A PRACH detection method, a RAR transceiving method and a device in a multi-UE scenario

Abstract

The present disclosure relates to a 5G communication system or a 6G communication system, and provides a PRACH detection method, a RAR transceiving method, and a device in a multi-UE scenario for supporting faster access latency and larger access capacity than a 4G communication system such as long term evolution (LTE). According to one aspect of the present disclosure, a method performed by a network node in a communication system is provided, including: receiving a same random access signal from a first number of user equipments (UEs); and transmitting a response message for the same random access signal, the response message including: a second number of timing advance (TA) information and resource allocation information for the second number of UEs.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a PRACH detection method and the transmission and reception of a random access response (RAR). Background Technology

[0002] To meet the increased demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or near-5G communication systems. Therefore, 5G or near-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0003] 5G communication systems are implemented in higher frequency (millimeter wave, mmWave) bands, such as the 60GHz band, to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G communication systems.

[0004] In addition, in 5G communication systems, development is underway to improve system networks based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receiver interference cancellation.

[0005] In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM), while filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) have been developed as advanced access technologies. Summary of the Invention

[0006] According to embodiments of this disclosure, a method executed by a network node in a communication system is provided, comprising:

[0007] Receive the same random access signal from a first number of user equipment (UEs);

[0008] Send a response message for the same random access signal, the response message including: a second number of timing advance TA information and resource allocation information for a second number of UEs.

[0009] In one implementation, the first quantity is not less than the second quantity.

[0010] In one implementation, receiving the same random access signal from a first number of UEs includes:

[0011] Receive random access signals corresponding to the same random access preamble from the first number of UEs.

[0012] In one implementation, the response message further includes at least one of the following:

[0013] The second quantity;

[0014] Instructions for TA-related information, instructing the UE to obtain the corresponding TA-related information;

[0015] Random access preamble identification information;

[0016] Temporary Cell Radio Network Temporary Identifier (T-CRNTI).

[0017] In one implementation, the TA-related information includes at least one of the following:

[0018] Downlink path loss between UE and base station;

[0019] The reception and transmission times of system information block SIB1;

[0020] Signal strength related information and threshold information.

[0021] In one implementation, the method further includes:

[0022] Send SIB1 to the UE, wherein SIB1 includes the transmission time.

[0023] In one implementation, the signal strength-related information includes: Reference Signal Received Power (RSRP).

[0024] In one implementation, the threshold information includes first threshold information and threshold offset information.

[0025] In one implementation, the second quantity of TA information includes:

[0026] A first TA message and a third number of second TA messages.

[0027] In one implementation, the resource allocation information for the second number of UEs includes:

[0028] One uplink UL Grant message and a second demodulation reference signal (DMRS) message.

[0029] In one implementation, the response message includes a Random Access Response (RAR).

[0030] In one implementation, the response message further includes downlink control information (DCI), which carries at least one of the following: the second quantity; indication information of TA-related information, instructing the UE to obtain the corresponding TA-related information; random access preamble identification information; and first TA information, wherein the second quantity of TA information includes the first TA information and the third quantity of second TA information.

[0031] According to embodiments of this disclosure, a method executed by a user equipment (UE) in a communication system is provided, comprising:

[0032] Send a random access request to the base station;

[0033] Receive a response message from the base station, the response message including a second number of advance timing (TA) information and resource allocation information for a second number of UEs;

[0034] Obtain the TA information and resource allocation information corresponding to the UE from the response message;

[0035] Based on the obtained TA information and resource allocation information, uplink transmissions are sent to the base station.

[0036] In one implementation, obtaining the TA information and resource allocation information corresponding to the UE from the RAR includes:

[0037] Obtain the TA-related information of the UE;

[0038] Based on the TA-related information, the TA information and resource allocation information corresponding to the UE are obtained from the RAR.

[0039] In one implementation, the response message further includes at least one of the following:

[0040] The second quantity;

[0041] Instructions for TA-related information, instructing the UE to obtain the corresponding TA-related information;

[0042] Random access preamble identification information;

[0043] Temporary Cell Radio Network Temporary Identifier (T-CRNTI).

[0044] In one implementation, the method further includes:

[0045] Based on the second quantity, the response message is decoded.

[0046] In one implementation, the TA-related information includes at least one of the following:

[0047] Downlink path loss between UE and base station;

[0048] The reception and transmission times of system information block SIB1;

[0049] Signal strength related information and threshold information.

[0050] In one implementation, based on the TA-related information, the TA information and resource allocation information corresponding to the UE are obtained from the RAR, including:

[0051] Determine the TA estimation information of the UE;

[0052] The TA information with the smallest difference from the estimated TA information is determined from the second number of TA information contained in the response message and is taken as the TA information of the UE.

[0053] In one implementation, determining the TA estimation information of the UE includes:

[0054] Based on the downlink path loss between the UE and the base station, the first TA estimation information corresponding to the UE is determined.

[0055] In one implementation, determining the TA estimation information of the UE includes:

[0056] Based on the reception and transmission times of SIB1, the second TA estimation information corresponding to the UE is determined.

[0057] In one implementation, the method further includes:

[0058] The base station receives SIB1, which includes the transmission time.

[0059] In one implementation, determining the TA estimation information of the UE includes:

[0060] Determine the signal strength information of the UE;

[0061] Based on the signal strength range corresponding to the signal strength information of the UE, the third TA estimation information corresponding to the UE is determined.

[0062] In one implementation, the threshold information includes first threshold information and threshold offset information;

[0063] The method further includes: determining multiple signal strength ranges based on the first threshold information and the threshold offset information.

[0064] In one implementation, the signal strength-related information includes: Reference Signal Received Power (RSRP).

[0065] In one implementation, the second quantity of TA information includes:

[0066] A first TA message and a third number of second TA messages.

[0067] In one implementation, determining the TA information with the smallest difference from the estimated TA information among the second number of TA information contained in the response message as the TA information of the UE includes:

[0068] Based on the TA estimation information and the first TA information, the third TA information is determined;

[0069] The TA information of the UE is determined from the second TA information with the smallest difference from the third TA information based on the second quantity of second TA information.

[0070] In one implementation, the resource allocation information for the second number of UEs includes:

[0071] One uplink UL Grant message and a second demodulation reference signal (DMRS) message.

[0072] In one implementation, obtaining the TA information and resource allocation information corresponding to the UE from the RAR includes:

[0073] Based on the obtained TA information corresponding to the UE, the DMRS information corresponding to the UE is determined from the second number of DMRS information;

[0074] Based on the DMRS information corresponding to the UE, the port information for sending uplink transmission is determined.

[0075] In one implementation, the response message includes a Random Access Response (RAR).

[0076] In one implementation, the response message further includes downlink control information (DCI), the DCI carrying at least one of the following: the second quantity; indication information of TA-related information, instructing the UE to obtain the corresponding TA-related information; random access preamble identification information; first TA information, wherein the second quantity of TA information includes the first TA information and the second quantity of second TA information.

[0077] According to embodiments of this disclosure, a method executed by a network node is provided, comprising:

[0078] The random access signal is processed to obtain multiple feature sequences corresponding to the candidate preamble of the random access signal;

[0079] The multiple feature sequences are input into an artificial intelligence (AI) model to obtain output information related to random access of multiple UEs. The output information includes the number of UEs and preamble identification information.

[0080] In one implementation, processing the random access signal includes:

[0081] Based on the correlation operation between the random access signal and the candidate preamble, the power delay spectrum (PDP) sequence corresponding to each candidate preamble is obtained;

[0082] For each candidate preamble:

[0083] Obtain the target detection window of the candidate preamble, the target detection window comprising multiple user signal clusters;

[0084] A valid PDP signal is obtained based on the PDP sequence corresponding to the candidate preamble.

[0085] Candidate user signal clusters are determined based on the index of valid PDP signals, wherein the candidate user signal clusters include the index of at least one valid PDP signal.

[0086] The first number of PDP signals in the candidate user signal cluster and at least one statistical characteristic value of the first number of PDP signals are used as the feature sequence of the candidate preamble.

[0087] In one implementation, obtaining a valid PDP signal includes:

[0088] The first PDP signal for decision signal and noise is obtained based on the statistical characteristics of the corresponding PDP sequence;

[0089] A PDP signal whose peak value is not less than the peak value of the first PDP signal is determined as a valid PDP signal.

[0090] In one implementation, determining the candidate user signal cluster includes:

[0091] Obtain the time index corresponding to the PDP before sorting the valid PDP signal, and merge the PDP signals with adjacent time index intervals less than the FFT upsampling rate into an FFT cluster.

[0092] Using the index with the largest PDP peak among all FFT clusters as the center, and the maximum delay interval as the interval, determine the maximum delay cluster;

[0093] The FFT clusters within the maximum delay cluster that arrive later than the center of the maximum delay cluster and whose PDP amplitude does not conform to the multipath fading characteristics are treated as a separate user signal cluster, while the other clusters within the maximum delay cluster are treated as a single user signal cluster.

[0094] In one implementation, obtaining the first PDP signal includes the following operations:

[0095] The corresponding PDP sequences are arranged sequentially to obtain the sorted PDP sequences;

[0096] A first index is obtained by comparing the difference sequence or moving average sequence of the sorted PDP sequence with a first threshold. The difference sequence value or moving average sequence value corresponding to the first index is the minimum value among the difference sequence values ​​or moving average sequence values ​​greater than the first threshold.

[0097] The PDP signal corresponding to the first index is determined as the first PDP signal.

[0098] In one implementation, the number of UEs is associated with preamble identification information, and the number of UEs associated with each preamble identification information is related to the number of user signal clusters corresponding to the preamble identification information.

[0099] In one implementation, the TA information is determined based on the time-domain location of the first valid PDP signal in the candidate user signal cluster.

[0100] In one implementation, the method further includes: applying a MoE-based feature enhancer based on the signal amplitude distribution characteristics within the target detection window to obtain an enhanced PDP sequence.

[0101] In one implementation, the method further includes: selecting the PDP sequence corresponding to the antenna or symbol with the largest PDP peak value as the standard PDP sequence based on the number of receiving antennas or the number of OFDM symbols corresponding to the PRACH configuration.

[0102] Calculate the similarity between the PDP sequences on the remaining antennas and symbols and the standard PDP sequence;

[0103] PDP sequences with similarity greater than a similarity threshold are merged to obtain merged PDP sequences for antennas or symbols.

[0104] According to embodiments of this disclosure, a user equipment (UE) in a communication system is provided, comprising:

[0105] A transceiver is configured to transmit and / or receive signals;

[0106] A controller is configured to control the UE to perform the method described according to embodiments of the present disclosure.

[0107] According to embodiments of this disclosure, a network node in a communication system is provided, comprising:

[0108] A transceiver is configured to transmit and / or receive signals;

[0109] A controller is configured to control the network nodes to perform the methods described according to embodiments of this disclosure. Attached Figure Description

[0110] To gain a more complete understanding of this disclosure and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein like reference numerals denote like parts:

[0111] Figure 1 Example wireless networks according to various embodiments of this disclosure are shown;

[0112] Figure 2a and Figure 2b An example wireless transmission and reception path according to this disclosure is shown;

[0113] Figure 3a An example UE according to this disclosure is shown;

[0114] Figure 3b An example gNB according to this disclosure is shown;

[0115] Figure 4 An example flowchart of an AI-based PRACH receiver detection algorithm for multi-UE scenarios according to embodiments of the present disclosure is shown;

[0116] Figures 5-7 A schematic diagram illustrating the process of determining candidate multi-user signal clusters according to an embodiment of the present disclosure is shown;

[0117] Figure 8 An example flowchart of contention-based access in a multi-UE scenario according to embodiments of the present disclosure is shown;

[0118] Figure 9 A schematic diagram of RAR information configured only in the MAC RAR PDU according to an embodiment of the present disclosure is shown, wherein two UEs are detected under only one RAPID, DMRS is configured, TA obtains indication information (shown as TAflag in the figure), and the TAC field is configured with absolute timing advance (TA) values ​​(TA1, TA2 shown in the figure).

[0119] Figure 10 A schematic diagram of RAR information configured only in a MAC RAR PDU according to an embodiment of the present disclosure is shown, wherein two UEs are detected under a RAPID, DMRS is configured, TA obtains indication information (shown as TAflag in the figure), and the TAC field is configured with reference TA (shown as reference TA in the figure) and relative TA (shown as relative TA1 in the figure);

[0120] Figure 11 A schematic diagram of the joint configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of the present disclosure is shown, wherein DCI 1_0 carries RAPID, two UEs are detected under only one RAPID, DMRS is configured in MAC PDU, TA obtains indication information (shown as TA flag in the figure), and the TAC field configures the baseline TA and relative TA.

[0121] Figure 12 A schematic diagram of the joint configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of the present disclosure is shown. DCI 1_0 carries RAPID, baseline TA and number of UEs. The figure shows that 2 UEs are detected under one RAPID. DMRS is configured in MAC PDU, TA obtains indication information (shown as TA flag in the figure), and the TAC field is configured with relative TA value.

[0122] Figure 13 A schematic diagram of the joint configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of the present disclosure is shown. DCI 1_0 carries RAPID, number of UEs, baseline TA and absolute threshold (RSRP threshold shown in the figure). The figure shows that two UEs are detected under one RAPID. DMRS is configured in MAC PDU, TA obtains indication information (TAflag shown in the figure), threshold offset information (RSRP-offset shown in the figure), and the TAC field is configured with relative TA value.

[0123] Figure 14 A schematic diagram of the joint configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of the present disclosure is shown, wherein DCI 1_0 carries RAPID, number of UEs, reference TA, and TA acquisition indication information (shown as TAflag in the figure). The figure shows that two UEs are detected under one RAPID, DMRS is configured in the MAC PDU, and the TAC field is configured with relative TA value.

[0124] Figure 15A schematic diagram of the joint configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of the present disclosure is shown. DCI 1_0 carries RAPID, number of UEs, reference TA, TA acquisition indication information (shown as TAflag in the figure), absolute threshold information (shown as RSRP threshold in the figure), and shows that two UEs are detected under one RAPID. DMRS is configured in the MAC PDU, threshold offset information (shown as RSRP-offset in the figure), and the TAC field is configured with relative TA value.

[0125] Figure 16 A schematic diagram illustrating the joint configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of this disclosure is shown. DCI 1_0 carries RAPID and absolute threshold information (shown as RSRP threshold in the diagram). The diagram shows two UEs detected under one RAPID. The MAC PDU is configured with DMRS, the number of UEs, and the TAC field is configured with a reference TA and a relative TA value. Furthermore, in this design, DMRS is used by the base station to identify overlapping UL grant resources; all UEs identified under this RAPID have the same UL grant; the T-CRNTI field indicates the T-CRNTI of the reference UE.

[0126] Figure 17 A schematic diagram of a MAC PDU including RAR in a multi-UE scenario according to an embodiment of the present disclosure is shown;

[0127] Figure 18 A schematic diagram of the structure of a user equipment (UE) according to at least one embodiment of the present disclosure is shown;

[0128] Figure 19 A schematic diagram of the structure of a network node according to at least one embodiment of the present disclosure is shown. Detailed Implementation

[0129] The following description, with reference to the accompanying drawings, is provided to aid in a thorough understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. This description includes various specific details to aid understanding but should be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures may be omitted.

[0130] The terms and wording used in the following description and claims are not limited to their dictionary meanings, but are merely used by the inventors to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is for illustrative purposes only and not for limiting the purpose of this disclosure as defined in the appended claims and their equivalents.

[0131] It should be understood that the singular forms of “one,” “an,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, the reference to “component surface” includes one or more such surfaces.

[0132] The terms “comprising” or “may include” refer to the presence of a corresponding disclosed function, operation, or component that may be used in the various embodiments of this disclosure, rather than limiting the presence of one or more additional functions, operations, or features. Furthermore, the terms “comprising” or “having” may be interpreted as indicating certain characteristics, numbers, steps, operations, constituent elements, components, or combinations thereof, but should not be construed as excluding the possibility of the presence of one or more other characteristics, numbers, steps, operations, constituent elements, components, or combinations thereof.

[0133] The term "or" as used in the various embodiments of this disclosure includes any of the listed terms and all combinations thereof. For example, "A or B" may include A, may include B, or may include both A and B.

[0134] Unless otherwise defined, all terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of those skilled in the art as described herein. Common terms as defined in dictionaries are to be interpreted as having a meaning consistent with the context in the relevant technical field and should not be interpreted ideally or overly formally unless expressly defined in this disclosure.

[0135] The various embodiments of this disclosure can be applied to various communication systems, such as: Global System for Mobile Communications (GSM) systems, Code Division Multiple Access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) systems, General Packet Radio Service (GPRS), Long Term Evolution (LTE) systems, Frequency Division Duplex (FDD) systems, Time Division Duplex (TDD) systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5th Generation (5G) systems, or New Radio (NR), etc. Furthermore, the various embodiments of this disclosure can be applied to future-oriented communication technologies.

[0136] Figure 1 An example wireless network 100 according to various embodiments of the present disclosure is shown. Figure 1 The embodiment of the wireless network 100 shown is for illustrative purposes only. Other embodiments of the wireless network 100 can be used without departing from the scope of this disclosure.

[0137] Wireless network 100 includes gNodeB (gNB) 101, gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one Internet Protocol (IP) network 130 (such as the Internet, a proprietary IP network, or other data network).

[0138] Depending on the network type, other well-known terms such as "base station" or "access point" can be used instead of "gNodeB" or "gNB". For convenience, the terms "gNodeB" and "gNB" are used in this patent document to refer to network infrastructure components that provide wireless access for remote terminals. Furthermore, depending on the network type, other well-known terms such as "mobile station", "user station", "remote terminal", "wireless terminal", or "user device" can be used instead of "user equipment" or "UE". For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless devices that wirelessly access the gNB, whether the UE is a mobile device (such as a mobile phone or smartphone) or a fixed device as commonly understood (such as a desktop computer or vending machine).

[0139] gNB 102 provides wireless broadband access to network 130 to multiple first user equipments (UEs) within its coverage area 120. The multiple first UEs include: UE 111, which may be located in a small business (SB); UE 112, which may be located in an enterprise (E); UE 113, which may be located in a WiFi hotspot (HS); UE 114, which may be located in a first residence (R); UE 115, which may be located in a second residence (R); and UE 116, which may be a mobile device (M), such as a cellular phone, wireless laptop computer, wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 to multiple second UEs within its coverage area 125. The multiple second UEs include UE 115 and UE 116. In some embodiments, one or more of gNBs 101-103 are capable of communicating with each other and with UEs 111-116 using 5G, LTE, LTE-A, WiMAX, or other advanced wireless communication technologies.

[0140] The dashed lines indicate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular for illustrative and explanatory purposes only. It should be clearly understood that coverage areas associated with the gNB, such as coverage areas 120 and 125, can have other shapes, including irregular shapes, depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles.

[0141] As described in more detail below, one or more of gNB 101, gNB 102, and gNB 103 include a 2D antenna array as described in embodiments of this disclosure. In some embodiments, one or more of gNB 101, gNB 102, and gNB 103 support codebook design and architecture for systems having 2D antenna arrays.

[0142] although Figure 1 An example of a wireless network 100 is shown, but it is possible to... Figure 1 Various modifications can be made. For example, wireless network 100 can include any number of gNBs and any number of UEs in any suitable arrangement. Furthermore, gNB 101 can communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each gNB 102-103 can communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. In addition, gNBs 101, 102, and / or 103 can provide access to other or additional external networks (such as external telephone networks or other types of data networks).

[0143] Figure 2a and Figure 2b Example wireless transmit and receive paths according to this disclosure are shown. In the following description, transmit path 200 can be described as being implemented in a gNB (such as gNB 102), while receive path 250 can be described as being implemented in a UE (such as UE 116). However, it should be understood that receive path 250 can be implemented in a gNB, and transmit path 200 can be implemented in a UE. In some embodiments, receive path 250 is configured to support codebook design and structure for a system having a 2D antenna array as described in embodiments of this disclosure.

[0144] The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, an N-point inverse fast Fourier transform (IFFT) block 215, a parallel-to-serial (P-to-S) block 220, a cyclic prefix addition block 225, and an up-converter (UC) 230. The receive path 250 includes a down-converter (DC) 255, a cyclic prefix removal block 260, a serial-to-parallel (S-to-P) block 265, an N-point fast Fourier transform (FFT) block 270, a parallel-to-serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

[0145] In transmit path 200, channel coding and modulation block 205 receives a set of information bits, applies coding (such as low-density parity-check (LDPC) coding), and modulates the input bits (such as using quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulated symbols. Serial-to-parallel (S-to-P) block 210 converts (e.g., demultiplexes) the serial modulated symbols into parallel data to generate N parallel symbol streams, where N is the number of IFFT / FFT points used in gNB 102 and UE 116. N-point IFFT block 215 performs IFFT operations on the N parallel symbol streams to generate a time-domain output signal. Parallel-to-serial block 220 converts (e.g., multiplexes) the parallel time-domain output symbols from N-point IFFT block 215 to generate a serial time-domain signal. Cyclic prefix addition block 225 inserts a cyclic prefix into the time-domain signal. Upconverter 230 modulates (e.g., upconverts) the output of the added cyclic prefix block 225 to an RF frequency for transmission via a wireless channel. The signal can also be filtered at the baseband before being converted to the RF frequency.

[0146] The RF signal transmitted from gNB 102 reaches UE 116 after passing through the wireless channel, and UE 116 performs the opposite operation to that at gNB 102. Downconverter 255 downconverts the received signal to the baseband frequency, and cyclic prefix removal block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 265 converts the time-domain baseband signal into a parallel time-domain signal. N-point FFT block 270 performs an FFT algorithm to generate N parallel frequency-domain signals. Parallel-to-serial block 275 converts the parallel frequency-domain signals into a sequence of modulated data symbols. Channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0147] Each of gNBs 101-103 can implement a transmission path 200 similar to that used for transmission to UEs 111-116 in the downlink, and a reception path 250 similar to that used for reception from UEs 111-116 in the uplink. Similarly, each of UEs 111-116 can implement a transmission path 200 for transmission to gNBs 101-103 in the uplink, and a reception path 250 for reception from gNBs 101-103 in the downlink.

[0148] Figure 2a and Figure 2b Each of the components can be implemented using only hardware, or using a combination of hardware and software / firmware. As a specific example, Figure 2a and Figure 2bAt least some of the components can be implemented in software, while others can be implemented in configurable hardware or a combination of software and configurable hardware. For example, FFT block 270 and IFFT block 215 can be implemented as configurable software algorithms, wherein the value of the number of points N can be modified according to the implementation method.

[0149] Furthermore, although the description uses FFT and IFFT, this is merely illustrative and should not be construed as limiting the scope of this disclosure. Other types of transforms, such as the Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, can be used. It should be understood that for DFT and IDFT functions, the value of variable N can be any integer (such as 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N can be any integer that is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

[0150] although Figure 2a and Figure 2b An example of a wireless transmit and receive path is shown, but it is possible to modify it further. Figure 2a and Figure 2b Make various changes. For example, Figure 2a and Figure 2b The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. Furthermore, Figure 2a and Figure 2b This is intended to illustrate examples of the types of send and receive paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communication in a wireless network.

[0151] Figure 3a Example UE 116 according to this disclosure is shown. Figure 3a The embodiment of UE 116 shown is for illustrative purposes only, and Figure 1 UEs 111-115 can have the same or similar configurations. However, UEs have a wide variety of configurations, and Figure 3a This disclosure is not intended to limit the scope of any particular implementation of the UE.

[0152] UE 116 includes an antenna 301, a radio frequency (RF) transceiver 302, a transmit (TX) processing circuitry 303, a microphone 304, and a receive (RX) processing circuitry 305. UE 116 also includes a speaker 306, a controller / processor 307, an input / output (I / O) interface 308, multiple input devices 309, a display 310, and a memory 311. The memory 311 includes an operating system (OS) 312 and one or more applications 313.

[0153] RF transceiver 302 receives incoming RF signals transmitted by a gNB of wireless network 100 from antenna 301. RF transceiver 302 down-converts the incoming RF signals to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 305, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. RX processing circuitry 305 sends the processed baseband signal to speaker 306 (e.g., for voice data) or to controller / processor 307 (e.g., for web browsing data) for further processing.

[0154] TX processing circuitry 303 receives analog or digital voice data from microphone 304, or other outgoing baseband data (such as network data, email, or interactive video game data) from controller / processor 307. TX processing circuitry 303 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. RF transceiver 302 receives the processed baseband or IF signals from TX processing circuitry 303 and up-converts the baseband or IF signals into RF signals transmitted via antenna 301.

[0155] The controller / processor 307 may include one or more processors or other processing devices and execute an OS 312 stored in memory 311 to control the overall operation of the UE 116. For example, the controller / processor 307 may control the reception of forward channel signals and the transmission of reverse channel signals through the RF transceiver 302, the RX processing circuit 305, and the TX processing circuit 303 according to known principles. In some embodiments, the controller / processor 307 includes at least one microprocessor or microcontroller.

[0156] The controller / processor 307 is also capable of executing other processes and programs residing in the memory 311, such as operations for channel quality measurement and reporting for a system having a 2D antenna array as described in the embodiments of this disclosure. The controller / processor 307 is capable of moving data into or out of the memory 311 as needed for the execution of the process. In some embodiments, the controller / processor 307 is configured to execute an application 313 based on the OS 312 or in response to signals received from a gNB or operator. The controller / processor 307 is also coupled to an I / O interface IF 308, which provides the UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. The I / O interface 308 is the communication path between these accessories and the controller / processor 307.

[0157] The controller / processor 307 is also coupled to input devices(s) 309 and a display 310. An operator of the UE 116 can use the input devices(s) 309 to input data into the UE 116. The display 310 may be a liquid crystal display or another display capable of displaying text and / or at least limited graphics (such as from a website). Memory 311 is coupled to the controller / processor 307. A portion of memory 311 may include random access memory (RAM), while another portion of memory 311 may include flash memory or other read-only memory (ROM).

[0158] although Figure 3a An example of UE 116 is shown, but it is possible to... Figure 3a Make various changes. For example, Figure 3a The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. As a specific example, the controller / processor 307 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although... Figure 3a The UE116 is shown configured as a mobile phone or smartphone, but the UE can be configured to operate as other types of mobile or fixed devices.

[0159] Figure 3b An example gNB 102 according to this disclosure is shown. Figure 3b The embodiment of gNB 102 shown is for illustrative purposes only, and Figure 1 Other gNBs can have the same or similar configurations. However, gNBs have a wide variety of configurations, and Figure 3b The scope of this disclosure is not limited to any particular implementation of the gNB. It should be noted that gNB 101 and gNB 103 can include the same or similar structures as gNB 102.

[0160] like Figure 3b As shown, gNB 102 includes multiple antennas 370a-370n, multiple RF transceivers 372a-372n, transmit (TX) processing circuitry 374, and receive (RX) processing circuitry 376. In some embodiments, one or more of the multiple antennas 370a-370n include a 2D antenna array. gNB 102 also includes a controller / processor 378, a memory 380, and a backhaul or network interface 382.

[0161] RF transceivers 372a-372n receive incoming RF signals, such as signals transmitted by the UE or other gNBs, from antennas 370a-370n. RF transceivers 372a-372n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 376, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 376 sends the processed baseband signals to controller / processor 378 for further processing.

[0162] The TX processing circuit 374 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from the controller / processor 378. The TX processing circuit 374 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 372a-372n receive the outgoing processed baseband or IF signal from the TX processing circuit 374 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 370a-370n.

[0163] The controller / processor 378 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 378 may control the reception of forward channel signals and the transmission of reverse channel signals via RF transceivers 372a-372n, RX processing circuitry 376, and TX processing circuitry 374, according to known principles. The controller / processor 378 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 378 may perform a BIS process, such as by a blind interference sensing (BIS) algorithm, and decode the received signal after subtracting interference. The controller / processor 378 may support any of a wide variety of other functions in the gNB 102. In some embodiments, the controller / processor 378 includes at least one microprocessor or microcontroller.

[0164] The controller / processor 378 is also capable of executing programs and other processes, such as a basic operating system, residing in the memory 380. The controller / processor 378 is also capable of supporting channel quality measurement and reporting for systems having 2D antenna arrays as described in embodiments of this disclosure. In some embodiments, the controller / processor 378 supports communication between entities such as web RTCs. The controller / processor 378 is capable of moving data into or out of the memory 380 as needed for the execution of processes.

[0165] The controller / processor 378 is also coupled to a backhaul or network interface 382. The backhaul or network interface 382 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or over a network. The backhaul or network interface 382 is capable of supporting communication via any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G or new radio access technologies or NR, LTE, or LTE-A), the backhaul or network interface 382 allows the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the backhaul or network interface 382 allows the gNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. The backhaul or network interface 382 includes any suitable architecture supporting communication via a wired or wireless connection, such as an Ethernet or RF transceiver.

[0166] Memory 380 is coupled to controller / processor 378. A portion of memory 380 may include RAM, while another portion may include flash memory or other ROM. In some embodiments, multiple instructions, such as a BIS algorithm, are stored in memory. The multiple instructions are configured to cause controller / processor 378 to perform the BIS process and decode the received signal after subtracting at least one interference signal determined by the BIS algorithm.

[0167] As described in more detail below, the transmit and receive paths of the gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuitry 374, and / or RX processing circuitry 376) support aggregated communication with FDD and TDD cells.

[0168] although Figure 3b An example of gNB 102 is shown, but it is possible to compare it with other models. Figure 3b Various modifications can be made. For example, gNB102 can include any number of... Figure 3a Each component shown. As a specific example, an access point can include multiple backhaul or network interfaces 382, ​​and a controller / processor 378 can support routing functions to route data between different network addresses. As another specific example, although shown as a single instance including TX processing circuitry 374 and a single instance including RX processing circuitry 376, the gNB 102 can include multiple instances of each (such as one for each RF transceiver).

[0169] Exemplary embodiments of this disclosure are further described below with reference to the accompanying drawings.

[0170] The text and accompanying drawings are provided by way of example only to aid the reader in understanding this disclosure. They are not intended and should not be construed as limiting the scope of this disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based on the content disclosed herein, that changes may be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0171] In NR (New Radio) communication systems, a cell supports a maximum of 64 preambles, used for both CBRA (contention-based random access) and CFRA (contention-free random access). Resources for CBRA can be further divided into Group A and Group B, with the main difference between the groups being the size of the information used to transmit Message 3 (Msg3). Even in CFRA scenarios, such as transitioning from RRC-Inactive to RRC-Connected, beam recovery, or when downlink data arrives for access triggered by a PDCCH order or handover, if dedicated CFRA resources are not configured or exhausted, CFRA will automatically switch to CBRA. Furthermore, NR introduces more new random access scenarios, including RRC connection recovery, requests for other system information, and beam failure recovery. Different scenarios share the access resource pool, resulting in fewer resources available for specific CBRA scenarios.

[0172] Suppose that multiple UEs in the same cell initiate access requests in the same PRACH (physical random access channel) or RO (PRACH Occasion), and the available sequence resource size of the cell is r, with k UEs simultaneously accessing the same random access resource. When r = 64 and k = 64, the collision probability of k UEs simultaneously accessing the same access resource is as high as 26.4%; when k = r / 2, the collision probability can reach 10%.

[0173] In the future, the number of connected users will increase dramatically, and the probability of collisions will increase significantly, leading to increased access latency and UE power consumption, which will greatly affect the user experience. Access collision issues will become an important problem that urgently needs to be solved.

[0174] Embodiments of this disclosure relate to a method for detecting information related to the random access preamble during UE random access based on artificial intelligence (AI) performed by a base station (BS), and a transceiver configuration scheme for the random access response (RAR).

[0175] The following will first explain the relevant aspects of the detection algorithm and protocol process.

[0176] In communication systems, detection algorithms for the PRACH channel are mainly aimed at single UE access detection, including methods based on traditional threshold judgment and methods based on AI (Artificial Intelligence) detection.

[0177] Traditional threshold-based detection schemes first correlate the received PRACH preamble signal with a locally generated ZC sequence to obtain a power delay profile (PDP). Based on preamble-related information exchanged between the BS and UE via higher-level signaling, a search window (SW) can be specified within the PDP. If the maximum value of the PDP within the SW, such as the peak value, exceeds a preset threshold, the preamble ID (random access preamble ID, RAPID) and timing advance (TA) are identified as timing information corresponding to a specific SW.

[0178] The AI-based approach first performs TA pre-compensation on the time-domain results after IFFT transformation of the frequency domain correlation results to obtain the complex power delay spectrum curve (Complex PDP, CDP). Then, the CDP is fed into a binary classification AI model for PRACH preamble detection.

[0179] In multi-UE scenarios, when multiple UEs within a cell select the same preamble and initiate access on the same time-frequency resource, the BS assumes the preamble was sent from a specific UE and includes important preamble attributes in the RAR returned to the UE, including RAPID, Temporary CRNTI (Temporary Cell Radio Network Temporary Identifier (CRNTI), T-CRNTI), and uplink scheduling information (e.g., uplink grant (UL grant)). Assuming multiple UEs receive this RAR, they will each consider it sent to themselves and send message 3 (MSG3) to the BS according to the UL grant allocation. Each UE carries its own unique identifier (e.g., 5G System-Temporary Mobile Subscription Identifier (5GS-TMSI) or a random number). The BS also needs to receive MSG3 using the same T-CRNTI at the same or corresponding time-frequency location. However, the BS may not receive the MSG3 sent by each UE (due to interference between UEs), causing these UEs' access requests to fail. Assuming the BS receives MSG3 from at least one UE, the BS selects the identification number of one of the UEs according to its own algorithm criteria. Then, the BS sends this unique identification number to the UE along with other radio resource configuration information via message 4 (MSG4). Only UEs whose identification number in MSG4 matches the identification number they carried in MSG3 are allowed normal access, while the access requests of other UEs fail. This resolves the conflict.

[0180] Traditional threshold-based schemes are suitable for PRACH preamble detection in high signal-to-noise ratio (SNR) scenarios, primarily due to the ideal correlation characteristics of ZC sequences. However, in low SNR scenarios, relying on the correlation power of the PDP for PRACH preamble detection has inherent limitations, such as noise estimation errors and finite fixed threshold presets, leading to non-negligible false alarms and / or missed detections. Furthermore, in some real-world networks, channel path loss and / or the Doppler effect in high-speed scenarios can cause the PDP peak value of the true PRACH signal to fall below the preset threshold, potentially causing the detector to miss the preamble. Additionally, cell interference and multipath effects can further complicate PRACH signal detection. In multi-UE scenarios, mutual interference between multiple UEs exacerbates these problems.

[0181] For example, in the detection of PRACH signals, AI-based solutions suffer from phase deviations in pre-compensation due to inaccurate TA estimation at low SNR, which degrades the detection performance of the AI ​​model. On the other hand, the numerous configuration formats and parameters of PRACH preamble sequences result in varying search window (SW) lengths under different configurations, requiring different configurations and models, leading to excessive complexity and a lack of generalization ability.

[0182] In some implementations, AI-based solutions for multi-UE conflict scenarios typically focus on conflict avoidance, such as resource allocation and planning during the cell deployment phase, and therefore cannot fundamentally solve the conflict problem.

[0183] Moreover, in multi-UE scenarios, the base station can usually only respond to the access of one UE at most, and the conflict can only be resolved in MSG4 of the access procedure.

[0184] This disclosure provides an AI-based random access detection scheme for multi-UE collision scenarios in a wireless communication system. Furthermore, this disclosure also provides a Random Access Response (RAR) design and corresponding random access procedures for both the transmitter and receiver. For example, in one aspect, the method provided by this disclosure includes: applying a MoE-based feature enhancer based on the amplitude distribution characteristics of the PDP signal to obtain an enhanced PDP signal; performing adaptive merging based on the similarity between multiple antennas, multiple symbols, and / or multiple spurious peak windows to obtain a target window; identifying candidate multi-user signal clusters through signal amplitude feature analysis of the target window, and constructing feature engineering to perform AI-based Physical Random Access Channel (PRACH) detection. The AI-based PRACH detection algorithm and its related preprocessing are used to replace traditional threshold detection algorithms and are deployed at the physical layer. In another aspect, this disclosure provides a scheme for designing BS-side RAR transmission and UE-side RAR reception based on the detection results. In one implementation, a DCI_1_0 based on RA-RNTI scrambling and a PDSCH RAR are provided. The methods and RAR design provided in this disclosure better ensure that conflicts are resolved at least partially or completely in the first step of the random access phase, innovatively enabling simultaneous access by multiple UEs under conflict conditions. Furthermore, embodiments of this disclosure also provide a clustering-based adaptive detection window merging scheme for multi-antenna, multi-symbol, and high-speed train (HST) scenarios. The methods provided in this disclosure can improve access performance (e.g., reduce the probability of missed detections and / or false alarms). This performance improvement can, on the one hand, reduce access latency and increase access capacity, while simultaneously saving access resources. On the UE side, it can significantly improve the user experience and reduce UE power consumption.

[0185] According to one aspect of this disclosure, an AI-based access detection algorithm is provided for multi-UE conflict scenarios, aiming to solve the detection of conflicting UEs in such scenarios. According to another aspect of this disclosure, a design for a Random Access Response (RAR) is provided, including the RAR generation and transmission processes on the base station side, and the RAR reception and processing processes on the UE side. Through the design of the random access response transmission and reception scheme, simultaneous access by conflicting UEs in multi-UE scenarios can be better ensured.

[0186] In one aspect, the method according to this disclosure can be used to perform feature enhancement on PDP signals using a MoE-based feature enhancer, thereby enhancing the amplitude of the PDP signals while suppressing noise.

[0187] In another aspect, the method according to this disclosure can identify candidate multi-user signal clusters, perform signal-to-noise separation, and estimate noise power.

[0188] In another aspect, the method disclosed herein can evaluate the similarity between multiple pseudo-peak windows in high-speed scenarios (e.g., high-speed train (HST) scenarios) and achieve adaptive merging between multiple windows. By merging detection windows with similarity as target windows, SNR performance and detection performance can be improved. In addition, for detection windows with low similarity, only the detection window containing the maximum amplitude of PDP or CDP can be retained as the target window to improve false alarm performance.

[0189] In another aspect, the method disclosed herein can evaluate the similarity between multiple receiving antennas in a multi-antenna scenario, enabling adaptive merging among multiple antennas. By merging antennas with similarity as target antennas, SNR performance and detection performance can be improved. Furthermore, for antennas with low similarity, only the antenna with the maximum amplitude of PDP or CDP can be retained as the target antenna to improve false alarm performance.

[0190] In another aspect, the method disclosed herein can evaluate the similarity between multiple received symbols in a multi-symbol scenario, enabling adaptive merging between multiple symbols. By merging symbols with similarity as target symbols, SNR performance and detection performance can be improved. Furthermore, for symbols with low similarity, only the symbol containing the maximum amplitude of PDP or CDP can be retained as the target antenna to improve false alarm performance.

[0191] In another aspect, the method according to this disclosure can identify channel-related features and candidate user signal clusters within each target window. Identifying channel-related features includes: multipath feature identification, oversampling spurious peak identification, signal-noise feature separation, etc. Candidate user signal clusters refer to time windows where signals transmitted by the UE may exist. The method provided by this disclosure can improve the efficiency of AI-based detection and reduce detection complexity and / or model implementation complexity.

[0192] In another aspect, the method of this disclosure can be used to construct generalization-based feature engineering and propose confidence-based output judgments, thereby improving the robustness of the detection results.

[0193] In another aspect, the method disclosed herein can solve the problem of simultaneous access by multiple UEs in multi-UE conflict scenarios, and the specific method will be described in detail below.

[0194] In another aspect, the method according to this disclosure can solve the problem of simultaneous access by multiple UEs in multi-UE conflict scenarios, increase access capacity, and provide the possibility of removing the restriction set in future HST scenarios.

[0195] In another aspect, the method disclosed herein can be used to design PDCCH and PDSCHMSG2 on the BS side for multi-UE scenarios, and also provides a method for the UE to distinguish its own set of important attribute parameters.

[0196] The methods of embodiments of this disclosure will now be described in more detail in two parts: one part is an AI-based PRACH detection algorithm, and the other part is the RAR transceiver design.

[0197] For example, the overall process of an AI-based multi-user detection scheme is as follows:

[0198] BS receives PDP signals;

[0199] The BS first identifies candidate multi-user signal clusters by analyzing the amplitude characteristics of the PDP. Then, it performs feature selection on the candidate multi-user signal clusters and feeds the data into an AI-based classifier, which outputs whether a UE exists in each RAPID.

[0200] Finally, for RAPIDs with UEs present, the base station calculates the corresponding TA using the time information of the first peak in the relevant user signal cluster data.

[0201] Furthermore, if PRACH involves multiple symbols or multiple antenna receptions, or in high-speed scenarios, the BS will perform dynamic combination based on the spatiotemporal similarity of PDPs before identifying candidate user signal clusters.

[0202] In addition, to make the signal characteristics of multi-user signal clusters more apparent, a MoE feature enhancer based on signal amplitude distribution characteristics is applied to enhance the features before dynamic merging.

[0203] According to the AI-based PRACH detection algorithm of the embodiments of this disclosure, such as Figure 4 As shown, it mainly includes at least some of the following steps:

[0204] Step 0, receive the PDP signal; for example, the PDP signal is received from each antenna and / or each symbol.

[0205] Step 1: Apply MoE-based feature enhancers based on the signal amplitude distribution characteristics. For example, different enhancers are applied to enhance the characteristics of different input PDP signals. Specifically, first, identify whether the channel is multipath or single-path, and then select enhancers based on signal measurement characteristics, such as signal-to-noise ratio, fourth-order moment, and maximum delay spread. For AWGN channels, determine which enhancers to use and the order in which they are used based on the comparison between the measured SNR and a preset threshold.

[0206] Optional steps: Determine whether the signal involves multiple antennas or symbols, or whether it is a signal in a high-speed scenario.

[0207] Step 2: For high-speed and / or multi-antenna and / or multi-symbol scenarios, perform dynamic combination of the received PDP signals based on PDP similarity in the spatiotemporal domain. For example, first, perform a similarity assessment of the PDP signals, and then dynamically merge the PDP signals based on the assessment results; if the judgment result of the optional steps is a non-high-speed scenario and a single-antenna single-symbol scenario, then proceed directly to Step 3.

[0208] Similarity assessment of multiple pseudo peak windows related to the signal's PDP in high-speed (e.g., high-speed rail (HST)) scenarios;

[0209] In multi-antenna or multi-symbol scenarios, the similarity of PDP signals among antennas or symbols is evaluated.

[0210] By merging pseudo-peak windows or signals corresponding to multiple antennas or symbols with similarity, a target window or target antenna or target symbol can be obtained.

[0211] Step 3: Perform candidate user signal cluster identification based on PDP amplitude characteristics. For example, identify candidate user signal clusters for each search window (SW). This can be achieved by performing user signal cluster identification on each target window through data preprocessing to obtain candidate user signal clusters. Additionally, signal-noise separation points and, optionally, noise power can be obtained.

[0212] Step 4: Perform necessary feature selection for user signal cluster identification. For example, construct an initial feature engineering model, considering user signal cluster information, cell radius, etc., and construct a feature engineering model containing user signals through data preprocessing;

[0213] Step 5: Perform unified feature selection to achieve generalization. For example, based on the initial feature engineering, construct a unified feature engineering for various scenario configurations, such as considering the current network environment and the diverse configurations of PRACH channels, and perform feature screening and / or feature reconstruction based on candidate user signal clusters to design a generalizable AI-based PRACH detection scheme;

[0214] Step 6: Perform feature selection based on the scalar features of the PDP to enable the AI ​​classifier to identify the presence of RAPID. For example, perform AI-based PRACH detection;

[0215] Step 7, perform TA detection. For example, perform RAPID and TA detection, and sort and report based on the detection results. For example, feature selection and / or feature reconstruction results can be input into an AI-based PRACH detection model, and information such as RAPID and TA can be obtained by designing confidence-based detection outputs.

[0216] The embodiments of this disclosure also provide RAR transceiver designs, including BS-side RAR transmission designs and UE-side RAR reception designs. The BS-side RAR transmission design mainly considers the information composition, format, and carrying location of multiple UEs. The UE-side RAR reception design mainly considers how the UE selects its own parameters and information.

[0217] The principles and solutions of the present invention will now be described in conjunction with several exemplary aspects.

[0218] Example 1

[0219] In this example, the present invention introduces a method for detecting preamble-related information during a UE random access process in a communication system, executed by a BS based on an Artificial Intelligence (AI) model. The detection of preamble-related information may include, for example, obtaining information related to the index of the preamble used by the UE for random access, configuration information of the UE for carrying data transmitted on a RAR-scheduled uplink service channel (e.g., a Physical Uplink Shared Channel, PUSCH), and timing advance (TA) information. The process includes the following multiple stages, modes, or operations:

[0220] Step 1: The UE obtains the configuration information for Physical Random Access Channel (PRACH) transmission based on the received System Information Block 1 (SIB1). This PRACH configuration information includes: PRACH configuration index, PRACH frequency domain resource transmission start position (Msg 1 - Frequency Start), zero-correlation zone configuration, restricted set configuration information, and root sequence index. Based on the obtained PRACH configuration information, the UE determines the preamble sequence set, the root sequence number in the set type, and the cyclic shift offset Ncs, and generates and transmits the corresponding preamble on the configured time-frequency resources.

[0221] Step 2: Based on the received preamble time-domain signal, the BS acquires the time-domain detection signal within N search windows (or detection windows), where N represents the maximum number of search windows, corresponding to the number of candidate preambles in the cell. This can be a predefined or pre-configured value, for example, N = 64. The process includes the following stages, modes, or operations:

[0222] Step 2.1: The BS performs time-domain front-end processing on the received preamble time-domain signal, and obtains the preamble frequency-domain signal Y based on the configured preamble signal frequency-domain position information and PRACH configuration index. n (n = 0, 1, ..., L) RA -1), L RA Indicates the length of the preamble sequence, for example, L RA It can be 139, 839, 1157, or other values. The aforementioned time-domain front-end processing operations include removing the cyclic prefix (CP) portion of the preamble sequence, downsampling, and L... RA Point-based Discrete Fourier Transform (DFT) and / or symbol merging operations.

[0223] Step 2.2: BS processes the obtained frequency domain preamble sequence Y n With the pre-generated U frequency domain preambles X n,u Perform the relevant operations to obtain the frequency domain correlation sequence Z after U correlations. n,u The related operations can be represented as follows:

[0224]

[0225] in(.) * The conjugate operation for complex numbers, for example, denoted as X n =Real(X) n )+j*imag(X n ),but U represents the number of preamble root sequences configured; for example, U can be configured to a maximum of 64.

[0226] Based on the obtained frequency domain correlation sequence Z n,u Add N ifft -L RA Using zero elements, obtain the frequency domain correlation sequence Z′ after filling with zero elements. u (Z′ u =[Z n,u [,0…,0])n=0,1,…,L RA -1, and execute N ifftThe inverse fast fourier transform (IFFT) of the points yields the time-domain correlated signal x of U preambles. u .

[0227] x u [l] = IFFT(Z′) u (l=0,1,…,N) ifft -1,u=0,1,…,U)

[0228] Based on the configured cyclic offset N cs Preamble length L RA , and the number of points N in the Fourier transform ifft Obtain the preamble x of the i-th search window under the root sequence u. i,u [j],

[0229]

[0230] The length Nsw of each search window is represented as follows:

[0231] Nsw = Ncs * N ifft / L RA

[0232] The number of search windows corresponding to each root sequence is Number of root sequences required to generate N search windows

[0233] Obtain the power delay profile (PDP) of the preamble signal within each detection window. The PDP within the i-th search window is represented as follows:

[0234]

[0235] Step 3: Apply a MoE-based feature enhancer based on the signal amplitude distribution characteristics within each detection window. Apply different enhancers to different input PDP signals to obtain the enhanced PDP signals.

[0236] Step 4: For multi-antenna or multi-symbol scenarios, the BS selects the antenna and symbol containing the PDP signal with the largest PDP peak value as the standard PDP signal based on the number of receiving antennas and the corresponding number of OFDM symbols in the PRACH configuration. It then calculates the similarity between the PDP signals on the remaining antennas and symbols and the standard PDP signal, merges the similar PDP signals, and obtains the PDP sequence after antenna and symbol merging. For high-speed scenarios, specifically, the BS obtains the number of detection windows for the corresponding RAPID based on the restricted set resource configuration IE (e.g., restrictedSetConfig) in the PRACH configuration information. When restrictedSetConfig is configured as restrictedSetTypeA, it indicates that the high-speed cell uses restricted set A, and the corresponding number of detection windows is 3. The corresponding windows are denoted as follows: When restrictedSetConfig is configured as restrictedSetTypeB, it indicates that the high-speed cell uses restriction set B, with a corresponding detection window count of 5. The corresponding windows are denoted as follows: Among them, the cyclic shift value d u This refers to the cyclic shift value corresponding to the Doppler frequency offset defined by 3GPP. When restrictedSetConfig is configured as unrestrictedSet, it indicates that non-high-speed cells use an unrestricted set, with a corresponding detection window count of 1, and the corresponding window is denoted as...

[0237] Based on the number of detection windows obtained, BS obtains the target window w corresponding to the i-th RAPID. target and the corresponding preamble PDP sequence P i,u [j].

[0238] If the number of detection windows obtained is 1, then the target window w target The corresponding PDP is as follows, and then proceed to step 5.

[0239]

[0240] If the number of detection windows obtained is greater than 1, then BS calculates the similarity between multiple detection windows, merges multiple windows with similarity, and obtains the target window w. target and corresponding PDP value P i,u [j];

[0241] The similarity calculation of the multiple detection windows can be based on the PDP of the preamble in the multiple detection windows, or it can be based on the CDP (Complex power delay profile) of the preamble in the multiple detection windows.

[0242] When selecting multiple detection windows based on PDP for similarity calculation, the detection window with the largest preamble PDP among the multiple windows is first selected as the standard window or reference window, denoted as w. standard ,

[0243] w standard =find(max(P) i,u [jd u ],P i,u [j],P i,u [j+d u ]))(j=i*Nsw,…(i+1)*Nsw-1)

[0244] Based on the selected standard window or reference window w standard Calculate the cosine similarity γ between other windows and the standard or reference window. For example, assuming the i-th window is chosen as the standard window, the cosine similarity γ between other windows and the standard window is calculated as follows:

[0245]

[0246] * represents the dot product of vectors.

[0247] Based on the results of cosine similarity calculation, it is determined whether other windows need to be merged with the standard window. For example, the cosine similarity γ is compared with a predefined threshold T. If the similarity is greater than T, the window is considered to have a high similarity with the standard window or the reference window; otherwise, the window is considered to have a low similarity with the standard window or the reference window. BS selects multiple windows with high similarity for merging. The merging method can be coherent merging based on PDP or merging based on CDP.

[0248] For example, multi-window merging based on PDP can be represented as:

[0249]

[0250] When selecting multiple detection windows based on CDP for similarity calculation, the window containing the maximum PDP value among the multiple detection windows is first selected as the standard window or reference window, denoted as w. target ,

[0251] w target =find(max(P) i,u [jd u ],P i,u [j],P i,u [j+d uBased on the selected standard or reference window, calculate the cosine similarity γ between other windows and the standard or reference window. For example, assuming the i-th window is selected as the standard window, the cosine similarity γ between other windows and the standard window is calculated as follows:

[0252]

[0253] * represents the dot product of vectors, Re represents the real part of the complex number, and Im represents the imaginary part of the complex number.

[0254] Based on the results of cosine similarity calculation, it is determined whether other windows need to be merged with the standard window. For example, the cosine similarity γ is compared with a predefined threshold T. If the similarity is greater than T, the window is considered to have a high similarity with the standard window or the reference window; otherwise, the window is considered to have a low similarity with the standard window or the reference window. BS selects multiple windows with high similarity for merging. The merging method can be coherent merging based on PDP or merging based on CDP.

[0255] The window obtained after merging is called the target window, denoted as w. target .

[0256] Step 5: Based on the obtained target detection window, the BS performs preprocessing operations and candidate user signal cluster identification operations on the target window corresponding to each obtained RAPID to obtain the channel time distribution characteristics and candidate user signal clusters within the target window corresponding to each RAPID. This is used to identify multiple conflicting UEs that may exist within the target window corresponding to the same RAPID. The preprocessing operation includes the following multiple stages, modes, or operations. The candidate user signal cluster represents the time window in which a UE may exist, and the number of candidate user signal clusters represents the number of possible UEs.

[0257] Step 5.1, data preprocessing operation. The main purpose of this operation is to determine candidate user signal clusters, obtain the boundary point between signal and noise for each user signal cluster (for example, the PDP or CDP corresponding to the boundary point can be called the first PDP signal), and calculate the noise power based on the result of the boundary point.

[0258] First, for each RAPID, the target window w is... target The PDP signals of the preamble signal within the window are sorted. This sorting operation can be performed by descending order based on the peak value of the PDP signals within the window, or by ascending order based on the peak value of the PDP signals within the window. For example, based on the PDP signal P within the target detection window corresponding to the i-th RAPID... i,u [j] Sort the PDP signals in descending order to obtain the sorted PDP signals. Where k = f(j), j = i*Nse,…(i+1)*Nsw-1, k represents the index corresponding to the PDP signal after descending order, j is the index corresponding to the PDP signal before sorting, and f(·) is the mapping function from the index before sorting to the index after sorting.

[0259] Secondly, based on the sorted PDP signals Determine the boundary between signal and noise. For example, this can be done by analyzing the sorted PDP signals. An N-order difference operation is performed to obtain the boundary between signal and noise. For example, the corresponding sequence after N-order difference can be obtained. The boundary between signal and noise is determined by judging the result of the N_order difference. N_order can be configured as 1, 2, or a number greater than 2. For example, in the case of N_order = 1, the sequence after the first-order difference calculation... It can be represented as:

[0260]

[0261] For the case where N_order=2, the sequence after second-order difference calculation It can be represented as:

[0262]

[0263] The method for determining the boundary between signal and noise involves comparing the N-order difference sequence described above with a predefined threshold.

[0264] For descending order, find the first index in the N_order difference sequence. Less than the threshold T th The index corresponding to the element value As the dividing point between the signal and the noise:

[0265]

[0266] For ascending order, find the first index in the N_order difference sequence. Greater than the threshold T th The index corresponding to the element value As the dividing point between the signal and the noise:

[0267]

[0268] The method for determining the boundary between signal and noise can also be achieved by comparing the sequence obtained from the moving average of the Nth-order difference with a predefined threshold.

[0269] For descending order, find the first index in the sequence after N-stage differential moving average. Less than the threshold T th The index corresponding to the element value As the boundary between the signal and noise, where:

[0270]

[0271] For ascending order, find the first index in the sequence after N-stage differential moving average. Greater than the threshold T th The index corresponding to the element value As the boundary between the signal and noise, where:

[0272]

[0273] The sequence resulting from the moving average of the Nth-order difference can be represented as follows:

[0274]

[0275] Where L is the length of the predefined moving average.

[0276] Furthermore, the boundary between the obtained signal and noise can be used as a basis. Calculate the corresponding noise power.

[0277] For descending order, the noise power can be calculated as follows:

[0278]

[0279] For ascending order, the noise power can be calculated as follows:

[0280]

[0281] Step 5.2: Based on the PDP value of the preamble within the target window corresponding to each RAPID and the corresponding index, obtain the candidate user signal clusters within the target window corresponding to each RAPID. The method for obtaining the candidate user signal clusters includes the following multiple stages, modes, or operations;

[0282] First, based on the determined boundary between signal and noise. Obtain the index of the user signal cluster within the target detection window. in f -1 (·) represents the mapping function from the sorted index to the unsorted index. This is applied to the indexes of the obtained user signal clusters. In this process, user signal clusters with an interval less than Nfft / Lra are merged into a single FFT cluster (e.g., an oversampled cluster), see [link to FFT]. Figure 5 Within all FFT clusters, the time point containing the cluster with the largest PDP peak is identified as the central cluster. The maximum delay spread cluster is obtained by defining the intervals on either side of the maximum delay spread. (See...) Figure 6 Within a maximum delay spread cluster, if the PDP peak value of a signal arriving later than the central cluster does not exhibit exponential decay, then the cluster containing this PDP peak value is considered a separate user signal cluster. (See below) Figure 7 .

[0283] The above-mentioned methods for obtaining candidate user signal clusters can be combined with the distribution of UEs within the cell, preamble resources used for random access, or BS scheduling and processing capabilities. For example, it can be based on the index of valid signals from adjacent user signal clusters. Make a judgment, for example, if the index of the valid signal corresponding to the i-th user signal cluster is... Index of the valid signal corresponding to the (i+1)th user signal cluster The distance is less than the predefined threshold T, that is Therefore, adjacent user signal clusters can be considered to correspond to the same UE.

[0284] Step 6: Based on the user signal clusters corresponding to each identified RAPID, perform feature filtering and / or feature reconstruction operations. The PDP sequence obtained from feature filtering and / or feature reconstruction is used as input to subsequent artificial intelligence or deep learning models for inference to determine whether a UE is detected in that user signal cluster, obtaining at least one of the estimated values ​​of the number of UEs, the corresponding RAPID, and TA. The feature filtering operation involves extracting data from the user signal cluster... A continuous PDP signal, in which For predefined or preconfigured values. For example, The tolerance for TA detection error can be based on delta. TA To configure for feature filtering, such as by t in each user signal cluster. start Starting from the first point, extract continuous delta. TA A continuous PDP signal The PDP signal, after feature filtering, is used as input to artificial intelligence and / or deep learning models.

[0285]

[0286] It can also be based on t in each user signal cluster start Use the intermediate point to extract the valid ones. A continuous PDP signal The PDP signal, after feature filtering, is used as input to artificial intelligence and / or models.

[0287]

[0288] The aforementioned feature reconstruction involves constructing other useful features to characterize the signal's properties based on the feature-selected PDP signal. For example, features can be constructed based on the peak-to-average power ratio (PAPR) or the variance of the feature-selected PDP signal. For instance, the PAPR-based feature construction can be expressed as:

[0289]

[0290] Step 7: The base station uses the PDP sequence after feature filtering and feature reconstruction as input to the AI / ML model for RAPID and TA estimation detection. In one implementation, to further improve the reliability of the detection results, the estimated signal-to-noise ratio (SNR) can also be used as the model input. The SNR can be used to improve the confidence of the activation decision function. For example, when the model uses a sigmoid decision output, based on the estimated SNR, the corresponding activation decision function can be modified as follows:

[0291]

[0292] The estimated SNR is expressed as

[0293] The higher the estimated SNR, the more reliable the detection result; conversely, the lower the estimated SNR, the less reliable the detection result.

[0294] Confidence calibration is performed based on the input of the AI / ML model. For example, if the output result E_g(z) is less than the predefined value X, it means that no UE was detected in the detection window. Conversely, if it is greater than the predefined value X, it means that a UE was detected in the detection window. The predefined value X can be set to 0.5.

[0295] This application does not impose any restrictions on the selected AI / ML model; it can be a multilayer perceptron (MLP), a convolutional neural network (CNN), a residual neural network (ResNet), a kernel machine, or other models.

[0296] The method provided in this example, using a MoE-based feature enhancer, can avoid both false alarms caused by excessive noise due to low signal-to-noise ratio and missed detections due to weak signal amplitude, thus improving overall detection performance.

[0297] The method provided in this example employs an adaptive merging method of multiple detection windows for HST in multi-antenna, multi-symbol, and / or high-speed scenarios. This can avoid the missed detection problem caused by power dispersion under the Doppler effect, as well as the false alarm problem caused by multi-window merging in noisy environments, thus improving the overall detection performance.

[0298] The method provided in this example allows for the prediction of the possible number of UEs corresponding to the same preamble ID by acquiring candidate user signal clusters. In one implementation, further, by extracting channel features, multipath components and the distinction between different UE signals can be achieved, thereby improving the accuracy of detection information for multiple UEs corresponding to the same preamble ID. Furthermore, in another implementation, feature filtering and reconstruction can further reduce the complexity of the AI / ML model while also improving its generalization ability.

[0299] Furthermore, the method provided in this example, by employing a multi-window similarity metric and a candidate user signal cluster detection method, can improve the detection performance of multiple UEs under collisions. Compared to single UE transmission and detection, it can save the preamble resource overhead for UE random access and increase the possibility of subsequently canceling the PRACH transmission resource restriction set, thereby further saving resources.

[0300] Furthermore, using the method provided in this example, the accuracy of TA estimation can be improved by selecting the strongest path of the signal PDP from the signals within each candidate user signal cluster as the TA for this UE. In one implementation, a confidence level based on SNR is designed on top of the original sigmoid activation function, which can improve the robustness of detection.

[0301] The following describes an example flowchart of a multi-UE access scenario according to embodiments of the present disclosure. Figure 8 An example flowchart of contention-based access in a multi-UE scenario according to embodiments of the present disclosure is shown.

[0302] like Figure 8 As shown, multiple UEs (e.g., a first number of UEs, Figure 8 The diagram shows two UEs sending a random access preamble (msg1) to a base station (e.g., gNB). For example, the two UEs randomly select a preamble from 64 preamble resources and select the same preamble (e.g., corresponding to the same random access signal), and use the selected preamble to send their MSG1 on PRACH.

[0303] When the base station receives MSG1, it uses a detection algorithm to detect multiple users. In this case, two UEs will have the same random access preamble identification information (e.g., RAPID). The base station can use an AI-based PRACH receiver to efficiently detect multiple users based on the PDP amplitude characteristics.

[0304] Next, the BS sends a response message for the same preamble. For example, the BS indicates the scheduling information for MSG2 PDSCH RAR via MSG2PDCCH. Within the RAR window, the UE listens to the PDCCH to receive PDSCH RAR.

[0305] In addition, the BS performs RAR transmission. For example, the RAR contains RAPID, T-CRNTI, TA, UL authorization, UE number indication information for uplink synchronization of the UE, and subsequent MSG3 transmission. For example, the TA included in the RAR can be an absolute TA value, or it can be first TA information and second TA information, such as a reference TA and a relative TA, where the reference TA is the TA value of one UE, and the TA value of the other UE can be obtained through the reference TA and the relative TA.

[0306] For example, the BS can send a RAR to each UE seeking access. The RAR includes: a TA for at least one UE (e.g., a second number of UEs) requesting random access, TA acquisition indication information (e.g., referred to as a TA flag, or TA-related information indication information, instructing the UE to acquire the corresponding TA-related information), and uplink transmission resource information (or resource allocation information for the second number of UEs).

[0307] For example, TA-related information includes at least one of the following: downlink path loss between the UE and the base station; reception and transmission times of System Information Block (SIB1); signal strength-related information and threshold information. For example, the TA flag indicates the method used by the UE to obtain its TA or TA estimate, such as one of three methods: a threshold-based method, a SIB1 reception time-based method, or a path loss-based method.

[0308] For example, the BS can include DMRS-related information in the RAR, indicating overlapping UL authorizations through spatially multiplexed DMRS.

[0309] For example, the UE's T-CRNTI, DMRS, and UL authorization can be mapped through the UE's TA mode:

[0310] DMRS UE =DMRS TA_index

[0311] TCRNTI UE=TCRNTI_reference UE +TCRNTI offset

[0312] in,

[0313] TA_index is the index of the TA obtained by the UE in the RAR in the corresponding TAC field of the RAR;

[0314] The TA index corresponds to the DMRS indicator port on which the base station receives UL authorization;

[0315] TCRNTI offset The offset between the TA index of the UE and the TA index of the reference UE, i.e.

[0316]

[0317] For example, the number of UEs indicated by the UE quantity indication information (e.g., the second quantity) can represent the length of the RAR.

[0318] During the Random Access Response (RAR) window, the base station sends message 2 (msg2) to these UEs, such as the PDCCH of message 2 (e.g., including DCI 1_0) and the PDSCH of message 2, which includes the Random Access Response (RAR). Through message 2, the base station can send information for uplink transmission (e.g., first information related to UE access) to multiple UEs, such as at least one of the following: preamble identification information (e.g., RAPID), number of UEs, DMRS resources, timing advance (TA) related information (e.g., absolute TA value, or reference TA value and / or relative TA value or TA offset value), TA acquisition indication information (e.g., shown as TA flag in the figure), uplink grant (UL grant), temporary cell radio network temporary identifier (T-CRNTI), etc. In some implementations, the above-mentioned information for uplink transmission may also include threshold-related information, such as the RSRP threshold used by the UE to determine the TA estimate (e.g., referred to as first threshold information), or may also include threshold offset information, such as RSRP threshold offset (or threshold-related step size). The information used for uplink transmission described above can be sent to multiple UEs via PDCCH and PDSCH, or it can be sent to multiple UEs via PDSCH. For example, a portion of the information used for uplink transmission (e.g., the first portion) can be carried in the PDCCH via DCI, and another portion (e.g., the second portion) can be carried in the PDSCH via MAC PDU. Alternatively, all the information used for uplink transmission described above can be carried in the PDSCH via MAC PDU. In some implementations, for example, the first portion may include at least one of the following: RAPID, number of UEs, TA acquisition indication information, reference TA, RSRP threshold, and the second portion may include the remaining information in the information used for uplink transmission described above. The RSRP threshold is just one example of threshold-related information; other thresholds may also be used, such as thresholds related to radio conditions or signal reception, such as RSRQ threshold, RSSI threshold, SINR, SNR, etc.

[0319] Within the RAR window, the UE receives the RAR. For example, after the UE receives MSG2, the UE decodes the RAR and obtains the parameters used for MSG3 transmission. For example, the UE obtains its TA based on the TA acquisition indication information (e.g., TA flag), and obtains its DMRS and T-CRNTI based on the obtained TA.

[0320] Upon receiving the RAR, the UE can perform scheduled uplink transmissions (e.g., MSG3 PUSCH) based on the information in the RAR.

[0321] For example, the UE sends MSG3 on the corresponding DMRS port based on the TA, UL Grant, and T-CRNTI, carrying the UE's identifier. For instance, the corresponding DMRS port is the port corresponding to the DMRS obtained by the UE based on the acquired TA.

[0322] After receiving the PUSCH transmission, the base station can send a PDSCH (MSG4) containing contention resolution information related to multiple UEs during the contention resolution (CR) timer. For example, the BS decodes each MSG3 on each DMRS port to obtain the identifier of each UE.

[0323] In addition, the BS sends message 4 (MSG4) to each UE, which carries the UE's identifier.

[0324] During the CR timer period, the UE monitors MSG4 and checks whether the identifier carried in MSG4 is the same as the identifier sent by the UE in MSG3. If they are the same, the access is considered successful.

[0325] It should be understood that, for ease of expression, this disclosure sometimes does not strictly distinguish between the RAR of message 2 and PDCCH or DCI 1_0. In such cases, the RAR mentioned can be understood as message 2, including PDCCH and PDSCH. For example, the phrase "after receiving the RAR" mentioned above can refer to receiving message 2, and the phrase "based on the information in the RAR" mentioned above can refer to the information in message 2, including the information in DCI 1_0 in PDCCH and the information in the RAR included in PDSCH.

[0326] In some implementations, the MSG2 may include TA acquisition indication information or fields related to TA acquisition indication information (e.g., TA flag field). This TA acquisition indication information can be used to indicate to the UE which method to use to obtain the TA estimate, such as a threshold-based method, a SIB1 reception time-based method, or a path loss-based method. Example methods for obtaining TA estimates based on various methods will be described in detail later.

[0327] In some implementations, MSG2 may not include TA acquisition indication information, or fields related to TA acquisition indication information, and the UE may default to using a threshold-based method to obtain the TA estimate. For example, in some implementations, MSG2 may include threshold-related information, which the UE can use to obtain the TA estimate. Alternatively, MSG2 may also include threshold offset information, or threshold step size related information, which the UE can use to obtain the TA estimate.

[0328] In some implementations, the MSG2's DCI may include at least one of the following: RAPID, number of UEs, TA acquisition indication information, reference TA, and RSRP threshold. This allows UEs to obtain information related to uplink transmissions more quickly, or reduces the complexity of UE decoding or detection.

[0329] Using the methods described above, the base station can resolve multi-UE access conflicts to some extent through message 2, enabling multiple UEs to access the system more quickly. This method can reduce access latency.

[0330] The methods of this disclosure will be described in more detail below with reference to several examples.

[0331] Example 2

[0332] In this example, the method for the BS side to send a random access response MSG2 RAR in a multi-UE scenario proposed in this invention will be introduced.

[0333] After receiving MSG1, the BS detects the preamble according to the AI-based PRACH detection method in the multi-UE scenario described in Example Aspect 1 above, and obtains the information of the PUSCH transmission scheduled by RAR (e.g., first information related to UE access). This information includes the RAPID, the number of UEs under the same RAPID, optional DMRS resource indications, TA, TA acquisition indication information (e.g., represented as TA flag), T-CRNTI, UL Grant resources, etc. This information is sent to the UE in the MAC RAR PDU. In one implementation, the aforementioned PUSCH transmission information is sent to the UE via message 2 (Msg2). Msg2 may include PDCCH and PDSCH RAR, and the PUSCH transmission information can be sent to the UE via the PDCCH and / or PDSCH RAR of Msg2.

[0334] The MAC RAR PDU consists of one or more RAR subPDUs, one or more multi RAR subPDUs, and optional padding.

[0335] When the BS detects random access requests from multiple UEs on the same PRACH or PRACH occasion (RO) resource, that is, when these UEs have the same RA-RNTI but different RAPIDs, it responds to these access requests using one or more RARsubPDUs.

[0336] When the BS detects random access requests from multiple UEs on the same PRACH or PRACH occasion (RO) resource, i.e., these UEs have the same RA-RNTI but each UE has the same RAPID, it responds to these access requests using one or more multiRAR subPDUs. For example, the multiRAR subPDU may include uplink transmission-related information about multiple UEs with the same RAPID. The payload length of the multiRAR subPDU may be extended relative to the payload of the RAR subPDU, or the multiRAR subPDU may be regarded as multiple RAR subPDUs.

[0337] Among them, RA-RNTI is obtained by BS when decoding the preamble, and is used to scramble MSG2 DCI format 1_0 with this RA-RNTI and then send it out through PDCCH.

[0338] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0339] The information transmitted via PUSCH can be carried in PDCCHDCI1_0 and PDSCH. RAR is carried together, for example For example, the first part of the information transmitted by the PUSCH is carried in DCI1_0, and the second part of the information transmitted by the PUSCH... Some of them are carried in PDSCH.

[0340] For the same RAPID with N>1 UEs (e.g., the second number of UEs), that is, the number of UEs under the same RAPID is N (e.g., the second number):

[0341] Format 1:

[0342] RAPID is carried in the DCI 1_0 field:

[0343] Assuming there are N RAPIDs and M RAPIDs, the RAPIDs are carried in the Reserved field of DCI 1_0 using 6 Mbit.

[0344] Other information is carried in the subheader or payload of the PDSCH RAR. This other information includes the number of UEs N (or first UE quantity information) under the same RAPID (e.g., referred to as the first RAPID or first preamble identification information), TA, TA acquisition indication information (e.g., indication information of TA-related information, instructing the UE to acquire the corresponding TA-related information), T-CRNTI, UL Grant resources, and / or DMRS resource indications. For example, TA-related information includes at least one of the following: downlink path loss between the UE and the base station; reception and transmission times of System Information Block SIB1; signal strength-related information and threshold information.

[0345] in,

[0346] The number of UEs N under the same RAPID is indicated in the UE information field of the RAR subheader, occupying log2 N bits.

[0347] If DMRS resource information exists, it can also be indicated in the UE information field of the RAR subheader, placed after the UE number information, occupying N*log2 N bits.

[0348] When DMRS resource information exists, the UE information field occupies a total of ceil((N*log2 N+log2N) / 8) bytes. If it is less than a whole byte, the beginning of the field is ceil((N*log2 N+log2 N) / 8)*8-N*log2 N-log2Nbit as the Reserved field.

[0349] If DMRS resource information is not available, the UE information field occupies a total of ceil(log2 N / 8) bytes. If it is less than a whole byte, the first bit of the field, ceil(log2 N / 8)*8-log2 N bits, is used as the Reserved field.

[0350] In one implementation, the TA acquisition indication information in the other information is carried in a field of the RAR payload (e.g., the TA Flag field). It should be understood that the field name TA Flag used in this disclosure is merely an example, and other names may also be used.

[0351] The TA acquisition indication information is used to indicate the method used by the UE to acquire the TA, for example, it occupies 2 bits.

[0352] When TA Flag = 0 or no TA Flag is configured, the UE is instructed to obtain TA using a threshold-based method; wherein, the absolute threshold portion (e.g., referred to as first threshold information) is carried in DCI1_0, for example, occupying 7 bits; the relative threshold (e.g., referred to as threshold offset information) is carried in a field of the RAR payload (e.g., RSRP_offset field), for example, occupying 1 bit. It should be understood that the field name RSRP_offset used in this disclosure is merely an example and other names may also be used.

[0353] When TA Flag=1, it instructs the UE to obtain TA based on the free space fading model. For example, the UE can obtain the TA estimate based on the path loss value, and then obtain the UE's TA value based on the TA estimate and the TA-related information in the DCI and / or RAR.

[0354] When TA Flag = 2, it instructs the UE to obtain the TA using the SIB1 reception time; where the SIB1 transmission time is carried in the SIB1. For example, the UE can obtain the TA estimate based on the SIB1 reception time and transmission time, and then obtain the UE's TA value based on the TA estimate and the TA-related information in the DCI and / or RAR.

[0355] In one implementation, the RAR may not include TA acquisition indication information or the TA Flag field. In this case, the UE defaults to using a threshold-based method to determine the TA estimate.

[0356] The TA in the information is carried in the TAC field of the RAR payload:

[0357] It can be the absolute TA value of each UE, arranged in ascending order, occupying 12N bits.

[0358] It can also be the baseline TA value TA_baseline (or it can also be called the second TA, reference TA, or standard TA, or it can also be expressed as reference TA or TA). reference And N-1 relative TA values ​​delta_TA (or also called difference TA, TA difference, etc.) relative to the base TA, occupying 12+(N-1)*8 bits.

[0359] The benchmark TA is selected from the minimum TA among N UEs with the same RAPID.

[0360] delta_TA=(TA-TA_baseline) / unit_TA

[0361] Where unit_TA is the minimum time precision that the BS-side algorithm can identify among N UEs. For example, a predefined maximum delay spread Max_dalay_spread_sample can be selected as the minimum time precision for distinguishing among N UEs.

[0362] unit_TA=Max_dalay_spread_sample*16 / (15K*2048)

[0363] The UL Grant mentioned in the information is carried in the UL Grant field of the RAR payload:

[0364] The same PUSCH time-frequency domain resources can be allocated to N UEs, occupying a total of 27 bits.

[0365] Orthogonal PUSCH time-frequency domain resources can be allocated to N UEs, with each UE occupying 27 bits, for a total of N*27 bits.

[0366] The T-CRNTI in the aforementioned information is carried in the T-CRNTI field of the RAR payload:

[0367] Assign random T-CRNTI sequences to N UEs, occupying N*16 bits.

[0368] Form 2:

[0369] The RAPID and the number of UEs N are carried in the DCI1_0 field:

[0370] Assuming the number of RAPIDs with multiple UEs is M, the RAPID is carried in the Reserved field of DCI1_0 using 6Mbit; the number of UEs is carried in 6Mbit, occupying a total of M*12 bits.

[0371] Other information is carried in the subheader or payload of the PDSCH RAR. This other information includes the TA, T-CRNTI, UL Grant resources, and optional DMRS resource indications under the same RAPID.

[0372] If DMRS resource information exists, it can be indicated in the UE information field of the RAR subheader, occupying N*log2 N bits, and a total of ceil(N*log2 N / 8) bytes. If it is less than a whole byte, the beginning of the field is ceil(N*log2 N / 8)*8-N*log2 N bits as the Reserved field.

[0373] Other information is carried in the same way as described in the first form, including TA under the same RAPID, TA acquisition instruction information, T-CRNTI, and UL Grant resources.

[0374] Form 3:

[0375] RAPID, UE number N, and baseline TA are carried in the DCI1_0 field:

[0376] Assuming there are N RAPIDs and the number of RAPIDs is M, then the RAPID is carried in the Reserved field of DCI1_0 using 6 Mbits; the number of UEs is carried in 6 Mbits; the base TA occupies 12 Mbits, for a total of 24 Mbits.

[0377] Other information is carried in the subheader or payload of the PDSCH RAR. This other information includes the TA under the same RAPID, TA acquisition instruction information, T-CRNTI, UL Grant resources, and optional DMRS resource instructions.

[0378] The TA information for N-1 UEs is carried in the TAC field of the PDSCH payload:

[0379] It can be an absolute TA value, arranged in first order, such as from smallest to largest, occupying 12*(N-1) bits.

[0380] It can be a relative TA value delta_TA relative to the base TA, occupying 8*(N-1) bits.

[0381] The optional method of carrying DMRS resource information is the same as described in the second form.

[0382] Other information is carried in the same way as described in the first form, including T-CRNTI, TA acquisition instruction information, and UL Grant resources.

[0383] The information transmitted by the PUSCH can be carried only in the subheader and payload of the PDSCH RAR.

[0384] The number of UEs, N, is indicated in the UE information field of the RAR subheader, occupying log2 N bits.

[0385] If DMRS resource information exists, it can also be indicated in the UE information field of the RAR subheader, placed after the UE number information, occupying N*log2 N bits.

[0386] When DMRS resource information exists, the UE information field occupies a total of ceil((N*log2 N+log2N) / 8) bytes. If it is less than a whole byte, the beginning of the field is ceil((N*log2 N+log2 N) / 8)*8-N*log2 N-log2Nbit as the Reserved field.

[0387] When DMRS resource information exists, the UE information field occupies a total of ceil(log2 N / 8) bytes. If it is less than a whole byte, the beginning of the field is ceil(log2 N / 8)*8-log2 Nbit as the Reserved field.

[0388] Other information is carried in the PDSCH RAR payload, including TA, T-CRNTI, and UL Grant resources, in the same manner as the first form carried by both PDCCH DCI1_0 and PDSCH RAR.

[0389] The information transmitted by the PUSCH can be carried only in the PDSCH RAR.

[0390] The number of UEs, N, and the optional DMRS resources are carried in the UE information subheader within the PDSCH RAR subheader. The number of UEs occupies log2 N bits, and the optional DMRS resource indication occupies N*log2 N bits. Bits that are not integer bytes are set to reserved at the beginning of the subheader.

[0391] Other information is carried in the PDSCH RAR payload.

[0392] The TA information is located in the TAC field. If it is an absolute TA value, it occupies 12N bits; if it is a base TA or a relative TA, it occupies 12+(N-1)*8 bits.

[0393] In the UL Grant field, if orthogonal PUSCH resources are allocated, it occupies N*27 bits; if the same set of PUSCH resources is allocated, it occupies 27 bits.

[0394] The T-CRNTI field occupies N*16 bits.

[0395] The PDSCH RAR payload occupies less than an integer number of bits, so the beginning of the payload area is set to Reserved.

[0396] The method provided in this example implements feedback of multi-UE information by designing a way to carry multi-UE detection information in random access responses, which is the basic guarantee for simultaneous access of conflicting UEs in multi-UE scenarios.

[0397] The method provided in this example improves latency by carrying RAPID, and / or the number of UEs, and / or the baseline TA in the PDCCH, allowing the UE to begin estimating or acquiring TA before decoding the PDSCH.

[0398] The method provided in this example, which instructs the UE to obtain the TA through the TA indicator information, is used by the UE to obtain the TA more accurately.

[0399] The method provided in this example saves resource overhead by using a base TA and a relative TA to jointly indicate the form of TA.

[0400] The method provided in this example speeds up the time for the UE to search for and select the TA by arranging the TAs in ascending order into the TAC field, thereby reducing the UE's power consumption.

[0401] The method provided in this example offers a way to obtain T-CRNTI and / or UL Grant and / or DMRS based on TA index, which speeds up the time for UE to obtain information and reduces UE power consumption.

[0402] The method provided in this example allows multiple UEs to share a single time-frequency domain resource for UL grants, and distinguishes UEs by orthogonal DMRS resources or T-CRNTI randomization, thus saving uplink resources.

[0403] Example 3

[0404] In this example, the method for receiving Random Access Response (RAR) on the UE side in a multi-UE scenario proposed in this invention will be introduced.

[0405] After the UE sends the preamble (e.g., the information corresponding to the first preamble identification information), the UE can receive message 2 (Msg2). For example, the information content that Msg may include (e.g., the information transmitted by PUSCH as described above) can be referred to the description in Example Aspect 2 above, and will not be repeated here. The UE will perform the following steps on Msg2RAR:

[0406] Step 1: Calculate the RA-RNTI associated with the PRACH. During the message waiting window ra-ResponseWindow, continuously listen to the PDCCH to receive the RAR. Any RAR received by the UE within this window is considered valid. If the UE does not receive a RAR from the BS within the RAR time window, the random access procedure is considered to have failed, and the UE retransmits MSG1. The RA ResponseWindow is obtained through the rar-WindowLengthIE of the SIB message. The PDCCH is located in the Type 1 PDCCH Common Search Space (CSS), carries DCI format 1_0, and is scrambled using the RA-RNTI.

[0407] Step 2: After successfully decoding the PDCCH, the UE will obtain the RB resource information of the PDSCH RAR to receive downlink transport blocks transmitted via the PDSCH, and / or detection result information. The detection result information includes an optional RAPID, an optional number of UEs, an optional baseline TA, and an optional absolute threshold.

[0408] Step 3: If the PDCCH carries relevant detection result information, the UE obtains its own TA (e.g., TA estimation information) based on the parsed detection result information. Otherwise, proceed to step 4.

[0409] Format 1: For the case where PDCCH DCI 1_0 only contains RAPID

[0410] The UE parses the lower 6 Mbits of DCI 1_0 and checks if the RAPID therein is the same as the RAPID of its own preamble. If they are the same, it means that there are multiple UEs under this RAPID. The UE estimates or obtains its own TA (e.g., TA estimation information) according to the configuration method for obtaining indication information.

[0411] When TA_flag = 0 or TA_flag is not configured, the UE-side TA estimation uses a threshold-based method to obtain the TA, where the absolute threshold is obtained from DCI1_0 and the relative threshold is obtained from the RAR payload. The UE then obtains the TA using the following method:

[0412]

[0413] When TA_flag=1, the UE obtains TA based on the free space fading model: The UE first calculates the downlink (DL) path loss PL, then calculates the distance d between the BS and the UE based on the relationship between free space path loss and distance, and finally estimates TA based on the relationship between distance and time.

[0414] PL=Prx–Ptx=RSRP_DL–reference power

[0415] PL = 20log(d) + 20log(f) - 147.55

[0416] TA_est=10^((PL-20log(f)+147.55) / 20)*(15K*2048) / (16*3*1e8)

[0417] Where f is the signal carrier frequency, RSRP_DL is the downlink received reference signal power measured by the UE side, and reference power is the reference signal power ss-PBCH-BlockPower, which is carried in SIB.

[0418] When TA_flag = 2, the UE obtains the TA based on the SIB1 reception time, where the SIB1 transmission time is carried in SIB1:

[0419] TA_est = receiveTime sIB1 -transTime SIB1

[0420] Form 2: For PDCCH DCI 1_0, which includes both RAPID and UE number:

[0421] The UE parses the lower 12Mbits of DCI 1_0 and checks if the RAPID therein is the same as the RAPID it sent. If they are the same, the UE parses the next 6 bits of the RAPID to obtain the number of UEs and then uses this information to determine the PDSCH RAR decoding length. After parsing the information, the UE needs to continue estimating or obtaining its own TA.

[0422] The method for estimating or obtaining TA for UE is the same as form 1 in this step.

[0423] Form 3: For PDCCH DCI 1_0, which includes RAPID, number of UEs, and baseline TA:

[0424] The UE parses the lower 24Mbits of DCI 1_0 and checks if the RAPID is the same as the RAPID it sent. If they are the same, the UE parses the next 6 bits of the RAPID to obtain the number of UEs and thus the PDSCH RAR decoding length; the UE parses the next 12 bits of the UE number to obtain the minimum reference TA value for this RAPID. After parsing the information, the UE needs to continue estimating or obtaining its own TA.

[0425] The method for estimating or obtaining TA for UE is the same as form 1 in this step.

[0426] Additionally, if the TA value in the PDSCH RAR payload is a relative TA value, the UE can continue to estimate its own relative TA value delta_TA.

[0427] delta_TA=min(abs(delta_TA_RAR-(TA_UE-TA_baseline) / unit_TA))

[0428] Step 4: The UE decodes the PDSCH carrying Mgs2 RAR data and selects the necessary information for the PUSCH transmission of the RAR schedule (e.g., some of the information transmitted in the PUSCH mentioned above).

[0429] Format 1: For the case where PDCCH DCI1_0 only contains RAPID

[0430] The required information includes the RAPID, the number of UEs under the same RAPID, and second information related to uplink transmission, such as optional DMRS resource indication, TA, T-CRNTI, and UL Grant resources. In one implementation, the required information further includes TA acquisition indication information as described above, based on which the UE can use appropriate methods to obtain a TA estimate.

[0431] The UE finds the MAC subPDU that matches the transmitted RAPID by decoding the RAPID subheader. Then, it obtains the number of UEs and the length of the PDSCH RAR payload to be decoded through the UEinformation subheader, and then decodes the PDSCH RAR payload.

[0432] If the TAC field in the PDSCH RAR payload is an absolute TA value, the UE compares its estimated TA with the TA results in the RAR payload and selects the closest absolute TA value as its own TA value final_TA (for example, it can also be called the first TA information), and records the index (delta_TA) of final_TA in the TAC.

[0433] final_TA=min(abs(TA_UE-TA_RAR))

[0434] If the TAC field in the PDSCH RAR payload is a relative TA value delta_TA, the UE compares its estimated TA with the first baseline TA in the RAR payload to calculate the relative TA value; then it selects the closest relative TA value delta_TA as its own relative TA value; finally, based on the relationship between the relative TA and the absolute TA value, it obtains the UE's final TA value final_TA, and records the index (delta_TA) of final_TA in the TAC.

[0435] delta_TA=min(abs(delta_TA_RAR-(TA_UE-TA_baseline) / unit_TA))

[0436] final_TA=delta_TA*unit_TA+TA_baseline

[0437] If DMRS resources exist, the UE selects the DMRS resource with index (delta_TA) in the UE information subheader.

[0438] The UE selects the T-CRNTI corresponding to the index index(delta_TA) in the T-CRNTI field.

[0439] The UE selects UL Grant information through the UL Grant field. If the PDSCH RAR payload contains the same set of UL Grant information, all UEs use the same set of UL Grant resources. If the PDSCH RAR payload contains orthogonal UL Grant information, the UE selects the UL Grant resource corresponding to index (delta_TA).

[0440] Form 2: For PDCCH DCI1_0, which includes RAPID and UE number.

[0441] The required information includes optional DMRS resource indication, TA, T-CRNTI, and UL Grant resources. In one implementation, the required information further includes TA acquisition indication information as described above, based on which the UE can use appropriate methods to obtain a TA estimate.

[0442] The UE has already obtained the PDSCH RAR length through the PDCCH. The UE then retrieves the above information from different fields in the PDSCH RAR subheader or payload. The retrieval method is the same as in step 1 of this document.

[0443] Form 3: For PDCCH DCI1_0, including RAPID, number of UEs, and baseline TA.

[0444] The required information includes optional DMRS resource indications, N-1 TAs other than the base TA, T-CRNTI, and UL Grant resources. In one implementation, the required information also includes TA acquisition indication information as described above, based on which the UE can use appropriate methods to obtain a TA estimate.

[0445] The UE has already obtained the PDSCH RAR length through the PDCCH and its relative and / or absolute TA values. The UE then retrieves this information from different fields in the PDSCH RAR subheader or payload. The retrieval method is the same as in step 1 of this document.

[0446] Form 4: All information is carried in the PDSCH RAR.

[0447] The information includes RAPID, the number of UEs under the same RAPID, optional DMRS resource indication, TA, T-CRNTI, and UL Grant resources. In one implementation, the required information further includes TA acquisition indication information as described above, based on which the UE can use appropriate methods to obtain a TA estimate.

[0448] The UE decodes the RAPID in the RAPID subheader and checks if it is the same as the sent RAPID. If they are the same, the UE continues to decode to obtain the information required for RAR scheduling PUSCH. The required information includes the number of UEs under the same RAPID, the optional DMRS resource indication, TA, TA acquisition indication information, T-CRNTI, and UL Grant resources. If it is not the same as the sent RAPID, the random access procedure is considered to have failed, and the UE retransmits MSG1.

[0449] Obtaining other information follows the same procedure as step 1.

[0450] Step 5: The UE obtains the RAR-scheduled PUSCH scheduling information based on the decoding response result and sends the RAR-scheduled PUSCH. In one implementation, the UE can obtain the DMRS resource indication corresponding to the UE based on the obtained TA-related information, and can also obtain the uplink resource corresponding to the UE or the uplink resource in the RAR that can be used by multiple UEs based on the TA-related information. In one implementation, the DMRS resource indication includes DMRS port information. For example, based on the obtained TA-related information, the UE sends the PUSCH on the uplink resource corresponding to the UE through the DMRS port corresponding to the obtained DMRS resource indication. After sending the PUSCH, the UE will simultaneously start the ra-ContentionResolutionTimer. Before the timer expires, the UE will continuously listen to the PDCCH of Msg4. If the timer expires, the UE considers the contention to have failed and re-initiates the random access procedure.

[0451] The UE adjusts the TA based on the acquired TA value. The UE saves the T-CRNTI for the DCI of PUSCH retransmission during RAR scheduling or the DCI of MSG4, and uses it for scrambling during PUSCH transmission. The UE determines the PUSCH transmission configuration and time-domain resource information through the UL Grant. For example, the UE can obtain its corresponding T-CRNTI based on the acquired TA value and use this T-CRNTI to scramble uplink transmissions.

[0452] The method provided in this example designs how multiple UEs receive RAR on the UE side, ensuring that each UE correctly obtains its own information without interfering with each other, which is the key to ensuring that conflicting UEs can access the network simultaneously.

[0453] The method provided in this example offers a feasible approach for the UE to obtain the TA, and provides guidance for the UE to select the TA.

[0454] The exemplary embodiments of this disclosure will now be described in more detail with reference to several more specific examples.

[0455] Example 1

[0456] This embodiment introduces a method proposed in this invention for detecting Preamble-related information during UE random access in a communication system, executed by the BS based on Artificial Intelligence (AI). The Preamble-related information includes RAPID, TA acquisition indication information, TA, and RAR-scheduled uplink shared channel (PUSCH) scheduling information. The process includes the following multiple stages, modes, or operations:

[0457] Step 1: The UE obtains the configuration information for PRACH transmission based on the received System Information Block 1 (SIB1), generates and transmits a data structure of length N generated by cyclic shifting. cs The preamble of the zero-correlation region is -1. The configuration information for PRACH transmission includes PRACH transmission parameters, limit set resources, root sequence number, and cyclic shift offset N. cs .

[0458] Step 2: Based on the received Preamble time-domain signal, the BS acquires the time-domain detection signals within N SWs, for example, N=64. This process includes the following stages, modes, or operations:

[0459] Step 2.1: The BS performs front-end processing on the received Preamble time-domain signal and obtains the Preamble frequency-domain signal Y based on the configured Preamble signal frequency-domain resource information. n The front-end processing includes removing the cyclic prefix (CP) of the preamble sequence, downsampling, and L. RA The Discrete Fourier Transform (DFT) of a point.

[0460] Step 2.2, BS receives the Preamble sequence Y n and U pre-generated frequency domain preamble sequences X u,n Do the correlation, and after obtaining the correlation, L RA Long frequency domain correlation sequence Z u,n The related operations can be represented as follows:

[0461]

[0462] Where (.)* represents the conjugate operation of complex numbers; L RA It can be 139, 839, 1157, or other values.

[0463] Step 2.3, for Z u,n Execute N ifft The inverse fast fourier transform (IFFT) is used to obtain the time-domain correlation result x.

[0464] x(i) = IFFT(z) u,n ), i = 0, 1, ... N ifft-1

[0465] Step 2.4, based on N in Step 1 cs Extract the temporal correlation result x of the k-th search window (SW). k Also known as CDP (Complex PDP), x k It is expressed as follows:

[0466]

[0467] Where m is the number of sample points within SW, N is the number of SWs, and Nsw represents the length of SW, calculated as follows:

[0468]

[0469] Step 2.5: Obtain the power delay profile (PDP) of the preamble signal within each SW. The PDP of the k-th SW is p. k , means as follows:

[0470] p k =|x k | 2

[0471] Step 3: The BS obtains the number of detection windows for the corresponding RAPID based on the restrictedSetConfig resource configuration from Step 1. Then, based on the number of detection windows, it obtains the target window, denoted as w. target .

[0472] The method for obtaining the number of detection windows corresponding to the RAPID is as follows:

[0473] When restrictedSetConfig is configured as restrictedSetTypeA, it indicates that the high-speed cell uses restriction set A, with a corresponding number of detection windows of 3. The corresponding windows are denoted as follows: When restrictedSetConfig is configured as restrictedSetTypeB, it indicates that the high-speed cell uses restriction set B, with a corresponding detection window count of 5. The corresponding windows are denoted as follows: Among them, the cyclic shift value d u This refers to the cyclic shift value corresponding to the Doppler frequency offset defined by 3GPP. When restrictedSetConfig is configured as unrestrictedSet, it indicates that non-high-speed cells use an unrestricted set, with a corresponding detection window count of 1, and the corresponding window is denoted as...

[0474] The method for obtaining the target window is as follows:

[0475] When the number of detection windows is 1 That is, w target Proceed to step 4.

[0476] When the number of detection windows is greater than 1, BS first calculates the similarity between each detection window, merges detection windows with similarity, and obtains w. target .

[0477] The similarity calculation between the detection windows can first select the detection window containing the maximum PDP value as the standard window, denoted as w. standard Based on w standard Calculate the remaining detection windows and w standard The cosine similarity γ between them.

[0478] For example, assuming For w standard ,but With w standard The γ values ​​are calculated as follows:

[0479]

[0480] in, for The CDP value of the m-th sample point. Re(.) represents the real part, and Im(.) represents the imaginary part.

[0481] Alternatively, the remaining detection windows and w can be calculated. standard The Euclidean distance between them is used as the similarity measure γ.

[0482]

[0483] Then, BS will compare γ with the predefined threshold Thr. sim Comparison, if r > Thr sim Then it is believed and They are similar; otherwise, they are considered to be similar. and They are not similar.

[0484] BS merges windows with similarity to obtain w target And discard detection windows that do not have similarity; when the number of detection windows with similarity is zero, w standard That is, w target .

[0485] The merging method can be coherent merging based on PDP or merging based on CDP.

[0486] assumed and They have similarity.

[0487] The coherent merging method based on PDP is as follows:

[0488]

[0489] Among them, w target , PDP (m) represents w target The PDP value of the m-th sample point.

[0490] The merging method based on CDP is as follows:

[0491]

[0492] Among them, w target , CDP (w) represents w target The CDP value of the m-th sample point, where 1j represents the imaginary unit.

[0493] Step 4, BS to w target Perform preprocessing and candidate user signal cluster identification operations to obtain w target The channel time distribution characteristics and possible user signal clusters are used to identify w target The preprocessing operation includes the following multiple stages, modes, or operations; the candidate user signal cluster represents the time window in which a single UE may exist, that is, the time distinguishability between different UEs, and the number of possible user signal clusters represents the number of possible UEs.

[0494] Step 4.1, data preprocessing operation. The main purpose of this operation is to identify candidate multi-user signal clusters, determine the boundary between signal and noise, and calculate noise power based on the boundary results.

[0495] First, regarding w target The PDP values ​​within the window are sorted to obtain the sorted target window, denoted as . Simultaneously, the index Ψm of the original sequence corresponding to the sorted sequence is recorded. The sorting operation can be either descending or ascending order.

[0496]

[0497] Where, ψm=f⁻¹(m), f -1 (.) is a mapping function from sorted indices to unsorted indices.

[0498] Secondly, for Perform N orderThe order difference operation yields a length of N. SW -N order The differencing sequence. The boundary between signal and noise is determined using the differencing sequence results, where N... order It can be 1 or 2.

[0499] The first-order difference sequence is denoted as It is expressed as follows:

[0500]

[0501] in, express The PDP value of the m-th sample point in the first-order difference sequence.

[0502] The second-order differencing sequence Represented as:

[0503]

[0504] in, express The PDP value of the m-th sample point in the second-order difference sequence.

[0505] The method for determining the signal-noise boundary point can be achieved by analyzing the above-mentioned difference results. Compare with a predefined threshold to find PDP value self-indexing The starting index value that is always less than the threshold is the boundary between noise and signal.

[0506] The method for determining the boundary between signal and noise can also be achieved through... The sequence obtained by performing a moving average Compare with a predefined threshold to find PDP value self-indexing The starting index value that is always less than the threshold is the boundary between noise and signal.

[0507] The moving average result sequence of the N-order difference It can be represented as:

[0508]

[0509] Among them, L w The length of the predefined moving average window.

[0510] Secondly, based on the obtained signal and noise boundary points The noise power σ is calculated, and the calculation of σ can be expressed as:

[0511]

[0512] Step 4.2, based on ψ m as well as Get w target Candidate multi-user signal clusters. The method for obtaining the candidate multi-user signal clusters includes the following multiple stages, modes, or operations:

[0513] First, obtain the index of the signal before sorting by using the index corresponding to the sorted signal; Figure 5 In the sequence, the indices before signal sorting are [2,3,4,5,10,12,14,16,25,26,27,28].

[0514]

[0515] Secondly, Match w in sequence target Within, FFT upsampling clusters are obtained based on FFT upsampling; Figure 5 The image shows three FFT clusters;

[0516] Next, based on the FFT cluster, the center of the maximum delay spread cluster is found by the maximum peak value of PDP, and the maximum delay spread cluster is obtained according to the maximum delay spread value. Figure 6 The image shows a single maximum delay spread cluster.

[0517] Finally, based on the multipath channel amplitude attenuation characteristics, clusters that do not conform to the attenuation characteristics are identified as separate user signal clusters, such as... Figure 7 The image shows two candidate multi-user signal clusters.

[0518] The final acquisition of the aforementioned candidate user signal clusters can be based on the distribution of UEs within the cell, preamble resources, BS scheduling and processing capabilities, and signal indexes of adjacent user signal clusters. Further screening will be conducted.

[0519] For example, when there are many UEs in the cell and the uplink resources currently available for scheduling are limited, the BS can limit the number of candidate user signal clusters.

[0520] When the first path signal corresponding to the i-th user signal cluster The first path signal corresponding to the (i+1)th user signal cluster The spacing is less than the predefined threshold T. Then it is assumed that adjacent user signal clusters correspond to the same UE.

[0521] Step 5: Perform feature filtering and / or feature reconstruction on each candidate user signal cluster, and use it as input for subsequent AI model inference. The AI ​​model outputs whether a UE is detected in the candidate user signal cluster.

[0522] The feature selection process involves extracting features from candidate user signal clusters. A continuous PDP signal, in which For example, a predefined value. The tolerance range L for TA detection error can be used as a basis. TA_error_toler To select, based on L in the candidate user signal cluster start Starting from L, extract continuous L TA_error_toler A continuous signal is used as a feature, denoted as S. feature As input to the AI ​​model:

[0523] S feature =[L start ,L start +1,…L start +L TA_error_toler ]

[0524] It can also be based on L in the candidate user signal cluster start Extract L as the midpoint TA_error_toler A continuous signal is used as the input to the AI ​​model:

[0525]

[0526] The feature reconstruction is based on S feature Other signal properties can be constructed, such as peak-to-average power ratio (PAPR) and variance. One or more properties can be constructed.

[0527] The feature construction based on PAPR can be represented as:

[0528] f feature =[S feature PAPR]

[0529]

[0530] in, For S feature The average value of the internal PDP.

[0531] Step 6: Add confidence scores to the output of the AI ​​model to improve the robustness of detection performance.

[0532] For example, when the AI model uses sigmoid for decision output, an improved decision output E_g(z) is obtained by adding a confidence level based on the signal-to-noise ratio (SNR) to the sigmoid.

[0533] Among them, E_g(z) is expressed in the following form:

[0534]

[0535] Among them, SNR is

[0536] Finally, a threshold comparison is made on E_g(z). When E_g(z) < Thr, it means that no UE is detected in the candidate user signal cluster; on the contrary, when E_g(z) > Thr, it means that a UE is detected in the candidate user signal cluster, and the first path of the signal in this candidate user signal cluster is the TA. The predefined value Thr can be set to 0.5.

[0537] Based on this, the larger the SNR, the more reliable the detection result; on the contrary, the smaller the SNR, the less reliable the detection result.

[0538] In this embodiment, by adopting a method of adaptively combining multiple detection windows for the HST scenario, the problem of missed detection caused by power dispersion under the Doppler effect is optimized, and the false alarm problem caused by static combination of multiple detection windows in a noisy environment is also improved, thus overall improving the detection performance.

[0539] In this embodiment, the candidate user signal cluster is further screened according to the index distribution of the initial judgment result, improving the misjudgment and false alarm performance of multi-UE detection.

[0540] In this embodiment, by selecting the first path of the signal in each candidate user signal cluster as the TA of this UE, the accuracy of TA estimation is achieved.

[0541] Embodiment 2

[0542] After receiving the Preamble, the BS obtains detection information corresponding to multiple UEs under the same RAPID using the detection algorithm described in Example 1. Based on the obtained detection information, the BS configures RAR information for the UEs for PUSCH transmission during RAR scheduling, or as described above, PUSCH transmission information or first information. The RAR information includes the RAPID, the number of UEs under the same RAPID, optional DMRS resource indication, TA, TA acquisition indication, T-CRNTI, UL Grant resources, etc., and is configured for the UE in a MAC RAR PDU. In one implementation, the above-mentioned RAR information, or PUSCH transmission information, is sent to the UE via message 2 (Msg2). Msg2 may include PDCCH and PDSCH RAR, and the PUSCH transmission information can be sent to the UE via Msg2's PDCCH and / or PDSCH RAR.

[0543] The MAC RAR PDU consists of one or more RAR subPDUs, one or more multi RAR subPDUs, and optional padding.

[0544] This embodiment will introduce a method for configuring the Random Access Response (MSG2) on the BS side in a multi-UE scenario proposed in this invention. In this method, the RAR information is configured in the MAC RAR PDU and sent to the UE via PDSCH.

[0545] Suppose that the BS detects N UEs with the same RAPID, where N>1.

[0546] The number of UEs N and the optional DMRS resource information are configured in the UE information field of the RAR subheader, and the number of bits occupied are denoted as bits respectively. UE_N and bit DMRs The TA, T-CRNTI, and UL Grant resource information are configured in the TAC, T-CRNTI, and UL Grant fields of the RAR payload, respectively, and the number of bits occupied is denoted as bits. TAC bit TCRNTI and bit UL_Grant .

[0547] bit UE_N = log2 Nbit.

[0548] Optional DMRS resource information, when configured, is placed in the least significant bit next to the number of UEs. DMRs =Nlog2Nbit.

[0549] Optional DMRS resource information: When not configured, the UE information field only contains the number of UEs.

[0550] The UE information field occupies a total of bits. subheader =bit DMRS +bit UE_N The number of bytes occupied is The high-order free bytes of the RAR subheader subheader ×8-bit subheader Each bit is configured as a Reserved field.

[0551] For example, optional DMRS resource information, when configured,

[0552] The most significant byte of the RAR subheader subheader ×8-log2 N-Nlog2 Nbit is configured as a Reserved field.

[0553] Optional DMRS resource information, when not configured. The most significant byte of the RAR subheader subheader ×8-log2 Nbit configuration of the Reserved field.

[0554] TA information can be configured as absolute TA values, with each TA value arranged in the first order, such as ascending or descending. TAC =12Nbit;

[0555] It can also be configured as a baseline TAS TA (or referred to as the second TA, reference TA, standard TA, etc., shown as reference TA in the attached figure) and the remaining N-1 relative TAΔ TA (or referred to as difference TA, TA difference, etc.), where S TA The minimum or maximum TA value can be selected from the various TA values, occupying 12 bits, Δ TA For the remaining N-1 absolute TA values ​​relative to S TA The difference occupies 8 bits respectively. TAC = 12 + (N-1) × 8 bits.

[0556] Δ TA The calculation is expressed as follows:

[0557]

[0558] Among them, unitTA To enable the BS-side detection algorithm to identify the minimum time interval between different UEs, for example, the maximum delay spread can be selected as the unit. TA .

[0559] UL Grant can be configured as N orthogonal scheduling messages, bits UL_Grant = N*27 bits. It can also be configured with the same set of scheduling information, bits. UL_Grant =27 bits.

[0560] T-CRNTI is configured with N random and distinct values, bits TCRNTI = N*16 bits.

[0561] The PDSCH RAR payload field occupies the following number of bytes. The high-order byte of the RAR payload RAR_payload ×8-(bit TAC +bit UL_Grant +bit TCRNTI Set the bit to Reserved.

[0562] Figures 9-16 Examples of different configurations under this embodiment are shown, and the examples assume N=2.

[0563] For example, Figure 9 , Figure 11-16 (a) shows a schematic diagram of the DCI field in the PDCCH of the PDSCH that schedules RAR in this embodiment. Figure 9 , Figure 11-16 (b) Figure 10 Various examples of configuring the RAR information in a subPDU of a RAR PDSCH are shown, assuming that the same RAPID detects two UEs. For example, the RAPID corresponding to the subPDU shown in the figure can be included in the subheader of the subPDU, such as in the RAPID subheader.

[0564] In addition, although Figure 9-16 Only one RAR sub-PDU corresponding to a single RAPID is shown in the image, but this is merely for ease of description. It is understood that a PDU may include multiple sub-PDUs similar to RAPID. Figure 9-13 The sub-PDUs shown in the diagram correspond to different RAPIDs. Each sub-PDU corresponding to a RAPID can include the aforementioned RAR information about one or more UEs corresponding to that RAPID.

[0565] Therefore, it can be understood that for a RAPID corresponding to a UE of 1, its sub-PDU may not include the number of UEs (UE number in the various diagrams of this disclosure), and such a sub-PDU can be called a RAR subPDU; or, regardless of whether the number of UEs corresponding to the RAPID is 1 or not, its sub-PDU includes the UE number, and such a sub-PDU can be called a multi-RAR sub-PDU. Alternatively, the sub-PDU includes the UE number and RAR-related information for multiple UEs, such as the aforementioned TA, optional DMRS resource indication, T-CRNTI, etc., and such a sub-PDU is called a multi-RAR sub-PDU. In addition, a RAR that includes uplink transmission-related information for multiple UEs or a RAR that includes RAR-related information for multiple UEs can be called a multi-RAR, and the corresponding sub-PDU is called a multi-RAR sub-PDU.

[0566] Figure 17 An example structural diagram of a MAC PDU according to an embodiment of the present disclosure is shown. Figure 17 As shown, a MAC PDU can include multiple subPDUs and optional padding bits, such as MAC subPDU1 to MAC subPDUUn shown in the figure, and Padding (opt). Some of these subPDUs can be MAC RAR subPDUs (e.g., subPDU3 in the figure), and some can be MAC multi RAR subPDUs (e.g., subPDU4 in the figure).

[0567] Different MAC RAR subPDUs can be used for different RAPIDs, where each RAPID corresponds to one UE; different MAC multi RAR subPDUs can be used for different RAPIDs, where each RAPID corresponds to multiple UEs.

[0568] RAR subPDU can include RAPID and RAR information.

[0569] According to embodiments of this disclosure, a subheading dedicated to UE information (e.g., referred to as a UE information subheader) may be included in the multi RAR subPDU. The multi RAR subPDU may include the UE information subheader and the multi RAR, which includes information related to uplink transmissions of multiple UEs, such as TA information, uplink resource configuration information, T-CRNTI, optional DMRS resource indication, etc.

[0570] Figure 9 (b) shows that in a subPDU, the RAPID, number of UEs (UE number in the figure), and DMRS resource indication (DMRS_1, DMRS_2, etc. in various schematic diagrams of this disclosure) of the RAR information are carried in a subheader. The subheader can be a subheader for RAR information or for UE information, for example, shown as subheader in various schematic diagrams of this disclosure, but it can also be other names. Figure 9 (b) also shows that the payload of the subPDU (the payload in various schematic diagrams of this disclosure) carries TA acquisition instruction information (shown as TA_flag in the figure), absolute TA information (TA1, TA2, etc. in various schematic diagrams of this disclosure), uplink resource configuration information (ULgrant, etc. in various schematic diagrams of this disclosure), and T-CRNTI (Temporary C-RNTI, etc. in various schematic diagrams of this disclosure).

[0571] Figure 10 The diagram shows that the subheader of the PDU carries RAPID, number of UEs, and DMRS resource indication, and the payload of the subPDU carries reference TA information (reference TA in various schematic diagrams of this disclosure), relative TA information (relative TA 1, etc. in various schematic diagrams of this disclosure), uplink resource configuration information, and T-CRNTI.

[0572] Figure 11 (a) shows that RAPID is carried in the DCI of message 2. Figure 11 (b) shows that the subheader of the PDU carries RAPID, number of UEs, and DMRS resource indication. The payload of the subPDU carries TA acquisition indication information (shown as TA_flag in the figure), reference TA information (reference TA in the figure), relative TA information (relative TA 1 in the figure), uplink resource configuration information (UL grant in the figure), and T-CRNTI (Temporary C-RNTI in the figure).

[0573] Figure 12 (a) shows that the RAPID, number of UEs, and reference TA (reference TA in the figure) are carried in the DCI of message 2. Figure 12(b) shows that the PDU's subheader carries RAPID and DMRS resource indication, and the subPDU's payload carries TA acquisition indication information (shown as TA_flag in the figure), relative TA information (relativeTA 1 in the figure), uplink resource configuration information (UL grant in the figure), and T-CRNTI (Temporary C-RNTI in the figure).

[0574] Figure 13 (a) shows that the RAPID, number of UEs, reference TA (reference TA in the figure), and threshold (e.g., RSRP threshold in the figure) are carried in the DCI of message 2. Figure 13 Figure (b) shows that the PDU's subheader carries RAPID and DMRS resource indication, and the subPDU's payload carries TA acquisition indication information (shown as TA_flag in the figure), threshold offset value (e.g., RSRP_offset in the figure), relative TA information (relative TA 1 in the figure), uplink resource configuration information (UL grant in the figure), and T-CRNTI (Temporary C-RNTI in the figure).

[0575] Figure 14 (a) shows that message 2 carries RAPID, number of UEs, reference TA (TA in the figure), and TA acquisition indication information (shown as TA flag in the figure) in the DCI. Figure 14 (b) shows that the PDU's subheader carries RAPID and DMRS resource indication, and the subPDU's payload carries relative TA information (relative TA 1 in the figure), uplink resource configuration information (UL grant in the figure), and T-CRNTI (Temporary C-RNTI in the figure).

[0576] Figure 15 (a) shows that message 2 carries RAPID, number of UEs, reference TA (TA in the figure), TA acquisition indication information (TA flag in the figure), and thresholds (e.g., RSRP threshold in the figure) in the DCI. Figure 15 (b) shows that the PDU's subheader carries RAPID and DMRS resource indication, and the subPDU's payload carries threshold offset values ​​(e.g., RSRP-offset in the figure), relative TA information (relative TA 1 in the figure), uplink resource configuration information (UL grant in the figure), and T-CRNTI (Temporary C-RNTI in the figure).

[0577] Figure 16 A schematic diagram of the co-configuration of RAR information in DCI 1_0 and MAC RAR PDU according to an embodiment of the present disclosure is shown. Figure 16 (a) shows that message 2's DCI 1_0 carries RAPID, absolute threshold information (shown as the RSRP threshold in the figure). Figure 16 (b) shows the detection of two UEs under a RAPID, with DMRS configured in the MAC PDU, the number of UEs, and the reference TA and relative TA values ​​configured in the TAC field. Additionally, in this design, DMRS is used by the base station to identify overlapping UL grant resources; all UEs identified under this RAPID have the same UL grant; the T-CRNTI field indicates the T-CRNTI of the reference UE.

[0578] It should be understood that although the accompanying drawings show that the MSG2's DCI or PDU includes TA acquisition indication information, this is merely an example. The MSG2 may also omit TA acquisition indication information or fields related to TA acquisition indication information. In this case, enabling threshold-based TA estimation can be considered as the default or preset method. The UE can obtain the TA estimation value based on threshold-related information (e.g., RSRP threshold, or RSRP threshold and threshold offset information). Alternatively, in some implementations, for a scheme where the TA acquisition indication information is included in the payload of the sub-PDU, it can be replaced by including the TA acquisition indication information in the PDU's subheader.

[0579] In this embodiment, the design of multi-RAR enables the configuration of multiple UE detection information in the random access response, which is the key to allowing conflicting UEs to access the network simultaneously.

[0580] In this embodiment, through S TA and Δ TA The shared configuration method saves resources compared to absolute TA information configuration.

[0581] In this embodiment, the sorting design in the TAC field speeds up the time for the UE to search for and select a TA, thereby reducing the UE's power consumption.

[0582] In this embodiment, the same set of UL Grant scheduling information is configured for each UE, and each UE is distinguished by orthogonal DMRS resources or randomization of T-CRNTI. Compared with configuring orthogonal UL Grant scheduling information for each UE, uplink resources are saved.

[0583] Example 3

[0584] This embodiment will introduce a configuration method for the BS side to send the Random Access Response (MSG2) RAR in a multi-UE scenario, as proposed in this invention. The RAR information in this method is configured in the PDCCH (e.g., DCI 1_0) and the MAC RAR PDU, and sent to the UE via the PDCCH and PDSCH.

[0585] Suppose the BS detects N UEs with the same RAPID, where N > 1. The number of such RAPID groups is M.

[0586] The RAPID configuration in the RAR information is located in the low-order bits of the DCI 1_0 field, occupying 10 bits. RAPID =6M.

[0587] Other information is configured in the subheader or payload of the PDSCH RAR. This other information includes the number of UEs (N), optional DMRS resources, TA, T-CRNTI, and UL Grant resources. The configuration method is the same as in Example 2.

[0588] Figure 11 This example demonstrates a configuration under this embodiment, which assumes that the number of UEs corresponding to RAPID is N=2. Figure 11 (a) shows a field diagram in DCI 1_0, where it is assumed that the RAPID field indicates two different RAPIDs, each indicated by 6 bits. Figure 11 (b) shows the configuration for a sub-PDU for one of the RAPIDs, where it is assumed that the RAPID corresponds to 2 UEs.

[0589] In this embodiment, by configuring RAPID in the DCI1_0 field, the UE can start estimating or obtaining its own TA in advance after decoding the PDCCH, thereby improving access latency and achieving low power consumption on the UE side.

[0590] In this embodiment, by configuring RAPID in the DCI 1_0 field, the Reserved field of PDCCH is fully utilized, thereby improving resource utilization.

[0591] Example 4

[0592] This embodiment will introduce a configuration method for the BS side to send the Random Access Response (MSG2) RAR in a multi-UE scenario, as proposed in this invention. The RAR information in this method is configured in the PDCCH DCI1_0 and the MAC RAR PDU, and sent to the UE via the PDCCH and PDSCH.

[0593] Suppose the BS detects N UEs with the same RAPID, where N > 1. The number of such RAPID groups is M.

[0594] The RAPID and UE number N in the RAR information are configured in the DCI1_0 field.

[0595] The RAPID configuration is the same as the RAPID configuration method in Example 3. The number of UEs is placed next to the RAPID in the low-order bits of DCI1_0. UE_N =Mlog2 N, occupying a total of M×(6+log2 N) bits.

[0596] Other information is configured in the PDSCH RAR subheader or payload. This other information includes optional DMRS resources, TA, T-CRNTI, and UL Grant resources, configured using the same method as in Example 2.

[0597] The optional DMRS resource information is configured in the UE information field of the RAR subheader, and the number of bits occupied is recorded as bits. DMRS .

[0598] Optional DMRS resource information, when configured, bits DMRS =Nlog2 N, the number of bytes occupied is The high-order free bytes of the RAR subheader subheader ×8-bit DMRS Each bit is configured as a Reserved field.

[0599] The configuration method for TA, T-CRNTI, and UL Grant resource information is the same as in Example 2.

[0600] Figure 12 This example demonstrates a configuration under this embodiment, which assumes that the number of UEs corresponding to a certain RAPID is N=2. Figure 12 (a) shows a field diagram in DCI 1_0, where it is assumed that the RAPID field indicates two different RAPIDs and their corresponding number of UEs, with each RAPID indicated by 6 bits and each number of UEs indicated by 2 bits. Figure 12 (b) shows the configuration for a sub-PDU of one of the RAPIDs, assuming that the RAPID corresponds to 2 UEs. In one implementation, in the DCI field, the bits of each RAPID and its corresponding number of UEs are placed adjacent to each other, or the bits of all RAPIDs are placed adjacent to each other, and there is a positional correspondence between the bits of each RAPID and its corresponding number of UEs. For example, the placement order of the number of UEs bits is consistent with the placement order of the bits of its corresponding RAPID.

[0601] In this embodiment, by configuring RAPID in the DCI 1_0 field, the UE can start estimating or obtaining its own TA in advance after decoding the PDCCH, thereby improving access latency and achieving low power consumption on the UE side.

[0602] In this embodiment, by configuring the number of UEs in the DCI 1_0 field, the UE can start calculating the length of the PDSCH payload to be decoded in advance after decoding the PDCCH, thereby improving access latency and achieving low power consumption on the UE side.

[0603] Example 5

[0604] This embodiment will introduce a configuration method for the BS side to send the Random Access Response (MSG2) RAR in a multi-UE scenario, as proposed in this invention. The RAR information in this method is configured in the PDCCH DCI1_0 and the MAC RAR PDU, and sent to the UE via the PDCCH and PDSCH.

[0605] Suppose the BS detects N UEs with the same RAPID, where N > 1. The number of such RAPID groups is M.

[0606] The RAPID, number of UEs N and S in the RAR TA (Also known as the reference TA or baseline TA, shown as reference TA in the diagram) is configured in the DCI1_0 field, S TA The description is the same as S in Example 2. TA .

[0607] The RAPID configuration is the same as the RAPID configuration method in Example 3. The UE number configuration is the same as the UE number configuration method in Example 4.

[0608] S TA The number of UEs is placed next to the low-order bits of DCI1_0, occupying 100 bits.

[0609] Other information is configured in the PDSCH RAR subheader or payload. This other information includes optional DMRS resources and N-1 Δ... TA T-CRNTI, UL Grant resource. Δ TA The description is the same as Δ in Example 2. TA .

[0610] The optional DMRS resource configuration method is the same as the DMRS resource configuration in Embodiment 4.

[0611] N-1 Δ TAThe information is configured in the TAC field of the RAR payload, occupying 100 bits.

[0612] The configuration method for T-CRNTI and UL Grant resource information is the same as that for T-CRNTI and UL Grant configuration in Example 2.

[0613] The PDSCH RAR payload field occupies the following number of bytes. High bits of the RAR payload Set to Reserved.

[0614] Figures 12-13 This example demonstrates a configuration under this embodiment, which assumes that the number of UEs corresponding to a certain RAPID is N=2.

[0615] Figure 12 and 13 Figure (a) shows a schematic diagram of the fields in DCI 1_0, where it is assumed that the RAPID field indicates that there are multiple UEs under this RAPID. The DCI also includes information on the number of UEs and the reference TA corresponding to the RAPID. Each RAPID is indicated by 6 bits, each number of UEs is indicated by 2 bits, and each reference TA is indicated by 12 bits. In one implementation, in the DCI field, the bits of each RAPID and its corresponding number of UEs and reference TA are placed adjacent to each other, or the bits of all RAPIDs are placed adjacent to each other, and the bits of all reference TAs are placed adjacent to each other. Furthermore, there is a corresponding relationship between the bits of each RAPID and the bits of its corresponding number of UEs and reference TA. For example, the placement order of the bits of the number of UEs and the placement order of the bits of the reference TA are consistent with the placement order of the bits of their corresponding RAPIDs.

[0616] In one implementation, such as Figure 13 As shown in (a), DCI 1_0 may also include threshold-related information, such as the RSRP threshold shown in the figure, which can be indicated by 7 bits. For example, the RSRP threshold can be used by the UE to determine the TA estimate, as previously described.

[0617] Figure 12 and 13 (b) shows the configuration for a sub-PDU for one of the RAPIDs, where it is assumed that the RAPID corresponds to 2 UEs. Figure 12 (b) shows that the payload portion includes relative TA information for the two UEs relative to the reference TA. Figure 13Figure (b) shows that the payload portion includes relative TA information for the two UEs relative to the reference TA and a threshold offset value (e.g., RSRP-offset shown in the figure). In one implementation, such as Figure 12 and 13 As shown in (b) above, the payload portion of the sub-PDU may also include TA acquisition instruction information (TA_flag as shown in the figure).

[0618] In one implementation, the payload portion of the sub-PDU may include a threshold offset value but excludes TA acquisition indication information. Without TA acquisition information, the UE defaults to obtaining the TA estimate based on a threshold. For example, the UE can perform TA estimation based on threshold-related information obtained from the DCI (e.g., the RSRP threshold) and the threshold offset value in the payload portion of the sub-PDU, as described above, and will not be repeated here.

[0619] In this embodiment, the benchmark TAS is used. TA Configured in DCI 1_0, this allows the UE to begin estimating or acquiring its own TA before decoding the PDSCH, and to communicate with S TA By comparing the results, we can estimate the approximate position of our TA in the payload, improve latency, and achieve low power consumption on the UE side.

[0620] Example 6

[0621] This embodiment will introduce the method proposed in this invention for the UE side to receive Random Access Response (RAR) in a multi-UE scenario, and to obtain PUSCH transmission information based on RAR scheduling. The PUSCH transmission information includes the number of UEs, optional DMRS resource indication, TA, TA acquisition indication information, T-CRNTI, and UL Grant resources.

[0622] The UE receives the RAR, specifically involving the following steps:

[0623] Step 1: Listen to the PDCCH during the message waiting window ra-ResponseWindow to receive the RAR. Any RAR received by the UE within this window is considered valid; if the UE does not receive a RAR within the RAR time window, the random access procedure is considered to have failed, and the UE retransmits the MSG1 Preamble. The ra-ResponseWindow is configured via the rar-WindowLength in the SIB message.

[0624] Step 2: After successfully decoding the PDCCH, the UE will obtain the RB resource information of the PDSCH RAR to receive downlink transport blocks transmitted via the PDSCH, and optional detection result information. The optional detection result information includes optional RAPID, optional number of UEs, optional reference TA, and optional TA acquisition indication information. Figure 14 (a) shows a schematic diagram of the fields in DCI 1_0.

[0625] When the PDCCH carries a RAPID, the UE parses the lower 6Mbits of the PDCCH and checks if the RAPID matches the RAPID it sent. If they match, the UE obtains the indication information based on the TA, estimates its own TA according to the indicated method, and records it as TA. est .

[0626] TA est The estimation method is as described above. For example, based on the indication information obtained from the TA, the UE obtains the estimated TA value based on the threshold value. The UE compares the measured RSRP with the RSRP threshold. If the RSRP is greater than the threshold, the smaller TA is selected; if the RSRP is less than the threshold, the larger TA is selected.

[0627] For example, obtaining indication information based on TA indicates obtaining TA based on path loss. est The method can be as follows: First, calculate the downlink (DL) path loss PL. Then, based on the relationship between free space PL and distance, estimate the distance d between the BS and UE. Finally, based on the relationship between d and time, estimate TA, denoted as TA. est .

[0628] PL=Prx–Ptx=RSRP_DL–reference power

[0629] PL = 20log(d) + 20log(f) - 147.55

[0630] d = TA est *16*3*1e8 / (15K*2048)

[0631] Where f is the signal carrier frequency, RSRP_DL is the downlink received reference signal power measured by the UE side, and reference power is the reference signal power ss-PBCH-BlockPower, which is carried in SIB.

[0632] For example, the indication information obtained based on the TA indicates that the TA is obtained based on the SIB reception time. est Alternatively, the UE side can determine the TA estimate based on the SIB1 reception time, as described above.

[0633] Step 3: The UE decodes the PDSCH carrying Mgs2 RAR data to obtain the information required for PUSCH transmission scheduled by RAR. This information includes the number of UEs, optional DMRS resource indications, TA, T-CRNTI, and UL Grant resources.

[0634] The UE obtains the number of UEs and the length of the PDSCH RAR payload to be decoded by decoding the RAR, and then parses it.

[0635] The UE obtains the TA information by parsing the TAC field, and denotes it as TA. TAC .

[0636] When the TAC field contains an absolute TA value, the UE will... est With TA TAC Compare and choose TA TAC The closest one is taken as its own TA value. final Simultaneously record TA final Index TA final,i .

[0637]

[0638] When the TAC field is S TA and Δ TA At that time, UE through TA est With S TA Calculate the relative TA value; then select the closest Δ. TA As its relative TA value delta TA Finally, based on delta TA The relationship between TA and absolute TA value, to obtain TA final Simultaneously record TA final Index TA final,i .

[0639]

[0640] TA final =S TA ±delta TA ×unit TA

[0641] TA final,i =Δ TA,i

[0642] Here, '+' is used to sort TA in ascending order, that is, S TA The minimum TA; '-' is used to sort TA in descending order, i.e., S TA The maximum TA.

[0643] The method described above for selecting the closest TA value can also be used to select the TA value. est and TA TAC Difference and predefined threshold Thr TA Comparison, when TA est -TA TAC >Thr TA If no matching TA is found, the UE fails to acquire the TA and re-initiates random access; otherwise, the UE successfully acquires the TA. final And TA final,i .

[0644] Optional DMRS resources, if carried, are selected by the UE in the UE information with index TA. final,i DMRS resources.

[0645] UE selects index TA in the T-CRNTI field final,i The corresponding T-CRNTI.

[0646] The UE selects UL Grant information through the UL Grant field. Specifically, when there is only one UL Grant configuration, the UE can read it directly; when orthogonal UL Grant resources are configured, the UE selects the index TA. final,i The corresponding ULGrant resource.

[0647] Step 4: The UE obtains the RAR scheduling PUSCH scheduling information based on the decoding response and sends the RAR scheduling PUSCH. After sending the PUSCH, the UE also starts a ra-ContentionResolutionTimer. Before this timer expires, the UE continuously listens for the Msg4 PDCCH. If the timer expires, the UE considers the contention to have failed and re-initiates the random access procedure.

[0648] The UE adjusts the TA based on the acquired TA value. The UE saves the T-CRNTI for de-RAR-scheduled PUSCH retransmission DCI or MSG4 DCI and uses it for scrambling processing during PUSCH transmission. The UE determines the PUSCH transmission configuration and time-domain resource information through the UL Grant.

[0649] This embodiment designs a method for how UEs receive RAR in multi-UE scenarios, ensuring that UEs correctly obtain their own information and do not interfere with each other, which is the key to ensuring that conflicting UEs can access the network at the same time.

[0650] In this embodiment, the method designed for the UE to estimate or obtain the TA is the key time synchronization information for the UE to perform PUSCH transmission.

[0651] In this embodiment, a method is designed to obtain the corresponding T-CRNTI, UL Grant, and optional DMRS through TA information, thereby accelerating the time for the UE to obtain the information required for PUSCH transmission and reducing UE power consumption.

[0652] In this embodiment, the UE obtains its TA in advance by acquiring the RAPID through the PDCCH, which improves the efficiency of decoding RAR and reduces the UE power consumption.

[0653] Example 7

[0654] This embodiment will introduce the method proposed in this invention for the UE side to receive Random Access Response (RAR) in a multi-UE scenario, and to obtain PUSCH transmission information based on RAR scheduling. The PUSCH transmission information includes the number of UEs, optional DMRS resource indication, TA, TA acquisition indication information, T-CRNTI, and UL Grant resources.

[0655] The steps involved in the UE receiving the RAR are the same as in Example 6.

[0656] In step 2, when the PDCCH carries the RAPID and the number of UEs, the TA obtains the indication information:

[0657] The UE parses the lower M×(6+log2 N) bits of the PDCCH and checks if the RAPID matches its own transmitted RAPID. If they match, the UE obtains the corresponding UE number and calculates the range of PDSCH RAR payloads that need to be decoded. Additionally, the UE obtains indication information based on the TA and estimates its own TA according to the indicated method, denoted as TA. est The method is the same as in Example 6.

[0658] Step 3: The UE decodes the PDSCH carrying Mgs2 RAR data to obtain the information required for PUSCH transmission scheduled by RAR. This information includes optional DMRS resource indication, TA, T-CRNTI, and UL Grant resources. The acquisition method is the same as in Example 6.

[0659] In this embodiment, the UE obtains the number of UEs by PDCCH, which ensures that the UE obtains the PDSCH decoding range in advance, improves the efficiency of RAR decoding, and reduces UE power consumption.

[0660] Example 8

[0661] This embodiment will introduce the method proposed in this invention for the UE side to receive Random Access Response (RAR) in a multi-UE scenario, and to obtain PUSCH transmission information based on RAR scheduling. The PUSCH transmission information includes the number of UEs, optional DMRS resource indication, TA, TA acquisition indication information, T-CRNTI, and UL Grant resources.

[0662] The steps involved in the UE receiving the RAR are the same as in Example 6.

[0663] In step 2, when the PDCCH carries the RAPID, the number of UEs, the TA obtains indication information and S TA :

[0664] The UE parses the lower M×(18+log2 N) bits of the PDCCH and checks if the RAPID matches the RAPID it sent. If they match, the UE obtains the corresponding UE number and calculates the range of PDSCH RAR payloads that need to be decoded. Additionally, the UE obtains indication information based on the TA and estimates its own TA according to the indicated method, denoted as TA. est The method is the same as in Example 6; simultaneously, the UE can obtain TA. est and S TA The difference Δ TA,est When the PDSCH TAC field carries an absolute TA value, Δ TA,est =|TA est -S TA |;When the PDSCH TAC field carries Δ TA ,

[0665] Step 3: The UE decodes the PDSCH carrying Mgs2 RAR data to obtain the information required for PUSCH transmission scheduled by RAR. This information includes optional DMRS resource indications, the remaining N-1 TAs, T-CRNTI, and UL Grant resources. The acquisition method is the same as in Example 6.

[0666] In this embodiment, the UE obtains S through the PDCCH. TA This ensures that the UE obtains Δ in advance. TA,est This improves the efficiency of RAR decoding and reduces UE power consumption.

[0667] Example 9

[0668] This embodiment will introduce the method proposed in this invention for the UE side to receive Random Access Response (RAR) in a multi-UE scenario, and to obtain PUSCH transmission information based on RAR scheduling. The PUSCH transmission information includes the number of UEs, optional DMRS resource indication, TA, TA acquisition indication information, T-CRNTI, and UL Grant resources.

[0669] The steps involved in the UE receiving the RAR are the same as in Example 6.

[0670] In step 2, after successfully decoding the PDCCH, the UE will obtain the RB resource information of the PDSCH RAR to receive the downlink transport block transmitted through the PDSCH. That is, the PDCCH does not carry UE detection related information, so the UE proceeds to step 3.

[0671] Step 3: The UE decodes the PDSCH carrying Mgs2 RAR data to obtain the information required for PUSCH transmission scheduled by RAR. This information includes the number of UEs, optional DMRS resource indications, TA, TA acquisition indication information, T-CRNTI, and UL Grant resources. The acquisition method is the same as in Example 6.

[0672] In this embodiment, the UE enables multiple UEs to successfully receive multi-RAR by decoding PUSCH transmission information based on RAR scheduling through PDSCH, which is the key to ensuring simultaneous access of multiple UEs.

[0673] Figure 18 A schematic diagram of the structure of a user equipment 1600 according to at least one embodiment of the present disclosure is shown. (Reference) Figure 18 The user equipment 1600 includes a transceiver 1601 and a controller 1602. The transceiver 1601 is configured to transmit data or signals and receive data or signals. The controller 1602 is coupled to the transceiver 1601 and configured to perform control to cause the user equipment 1600 to perform methods according to embodiments of the present disclosure. In one implementation, the user equipment 1600 may further include a memory (not shown) storing computer-executable instructions that, when executed by the controller 1602, allow the user equipment 1600 to perform at least one method corresponding to the above embodiments of the present disclosure.

[0674] Figure 19 A schematic diagram of the structure of a network node 1700 according to at least one embodiment of the present disclosure is shown. (See reference...) Figure 19The network node 1700 includes a transceiver 1701 and a controller 1702. The transceiver 1701 is configured to transmit or receive data or signals. The controller 1702 is coupled to the transceiver 1701 and configured to perform control to cause the network node 1700 to perform methods according to embodiments of the present disclosure. In one implementation, the network node 1700 may further include a memory (not shown) storing computer-executable instructions that, when executed by the controller 1702, allow the network node 1700 to perform at least one method corresponding to the above embodiments of the present disclosure. The network node may be, for example, a base station or other network-side equipment.

[0675] The above description is merely an example embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0676] Those skilled in the art will understand that this invention includes devices for performing one or more of the operations described in this application. These devices may be specifically designed and manufactured for the desired purpose, or may include known devices found in general-purpose computers. These devices have computer programs stored therein that can be selectively activated or reconfigured. Such computer programs may be stored in a device (e.g., a computer)-readable medium or in any type of medium suitable for storing electronic instructions and coupled to a bus, including but not limited to any type of disk (including floppy disks, hard disks, optical disks, CD-ROMs, and magneto-optical disks), ROM (Read-Only Memory), RAM (Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, magnetic cards, or optical cards. That is, a readable medium includes any medium by which a device (e.g., a computer) stores or transmits information in a readable form.

[0677] Those skilled in the art will understand that each block in these structural diagrams and / or block diagrams and / or flow diagrams, as well as combinations of blocks in these structural diagrams and / or block diagrams and / or flow diagrams, can be implemented using computer program instructions. Those skilled in the art will also understand that these computer program instructions can be provided to a processor of a general-purpose computer, a specialized computer, or other programmable data processing method for implementation, thereby enabling the processor of the computer or other programmable data processing method to execute the schemes specified in the blocks or plurality of blocks of the structural diagrams and / or block diagrams and / or flow diagrams disclosed herein.

[0678] Those skilled in the art will understand that the steps, measures, and schemes in the various operations, methods, and processes discussed in this invention can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this invention can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the prior art that are similar to those disclosed in this invention can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0679] The above description is only a partial embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method executed by a user equipment (UE) in a communication system, comprising: Send a random access request to the base station; Receive a response message from the base station, the response message including a second number of advance timing (TA) information and resource allocation information for a second number of UEs; Obtain the TA information and resource allocation information corresponding to the UE from the response message; Based on the obtained TA information and resource allocation information, uplink transmissions are sent to the base station.

2. The method according to claim 1, wherein, Obtaining the TA information and resource allocation information corresponding to the UE from the RAR includes: Obtain the TA-related information of the UE; Based on the TA-related information, the TA information and resource allocation information corresponding to the UE are obtained from the RAR.

3. The method according to claim 1, wherein, The response message also includes at least one of the following: The second quantity; Instructions for TA-related information, instructing the UE to obtain the corresponding TA-related information; Random access preamble identification information; Temporary Cell Radio Network Temporary Identifier (T-CRNTI).

4. The method according to claim 3, wherein, Also includes: Based on the second quantity, the response message is decoded.

5. The method according to claim 2, wherein, The TA-related information includes at least one of the following: Downlink path loss between UE and base station; The reception and transmission times of system information block SIB1; Signal strength related information and threshold information.

6. The method according to claim 5, wherein, Based on the TA-related information, the TA information and resource allocation information corresponding to the UE are obtained from the RAR, including: Determine the TA estimation information of the UE; The TA information with the smallest difference from the estimated TA information is determined from the second number of TA information contained in the response message and is taken as the TA information of the UE.

7. The method according to claim 6, wherein, Determining the TA estimation information of the UE includes: Based on the downlink path loss between the UE and the base station, the first TA estimation information corresponding to the UE is determined.

8. The method according to claim 6, wherein, Determining the TA estimation information of the UE includes: Based on the reception and transmission times of SIB1, the second TA estimation information corresponding to the UE is determined.

9. The method according to claim 8, wherein, Also includes: The base station receives SIB1, which includes the transmission time.

10. The method according to claim 6, wherein, Determining the TA estimation information of the UE includes: Determine the signal strength information of the UE; Based on the signal strength range corresponding to the signal strength information of the UE, the third TA estimation information corresponding to the UE is determined.

11. The method according to claim 10, wherein, The threshold information includes first threshold information and threshold offset information; The method further includes: determining multiple signal strength ranges based on the first threshold information and the threshold offset information.

12. The method according to claim 10, wherein, The signal strength-related information includes: Reference Signal Received Power (RSRP).

13. The method according to claim 6, wherein, The second quantity of TA information includes: A first TA message and a third number of second TA messages.

14. The method according to claim 11, wherein, Determining the TA information with the smallest difference from the estimated TA information among the second number of TA information contained in the response message as the TA information of the UE includes: Based on the TA estimation information and the first TA information, the third TA information is determined; The TA information of the UE is determined from the second TA information with the smallest difference from the third TA information based on the second quantity of second TA information.

15. The method according to claim 1, wherein, The resource allocation information for the second number of UEs includes: One uplink UL Grant message and a second demodulation reference signal (DMRS) message.

16. The method according to claim 15, wherein, Obtaining the TA information and resource allocation information corresponding to the UE from the RAR includes: Based on the obtained TA information corresponding to the UE, the DMRS information corresponding to the UE is determined from the second number of DMRS information; Based on the DMRS information corresponding to the UE, the port information for sending uplink transmission is determined.

17. The method according to any one of claims 1-16, wherein, The response message includes: Random Access Response (RAR).

18. The method according to claim 17, wherein, The response message further includes downlink control information (DCI), which carries at least one of the following: the second quantity; indication information of TA-related information, instructing the UE to obtain the corresponding TA-related information; random access preamble identification information; first TA information, wherein the second quantity of TA information includes the first TA information and the second quantity of second TA information.

19. A method executed by a network node in a communication system, comprising: Receive the same random access signal from a first number of user equipment (UEs); Send a response message for the same random access signal, the response message including: a second number of timing advance TA information and resource allocation information for a second number of UEs.

20. A user equipment (UE) in a communication system, comprising: A transceiver is configured to transmit and / or receive signals; The controller is configured to control the UE to perform the method according to any one of claims 1-18.

21. A network node in a communication system, comprising: A transceiver is configured to transmit and / or receive signals; The controller is configured to control the network node to perform the method according to claim 19.

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