Physical layer processing method for multicast and broadcast services in SFN mode in NR system

Abstract

This application provides a physical layer processing method for multicast broadcast services in SFN mode within an NR system. The method includes: for a single-frequency network (SFN) area, a gNB configures several MBS channels (MCHs) for the SFN area, and configures a physical MBS channel (PMCH) for each MCH; among the configured MCHs, one MCH is selected to carry the MBS control channel (MCCH); the gNB performs channel coding on each TB on the MCH, and performs physical layer-related processing on the bit sequence mapped to the PMCH. This method solves the problem of physical layer processing of transmission channels and physical channels for multicast broadcast services in SFN mode within an NR system.

Description

Technical Field

[0001] This application relates to communication technology, and more particularly to a physical layer processing method for multicast broadcast services in SFN mode in an NR system. Background Technology

[0002] With the continuous development of wireless communication technology, New Radio Access (NR) systems have entered people's lives. In order to provide Multicast / Broadcast Service (MBS) in NR cells, a WorkItem (WI): NR MBS was established in Release 17 (R17) at the 3rd Generation Partnership Project (3GPP) Radio Access Network (RAN) plenary meeting in December 2019.

[0003] In the NR system, the transmission path of an MBS session is as follows: Figure 1 As shown. The data network provides each MBS session and transmits the MBS session data to the 5G Core Network (5GC). The 5GC then transmits the MBS session to the Next Generation Radio (NG-RAN), which transmits the MBS session to the UE over the air interface. NG-RAN can also be represented by gNB, where gNB is the base station for the NR cell.

[0004] The NR MBS project introduces two transmission modes for MBS sessions: multicast mode and broadcast mode, used for transmitting multicast and broadcast sessions respectively. For MBS sessions transmitted in multicast / broadcast mode, when the MBS session is transmitted across several cells using PTM (Presentation Time Management), the scheduling of the MBS session in different cells is independent. Different cells typically use different time-frequency resources to transmit the MBS session using PTM. For a UE receiving the MBS session using PTM, signals from different cells cannot be combined.

[0005] To improve the reception quality of MBS sessions, a Single Frequency Network (SFN) can be used to transmit MBS sessions in PTM mode. Specifically, in a co-frequency NR system, for MBS sessions transmitted simultaneously by various cells within an area, each cell uses the same time-frequency resources to transmit the same MBS session data in PTM mode at the same time, generating the same MBS signal. For a UE receiving the MBS session in PTM mode, the signals from different cells are multipath signals of the same signal, which can be combined using diversity merging, thereby improving the reception quality of the MBS session.

[0006] However, when sending MBS sessions in the SFN manner, how to perform physical layer-related processing on the transmission channel and physical channel carrying MBS session and MBS control information is a problem that needs to be solved. Summary of the Invention

[0007] This application provides a physical layer processing method and device for multicast broadcast services in SFN mode in an NR system, to solve the problem of processing the transmission channel and physical channel of multicast broadcast services in SFN mode at the physical layer in an NR system.

[0008] Firstly, this application provides a physical layer processing method for multicast broadcast services in SFN mode in an NR system, applied to a next-generation radio access network (gNB), comprising:

[0009] For a given SFN area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions in the SFN area;

[0010] The gNB configures several MBS Channels (MCHs) for the SFN area, and configures one Physical MBS Channel (PMCH) for each MCH. The MCH is a dedicated transmission channel for MBS sessions within the SFN area, and the PMCH is a dedicated physical channel for MBS within the SFN area. Each MCH is configured with at least one Modulation and Coding Scheme (MCS), and each data MCS is the MCS used when transmitting the MBS Traffic Channel (MTCH). One of the configured MCHs is selected to carry the MBS Control Channel (MCCH). For an MCH with an configured MCCH, a signaling MCS is configured for that MCH, and this signaling MCS is the MCS used when transmitting the MCCH. The gNB configures a mapping type and related parameters for each PMCH, configures a mapping type and related parameters for the Demodulation Reference Signal (DMRS) of each PMCH, and configures a Phase Tracking Reference Signal (PMRS) for each PMCH. Configure relevant parameters for Signal, PTRS;

[0011] For any Transport Block (TB) on any MCH in the SFN region, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained by channel coding to the PMCH corresponding to the MCH.

[0012] The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping.

[0013] The gNB generates the DMRS of the PMCH;

[0014] The gNB generates the PTRS of the PMCH;

[0015] The gNB transmits the PMCH, the PMCH DMRS, and the PMCH PTRS.

[0016] Furthermore, for any transport block (TB) on any MCH in the SFN region, the gNB performs channel coding on the TB using the corresponding MCS, and maps the channel-coded bit sequence to the PMCH corresponding to the MCH, including:

[0017] The gNB generates 24 cyclic redundancy check (CRC) bits from the TB, adds the 24 CRC bits to the end of the bit sequence corresponding to the TB, and then performs channel coding on the synthesized bit sequence;

[0018] When the TB consists of data on the MCCH, the signaling MCS configured for the MCH is used when channel coding the TB;

[0019] The TB can be encoded using one of the following methods:

[0020] Encoding Method 1: The TB uses Low Density Parity Check (LDPC) encoding;

[0021] Encoding method two: The TB adopts POLAR encoding;

[0022] Preferably, POLAR coding is used when channel coding the TB, and preferably, QPSK is used when modulation the TB.

[0023] Furthermore, for any transport block (TB) on any MCH in the SFN region, the gNB performs channel coding on the TB using the corresponding MCS, and maps the channel-coded bit sequence to the PMCH corresponding to the MCH, including:

[0024] The gNB generates 24 cyclic redundancy check (CRC) bits from the TB, adds the 24 CRC bits to the end of the bit sequence corresponding to the TB, and then performs channel coding on the synthesized bit sequence;

[0025] When the TB consists of data from several MTCHs, the data MCS configured for the MCH is used when channel coding the TB; LDPC coding is used for the TB.

[0026] When the gNB configures a data MCS for the MCH, it uses that data MCS when sending any TB on the MCH; when the gNB configures multiple data MCSs for the MCH, the gNB needs to determine the data MCS to be used for each TB when sending each TB on the MCH from the multiple data MCSs.

[0027] Furthermore, the gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including:

[0028] The gNB performs bit scrambling on the bit sequence of the PMCH. In the bit scrambling, the gNB generates c using the following formula. init Initialize the scrambling sequence generator:

[0029] c init =n RNTI ·2 15 +q·2 14 +n ID (1)

[0030] In the above formula:

[0031] n RNTI The ID of the SFN region; q = 0;

[0032] n ID ∈{0, 1, ..., 1023} represents the scrambling code identifier ID used by the PMCH. If this parameter is not configured, the default value is n. ID =0 or default n ID The ID of the SFN region;

[0033] Ideally, n should be uniformly configured for an SFN region. ID Each PMCH in the SFN region uses the same n ID .

[0034] Furthermore, the gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including:

[0035] The gNB uses a corresponding MCS to modulate the scrambled bit sequence to generate a corresponding symbol sequence.

[0036] Furthermore, the gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including:

[0037] The gNB performs a single-layer mapping on the generated symbol sequence to generate a layer-mapped symbol sequence.

[0038] Furthermore, the gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including:

[0039] The gNB maps the generated symbol sequence after layer mapping to a dedicated antenna port of a PMCH.

[0040] Furthermore, the gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including:

[0041] The gNB performs VRB mapping, in which the gNB maps a symbol sequence mapped to a dedicated antenna port of a PMCH to the CRB occupied by the CFR in the SFN area. However, the gNB cannot map the symbol sequence to the following REs of the CFR:

[0042] (3) The DMRS of the PMCH occupies the RE;

[0043] (4) The PTRS of the PMCH occupies the RE.

[0044] Furthermore, the gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including:

[0045] The gNB performs VRB to PRB mapping. When the VRB to PRB mapping method configured for the PMCH is interleaved mapping, the gNB performs interleaved mapping; otherwise, the gNB performs non-interleaved mapping; if no mapping method is configured for the PMCH, the gNB performs non-interleaved mapping.

[0046] When an interleaving map is configured for the PMCH, the number of RBs contained in each CRB bundle is determined in the following manner:

[0047] Use respectively and The index of the starting CRB of the CFR and the number of consecutive CRBs occupied by the CFR are represented by L. CFR Indicating the number of RBs contained in each CRB bundle, the CFR of the SFN region contains... One CRB bundle; the CRB bundles are numbered in ascending order of their CRB subscripts:

[0048] The CRB bundle with index 0 contains One RB;

[0049] like The subscript is N bundle -1 CRB bundle contains

[0050] RB; otherwise, the subscript is N. bundle -1 CRB bundle contains L CFR One RB;

[0051] Other CRB bundles include L CFR RB.

[0052] Further, the gNB generates the DMRS of the PMCH, including:

[0053] The gNB generates the first sequence r(n) according to the following formula:

[0054]

[0055] In the above formula:

[0056] c(i) is a pseudo-random sequence. The initial values ​​of the pseudo-random sequence generator that generates c(i) are determined according to the following formula:

[0057]

[0058] In the above formula:

[0059] l is the subscript The subscript of the symbol in the time slot; This is the scrambling ID for the PMCH's DMRS. If not configured, it will use the default. Or default The ID of the SFN region;

[0060] when When configurable, DMRS can be configured individually for each PMCH in the SFN region. Different PMCHs can have different DMRS.

[0061] Better, when When configurable, provide unified configuration for the SFN region. The DMRS of each PMCH in the SFN region uses the same

[0062] The gNB performs the mapping of the first sequence r(n) to physical resources: the gNB maps the first sequence r(n) to the CRB occupied by the CFR in the SFN region according to the following formula:

[0063]

[0064] In the above equation, r(2n+k′) is mapped to RE(k,l);

[0065] When DMRS uses configuration type 1, k = 4n + 2k′ + Δ, k′ = 0, 1, ..., n = 0, 1, ...

[0066] When DMRS uses configuration type 2, k = 6n + k′ + Δ, k′ = 0, 1, n = 0, 1, ...

[0067] In the above formula, β PMCH The transmit power of the PMCH is determined by its transmit power, which is: β PMCH *β PMCH ;

[0068] Δ is a parameter of PMCH. For DMRS configuration type 1, the value of Δ is 0 or 1; for DMRS configuration type 2, the value of Δ is 0, 2 or 4.

[0069] Further, the gNB generates the PTRS of the PMCH, including:

[0070] The gNB generates the second sequence corresponding to the PTRS of the PMCH according to the following formula:

[0071] r k =r(2m+k′) (5)

[0072] In the above formula, r(n) is the first sequence corresponding to the DMRS of the PMCH; the value of l in r(2m+k′) is l0;

[0073] The gNB maps the second sequence corresponding to the PTRS of the PMCH to physical resources. Optionally, the gNB maps the second sequence corresponding to the PTRS to the CRB occupied by the CFR in the SFN region according to the following formula:

[0074]

[0075] In the above formula, based on the parameter L of PTRS PT-RS ∈{1, 2, 4} determines l;

[0076] k is determined according to the following formula:

[0077]

[0078] like but

[0079] otherwise,

[0080] In the above formula, i = 0, 1, 2, ...; K PT-RS ∈{2, 4} is a parameter of PTRS; n RNTI This is the ID for the SFN region.

[0081] Secondly, this application provides a device for implementing a physical layer processing method for multicast broadcast services in SFN mode in an NR system. The device is a gNB, and the gNB includes the following functions:

[0082] For a given SFN area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions in the SFN area;

[0083] The gNB configures several MBS Channels (MCHs) for the SFN area, and configures one Physical MBS Channel (PMCH) for each MCH. The MCH is a dedicated transmission channel for MBS sessions within the SFN area, and the PMCH is a dedicated physical channel for MBS within the SFN area. Each MCH is configured with at least one Modulation and Coding Scheme (MCS), and each data MCS is the MCS used when transmitting the MBS Traffic Channel (MTCH). One of the configured MCHs is selected to carry the MBS Control Channel (MCCH). For an MCH with an configured MCCH, a signaling MCS is configured for that MCH, and this signaling MCS is the MCS used when transmitting the MCCH. The gNB configures a mapping type and related parameters for each PMCH, configures a mapping type and related parameters for the Demodulation Reference Signal (DMRS) of each PMCH, and configures a Phase Tracking Reference Signal (PMRS) for each PMCH. Configure relevant parameters for Signal, PTRS;

[0084] For any Transport Block (TB) on any MCH in the SFN region, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained by channel coding to the PMCH corresponding to the MCH.

[0085] The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping.

[0086] The gNB generates the DMRS of the PMCH;

[0087] The gNB generates the PTRS of the PMCH;

[0088] The gNB transmits the PMCH, the PMCH DMRS, and the PMCH PTRS.

[0089] This application provides a physical layer processing method for multicast broadcast services in SFN mode in an NR system. The method includes: for an SFN area, a gNB configures a Common Frequency Resource (CFR) for the SFN area for transmitting MBS sessions; the gNB configures several MBS Channels (MCHs) for the SFN area, and configures a Physical MBS Channel (PMCH) for each MCH, where each MCH is a dedicated transmission channel for MBS sessions in the SFN area, and each PMCH is a dedicated physical channel for MBS in the SFN area; at least one Modulation and Coding Scheme (MCS) is configured for each MCH, where each MCS is the MCS used when transmitting MBS Traffic Channels (MTCHs); and one MCH is selected from the configured MCHs to carry the MBS Control Channel (MBS). For a Control Channel (MCCH), a signaling MCS is configured for the MCH, which is the same MCS used when transmitting the MCCH. The gNB configures the mapping type and related parameters for each PMCH, the demodulation reference signal (DMRS) for each PMCH, and the phase tracking reference signal (PTRS) for each PMCH. For any Transport Block (TB) on any MCH in the SFN area, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained from the channel coding onto the corresponding PMCH. The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping. The gNB generates the DMRS for the PMCH. The gNB generates the PTRS for the PMCH. The gNB transmits the PMCH, PMCH DMRS, and PMCH. PTRS. The physical layer processing method for multicast services under SFN mode in the NR system solves the problem of physical layer processing of MBS under SFN mode in the NR system.

[0090] This application also provides a device for implementing a physical layer processing method for multicast broadcast services in SFN mode in an NR system. The device is a gNB, which is used to implement the physical layer processing method for multicast broadcast services in SFN mode in an NR system provided in this application. Attached Figure Description

[0091] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0092] Figure 1 A schematic diagram of the transmission path for multicast broadcast services in the NR system provided in this application;

[0093] Figure 2 A flowchart illustrating a physical layer processing method for multicast broadcast services in SFN mode in an NR system, provided in Embodiment 1 of this application;

[0094] Figure 3 This is a flowchart illustrating a method for processing bit sequences on a PMCH according to Embodiment 2 of this application.

[0095] Figure 4 This is a flowchart illustrating a method for generating a demodulation reference signal for a PMCH according to Embodiment 3 of this application.

[0096] Figure 5 This is a flowchart illustrating a method for generating a phase tracking reference signal for a PMCH, as provided in Embodiment 4 of this application.

[0097] The embodiments of this disclosure illustrated in the foregoing figures will be described in more detail below. These figures and descriptions are not intended to limit the methods of this disclosure in any way, but rather to illustrate the methods of this disclosure to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0098] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0099] Before introducing the embodiments of this application, the application background of the embodiments of this application will be explained first:

[0100] To improve the reception quality of MBS sessions in NR systems, a single-frequency network can be used to transmit MBS sessions in PTM mode. Specifically, in a co-frequency NR system, for MBS sessions transmitted simultaneously by various cells within a region, each cell uses the same time-frequency resources to transmit the same MBS session data in PTM mode at the same time, generating the same MBS signal. For a UE receiving the MBS session in PTM mode, the signals from different cells are multipath signals of the same signal, which can be combined using diversity merging, thereby improving the reception quality of the MBS session.

[0101] However, when sending MBS sessions via SFN, the problem that needs to be solved is how to perform physical layer-related processing on the transmission channel and physical channel carrying MBS session and MBS control information.

[0102] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0103] Figure 2 This is a flowchart illustrating a physical layer processing method for multicast / broadcast services in an NR system using SFN mode, as provided in Embodiment 1 of this application. It is applied to Next Generation Radio Access Network (NG-RAN). NG-RAN can be represented by gNB. Figure 2 As shown in Embodiment 1 of this application, a physical layer processing method for multicast broadcast services in an NR system using SFN mode includes:

[0104] Step 21: For an SFN area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions in the SFN area.

[0105] In this step, for any SFN area, the gNB configures a CFR for that SFN area. The CFR of the SFN area is a portion of the bandwidth of the carrier frequency used by the SFN area, consisting of a set of consecutive Common Resource Blocks (CRBs). The gNB determines the subcarrier spacing and Cyclic Prefix (CP) type used in the CFR of the SFN area. The CFR of the SFN area is used to transmit MBS sessions in the SFN area.

[0106] Preferably, when one or more MBS sessions of the SFN region are sent through the CFR of the SFN region in a time slot, each Resource Element (RE) corresponding to the CRB occupied by the CFR in the time slot is exclusively occupied by the MBS session of the SFN region.

[0107] Step 22: The gNB configures several MBS Channels (MCHs) for the SFN area, and configures a Physical MBS Channel (PMCH) for each MCH. The MCH is a dedicated transmission channel for MBS sessions within the SFN area, and the PMCH is a dedicated physical channel for MBS within the SFN area. At least one Modulation and Coding Scheme (MCS) is configured for each MCH, and each data MCS is the MCS used when transmitting the MBS Traffic Channel (MTCH). One MCH is selected from the configured MCHs to carry the MBS Control Channel (MCCH). For an MCH with an configured MCCH, a signaling MCS is configured for that MCH, and this signaling MCS is the MCS used when transmitting the MCCH. The gNB configures a mapping type and related parameters for each PMCH, configures a mapping type and related parameters for the Demodulation Reference Signal (DMRS) of each PMCH, and configures a Phase Tracking Reference Signal (PMRS) for each PMCH. Configure relevant parameters for Signal, PTRS.

[0108] In this step, the gNB configures several MCHs for the SFN area, configures one PMCH for each MCH, carries one or more MBS sessions of the SFN area on each MCH, and maps each MCH to the corresponding PMCH.

[0109] The gNB configures at least one data MCS for each MCH, which is the MCS used when sending MTCH. In a first feasible implementation, the gNB configures only one data MCS for an MCH, and each TB on the MCH uses this data MCS. In a second feasible implementation, the gNB configures multiple data MCSs for an MCH, and different types / QoS requirements of MBS sessions on the MCH use different data MCSs. In a third feasible implementation, the gNB configures multiple data MCSs for an MCH, and different QoS requirements of MTCHs on the MCH use different data MCSs.

[0110] The gNB selects one MCH from the configured MCHs to carry the MCCH. For an MCH with an MCCH configured, a signaling MCS is configured for that MCH. The signaling MCS is the MCS used when sending the MCCH.

[0111] The gNB configures a mapping type and related parameters for each PMCH, a mapping type and related parameters for each PMCH's DMRS, and related parameters for each PMCH's PTRS. Specifically, the PMCH mapping type and related parameters determine the symbol resources occupied by the PMCH during transmission in each time slot; the PMCH DMRS mapping type and related parameters determine the positions of each symbol occupied by the PMCH's DMRS and the frequency domain position occupied by the DMRS at each occupied symbol position; the PMCH PTRS related parameters determine the symbol positions occupied by the PMCH PTRS and the frequency domain position occupied by the PTRS at each occupied symbol position. There are two mapping types for the PMCH: PMCH mapping type A and PMCH mapping type B; and two mapping types for the PMCH DMRS: mapping type 1 and mapping type 2.

[0112] Step 23: For any Transport Block (TB) on any MCH in the SFN region, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained by channel coding to the PMCH corresponding to the MCH.

[0113] Specifically, for any MCH in the SFN region, only one TB is carried on the MCH each time it is transmitted. The gNB generates a 24-bit Cyclic Redundancy Check (CRC) bit from the TB, adds the 24 CRC bits to the end of the bit sequence corresponding to the TB, and then performs channel coding on the synthesized bit sequence. The method for generating the 24 CRC bits is an existing method and will not be described in detail here.

[0114] Furthermore, when the TB consists of data from the MCCH, the signaling MCS configured for the MCH is used when channel coding the TB. The TB can be coded using Low Density Parity Check (LDPC) or Polarized Polar (POLAR) coding. For the specific coding method when using LDPC coding for the TB, see section 7.2 of the 3GPP NR protocol TS38.212; for the specific coding method when using POLAR coding for the TB, see section 7.3.3 of the 3GPP NR protocol TS38.212.

[0115] When the TB consists of data on the MCCH, preferably, POLAR coding is used when channel coding the TB, and preferably, QPSK is used when modulating the TB.

[0116] Furthermore, when the TB consists of data from several MTCHs, the data MCS configured for the MCH is used when channel coding the TB, and LDPC coding is applied to the TB. The specific channel coding method is described in Section 7.2 of TS38.212 in the 3GPP NR protocol.

[0117] When a data MCS is configured for the MCH, that data MCS is used when sending any TB on the MCH. When multiple data MCSs are configured for the MCH, the gNB needs to determine the data MCS used for each TB from among the multiple data MCSs when sending each TB on the MCH. The TB can consist of data from several QoS streams within the same MBS session; the TB can also consist of data from multiple MBS sessions. How the gNB determines the data MCS used for a TB when multiple data MCSs are configured for an MCH is not the focus of this invention and will not be elaborated further.

[0118] Step S24: The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB to PRB mapping.

[0119] When the TB in step S23 consists of data on the MCCH, the corresponding MCS in this step is the signaling MCS; when the TB in step S23 consists of data on the MTCH, the corresponding MCS in this step is the data MCS used by the TB.

[0120] Step 25: gNB generates the DMRS of the PMCH.

[0121] Step 26: gNB generates the PTRS of the PMCH.

[0122] Step 27: gNB sends the PMCH, the PMCH DMRS, and the PMCH PTRS.

[0123] In this step, the gNB uses a dedicated antenna port for the PMCH to transmit the PMCH, the PMCH's DMRS, and the PMCH's PTRS. Typically, the dedicated antenna port for the PMCH differs from existing antenna ports used for transmitting downlink physical channels or physical signals. Let antenna port X represent the dedicated antenna port for the PMCH; then the PMCH, the PMCH's DMRS, and the PMCH's PTRS are all transmitted through antenna port X.

[0124] In summary, the physical layer processing method for multicast broadcast services in SFN mode in an NR system provided in Embodiment 1 of this application includes:

[0125] For a single Private Server Network (SFN) area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions. The gNB configures several MBS Channels (MCHs) for the SFN area, and each MCH is configured with a Physical MBS Channel (PMCH). Each MCH is a dedicated transmission channel for MBS sessions within the SFN area, and each PMCH is a dedicated physical channel for MBS sessions within the SFN area. Each MCH is configured with at least one Modulation and Coding Scheme (MCS), and each MCS is the MCS used when transmitting MBS Traffic Channels (MTCHs). One of the configured MCHs is selected to carry the MBS Control Channel. For a channel (MCCH), a signaling MCS is configured for the MCH, which is the MCS used when transmitting the MCCH. The gNB configures a mapping type and related parameters for each PMCH, configures a mapping type and related parameters for the demodulation reference signal (DMRS) of each PMCH, and configures related parameters for the phase tracking reference signal (PTRS) of each PMCH. For any transport block (TB) on any MCH in the SFN area, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained by channel coding to the PMCH corresponding to the MCH. The gNB uses the corresponding MCS to sequentially perform the following on the bit sequence of the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB to PRB mapping. The gNB generates the DMRS of the PMCH. The gNB generates the PTRS of the PMCH. The gNB transmits the PMCH, the DMRS of the PMCH, and the PTRS of the PMCH. The method for handling multicast broadcast services in the SFN mode of the NR system at the physical layer solves the problem of handling MBS in the SFN mode at the physical layer in the NR system.

[0126] Figure 3 This is a flowchart illustrating a method for processing bit sequences on a PMCH according to Embodiment 2 of this application. Figure 2This illustrates a specific implementation method for step 24 in the physical layer processing method of multicast broadcast service under SFN mode in an NR system. The bit sequence processing method on the PMCH includes:

[0127] Step 31: gNB performs bit scrambling on the bit sequence of the PMCH.

[0128] For example, the gNB performs bit scrambling on the bit sequence of the PMCH. In the bit scrambling, the gNB uses the following formula to generate c. init Initialize the scrambling sequence generator:

[0129] c init =n RNTI ·2 15 +q·2 14 +n ID (1)

[0130] In the above formula:

[0131] n RNTI The ID of the SFN region; q = 0;

[0132] n ID ∈{0, 1, ..., 1023} represents the scrambling code identifier ID used by the PMCH. If this parameter is not configured, the default value is n. ID =0 or default n ID This is the ID for the SFN region.

[0133] Ideally, n should be uniformly configured for an SFN region. ID Each PMCH in the SFN region uses the same n ID .

[0134] The detailed process of generating and scrambling scrambling sequences can be found in Section 7.3.1.1 of the 3GPP NR protocol TS38.211. That is, the scrambling process for the bit sequence on the PMCH is the same as the scrambling process for the bit sequence on the PDSCH, except that the PMCH uses parameters specific to the SFN region to generate the scrambling sequence.

[0135] Step 32: gNB modulates the scrambled bit sequence using the corresponding MCS.

[0136] The method for determining the corresponding MCS used by gNB in ​​this step is described in [link to relevant documentation]. Figure 2 The description of step S24 in the illustrated embodiment will not be repeated here.

[0137] The gNB uses a corresponding MCS to modulate the scrambled bit sequence to generate a corresponding symbol sequence.

[0138] Since the modulation method corresponding to the MCS is one of the existing modulation methods, the process by which the gNB modulates the scrambled bit sequence using the corresponding MCS and generates the corresponding symbol sequence is the existing method and will not be described in detail here.

[0139] Step 33: gNB performs layer mapping on the modulated symbol sequence.

[0140] For example, PMCH uses single-layer transmission, transmitting only one codeword with the codeword index q=0.

[0141] The gNB performs a single-layer mapping on the generated symbol sequence to produce a layer-mapped symbol sequence. The layer-mapped symbol sequence is essentially the same as the original symbol sequence before the layer mapping.

[0142] Step 34: Mapping from gNB execution layer to antenna port

[0143] For example, the PMCH is transmitted using a single antenna port.

[0144] The gNB maps the generated symbol sequence after layer mapping to a dedicated antenna port of a PMCH.

[0145] If antenna port X represents the single antenna port used by the PMCH during transmission, then the gNB will map the generated symbol sequence after layer mapping onto the dedicated antenna port X of the PMCH.

[0146] Step 35: gNB performs VRB mapping

[0147] For example, the gNB performs VRB mapping, in which the gNB maps a symbol sequence mapped to an antenna port dedicated to a PMCH to a CRB occupied by the CFR in the SFN area, but the gNB cannot map the symbol sequence to the following REs of the CFR:

[0148] (1) The DMRS of the PMCH occupied on the RE

[0149] (2) The PTRS of the PMCH occupies the RE

[0150] STEP 36: gNB performs VRB to PRB mapping

[0151] The gNB performs VRB to PRB mapping. When the VRB to PRB mapping method configured for the PMCH is interleaved mapping, the gNB performs interleaved mapping; otherwise, the gNB performs non-interleaved mapping; if no mapping method is configured for the PMCH, the gNB performs non-interleaved mapping.

[0152] When an interleaving map is configured for the PMCH, the number of RBs contained in each CRB bundle in the interleaving map is determined as follows:

[0153] Use respectively and The index of the starting CRB of the CFR and the number of consecutive CRBs occupied by the CFR are represented by L. CFR Indicating the number of RBs contained in each CRB bundle, the CFR of the SFN region contains... One CRB bundle; the CRB bundles are numbered in ascending order of their CRB subscripts:

[0154] The CRB bundle with index 0 contains One RB;

[0155] like The subscript is N bundle -1 CRB bundle contains

[0156] RB; otherwise, the subscript is N. bumdle -1 CRB bundle contains L CFR One RB;

[0157] Other CRB bundles include L CFR RB.

[0158] Specifically, N bundle The interleaving mapping process for each CRB bundle is described in section 7.3.1.6 of the 3GPP NR protocol TS38.211.

[0159] Figure 4 This is a flowchart illustrating a method for generating DMRS for a PMCH according to Embodiment 3 of this application, used for detailed explanation. Figure 2 The specific implementation method of step 25 in the physical layer processing method for multicast broadcast services is shown. The method for generating the DMRS of the PMCH includes:

[0160] Step 41: gNB generates the first sequence r(n) corresponding to the DMRS of PMCH.

[0161] Specifically, gNB generates the first sequence r(n) according to the following formula:

[0162]

[0163] In the above formula:

[0164] The definition of c(i) can be found in Section 5.2.1 of 3GPP NR Protocol TS38.211. The initialization value of the pseudo-random sequence generator that generates c(i) is determined according to the following formula.

[0165]

[0166] In the above formula:

[0167] l is the subscript The subscript of the symbol in the time slot; This is the scrambling ID for the PMCH's DMRS. If not configured, it will use the default. Or default This is the ID for the SFN region.

[0168] when When configurable, DMRS can be configured individually for each PMCH in the SFN region. Different PMCHs can have different DMRS.

[0169] Better, when When configurable, provide unified configuration for the SFN region. The DMRS of each PMCH in the SFN region uses the same

[0170] Step 42: gNB performs the mapping of the first sequence r(n) to physical resources.

[0171] Specifically, the first sequence r(n) is mapped to the CRB occupied by the CFR according to the following formula.

[0172]

[0173] Specifically, r(2n+k′) is mapped to RE(k,l).

[0174] When DMRS uses configuration type 1, k = 4n + 2k′ + Δ, k′ = 0, 1, ..., n = 0, 1, ...

[0175] When DMRS uses configuration type 2, k = 6n + k′ + Δ, k′ = 0, 1, n = 0, 1, ...

[0176] In the above formula, β PMCH The transmit power of the PMCH is determined by its transmit power, which is: β PMCH *β PMCH .

[0177] Δ is a parameter of PMCH. For DMRS configuration type 1, the value of Δ is 0 or 1; for DMRS configuration type 2, the value of Δ is 0, 2 or 4.

[0178] The values ​​of the relevant parameters in formula (4) are shown in Tables 1, 2 and 3. The reference point of k in formula (4) is the subcarrier with the smallest subscript in CFR and a subscript of 0 in CRB.

[0179] For PMCH configuration type A: l is defined relative to the start point of the time slot, the position of the first DMRS symbol is represented by l0;

[0180] For PMCH configuration type B: l is defined relative to the start symbol of PMCH within a time slot, the position l0 of the first DMRS symbol is 0;

[0181] For PMCH configuration type A, l d The number of symbols between the first OFDM symbol in the time slot and the last OFDM symbol in the PMCH within the time slot; for PMCH configuration type B, l d This represents the number of symbols occupied by PMCH within a time slot.

[0182] Table 1 / 2 defines not only the positions of the half DMRS symbols configured for the PMCH, but also the positions of any additional DMRS symbols configured for the PMCH. In Table 1 / 2, pos0 / pos1 / pos2 / pos3 represent 0 / 1 / 2 / 3 additional DMRS symbols, respectively. Additional DMRS symbols can be configured for the PMCH to improve its decoding performance.

[0183] Table 1: PMCH using a single DMRS symbol The value of

[0184]

[0185] Table 2: PMCH using two DMRS symbols The value of

[0186]

[0187] Table 3: l′ and antenna port p in PMCH

[0188]

[0189] Figure 5 This is a flowchart illustrating a method for generating PTRS for a PMCH, provided in Embodiment 4 of this application, for detailed explanation. Figure 2 The specific implementation method of step 26 in the physical layer processing method for multicast broadcast services is shown. The method for generating the PTRS of the PMCH includes:

[0190] Step 51: gNB generates the second sequence corresponding to the PTRS of PMCH.

[0191] For example, gNB generates the second sequence corresponding to PTRS according to the following formula.

[0192] r k=r(2m+k′) (5)

[0193] In the above formula, r(n) is the first sequence corresponding to the DMRS of PMCH; the value of l in r(2m+k′) is l0, and the values ​​of other parameters are given in step 25 or Figure 4 The example shown.

[0194] Step 52: gNB maps the second sequence corresponding to PTRS to physical resources.

[0195] For example, gNB maps the second sequence corresponding to PTRS to the CRB occupied by CFR according to the following formula.

[0196]

[0197] In formula (6), based on the parameter L of PTRS PT-RS ∈{1, 2, 4} determines l, based on the parameter L PT-RS The method for determining 'l' is described in Section 7.4.1.2.2 of the 3GPP NR protocol TS38.211. That is, the method for determining the symbol position occupied by the PTRS of the PMCH is the same as the method for determining the symbol position occupied by the PTRS of the PDSCH.

[0198] In formula (6), k is determined according to the following formula:

[0199]

[0200] like but

[0201] otherwise,

[0202] In formula (6):

[0203] The values ​​of are shown in Table 4; i = 0, 1, 2, ...; K PT-RS ∈{2, 4} is a parameter of PTRS; n RNTI This is the ID for the SFN region.

[0204] Table 4: The value of

[0205]

[0206] In Table 4, resourceElementOffset is a parameter of PTRS, with values ​​of offset00, offset01, offset10, or offset11. The parameter values ​​0 / 1 / 2 / 3 indicate offset00 / offset01 / offset10 / offset11.

[0207] This application provides a device for implementing a physical layer processing method for multicast / broadcast services in an NR system using the SFN (Single-Frequency Network) approach, as provided in Embodiment 5 of this application. This device is a gNB (Garden-Based NodeB) used to implement the physical layer processing method for multicast / broadcast services in an NR system using the SFN approach, as provided in Embodiment 1 of this application. Specifically, the gNB includes the following functions:

[0208] For a given SFN area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions within the SFN area.

[0209] The gNB configures several MCHs for the SFN area, and configures one PMCH for each MCH. The MCH is a dedicated transport channel for MBS sessions in the SFN area, and the PMCH is a dedicated physical channel for MBS in the SFN area. Each MCH is configured with at least one data MCS, and each data MCS is the MCS used when transmitting MBS traffic channels (MTCH). One MCH is selected from the configured MCHs to carry the MBS control channel (MCCH). For an MCH with an MCCH configured, a signaling MCS is configured for that MCH, and the signaling MCS is the MCS used when transmitting the MCCH. The gNB configures a mapping type and related parameters for each PMCH, configures a mapping type and related parameters for the demodulation reference signal (DMRS) of each PMCH, and configures related parameters for the phase tracking reference signal (PTRS) of each PMCH.

[0210] For any MCH in the SFN region, the gNB performs channel coding on the Transport Block (TB) on the MCH and maps the channel-coded bit stream to the PMCH corresponding to the MCH.

[0211] The gNB sequentially performs the following operations on the bit stream on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping.

[0212] The gNB generates DMRS for PMCH.

[0213] The gNB generates the PTRS of PMCH.

[0214] The gNB transmits PMCH, PMCH DMRS, and PMCH PTRS through the same antenna port.

[0215] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

Claims

1. A physical layer processing method for multicast broadcast service in a SFN mode in a NR system, characterized in that, Applications in next-generation radio access networks (gNBs) include: For an SFN area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions in the SFN area; The gNB configures several MBS Channels (MCHs) for the SFN area, and configures one Physical MBS Channel (PMCH) for each MCH. The MCH is a dedicated transmission channel for MBS sessions within the SFN area, and the PMCH is a dedicated physical channel for MBS within the SFN area. Each MCH is configured with at least one Modulation and Coding Scheme (MCS), and each data MCS is the MCS used when transmitting the MBS Traffic Channel (MTCH). One of the configured MCHs is selected to carry the MBS Control Channel (MCCH). For each MCH with an configured MCCH, a signaling MCS is configured, which is the MCS used when transmitting the MCCH. The gNB configures a mapping type and related parameters for each PMCH, configures a mapping type and related parameters for the Demodulation Reference Signal (DMRS) of each PMCH, and configures a Phase Tracking Reference Signal (PMRS) for each PMCH. Configure relevant parameters for Signal, PTRS; For any Transport Block (TB) on any MCH in the SFN region, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained by channel coding to the PMCH corresponding to the MCH; The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping. The gNB generates the DMRS of the PMCH; The gNB generates the PTRS of the PMCH; The gNB transmits the PMCH, the PMCH DMRS, and the PMCH PTRS.

2. The method according to claim 1, characterized in that, For any transport block (TB) on any MCH in the SFN region, the gNB performs channel coding on the TB using the corresponding MCS, and maps the channel-coded bit sequence to the PMCH corresponding to the MCH, including: The gNB generates 24 cyclic redundancy check (CRC) bits from the TB, adds the 24 CRC bits to the end of the bit sequence corresponding to the TB, and then performs channel coding on the synthesized bit sequence; When the TB consists of data on the MCCH, the signaling MCS configured for the MCH is used when channel coding the TB; The TB can be encoded using one of the following methods: Encoding Method 1: The TB uses Low Density Parity Check (LDPC) encoding; Encoding method two: The TB adopts POLAR encoding; POLAR coding is used when channel coding the TB, or QPSK is used when modulation the TB.

3. The method according to claim 1, characterized in that, For any transport block (TB) on any MCH in the SFN region, the gNB performs channel coding on the TB using the corresponding MCS, and maps the channel-coded bit sequence to the PMCH corresponding to the MCH, including: The gNB generates 24 cyclic redundancy check (CRC) bits from the TB, adds the 24 CRC bits to the end of the bit sequence corresponding to the TB, and then performs channel coding on the synthesized bit sequence; When the TB consists of data from several MTCHs, the data MCS configured for the MCH is used when channel coding the TB; LDPC coding is used for the TB. When the gNB configures a data MCS for the MCH, it uses that data MCS when sending any TB on the MCH; when the gNB configures multiple data MCSs for the MCH, the gNB needs to determine the data MCS to be used for each TB when sending each TB on the MCH from the multiple data MCSs.

4. The method according to claim 1, characterized in that, The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including: The gNB performs bit scrambling on the bit sequence of the PMCH. During bit scrambling, the gNB is generated using the following formula. Initialize the scrambling sequence generator: （1） In the above formula: The ID of the SFN region; q=0; This is the scrambling code identifier ID used by the PMCH. If this parameter is not configured, the default value is used. Or default The ID of the SFN region; Configure a single SFN region uniformly. Each PMCH in the SFN region uses the same .

5. The method according to claim 1, characterized in that, The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including: The gNB uses a corresponding MCS to modulate the scrambled bit sequence to generate a corresponding symbol sequence.

6. The method according to claim 1, characterized in that, The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including: The gNB performs a single-layer mapping on the generated symbol sequence to generate a layer-mapped symbol sequence.

7. The method according to claim 1, characterized in that, The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including: The gNB maps the generated symbol sequence after layer mapping to a dedicated antenna port of a PMCH.

8. The method according to claim 1, characterized in that, The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including: The gNB performs VRB mapping, in which the gNB maps a symbol sequence mapped to a dedicated antenna port of a PMCH to the CRB occupied by the CFR in the SFN area. However, the gNB cannot map the symbol sequence to the following REs of the CFR: (1) The DMRS of the PMCH occupies the RE; (2) The PTRS of the PMCH occupies the RE.

9. The method according to claim 1, characterized in that, The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping, including: The gNB performs VRB to PRB mapping. When the VRB to PRB mapping method configured for the PMCH is interleaved mapping, the gNB performs interleaved mapping; otherwise, the gNB performs non-interleaved mapping; if no mapping method is configured for the PMCH, the gNB performs non-interleaved mapping. When an interleaving map is configured for the PMCH, the number of RBs contained in each CRB bundle is determined in the following manner: Use respectively and The index of the starting CRB of the CFR and the number of consecutive CRBs occupied by the CFR are indicated by... Indicating the number of RBs contained in each CRB bundle, the CFR of the SFN region contains... One CRB bundle; the CRB bundles are numbered in ascending order of their CRB subscripts: The CRB bundle with index 0 contains One RB; like , subscript The CRB bundle contains One RB; otherwise, the subscript is The CRB bundle contains One RB; Other CRB bundles include RB.

10. The method according to claim 1, characterized in that, The gNB generates the DMRS of the PMCH, including: The gNB generates the first sequence according to the following formula. : （2） In the above formula: The pseudo-random sequence is generated according to the following formula. Initialization values ​​for the pseudo-random sequence generator: （3） In the above formula: For subscript The subscript of the symbol in the time slot; This is the scrambling ID for the PMCH's DMRS. If not configured, it will use the default. Or default The ID of the SFN region; when When configurable, DMRS can be configured individually for each PMCH in the SFN region. Different PMCHs can have different DMRS. ; when When configurable, provide unified configuration for the SFN region. The DMRS of each PMCH in the SFN region uses the same ; The gNB executes the first sequence. Mapping to physical resources: The gNB will map the first sequence Map the CFR-occupied CRB of the SFN region according to the following formula: （4） In the above formula, Mapping to RE ( , )superior; When DMRS uses configuration type 1 When DMRS uses configuration type 2 In the above formula, + ; The transmit power of the PMCH is determined by its transmit power, which is: ; This is a parameter of PMCH, for DMRS configuration type 1. The value can be 0 or 1; for DMRS configuration type 2, .

11. The method according to claim 1, characterized in that, The gNB generates the PTRS of the PMCH, including: The gNB generates the second sequence corresponding to the PTRS of the PMCH according to the following formula: （5） In the above formula, This is the first sequence corresponding to the DMRS of the PMCH; middle The value is ; The gNB maps the second sequence corresponding to the PTRS of the PMCH to physical resources. Optionally, the gNB maps the second sequence corresponding to the PTRS to the CRB occupied by the CFR in the SFN region according to the following formula: （6） In the above formula, based on the parameters of PTRS Sure ; Determined according to the following formula: like ,but otherwise, In the above formula, ; It is a parameter of PTRS; This is the ID for the SFN region.

12. A device for implementing a physical layer processing method for multicast broadcast services in SFN mode in an NR system, the device being a gNB, the gNB including the following functions: For an SFN area, the gNB configures a Common Frequency Resource (CFR) for the SFN area to transmit MBS sessions in the SFN area; The gNB configures several MBS Channels (MCHs) for the SFN area, and configures one Physical MBS Channel (PMCH) for each MCH. The MCH is a dedicated transmission channel for MBS sessions within the SFN area, and the PMCH is a dedicated physical channel for MBS within the SFN area. Each MCH is configured with at least one Modulation and Coding Scheme (MCS), and each data MCS is the MCS used when transmitting the MBS Traffic Channel (MTCH). One of the configured MCHs is selected to carry the MBS Control Channel (MCCH). For each MCH with an configured MCCH, a signaling MCS is configured for that MCH, and the signaling MCS is the MCS used when transmitting the MCCH. The gNB configures the mapping type and related parameters for each PMCH, the demodulation reference signal (DMRS) for each PMCH, and the phase tracking reference signal (PTRS) for each PMCH. For any Transport Block (TB) on any MCH in the SFN region, the gNB uses the corresponding MCS to perform channel coding on the TB and maps the bit sequence obtained by channel coding to the PMCH corresponding to the MCH; The gNB uses the corresponding MCS to sequentially perform the following operations on the bit sequence on the PMCH: bit scrambling, modulation, layer mapping, antenna port mapping, VRB mapping, and VRB-to-PRB mapping. The gNB generates the DMRS of the PMCH; The gNB generates the PTRS of the PMCH; The gNB transmits the PMCH, the PMCH DMRS, and the PMCH PTRS.

Images