in the art is coupled to the processing unit 750. The scheduler may be included in the base station 770 or may be operated separately from the base station 770. The processing unit 750 implements various processing operations of the base station 770, such as signal encoding, data processing, power control, input / output processing, or any other function. The processing unit 750 may also support the methods and instructions described in detail above. Each processing unit 750 includes any suitable processing device or computing device for performing one or more operations. For example, each processing unit 750 may include a microprocessor, a microcontroller, a digital signal processor, a field programmable gate array, or an application specific integrated circuit.

[0407] Each transceiver 752 includes any suitable structure for generating a signal for wireless transmission or wired transmission to one or more EDs or other devices. Each transceiver 752 also includes any suitable structure for processing signals received from one or more EDs or other devices by wireless or wired means. Although the transmitter and receiver are shown as a transceiver 752, the transmitter and receiver can be separate components. Each antenna 756 includes any suitable structure for sending or receiving wireless signals or wired signals. Although a common antenna 756 is shown coupled to the transceiver 752, one or more antennas 756 can be coupled to one or more transceivers 752, thereby allowing a separate antenna 756 to be coupled to the transmitter and receiver when the transmitter and receiver are configured as separate components. Each memory 758 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Each input / output device 766 supports interaction with users or other devices in the network (network communication). Each input / output device 766 includes any suitable structure for providing information to a user or receiving / providing information from a user, including network interface communication.

[0408] Figure 8 800 is a block diagram of a computing system 800 that can be used to implement the devices and methods disclosed herein. For example, the computing system can be any entity in a UE, an access network (AN), a mobility management (MM), a session management (SM), a user plane gateway (UPGW), or an access stratum (AS). A particular device may use all of the components shown or only a subset of the components, and the level of integration may vary from device to device. In addition, a device may include multiple instances of a component, such as multiple processing units, multiple processors, multiple memories, multiple transmitters, multiple receivers, etc. The computing system 800 includes a processing unit 802. The processing unit includes a central processing unit (CPU) 814, a memory 808, and may also include a mass storage 804, a video adapter 810, and an I / O interface 812 connected to a bus 820.

[0409] Bus 820 can be one or more of several bus architectures of any type, including a memory bus or storage controller, a peripheral bus or a video bus. CPU 814 can include any type of electronic data processor. Memory 808 can include any type of non-transient system memory, for example, static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM) or a combination thereof. In one embodiment, memory 808 can include a ROM for use at startup and a DRAM for storing programs and data used when executing a program.

[0410] Mass storage 804 may include any type of non-transitory storage device for storing data, programs, and other information and making the data, programs, and other information accessible via bus 820. For example, mass storage 804 may include one or more of a solid-state drive, a hard disk drive, a magnetic disk drive, or an optical disk drive.

[0411] The video adapter 810 and the I / O interface 812 provide interfaces for coupling external input and output devices to the processing unit 802. As shown, examples of input and output devices include a display 818 coupled to the video adapter 810 and a mouse, keyboard, or printer 816 coupled to the I / O interface 812. Other devices can be coupled to the processing unit 802, and additional or fewer interface cards can be used. For example, a serial interface such as a Universal Serial Bus (USB) (not shown) can be used to provide an interface for external devices.

[0412] The processing unit 802 also includes one or more network interfaces 806, which may include wired links, such as Ethernet cables, or wireless links to access nodes or different networks. The network interface 806 enables the processing unit 802 to communicate with remote units via a network. For example, the network interface 806 may provide wireless communication via one or more transmitters / transmit antennas and one or more receivers / receive antennas. In one embodiment, the processing unit 802 is coupled to a local area network 822 or a wide area network to process and communicate data with remote devices such as other processing units, the Internet, or remote storage facilities.

[0413] One way to increase network resources is to use more available spectrum resources, which include not only licensed spectrum resources of the same type as the macro, but also licensed spectrum resources of different types from the macro (for example, the macro is an FDD cell, but the small cell can use both FDD carriers and TDD carriers), and can also include unlicensed spectrum resources and shared licensed spectrum. Some spectrum resources are located in high frequency bands, for example, 6GHz to 60GHz. Unlicensed spectrum is generally available to any user, subject to regulatory requirements. Shared licensed spectrum is also not a spectrum dedicated to operators. Traditionally, cellular networks do not use unlicensed spectrum because it is usually difficult to ensure quality of service (QoS) requirements. Networks operating on unlicensed spectrum mainly include wireless local area networks (WLANs), such as Wi-Fi networks. Since licensed spectrum is usually scarce and expensive, cellular operators can consider using unlicensed spectrum. Note that on high frequency bands and unlicensed / shared licensed bands, TDD is usually used, so channel reciprocity can be used for communication.

[0414] In actual deployment, a gNB can control one or more cells. Multiple RF remote units can be connected to the same baseband unit of the gNB via optical cables, and the latency between the baseband unit and the RF remote unit is quite small. Therefore, the same baseband unit can handle the coordinated transmission / reception of multiple cells. For example, the gNB can coordinate the transmission of multiple cells to the UE, which is called coordinated multiple point (CoMP) or multi-TRP (mTRP, M-TRP) transmission. The gNB can also coordinate the reception of multiple cells from the UE, which is called CoMP / M-TRP reception. In this case, the backhaul link between these cells associated with the same gNB is a fast backhaul link, so the scheduling of data sent by the UE in different cells can be easily coordinated in the same gNB. The backhaul connection can also have lower latency and lower transmission rate.

[0415] Fig. 9 FIG. 4 shows the case of using carrier aggregation (CA), which is another deployment strategy. Fig. 9As shown, system 950 is a typical wireless network configured with carrier aggregation (CA), wherein communication controller 960 communicates with wireless device 965 via wireless link 970 (solid line), and communicates with wireless device 966 via wireless link 972 (dashed line) and wireless link 970, respectively. In some exemplary deployments, for wireless device 966, wireless link 970 may be referred to as a primary component carrier (PCC), and wireless link 972 may be referred to as a secondary component carrier (SCC). In some carrier aggregation deployments, PCC may carry feedback from UE to communication controller, while SCC may only carry data traffic. In 3GPP specifications, component carriers are referred to as cells. When multiple cells are controlled by the same eNB, cross-scheduling of multiple cells may be achieved because there may be a single scheduler in the same eNB to schedule multiple cells. Through CA, one eNB can operate and control several component carriers that form a primary cell (PCell) and a secondary cell (SCell).

[0416] Fig. 10A Physical layer channels and signals (including PSS / SSS, PBCH and its associated DMRS) provided by some embodiments are shown. Fig. 10B Some embodiments provide for multiplexing of signals / channels for more than one PDSCH (this may be for the same UE to receive one or more PDSCH transmissions from one or more TRPs). Fig. 10C Examples of non-zero power (NZP) CSI-RS for channel estimation, interference measurement, etc. provided by some embodiments are shown, where these NZP CSI-RS are multiplexed with PDSCH for use by one or more UEs.

[0417] Physical layer channels and signals include PSS / SSS, PBCH and its associated DMRS (see Fig. 10A etc., where the SS burst is embedded, i.e. multiplexed with the surrounding PBCH), PDSCH and its associated DMRS and phase tracking reference signal (PT-RS), PDCCH and its associated DMRS (see Fig. 10B etc., where some signals / channels are multiplexed for use by more than one UE), and CSI-RS. CSI-RS also includes CSI-RS for CSI acquisition, for beam management, and for tracking (see Fig. 10C, shows some examples of non-zero power (NZP) CSI-RS for channel estimation, interference measurement, etc., where the NZP CSI-RS is multiplexed with the PDSCH for use by one or more UEs). The CSI-RS used for tracking is also called a tracking reference signal (TRS).

[0418] The UE receives a timing advance (TA) command associated with a configured TA group (TAG) to adjust its uplink transmission timing so as to synchronize uplink transmissions with the network so that uplink transmissions from multiple UEs arrive at the base station approximately simultaneously within a transmission time interval (TTI). Similarly, the UE needs to receive DL reference signals (RS) or synchronization signal (SS) blocks, also known as SS / physical broadcast channel (PBCH) blocks SS / PBCH blocks (SSBs) to acquire and maintain DL synchronization by, for example, maintaining a DL timing tracking loop, according to which the UE places the starting point of its FFT window within the cyclic prefix (CP) of its DL reception. In addition, both the UL signal / channel and the DL signal / channel will be associated with some other signals to obtain signal / channel properties, such as delay spread, Doppler frequency deviation, etc.

[0419] A sounding reference signal (SRS) is a reference signal sent by a user equipment (UE) in the uplink to achieve uplink channel estimation over a certain bandwidth. Therefore, the network may be able to communicate with the UE based on the uplink channel estimation. In addition, due to the channel reciprocity between uplink and downlink in a time division duplex (TDD) communication system, the network can use SRS to perform dynamic scheduling. In other words, the network can use channel-dependent scheduling. In this case, time-frequency resources are dynamically scheduled, taking into account different traffic priorities and quality of service requirements. Typically, the UE monitors several Physical Downlink Control Channels (PDCCH) to obtain scheduling decisions, which are indicated to the UE by the network. When a valid PDCCH is detected, the UE receives (or sends) data according to the scheduling decision.

[0420] The configuration of SRS-related parameters (e.g., SRS transmission port, SRS transmission bandwidth, SRS resource set, transmission comb and cyclic shift, etc.) of the SRS to be sent in the uplink is semi-static in nature and can be provided through high-layer signaling such as radio resource control signaling. In addition, the association between downlink reference signals such as channel state information reference signal (CSI-RS) or demodulation reference signal (DMRS) and uplink SRS should be conveyed to the UE to accurately reflect the interference situation and perform optimal beamforming. Therefore, there is a need for an apparatus and method for indicating control information that accurately indicates a more dynamic configuration (not semi-static) of the above parameters, for example, using a subset of transmission ports associated with a specific set of downlink reference signals to transmit a portion of the transmission bandwidth required for a subset of SRS resource sets (thereby implicitly indicating the transmission comb and cyclic shift). The indication of the control information can be closely linked to the actual data transmission. The transmitted SRS can be a periodic SRS (i.e., periodic SRS, P-SRS, or P SRS) configured through layer 3 RRC configuration signaling, a semi-static SRS (i.e., semi-static SRS, SP-SRS, or SP SRS) activated / deactivated through layer 2 MAC CE, or an aperiodic SRS (i.e., aperiodic SRS, A-SRS, or AP-SRS, or A SRS, or AP SRS) indicated by layer 1 DCI in PDCCH.

[0421] Fig.11A A flow chart of a method 1100 performed by a network device provided in some embodiments is shown. The network device may include computer-readable code or instructions executed on one or more processors in the network device. For those of ordinary skill in the art, encoding software for implementing or executing method 1100 is well within the scope of the present disclosure. Method 1100 may include more or fewer operations than those shown and described, and may be implemented or executed in a different order. The computer-readable code or instructions of the software executable by the one or more processors may be stored in a non-transitory computer-readable medium, for example, in a memory of the network device.

[0422] Method 1100 begins at operation 1102, where the network device configures a first sounding reference signal (SRS) resource. The first SRS resource is associated with a first transmission parameter defined on a value set. In operation 1104, the network device configures the first transmission parameter for the first SRS resource to jump on a first value subset of the value set. In operation 1106, the network device receives a first SRS on the first SRS resource. The first SRS causes the first transmission parameter to jump according to the first value subset.

[0423] In some embodiments, the value set includes a second value subset for resource hopping of a second SRS resource. The network device may configure the second SRS resource. The second SRS resource may be associated with a second transmission parameter defined on the value set. The network device may configure the second transmission parameter for the second SRS resource to hop on the second value subset of the value set. The network device may receive a second SRS on the second SRS resource. The second SRS causes the second transmission parameter to hop according to the second value subset. The first SRS resource and the second SRS resource may at least partially overlap in the time domain or the frequency domain.

[0424] In some embodiments, the resource hopping may include a cyclic shift (CS) hopping. The first value subset may be a first subset of a CS value set used for the CS hopping. The second value subset may be a second subset of the CS value set used for the CS hopping.

[0425] In some embodiments, the resource hopping may include a comb offset hopping. The first value subset may be a first subset of a comb offset value set for the comb offset hopping. The second value subset may be a second subset of the comb offset value set for the comb offset hopping. The first value subset may include a first comb offset value, and the second value subset may include a second comb offset value.

[0426] In some embodiments, the first SRS resource may be configured for a first user equipment (UE). The second SRS resource may be configured for a second UE different from the first UE.

[0427] In some embodiments, the resource hopping may include a CS hopping.The first subset of values ​​may be a first subset of a CS value set used for the CS hopping.

[0428] In some embodiments, the resource hopping may include a comb offset hopping.The first subset of values ​​may be a first subset of a set of comb offset values ​​for the comb offset hopping.

[0429] In some embodiments, the first value subset of the first SRS can jump on the first value subset on multiple SRS transmission occasions according to an SRS hopping randomization identifier (identifier, ID), a pseudo-random integer sequence on the multiple SRS transmission occasions, a configured first resource value, the number of values ​​in the first value subset and a time domain index of the multiple SRS transmission occasions.

[0430] In some embodiments, the first SRS resource may be configured with multiple ports. The multiple ports may perform hopping according to the same pseudo-random integer sequence on the multiple SRS transmission opportunities. In each of the multiple SRS transmission opportunities, the multiple ports may all use the same pseudo-random integer value.

[0431] In some embodiments, the time domain index may be based on a system frame number (SFN), a time slot number within the SFN, and an orthogonal frequency-division multiplexing (OFDM) symbol index within a time slot.

[0432] In some embodiments, the first number of values ​​in the first subset may be 1, or the second number of values ​​in the second subset may be 1.

[0433] Fig. 11B A flowchart of a method 1120 performed by a user equipment (UE) provided in some embodiments is shown. The UE may include computer-readable code or instructions executed on one or more processors in the UE. For those of ordinary skill in the art, encoding software for implementing or executing method 1120 is fully within the scope of the present disclosure. Method 1120 may include more or fewer operations than those shown and described, and may be implemented or executed in a different order. The computer-readable code or instructions of the software executable by the one or more processors may be stored in a non-transitory computer-readable medium, for example, in a memory of the UE.

[0434] Method 1120 begins at operation 1122, where the UE receives a first resource configuration from a network device. The first resource configuration is used to configure a first sounding reference signal (SRS) resource. The first SRS resource is associated with a first transmission parameter defined on a value set. In operation 1124, the UE receives a first hopping configuration of the first SRS resource from the network device. The first hopping configuration is used to configure the first transmission parameter to hop on a first value subset of the value set. In operation 1126, the UE sends a first SRS to the network device on the first SRS resource. The first SRS causes the first transmission parameter to hop according to the first value subset.

[0435] In some embodiments, the UE may receive a second resource configuration from the network device. The second resource configuration may be used to configure the second SRS resource. The second SRS resource may be associated with a second transmission parameter defined on the value set. The UE may receive a second hopping configuration of the second SRS resource from the network device. The second resource configuration is used to configure the second transmission parameter to hop on a second value subset of the value set. The UE may send a second SRS to the network device on the second SRS resource. The second SRS may cause the second transmission parameter to hop according to the second value subset. The first SRS resource and the second SRS resource may at least partially overlap in the time domain or the frequency domain.

[0436] In some embodiments, the resource hopping may include a cyclic shift (CS) hopping. The first value subset may be a first subset of a CS value set used for the CS hopping. The second value subset may be a second subset of the CS value set used for the CS hopping.

[0437] In some embodiments, the resource hopping may include a comb offset hopping. The first value subset may be a first subset of a comb offset value set for the comb offset hopping. The second value subset may be a second subset of the comb offset value set for the comb offset hopping. The first value subset may include a first comb offset value, and the second value subset may include a second comb offset value.

[0438] In some embodiments, the resource hopping may include a CS hopping.The first subset of values ​​may be a first subset of a CS value set used for the CS hopping.

[0439] In some embodiments, the resource hopping may include a comb offset hopping.The first subset of values ​​may be a first subset of a set of comb offset values ​​for the comb offset hopping.

[0440] In some embodiments, the first value subset of the first SRS can jump on the first value subset on multiple SRS transmission occasions according to an SRS hopping randomization identifier (identifier, ID), a pseudo-random integer sequence on the multiple SRS transmission occasions, a configured first resource value, the number of values ​​in the first value subset and a time domain index of the multiple SRS transmission occasions.

[0441] In some embodiments, the first SRS resource may be configured with multiple ports. The multiple ports may perform hopping according to the same pseudo-random integer sequence on the multiple SRS transmission opportunities. In each of the multiple SRS transmission opportunities, the multiple ports may all use the same pseudo-random integer value.

[0442] In some embodiments, the time domain index may be based on a system frame number (SFN), a time slot number within the SFN, and an orthogonal frequency-division multiplexing (OFDM) symbol index within a time slot.

[0443] In some embodiments, the first number of values ​​in the first subset may be 1, or the second number of values ​​in the second subset may be 1.

[0444] Fig. 11C A flowchart of a method 1130 performed by a user equipment (UE) provided in some embodiments is shown. The UE may include computer-readable code or instructions executed on one or more processors in the UE. For those of ordinary skill in the art, encoding software for implementing or executing method 1130 is fully within the scope of the present disclosure. Method 1130 may include more or fewer operations than those shown and described, and may be implemented or executed in a different order. The computer-readable code or instructions of the software executable by the one or more processors may be stored in a non-transitory computer-readable medium, for example, in a memory of the UE.

[0445] Method 1130 starts at operation 1132, wherein the UE receives a configuration of a sounding reference signal (SRS) resource including 8 antenna ports, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource from a network device. The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a configured comb offset (k). k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. In operation 1134, the UE maps each of the 8 antenna ports to a corresponding CS and a corresponding resource element (RE) in the frequency domain. The corresponding RE is a subset of multiple REs, located on every K REs within the SRS transmission bandwidth, and has an offset based on the configured comb offset (k). In operation 1136, the UE sends an SRS to the network device using the 8 antenna ports according to the mapping.

[0446] In some embodiments, the corresponding RE may be located in an orthogonal frequency division multiplexing (OFDM) symbol.

[0447] In some embodiments, the usage of the SRS resources may be set to "codebook" or "antenna switching".

[0448] In some embodiments, the comb value K may be 2. The UE may map the 8 antenna ports to every K REs using the configured comb offset (k) within the SRS transmission bandwidth. Alternatively, within the SRS transmission bandwidth, the UE may map the first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port of the 8 antenna ports to every K REs using the configured comb offset (k), and map the second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port of the 8 antenna ports to every K REs using the comb offset (k+1) modulo K.

[0449] In some embodiments, the comb tooth value K may be 4. Within the SRS transmission bandwidth, the UE may use the configured comb tooth offset (k) to map the first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port of the eight antenna ports to every K REs, and use the comb tooth offset (k+2) modulo K to map the second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port of the eight antenna ports to every K REs.

[0450] In some embodiments, the comb tooth value K may be 8. The UE may use the configured comb tooth offset (k) to map the first antenna port and the fifth antenna port among the 8 antenna ports to every K REs, use the first comb tooth offset (k+2) modulo K to map the second antenna port and the sixth antenna port among the 8 antenna ports to every K REs, use the second comb tooth offset (k+4) modulo K to map the third antenna port and the seventh antenna port among the 8 antenna ports to every K REs, and use the third comb tooth offset (k+6) modulo K to map the fourth antenna port and the eighth antenna port among the 8 antenna ports to every K REs.

[0451] Fig.11D A flowchart of a method 1140 performed by a user equipment (UE) provided in some embodiments is shown. The UE may include computer-readable code or instructions executed on one or more processors in the UE. For those of ordinary skill in the art, encoding software for implementing or executing method 1140 is fully within the scope of the present disclosure. Method 1140 may include more or fewer operations than those shown and described, and may be implemented or executed in a different order. The computer-readable code or instructions of the software executable by the one or more processors may be stored in a non-transitory computer-readable medium, for example, in a memory of the UE.

[0452] Method 1140 starts at operation 1142, wherein the UE receives a configuration of a sounding reference signal (SRS) resource including 8 antenna ports and a time division multiplexing (TDM) parameter, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource from a network device. The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a comb offset k. k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. The SRS resource is mapped to m consecutive orthogonal frequency division multiplexing (OFDM) symbols in the same time slot. m is greater than or equal to 1. In operation 1144, the UE maps each of the m consecutive OFDM symbols to a corresponding subset of the 8 antenna ports according to m and s. s is determined according to the TDM parameters and is the number of subsets of the 8 antenna ports. In operation 1146, the UE transmits an SRS to the network device using the eight antenna ports according to the mapping.

[0453] In some embodiments, the UE may map an i-th subset of 8 / s antenna ports among the 8 antenna ports to every s OFDM symbols among the m consecutive OFDM symbols, starting from the i-th OFDM symbol among the m consecutive OFDM symbols, where i is 1 to s.

[0454] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same comb offset allocation and the same CS position.

[0455] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same physical resource block (PRB) allocation.

[0456] In some embodiments, the SRS transmission on the m consecutive OFDM symbols may be periodic, semi-static or aperiodic. The SRS transmission may be based on an SRS counter determined by s*R. R is a repetition factor configured for the SRS resource.

[0457] In some embodiments, m may be a multiple of s.

[0458] In some embodiments, m may be one of 2, 4, 8, 10, 12, or 14. s may be 2.

[0459] Fig.11E A flow chart of a method 1150 performed by a network device provided in some embodiments is shown. The network device may include computer readable code or instructions executed on one or more processors in the network device. For those of ordinary skill in the art, encoding software for implementing or executing method 1150 is well within the scope of the present disclosure. Method 1150 may include more or fewer operations than shown and described, and may be implemented or executed in a different order. The computer readable code or instructions of the software executable by the one or more processors may be stored in a non-transitory computer readable medium, for example, in a memory of the network device.

[0460] Method 1150 starts at operation 1152, wherein the network device sends a configuration of a sounding reference signal (SRS) resource including 8 antenna ports, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource to a user equipment (UE). The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a configured comb offset (k). k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. Each of the 8 antenna ports is mapped to a corresponding CS and a corresponding resource element (RE) in the frequency domain. The corresponding RE is a subset of a plurality of REs, located on every K REs within the SRS transmission bandwidth, and has an offset based on the configured comb offset (k). In operation 1154, the network device receives an SRS from the UE.

[0461] In some embodiments, the corresponding RE may be located in an orthogonal frequency division multiplexing (OFDM) symbol.

[0462] In some embodiments, the usage of the SRS resources may be set to "codebook" or "antenna switching".

[0463] In some embodiments, the comb value K is 2, and the 8 antenna ports can be mapped to every K REs using the configured comb offset (k) within the SRS transmission bandwidth. Alternatively, within the SRS transmission bandwidth, the first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port among the 8 antenna ports can be mapped to every K REs using the configured comb offset (k), and the second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port among the 8 antenna ports can be mapped to every K REs using the comb offset (k+1) modulo K.

[0464] In some embodiments, the comb value K is 4. The first antenna port, the third antenna port, the fifth antenna port, and the seventh antenna port among the 8 antenna ports can be mapped to every K REs using the configured comb offset (k). The second antenna port, the fourth antenna port, the sixth antenna port, and the eighth antenna port among the 8 antenna ports can be mapped to every K REs using the comb offset (k+2) modulo K within the SRS transmission bandwidth.

[0465] In some embodiments, the comb value K is 8. The first antenna port and the fifth antenna port among the 8 antenna ports can be mapped to each K RE using the configured comb offset (k). The second antenna port and the sixth antenna port among the 8 antenna ports can be mapped to each K RE using the first comb offset (k+2) modulo K. The third antenna port and the seventh antenna port among the 8 antenna ports can be mapped to each K RE using the second comb offset (k+4) modulo K. The fourth antenna port and the eighth antenna port among the 8 antenna ports can be mapped to each K RE using the third comb offset (k+6) modulo K.

[0466] Fig.11F A flow chart of a method 1160 performed by a network device provided by some embodiments is shown. The network device may include computer readable code or instructions executed on one or more processors in the network device. For those of ordinary skill in the art, encoding software for implementing or executing method 1160 is well within the scope of the present disclosure. Method 1160 may include more or fewer operations than shown and described, and may be implemented or executed in a different order. The computer readable code or instructions of the software executable by the one or more processors may be stored in a non-transitory computer readable medium, for example, in a memory of the network device.

[0467] Method 1160 begins at operation 1162, wherein the network device sends a configuration of a sounding reference signal (SRS) resource including 8 antenna ports and time division multiplexing (TDM) parameters, a transmission comb configuration of the SRS resource, and a cyclic shift (CS) configuration of the SRS resource to a user equipment (UE). The transmission comb configuration is used to indicate a comb value K. K is one of 2, 4, or 8. The transmission comb configuration is also used to indicate a comb offset k. k is an integer between 0 and K–1. The CS configuration is used to indicate a CS position. The SRS resource is mapped to m consecutive orthogonal frequency division multiplexing (OFDM) symbols in the same time slot. m is greater than or equal to 1. Each of the m consecutive OFDM symbols is mapped to a corresponding subset of the 8 antenna ports according to m and s. s is determined based on the TDM parameters and is the number of subsets of the 8 antenna ports. In operation 1164, the network device receives an SRS from the UE.

[0468] In some embodiments, the UE may map an i-th subset of 8 / s antenna ports among the 8 antenna ports to every s OFDM symbols among the m consecutive OFDM symbols, starting from the i-th OFDM symbol among the m consecutive OFDM symbols, where i is 1 to s.

[0469] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same comb offset allocation and the same CS position.

[0470] In some embodiments, the SRS transmissions on the m consecutive OFDM symbols may be mapped using the same physical resource block (PRB) allocation.

[0471] In some embodiments, the SRS transmission on the m consecutive OFDM symbols may be periodic, semi-static or aperiodic. The SRS transmission may be based on an SRS counter determined by s*R. R is a repetition factor configured for the SRS resource.

[0472] In some embodiments, m may be a multiple of s.

[0473] In some embodiments, m may be one of 2, 4, 8, 10, 12, or 14. s may be 2.

[0474] The present disclosure provides a numerical study of the path loss difference of TRP common SRS. According to a dense city with 200m ISD, 210 UEs are deployed in a 21-sector network. For each UE, the sector with the highest RSRP is selected as the serving cell / serving TRP, and the other three sectors with the second highest, third highest, and fourth highest RSRP are selected as the other CJT candidate TRPs. Since the transmission power of all sectors is the same, the path loss difference of each UE is equal to the RSRP difference. Then, the path loss difference between the candidate CJT TRP and the serving cell is calculated for each UE, and finally obtained Fig. 12A The three CDF curves in . Fig. 12A The cumulative distribution function (CDF) of the path loss difference between the second strongest cell and the serving cell, the CDF of the path loss difference between the third strongest cell and the serving cell, and the CDF of the path loss difference between the fourth strongest cell and the serving cell are shown. The vertical lines are located at 3dB, 6dB, and 10dB.

[0475] like Fig. 12A As shown, if only a 3dB path loss difference is allowed, about 28% of UEs can be served by 2 TRPs, about 5% of UEs can be served by 3 TRPs, and only about 1% of UEs can be served by 4 TRPs. Table 8 shows the percentage of UEs served by 2, 3, and 4 TRPs (path loss differences of up to 3dB, 6dB, and 10dB).

[0476] Table 8 Percentage of UEs served by 2, 3, and 4 TRPs (path loss difference is at most 3dB, 6dB, and 10dB)

[0477] 3dB 6dB 10dB 2 TRPs 28％ 50％ 73％ 3 TRPs 5％ 19％ 43％ 4 TRPs 1％ 5％ 20％

[0478] Then, the channel estimation performance under unbalanced received power and orthogonal / non-orthogonal SRS is studied. In the figure below, SRS1 consisting of 2 ports is sent on link 1, and SRS2 consisting of 2 ports is sent on link 2. These SRS are non-orthogonal or orthogonal through CDM (labeled as "cdm"), and one link may be weaker (labeled as "+6dB" due to higher path loss) or stronger (labeled as "–6dB" due to lower path loss). It should be noted that the 2 ports of the same RS have similar performance and their corresponding curves mostly overlap. Fig. 12B The channel estimation performance under received power imbalance and orthogonal / non-orthogonal SRS is shown.

[0479] The following are observations of cross-SRS interference under potential power imbalance. For non-orthogonal SRS, interference is observed to cause significant performance degradation, especially for the weaker of the two SRS signals. For orthogonal SRS, if the SRS are orthogonal (e.g., through CDM), the performance of both SRS is generally good, with slightly worse performance for weaker signals (if the signal is xdB weaker, the performance is approximately x dB lower), and slightly better performance for stronger signals (if the signal is x dB stronger, the performance is approximately x dB higher).

[0480] The following provides additional details and descriptions related to and / or expanding upon the above disclosure.

[0481] This disclosure provides a numerical study of cross-SRS interference and SRS performance.

[0482] SRS multiplexed within the CJT transmission area

[0483] If there is SRS interference generated by UEs within the CJT transmission area, the received power of the CJT TRP may be relatively high. Fig.13 The SRS performance under the same SRS sequence (cyclic shift interval is 1 or 2) or different SRS sequences (cyclic shift interval is 0 or 2) is shown. The 5th and 6th curves listed and the 7th and 8th curves listed are almost completely overlapped. Fig.13 In the simulation, two UEs multiplexed on the same time-frequency resources are simulated, each UE has two ports (unless otherwise specified, only one port is drawn because the performance of the two ports is similar). "cs04cs26" means that UE1 is configured with CS[0,4] and UE2 is configured with CS[2,6]. Unless otherwise specified, it is assumed that comb 2, 30ns delay spread and the same SRS sequence are used.

[0484] Fig.14 The SRS performance of the SRS port through CDM under CDL-C 300ns channel and cyclic shift interval of 1, 2 or 3 is shown.

[0485] If there is significant overlap of SRS in time / frequency / delay domain, for example, configured on the same RE with the same SRS sequence and one or more cyclic shifts, the performance of SRS will be significantly degraded. This also includes the case where the SRS sequence is the same, the delay spread is longer, and the cyclic shift interval is smaller, for example, the RMS delay spread is 300ns, but comb 4, CS0 and CS1 are configured. This problem can be avoided by configuring CS0 and CS2. The performance is worst when two SRS completely overlap / collide. This means that for SRS over CDM, when cyclic shift hopping / randomization is enabled, accidentally using the same cyclic shift on an OFDM symbol should be avoided.

[0486] For SRS with different SRS sequences, the interference may still be quite high.

[0487] The SRS with smaller overlap in the time domain, frequency domain, and delay domain has good channel estimation performance.

[0488] When the overlap in the time / frequency / delay domain is small, hopping / randomization can further improve the performance.

[0489] SRS interference outside the CJT transmission area

[0490] The SRS interference generated by UEs outside the CJT transmission area is usually uncoordinated, but their received power in the CJT TRP is usually relatively low, for example, at least 6dB lower than the expected SRS received power. Although the interference is weak, if the SRS happens to collide in the time domain / frequency domain / code domain / delay domain, for example, it happens to be configured on the same RE with the same SRS sequence and cyclic shift, the interference will still have an adverse effect on the channel estimation performance.

[0491] Fig.15 The SRS performance is shown for orthogonal ports, full collision ports, and partial collision with a weaker interfering port (last two curves listed, full collision of port 1 with the weaker interfering port, no interference of port 2).

[0492] This disclosure provides a numerical study of SRS cyclic shift hopping below.

[0493] SRS multiplexed within the CJT transmission area

[0494] For SRS ports through CDM, when one port is associated with long delay spread, the port will cause some interference to the other port. Without cyclic shift hopping, the interference may be quite persistent. To achieve interference randomization, cyclic shift hopping can be used for SRS ports through CDM. Fig.16 The SRS performance of cyclic shift hopping over the SRS port of CDM in the CDL-C 300ns channel is shown. Fig.16 The interference randomization effect due to cyclic shift hopping for a very long delay spread case is shown (for simplicity, only 1 port per UE is shown here). By cyclic shift hopping, the performance of different UEs becomes more uniform, which is desirable.

[0495] SRS interference outside the CJT transmission area

[0496] As described above, it may happen that a certain SRS outside the CJT transmission area is configured on the same RE with the same SRS sequence and cyclic shift as the SRS of the CJT UE. Although the interference power is weak, it will cause considerable channel estimation performance degradation. Fig.17 The SRS performance of cyclic shift hopping of the weaker interfering port is shown. Fig.17 In Figure 1, the first port of UE1 on CS0 is interfered by the weak SRS on CS0, while the second port on CS4 is not affected, which results in poor performance of the second port. If cyclic hopping is enabled, the effect of interference randomization can be seen.

[0497] The present disclosure provides below a numerical study of SRS fractional cyclic shift and the maximum number of SRS cyclic shifts.

[0498] For comb 4 and comb 8, the total number of possible SRS ports multiplexed by cyclic shift and comb offset is 48, which may not be suitable for channels with longer delay spread, such as channels with TDL-C 300ns. However, for channels with shorter delay spread, such as channels with TDL-C 30ns, 48 ​​ports can be multiplexed in an orthogonal manner. For shorter channels, even more ports can be used. How large the spacing between 2 ports should be configured depends on the delay spread of the channel impulse response of the potential interfering ports. The fractional cyclic shift can be configured accordingly to maximize the SRS capacity. Fig.18 The performance evaluation of one UE using CS 0 and another UE using CS 1 / f, where f = 2, 3, 4, 6, is shown for a CDL-C channel with an RMS delay spread of 30ns. Although the CS spacing between ports is only 1 / 6 of the normal CS spacing, the MSE performance is still generally acceptable. When the spacing of all fractional and integer CS values ​​is equal, the curve actually corresponds to an increasing maximum number of cyclic shifts (denoted as D), where D is equal to 16, 24, 32 and 48 respectively.

[0499] Fig.18 Performance evaluation of one UE using CS0 and performance evaluation of another UE using CS1 / f are shown.

[0500] The present disclosure provides SRS resource configuration and SRS resource set configuration (updated according to TS 38.331v17.1.0) below.

[0501]

[0502]

[0503]

[0504] By design, SEQUENCE(SIZE(1..maxNrofSRSHoppingSubset-1)) can be changed to length K TC or For example, changing to SEQUENCE(SIZE(1..8)) with a comb offset jump using comb 8, and so on.

[0505]

[0506]

[0507] It should be understood that one or more steps of the embodiment method provided herein can be performed by corresponding units or modules. For example, a signal can be sent by a sending unit or a sending module. A signal can be received by a receiving unit or a receiving module. A signal can be processed by a processing unit or a processing module. Other steps can be performed by a selection unit or a module, a determination unit or a module, or an allocation unit or a module. The corresponding unit / module can be hardware, software, or a combination thereof. For example, one or more units or modules can be an integrated circuit, for example, a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC).

[0508] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of the disclosure as defined by the appended claims.

Claims

1. A method, characterized in that include: The user equipment UE receives from the network device a configuration of a sounding reference signal SRS resource including 8 antenna ports, a transmission comb tooth configuration of the SRS resource, and a cyclic shift CS configuration of the SRS resource, wherein the transmission comb tooth configuration is used to indicate a comb tooth value K, K is one of 2, 4 or 8, the transmission comb tooth configuration is further used to indicate a configured comb tooth offset k, k is an integer between 0 and K-1, and the CS configuration is used to indicate a CS position; The UE maps each of the eight antenna ports to a corresponding CS and a corresponding resource unit RE in the frequency domain, wherein the corresponding RE of each port is located on every K REs, has an offset corresponding to each port based on the configured comb tooth offset k, and the corresponding RE is within the SRS transmission bandwidth; The UE sends the SRS to the network device using the eight antenna ports according to the mapping.

2. The method according to claim 1, characterized in that The corresponding RE is located in an orthogonal frequency division multiplexing OFDM symbol.

3. The method according to claim 1 or 2, characterized in that: The usage of the SRS resources is set to "codebook" or "antenna switching".

4. The method according to any one of claims 1 to 3, characterized in that When the comb tooth value K is 2, the UE maps each of the eight antenna ports to the corresponding RE, including: Mapping the 8 antenna ports to every K REs using the same offset equal to the configured comb offset k, or The first antenna port, the third antenna port, the fifth antenna port and the seventh antenna port among the 8 antenna ports are mapped to every K REs using the configured comb tooth offset k, and the second antenna port, the fourth antenna port, the sixth antenna port and the eighth antenna port among the 8 antenna ports are mapped to every K REs using the comb tooth offset (k+1) modulo K.

5. The method according to any one of claims 1 to 3, characterized in that The mapping includes: When the comb value K is 4: The first antenna port, the third antenna port, the fifth antenna port and the seventh antenna port among the 8 antenna ports are mapped to every K REs using the configured comb tooth offset k, and the second antenna port, the fourth antenna port, the sixth antenna port and the eighth antenna port among the 8 antenna ports are mapped to every K REs using the comb tooth offset (k+2) modulo K.

6. The method according to any one of claims 1 to 3, characterized in that The mapping includes: When the comb value K is 8: The first antenna port and the fifth antenna port among the 8 antenna ports are mapped to every K REs using the configured comb tooth offset k, the second antenna port and the sixth antenna port among the 8 antenna ports are mapped to every K REs using the first comb tooth offset (k+2) modulo K, the third antenna port and the seventh antenna port among the 8 antenna ports are mapped to every K REs using the second comb tooth offset (k+4) modulo K, and the fourth antenna port and the eighth antenna port among the 8 antenna ports are mapped to every K REs using the third comb tooth offset (k+6) modulo K.

7. A method, characterized in that include: The user equipment UE receives, from the network device, a configuration of a sounding reference signal SRS resource including 8 antenna ports and time division multiplexing TDM parameters, a transmission comb tooth configuration of the SRS resource, and a cyclic shift CS configuration of the SRS resource, wherein the transmission comb tooth configuration is used to indicate a comb tooth value K, K is one of 2, 4, or 8, the transmission comb tooth configuration is further used to indicate a comb tooth offset k, k is an integer between 0 and K–1, the CS configuration is used to indicate a CS position, and the SRS resource is mapped to m consecutive orthogonal frequency division multiplexing OFDM symbols in the same time slot, where m is greater than or equal to 1; The UE maps each of the m consecutive OFDM symbols to a corresponding subset of the eight antenna ports according to m and s, wherein s is determined according to the TDM parameter and is the number of the subsets of the eight antenna ports; The UE sends the SRS to the network device using the eight antenna ports according to the mapping.

8. The method according to claim 7, characterized in that The mapping includes: The UE maps an i-th subset of 8 / s antenna ports among the 8 antenna ports to every s OFDM symbols among the m consecutive OFDM symbols, starting from the i-th OFDM symbol among the m consecutive OFDM symbols, where i is 1 to s.

9. The method according to claim 7 or 8, characterized in that: The SRS transmissions on the m consecutive OFDM symbols are mapped using the same comb offset allocation and the same CS position.

10. The method according to any one of claims 7 to 9, characterized in that The SRS transmissions on the m consecutive OFDM symbols are mapped using the same physical resource block (PRB) allocation.

11. The method according to any one of claims 7 to 10, characterized in that The SRS transmission on the m consecutive OFDM symbols is periodic, semi-static or non-periodic, and the SRS transmission is based on an SRS counter, and the SRS counter counts according to s*R, where R is a repetition factor configured for the SRS resource.

12. The method according to any one of claims 7 to 11, characterized in that m is a multiple of s.

13. The method according to any one of claims 7 to 12, characterized in that m is one of 2, 4, 8, 10, 12 or 14, and s is 2.

14. A method, characterized in that include: The network device sends a configuration of a sounding reference signal SRS resource including 8 antenna ports, a transmission comb tooth configuration of the SRS resource, and a cyclic shift CS configuration of the SRS resource to a user equipment UE, wherein the transmission comb tooth configuration is used to indicate a comb tooth value K, K is one of 2, 4 or 8, the transmission comb tooth configuration is further used to indicate a configured comb tooth offset k, k is an integer between 0 and K-1, and the CS configuration is used to indicate a CS position, Each of the eight antenna ports is mapped to a corresponding CS and a corresponding resource unit RE in the frequency domain, the corresponding RE of each port is located on every K REs, has an offset corresponding to each port based on the configured comb tooth offset k, and the corresponding RE is within the SRS transmission bandwidth; The network device receives an SRS from the UE.

15. The method according to claim 14, characterized in that The corresponding RE is located in an OFDM symbol.

16. The method according to claim 14 or 15, characterized in that The usage of the SRS resources is set to "codebook" or "antenna switching".

17. The method according to any one of claims 14 to 16, characterized in that When the comb value K is 2: The eight antenna ports are mapped to every K REs, and the eight antenna ports have the same offset that is equal to the configured comb tooth offset k, or The first antenna port, the third antenna port, the fifth antenna port and the seventh antenna port among the 8 antenna ports are mapped to every K REs with the configured comb tooth offset k, and the second antenna port, the fourth antenna port, the sixth antenna port and the eighth antenna port among the 8 antenna ports are mapped to every K REs with a comb tooth offset (k+1) modulo K.

18. The method according to any one of claims 14 to 17, characterized in that When the comb value K is 4: The first antenna port, the third antenna port, the fifth antenna port and the seventh antenna port among the 8 antenna ports are mapped to every K REs with the configured comb tooth offset k, and the second antenna port, the fourth antenna port, the sixth antenna port and the eighth antenna port among the 8 antenna ports are mapped to every K REs with a comb tooth offset (k+2) modulo K.

19. The method according to any one of claims 14 to 17, characterized in that When the comb value K is 8: The first antenna port and the fifth antenna port among the 8 antenna ports are mapped to every K REs with the configured comb tooth offset k, the second antenna port and the sixth antenna port among the 8 antenna ports are mapped to every K REs with a first comb tooth offset (k+2) modulo K, the third antenna port and the seventh antenna port among the 8 antenna ports are mapped to every K REs with a second comb tooth offset (k+4) modulo K, and the fourth antenna port and the eighth antenna port among the 8 antenna ports are mapped to every K REs with a third comb tooth offset (k+6) modulo K.

20. A method, characterized in that include: The network device sends a configuration of a sounding reference signal SRS resource including 8 antenna ports and time division multiplexing TDM parameters, a transmission comb tooth configuration of the SRS resource, and a cyclic shift CS configuration of the SRS resource to a user equipment UE, wherein the transmission comb tooth configuration is used to indicate a comb tooth value K, K is one of 2, 4 or 8, the transmission comb tooth configuration is also used to indicate a comb tooth offset k, k is an integer between 0 and K-1, the CS configuration is used to indicate a CS position, and the SRS resource is mapped to m consecutive orthogonal frequency division multiplexing OFDM symbols in the same time slot, where m is greater than or equal to 1, Each of the m consecutive OFDM symbols is mapped to a corresponding subset of the eight antenna ports according to m and s, wherein s is determined according to the TDM parameter and is the number of the subsets of the eight antenna ports; The network device receives an SRS from the UE.

21. The method according to claim 20, characterized in that Starting from the i-th OFDM symbol among the m consecutive OFDM symbols, the i-th subset of 8 / s antenna ports among the 8 antenna ports is mapped to every s OFDM symbols among the m consecutive OFDM symbols, where i is 1 to s.

22. The method according to claim 21, characterized in that The SRS transmissions on the m consecutive OFDM symbols are mapped using the same comb offset allocation and the same CS position.

23. The method according to claim 21, characterized in that The SRS transmissions on the m consecutive OFDM symbols are mapped using the same physical resource block (PRB) allocation.

24. The method according to claim 21, characterized in that The SRS transmission on the m consecutive OFDM symbols is periodic, semi-static or aperiodic, and the SRS transmission is based on an SRS counter determined by s*R, where R is a repetition factor configured for the SRS resource.

25. The method according to claim 21, characterized in that m is a multiple of s.

26. The method according to claim 21, characterized in that m is one of 2, 4, 8, 10, 12 or 14, and s is 2.

27. A user equipment UE, characterized in that: include: at least one processor; A non-transitory computer-readable storage medium storing instructions, wherein when the instructions are executed by the at least one processor, the instructions cause the UE to perform the method according to any one of claims 1 to 6.

28. A user equipment UE, characterized in that: include: at least one processor; A non-transitory computer-readable storage medium storing instructions, wherein when the instructions are executed by the at least one processor, the instructions cause the UE to perform the method according to any one of claims 7 to 13.

29. A network device, characterized in that: include: at least one processor; A non-transitory computer-readable storage medium storing instructions, wherein when the instructions are executed by the at least one processor, the instructions cause the network device to perform the method according to any one of claims 14 to 19.

30. A network device, characterized in that: include: at least one processor; A non-transitory computer-readable storage medium storing instructions, wherein when the instructions are executed by the at least one processor, the instructions cause the network device to perform the method according to any one of claims 20 to 26.

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