Initial access method and apparatus, and device and readable storage medium

Abstract

The present application belongs to the field of communications. Disclosed are an initial access method and apparatus, and a device and a readable storage medium. The method in the embodiments of the present application comprises: a terminal receiving a first synchronization signal block (SSB), and performing time-frequency synchronization on the basis of the first SSB; and the terminal receiving a first signal, and performing time-frequency synchronization on the basis of the first signal.

Description

Initial access method, device, equipment and readable storage medium

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 7, 2024, with application number 202410175335.0 and invention name “Initial access method, device, equipment and readable storage medium”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communications, and specifically to an initial access method, apparatus, device, and readable storage medium. Background Art

[0003] In related technologies, terminals perform initial access by receiving synchronization signal blocks (SSBs). However, since SSBs occupy a small bandwidth and a small number of time-domain symbols, the time-frequency synchronization accuracy based on SSBs is relatively coarse, which affects the initial access performance of SSBs. Therefore, improving the initial access performance of the entire system is an urgent problem that needs to be solved. Summary of the Invention

[0004] The embodiments of the present application provide an initial access method, apparatus, device, and readable storage medium, which can improve the initial access performance of a terminal.

[0005] In a first aspect, an initial access method is provided, the method comprising:

[0006] The terminal receives a first synchronization signal block SSB and performs time and frequency synchronization according to the first SSB;

[0007] The terminal receives a first signal and performs time-frequency synchronization according to the first signal.

[0008] In a second aspect, an initial access method is provided, the method comprising:

[0009] The network side device sends a first synchronization signal block SSB, where the first SSB is used for the terminal to perform time and frequency synchronization;

[0010] The network side device sends a first signal, where the first signal is used for the terminal to perform time and frequency synchronization.

[0011] In a third aspect, an initial access device is provided, comprising:

[0012] A receiving unit, configured to receive a first synchronization signal block SSB;

[0013] a processing unit, configured to perform time and frequency synchronization according to the first SSB;

[0014] The receiving unit is further configured to: the terminal receives a first signal;

[0015] The processing unit is further configured to perform time-frequency synchronization according to the first signal.

[0016] In a fourth aspect, an initial access device is provided, comprising:

[0017] A sending unit, configured to send a first synchronization signal block SSB, where the first SSB is used for time and frequency synchronization of the terminal;

[0018] A first signal is sent, where the first signal is used for the terminal to perform time and frequency synchronization.

[0019] In a fifth aspect, a communication device is provided, which terminal includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the first aspect are implemented.

[0020] In the ninth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented, or the steps of the method described in the second aspect are implemented.

[0021] In the tenth aspect, a wireless communication system is provided, comprising: a terminal and a network side device, wherein the terminal can be used to execute the steps of the method described in the first aspect, and the network side device can be used to execute the steps of the method described in the second aspect.

[0022] In the eleventh aspect, a chip is provided, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the method as described in the first aspect, or to implement the method as described in the second aspect.

[0023] In the twelfth aspect, a computer program / program product is provided, which is stored in a storage medium and is executed by at least one processor to implement the steps of the method described in the first aspect or the steps of the method described in the second aspect.

[0024] In an embodiment of the present application, the terminal can first receive the first SSB, perform time-frequency synchronization based on the first SSB, obtain a preliminary time-frequency synchronization result, further receive the first signal, and perform further time-frequency synchronization based on the first signal, which is conducive to obtaining a more accurate time-frequency synchronization result, thereby improving the signal transmission performance during the initial access process and enhancing the overall performance and efficiency of the initial access. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic diagram of a communication system provided in an embodiment of the present application.

[0026] FIG2 shows a structure of an SSB.

[0027] FIG3 is a schematic diagram of the time-frequency resources occupied by SSB.

[0028] FIG4 is a schematic diagram of the association relationship between SSB and RO.

[0029] FIG5 is a schematic diagram of an initial access method provided in an embodiment of the present application.

[0030] FIG6 is a schematic diagram of an initial access device provided in an embodiment of the present application.

[0031] FIG7 is a schematic diagram of another initial access device provided in an embodiment of the present application.

[0032] FIG8 is a schematic diagram of a communication device provided in an embodiment of the present application.

[0033] FIG9 is a hardware structure diagram of a terminal provided in an embodiment of the present application.

[0034] FIG10 is a hardware structure diagram of a network-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will be combined with the accompanying drawings in the embodiments of this application to clearly describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0036] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects, for example, the first object can be one or more. In addition, "or" in this application represents at least one of the connected objects. For example, "A or B" covers three options, namely, Option 1: including A but not including B; Option 2: including B but not including A; Option 3: including both A and B. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0037] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). A direct indication can be understood as the sender explicitly informing the receiver of specific information, the operation to be performed, or the requested result, etc. in the instruction sent; an indirect indication can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the operation to be performed or the requested result, etc. based on the judgment result.

[0038] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the technology described can be used for the systems and radio technologies mentioned above, as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for illustrative purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) systems. th Generation, 6G) communication system.

[0039] FIG1 is a block diagram of a wireless communication system applicable to an embodiment of the present application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer), a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device (Wearable Device), an aircraft (Flight Vehicle), a vehicle-mounted device (VUE), a ship-mounted device, a pedestrian user equipment (PUE), a smart home (home appliances with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), a game console, a personal computer (PC), an ATM, or a self-service machine, or other terminal-side devices. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle-mounted device can also be called a vehicle-mounted terminal, vehicle-mounted controller, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit, etc. It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application.

[0040] A terminal may also be referred to as user equipment (UE), terminal device, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device, etc.

[0041] The network-side device 12 may include an access network device or a core network device, wherein the access network device may also be referred to as a radio access network (RAN) device, a radio access network function, or a radio access network unit. The access network device may include a base station, a wireless local area network (WLAN) access point (AP), or a wireless fidelity (WiFi) node. Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the next generation Node B (gNB), New Radio Node B (NR Node B), access point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B (home evolved Node B), Transmission Reception Point (TRP) or other appropriate terms in the field. As long as the same technical effect is achieved, the base station is not limited to specific technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is used as an example for introduction, and the specific type of the base station is not limited.

[0042] To facilitate understanding of the embodiments of the present application, the reception of the synchronization signal block (SSB) related to the present application is explained.

[0043] It should be noted that SSB can also be called synchronization signal / physical broadcast channel block (SS / PBCH block).

[0044] In the NR system, the terminal first performs initial access by receiving SSB. Figure 2 shows the structure of an SSB. Among them, SSB includes primary synchronization signals (PSS), secondary synchronization signals (SSS), physical broadcast channel (PBCH) and demodulation reference signal (DMRS) of PBCH. Among them, PSS and SSS are used for coarse synchronization of time and frequency, PBCH is used to carry the master information block (MIB) of broadcast messages, and DMRS of PBCH is used for demodulation of PBCH. In addition, the entire SSB occupies 4 orthogonal frequency-division multiplexing (OFDM) symbols in the time domain and a maximum of 20 (Resource Block, RB) in the frequency domain. Due to the limited time and frequency resources occupied by SSB, only relatively preliminary coarse time and frequency synchronization can be performed based on SSB.

[0045] When the terminal receives the SSB, the terminal can first detect the PSS sequence and obtain the physical cell identity (Identity, ID) according to the sequence correlation. And obtain preliminary time-frequency synchronization; then detect SSS and obtain the physical cell ID based on sequence correlation Thus, the complete physical cell ID (eg, physical cell identifier (PCI)) is obtained, that is, The terminal can further adjust the frequency offset based on the PSS and SSS. The terminal then detects the DMRS of the PBCH to perform channel estimation and demodulate the PBCH.

[0046] To facilitate understanding of the embodiments of the present application, the random access process related to the present application is described.

[0047] After the terminal demodulates the PBCH, it initiates a random access procedure. The random access procedure can be either contention-based or non-contention-based. The random access procedure can be divided into a four-step random access procedure (also called a Type-1 random access procedure) and a two-step random access procedure (also called a Type-2 random access procedure).

[0048] In some scenarios, the contention-based 4-step random access procedure may include the following steps:

[0049] The terminal first sends message 1 (Msg1), which is the random access preamble, to the network.

[0050] After the network detects the preamble sent by the terminal, it will send message 2 (Msg2), namely Random Access Response (RAR), which includes the preamble number detected by the network, namely the Random Access Channel Preamble ID (RAPID), the uplink physical uplink shared channel (PUSCH) resources (uplink grant (UL grant) information) allocated to the terminal to send message 3 (Msg3), the temporary cell radio network temporary identity (TC-RNTI), the timing advance (TA) command (command), etc.

[0051] After receiving Msg2, if the terminal confirms that at least one of the preamble numbers carried in Msg2 is consistent with the preamble number it sent, it will send Msg3 containing contention resolution information based on the uplink resources indicated in the RAR. If the network does not receive the Msg3 PUSCH, it can schedule the retransmission of Msg3 PUSCH in the TC-RNTI-scrambled Physical Downlink Control Channel (PDCCH). After receiving Msg3, the network will send Message 4 (Msg4) containing contention resolution information. When the terminal receives Msg4, it confirms that the resolution information is consistent with the one it sent in Msg3, thus completing the four-step random access.

[0052] For the contention-based random access process, different terminals randomly select preambles for transmission. In this way, different UEs may select the same preamble to send at the same random access opportunity. This situation can be understood as a UE preamble conflict. At this time, different terminals will receive the same RAR, and different terminals will transmit Msg3 PUSCH according to the scheduling information of the UL grant in the RAR. However, the network can only decode the PUSCH (including contention resolution information) sent by one terminal on one Msg3 PUSCH scheduling resource. The network will include the contention resolution information received in Msg3 in Msg4. If the contention resolution information received by the terminal in Msg4 matches the contention resolution information sent by the UE in Msg3 PUSCH, the terminal considers that the contention resolution is successful. If they do not match, the contention resolution is considered unsuccessful. If the contention resolution is unsuccessful, the terminal reselects the RACH transmission resource, performs physical random access channel (PRACH transmission), and makes the next random access attempt.

[0053] In some scenarios, a two-step random access procedure (2-step RACH) is introduced. The first step is for the terminal to send message A (MsgA) to the network. After receiving MsgA, the network sends message B (MsgB) to the UE. If the terminal does not receive MsgB within a certain period of time, it increments the counter that counts the number of times MsgA has been sent and resends MsgA. If the counter for counting the number of times MsgA has been sent reaches a certain threshold, the UE switches from the 2-step random access procedure to the 4-step random access procedure.

[0054] MsgA consists of the MsgA preamble and the MsgA PUSCH. The preamble is sent on a 2-step RACH opportunity (RACH Occasion, RO), and the PUSCH is sent on the MsgA PUSCH resources associated with the sent MsgA preamble and RO. The MsgA PUSCH resources are a set of PUSCH resources configured for each PRACH time slot, including time-frequency resources and DMRS resources.

[0055] In the NR system, a cell can configure multiple frequency division multiplexing (FDM) PRACH transmission opportunities (PRACH transmission occasions, or physical random access channel opportunities (PRACH occasions)), referred to as ROs, at a time domain location for transmitting PRACH.

[0056] In some scenarios, at a time, the number of ROs that can be used for FDM can be: {1, 2, 4, 8}. As shown in Figure 3, at a time, there are 8 RO resources distributed on different frequency domain resources.

[0057] The preamble can only be transmitted on the time domain resources (i.e., RO resources) configured by the high-level parameters (PRACHConfigurationIndex), and can only be transmitted on the frequency domain resources n configured by the high-level parameters (PRACH-FDM). RA ∈{0,1,...,M-1}, where M is the high-level parameter prach-FDM. At the time of initial access, the frequency domain resource n of PRACH RA The frequency domain resources of PRACH are numbered in ascending order starting from the lowest RO resource in the initial active uplink bandwidth part. Otherwise, the frequency domain resources of PRACH are numbered in ascending order. RA The RO resources are numbered in ascending order, starting from the RO resource with the lowest frequency within the active uplink bandwidth part. As shown in Figure 3, the RO resources are numbered from RO#0 to RO#7 in ascending order of frequency.

[0058] In the NR system, there is an association between the RO and the SSB actually sent. One SSB may be associated with multiple ROs, or multiple SSBs may be associated with one RO (in this case, different SSBs correspond to different preambles). Usually, the base station can use different beams to send different SSBs, and the corresponding terminal sends the preamble on the RO associated with the SSB. In this way, the UE selects the RO or the combination of RO and preamble associated with the SSB with good RSRP strength based on the RSRP strength of the received SSB, and sends the preamble. In this way, the network can determine the SSB selected by the UE based on the RO or the combination of RO and preamble of the received preamble. The network then sends Msg2 on the downlink beam corresponding to the SSB to ensure the reception quality of the downlink signal.

[0059] Taking Figure 3 as an example, the number of FDM ROs at a given moment is eight, and the number of SSBs actually transmitted is four, namely SSB#0, SSB#1, SSB#2, and SSB#3. Each SSB is associated with two ROs. If the terminal determines to send the preamble on the RO corresponding to SSB#0, it can select an RO between RO#0 and RO#1 to send the PRACH.

[0060] Taking Figure 4 as an example, the number of ROs of FDM at a time is 2, and the number of SSBs actually transmitted is 8, namely SSB#0, SSB#1, ..., SSB#7, and every 2 SSBs are associated with 1 RO. When multiple SSBs share one RO, the preamble sets associated with the multiple SSBs are different (the same preamble cannot belong to the preamble set 0 associated with different SSBs at the same time). Taking RO#0 as an example, it has 60 preambles associated with SSBs, of which preambles with indexes 0 to 29 are associated with SSB#0, and preambles with indexes 30 to 59 are associated with SSB#1.

[0061] Before sending PRACH, the terminal first selects PRACH resources. For example, based on the RSRP of the received SSB, the terminal selects the SSB with RSRP higher than the threshold. If the RSRP of multiple SSBs is higher than the threshold, the terminal can select any SSB with RSRP higher than the threshold. When there is no SSB with RSRP higher than the threshold, the terminal selects an SSB based on the implementation.

[0062] Based on the network configuration, the terminal obtains the correspondence between the SSB and the RO. After selecting the SSB, the RO corresponding to the selected SSB is used as the RO for sending PRACH / preamble. If the selected SSB is associated with multiple ROs, the terminal can select one of the ROs for PRACH / preamble transmission.

[0063] For example: In the example shown in Figure 3, assuming that the terminal selects SSB#1, the terminal can select one from RO#2 and RO#3 to send PRACH / preamble; in the example shown in Figure 4, if the terminal selects SSB#1, the terminal can select the available RO closest to the current time among the ROs (RO#0 or #4) associated with SSB#1 to send PRACH / preamble.

[0064] In the selected RO, the terminal selects a preamble from the preamble set associated with the selected SSB for PRACH transmission. As shown in Figure 4, an RO is associated with two SSBs. In this case, the available preamble set associated with each SSB in the RO is divided into two subsets, one for each SSB. The terminal selects a preamble sequence from the preamble subset corresponding to the selected SSB for PRACH transmission.

[0065] In the NR system, Quasi Co-Location (QCL) refers to the average delay, delay spread, Doppler frequency offset, Doppler spread, and spatial reception parameters of the channel experienced by the symbols on a certain antenna port, which can be inferred from another antenna port.

[0066] NR has designed four different types of QCL relationships to cope with different transmission scenarios. The specific QCL reference types (qcl-Type) are as follows:

[0067] 1) Type A: {Doppler frequency deviation, Doppler spread, average delay, delay spread};

[0068] 2) Type B: {Doppler frequency deviation, Doppler spread};

[0069] 3) Type C: {Doppler frequency deviation, average delay};

[0070] 4)TypeD:{space receiving parameters}.

[0071] Before entering the Radio Resource Control (RRC) connected state, the reference source of the QCL reference type Type A transmitted by the PDCCH and the Physical Downlink Shared Channel (PDSCH) is the SSB.

[0072] During the initial access phase, SSB occupies a relatively small bandwidth and uses fewer time-domain symbols, resulting in coarse time-frequency synchronization accuracy. This impacts initial access performance. Therefore, improving the overall initial access performance of the network is an urgent issue.

[0073] The following describes in detail the initial access method provided in the embodiments of the present application through some embodiments and their application scenarios in conjunction with the accompanying drawings.

[0074] FIG5 is a schematic diagram of an initial access method provided by an embodiment of the present application. As shown in FIG5 , the method 500 includes at least part of the following:

[0075] S501, the terminal receives a first synchronization signal block SSB;

[0076] S502, the terminal performs time and frequency synchronization according to the first SSB;

[0077] In some embodiments, the method 500 further includes:

[0078] S503, the terminal receives a first signal;

[0079] S504: The terminal performs time-frequency synchronization according to the first signal.

[0080] It should be noted that in the embodiment of the present application, SSB may also be referred to as a synchronization signal / physical broadcast channel block (SS / PBCH block). The SSB includes at least one of the following modules: a synchronization signal (such as PSS and SSS), a broadcast signal, a broadcast channel, a demodulation reference signal, a reference signal for time-frequency tracking, and a broadcast channel for other system messages. The synchronization signal includes at least one of the following modules: a synchronization sequence, a synchronization pilot, and a reference signal for time-frequency tracking.

[0081] In some embodiments, the terminal receiving the first signal may include:

[0082] After receiving the first SSB, or after performing time and frequency synchronization based on the first SSB, the terminal receives a first signal.

[0083] In some embodiments, performing time-frequency synchronization according to the first signal may include:

[0084] Based on the time-frequency synchronization result of the first SSB, time-frequency synchronization is performed according to the first signal.

[0085] That is, the terminal can further perform time-frequency synchronization based on the first signal on the basis of the time-frequency synchronization result based on the first SSB, thereby improving the accuracy of time-frequency synchronization and thus improving the signal transmission performance during the initial access process. For example, performing random access based on the time-frequency synchronization result is conducive to improving the performance of random access, such as the success rate of random access.

[0086] In some embodiments, the terminal performing time and frequency synchronization according to the first SSB may include:

[0087] The first SSB is measured to obtain parameters related to time-frequency synchronization, that is, the time-frequency synchronization related parameters are measured based on the first SSB.

[0088] In some embodiments, the terminal performing time and frequency synchronization according to the first signal may include:

[0089] The first signal is measured to obtain parameters related to time-frequency synchronization, that is, the parameters related to time-frequency synchronization are measured based on the first signal.

[0090] That is, the time-frequency synchronization may include measuring parameters related to time-frequency synchronization.

[0091] In some embodiments, the terminal may receive multiple first SSBs during the cell search or SSB search phase. For example, the terminal may measure the multiple first SSBs to obtain measurement results corresponding to each first SSB. Then, the first SSB with the best measurement result is selected as the target first SSB, and time-frequency synchronization is performed.

[0092] Optionally, the measurement result may include but is not limited to at least one of the following:

[0093] Reference Signal Receiving Power (RSRP), Reference Signal Receiving Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Received Signal Strength Indication (RSSI).

[0094] In some embodiments, to reduce the complexity of searching and measuring the first SSB by the terminal, the design of the first SSB is generally simple, and is primarily used for the terminal to quickly complete preliminary time-frequency synchronization and obtain broadcast messages. Therefore, the accuracy of time-frequency synchronization achieved based on the first SSB is relatively low, or in other words, the time-frequency synchronization achieved based on the first SSB is coarse time-frequency synchronization, or so-called coarse time-frequency synchronization.

[0095] In some embodiments of the present application, the first SSB satisfies at least one of the following:

[0096] The frequency domain resources of the first SSB are predefined frequency domain resources;

[0097] The time domain resource of the first SSB is a predefined time domain resource;

[0098] The first SSB carries a physical broadcast channel (PBCH);

[0099] The first SSB is transmitted on an initial bandwidth part (Band Width Part, BWP).

[0100] In some embodiments, the frequency domain resource of the first SSB being a predefined frequency domain resource may include:

[0101] The frequency domain resources of the first SSB are the predefined minimum frequency domain resources.

[0102] Optionally, the frequency domain resources of the first SSB may include the bandwidth of the first SSB, the physical resource block (PRB) occupied by the first SSB, subcarriers, etc.

[0103] In a specific embodiment, the frequency domain resource of the first SSB being a predefined frequency domain resource may include:

[0104] The bandwidth of the first SSB is a predefined bandwidth, for example, a predefined minimum bandwidth.

[0105] Optionally, the time domain resources of the first SSB may include the time unit occupied by the first SSB. Optionally, the time unit may be an orthogonal frequency-division multiplexing (OFDM) symbol, a time slot, etc.

[0106] In a specific embodiment, the time domain resource of the first SSB being a predefined minimum time domain resource may include:

[0107] The time domain resources of the first SSB are predefined minimum time domain resources. For example, the minimum time domain resources may be N time units, where N is predefined.

[0108] In some embodiments, the first signal can be designed to improve the time and frequency synchronization accuracy of the terminal. Therefore, the design of the first signal can be more complex than that of the first SSB, such as occupying more time and frequency resources, including occupying a larger bandwidth, or a longer time domain span, etc.

[0109] For the sake of ease of distinction and explanation, the time-frequency synchronization based on the first SSB is called coarse time-frequency synchronization, and the time-frequency synchronization based on the first signal is called fine time-frequency synchronization.

[0110] In some embodiments of the present application, the first signal includes but is not limited to at least one of the following:

[0111] a repetitive signal of the first SSB;

[0112] an extended signal of the first SSB;

[0113] Second SSB;

[0114] Other reference signals besides SSB for time and frequency synchronization.

[0115] In some embodiments, the first signal includes a repeated signal of the first SSB, and the repeated signal may be a repetition of the first SSB in the frequency domain and / or time domain. Optionally, the repetition may be a repetition of a portion of the signal in the first SSB, for example, only a synchronization sequence in the first SSB. Alternatively, the repetition may be a repetition of the entire signal in the first SSB.

[0116] In some embodiments, the second SSB is different from the first SSB, for example, the time-frequency resources of the second SSB are different from the time-frequency resources of the first SSB. In some implementations, the second SSB occupies more time-frequency resources than the first SSB, for example, occupies a larger bandwidth, a longer time domain span, etc. Therefore, performing time-frequency synchronization based on the second SSB can further improve the time-frequency synchronization accuracy.

[0117] In some embodiments, the first signal includes other reference signals for time-frequency synchronization in addition to the SSB, and the other reference signals may include but are not limited to a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a synchronization signal, etc. The CSI-RS is used for measuring channel state information, the TRS is used for time-frequency tracking, and the synchronization signal may be a synchronization signal in the SSB, such as a PSS and / or SSS, for time-frequency synchronization.

[0118] Optionally, the time-frequency resources occupied by the other reference signal are different from the time-frequency resources occupied by the first SSB. For example, the other reference signal occupies more time-frequency resources than the first SSB, for example, occupies a larger bandwidth, a longer time domain span, etc. Therefore, time-frequency synchronization based on the other reference signal can further improve the time-frequency synchronization accuracy.

[0119] In some embodiments, the first signal includes an extended signal of the first SSB, where the extended signal may be obtained by extending the first SSB in the frequency domain and / or time domain, for example, by increasing the bandwidth of the first SSB, increasing the time domain span or the number of symbols of the first SSB, etc.

[0120] In some embodiments, the first SSB and the extended signal of the first SSB can be considered to constitute the second signal, that is, the first SSB and the extended signal of the first SSB are part of the second signal, for example, the second signal is the third SSB. In this case, the first signal only includes the extended signal of the first SSB, and the first SSB can be considered as a preset part of the third SSB. It should be noted that, in this case, the first SSB and the third SSB can also be understood as the same SSB. In this case, performing time-frequency synchronization according to the first signal includes:

[0121] Performing time-frequency synchronization according to the extended signal of the first SSB; or

[0122] Time and frequency synchronization is performed according to the second signal (ie, the third SSB).

[0123] For example, when receiving the third SSB, the terminal performs coarse time-frequency synchronization according to the preset part of the third SSB (i.e., the first SSB), and then performs fine time-frequency synchronization according to other parts of the third SSB (i.e., the extended signal of the first SSB) or according to the third SSB.

[0124] In some embodiments, performing time-frequency synchronization according to the first SSB includes:

[0125] Time-frequency synchronization is performed according to the minimum unit of the second signal.

[0126] In some implementations, the minimum unit of the second signal includes at least one of the following:

[0127] A first frequency domain resource, where the first frequency domain resource corresponds to a frequency domain resource of the first SSB;

[0128] A first time domain resource, where the first time domain resource corresponds to a time domain resource of the first SSB;

[0129] A first signal set includes at least a portion of the second signal.

[0130] In some embodiments, the minimum unit of the second signal is also called the minimum access unit.

[0131] For example, the first frequency domain resources include part or all of the frequency domain resources of the first SSB.

[0132] For example, the first time domain resources include part or all of the time domain resources of the first SSB.

[0133] In some embodiments, the first signal set may include some or all of the signals of the first SSB, or some and all of the first signals.

[0134] In a specific example, the minimum unit of the second signal is the first SSB.

[0135] In some embodiments, the first SSB is associated with at least one of the first signals.

[0136] Optionally, the association of the first SSB with at least one first signal may include but is not limited to:

[0137] The spatial reception parameter of the at least one first signal may refer to the spatial reception parameter of the first SSB, or in other words, the at least one first signal may be received using the spatial reception reference of the first SSB; or,

[0138] The QCL reference of the at least one first signal is a first SSB.

[0139] In some embodiments, after the terminal selects a target first SSB by measuring the first SSB (for the specific selection method, refer to the relevant description of the aforementioned embodiment), the terminal may only measure at least the first signal associated with the target first SSB, without having to measure all the first signals. Further optionally, the terminal may select the target first signal from the at least one measured first signal for time-frequency synchronization. For example, the first signal with the best measurement result (for example, the highest RSRP) is selected as the target first signal for time-frequency synchronization, which is conducive to improving the accuracy and efficiency of time-frequency synchronization.

[0140] It should be noted that in the application embodiment, the terminal may receive the first signal by default and perform time-frequency synchronization based on the first signal. Alternatively, the terminal may receive the first signal under specific conditions and perform time-frequency synchronization based on the first signal. For example, the terminal may decide on its own whether to perform time-frequency synchronization based on the first signal, or may determine whether to perform time-frequency synchronization based on the first signal based on the indication of the network-side device or the default agreed rules.

[0141] In some embodiments of the present application, the method 500 further includes:

[0142] Determining, according to the first information, whether to receive the first signal, or in other words, whether to perform time-frequency synchronization based on the first signal;

[0143] The first information includes at least one of the following:

[0144] a reception result of the first SSB;

[0145] Associating the random access result of the first SSB;

[0146] parameters of the first SSB;

[0147] The capabilities of the terminal.

[0148] In some embodiments, the reception result of the first SSB includes but is not limited to at least one of the following:

[0149] a first parameter obtained based on the first SSB measurement;

[0150] a change in a first parameter obtained based on multiple measurements of the first SSB;

[0151] The block error rate (BLER) corresponding to the PBCH in the first SSB.

[0152] In some embodiments, the BLER corresponding to the PBCH in the first SSB can reflect the performance of the time-frequency synchronization result based on the first SSB. For example, when the BLER corresponding to the PBCH in the first SSB is greater than or equal to a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB cannot meet the reception performance requirements of the PBCH. Therefore, it is necessary to further perform time-frequency synchronization based on the first signal, and then receive the PBCH based on the time-frequency synchronization result of the first signal, which is conducive to meeting the reception performance requirements of the PBCH; or, when the BLER corresponding to the PBCH associated with the first SSB is less than a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB can meet the reception performance requirements of the PBCH. Therefore, it is not necessary to perform time-frequency synchronization based on the first signal. In this way, the terminal can perform random access as early as possible, improve the speed of random access, and reduce the random access delay.

[0153] In some implementations, the first parameter obtained based on the first SSB measurement includes, but is not limited to, at least one of the following:

[0154] Timing parameters, such as downlink timing (Timing);

[0155] Frequency deviation parameters, such as Doppler frequency deviation;

[0156] Reception quality related results of the first SSB, such as RSRP, RSRQ, SINR, and RSSI;

[0157] The error vector magnitude (EVM) of the PBCH in the first SSB, that is, the EVM of the modulation symbol of the PBCH, such as the EVM of the constellation point.

[0158] In some implementations, the random access result associated with the first SSB includes at least one of the following:

[0159] The number of failed attempts to associate the physical random access channel (PRACH) of the first SSB;

[0160] The number of retransmissions of the random access response message associated with the first SSB;

[0161] Associate the BLER corresponding to the random access response message of the first SSB.

[0162] Optionally, the random access response message associated with the first SSB may refer to a downlink message in the random access process based on the first SSB, such as Msg2, Msg4, or MsgB. For example, the BLER corresponding to the random access response message associated with the first SSB is the BLER corresponding to the PDCCH of Msg2, Msg4, or MsgB, or the BLER corresponding to the PDSCH of Msg2, Msg4, or MsgB.

[0163] In some embodiments, the number of failures of the PRACH associated with the first SSB may refer to the number of failures of the PRACH sent based on the first SSB, and the failure number parameter may reflect the access effect of the PRACH sent based on the first SSB. For example, when the failure number parameter is greater than or equal to a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB cannot meet the random access performance requirements of the system, and therefore, it is necessary to further perform time-frequency synchronization based on the first signal, and then perform random access based on the first signal, which is conducive to meeting the random access performance requirements of the system; or, when the failure number parameter is less than a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB can meet the random access performance requirements of the system, and therefore, it is not necessary to perform time-frequency synchronization based on the first signal.

[0164] In some embodiments, the number of retransmissions of the random access response message associated with the first SSB may reflect the performance of the time-frequency synchronization result based on the first SSB. For example, when the number of retransmissions of the random access response message is greater than or equal to a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB cannot meet the random access performance requirements of the system. Therefore, it is necessary to further perform time-frequency synchronization based on the first signal, and then perform random access based on the time-frequency synchronization result of the first signal, which is conducive to meeting the random access performance requirements of the system; or, when the number of retransmissions of the random access response message is less than a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB can meet the random access performance requirements of the system. Therefore, it is not necessary to perform time-frequency synchronization based on the first signal.

[0165] In some embodiments, the BLER corresponding to the random access response message associated with the first SSB may reflect the performance of the time-frequency synchronization result based on the first SSB. For example, when the BLER corresponding to the random access response message associated with the first SSB is greater than or equal to a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB cannot meet the random access performance requirements of the system. Therefore, it is necessary to further perform time-frequency synchronization based on the first signal, and then perform random access based on the time-frequency synchronization result of the first signal, which is conducive to meeting the random access performance requirements of the system; or, when the BLER corresponding to the random access response message associated with the first SSB is less than a certain threshold, it can be understood that the time-frequency synchronization result based on the first SSB can meet the random access performance requirements of the system. Therefore, it is not necessary to perform time-frequency synchronization based on the first signal.

[0166] In some embodiments, the parameters of the first SSB include but are not limited to at least one of the following:

[0167] frequency domain resources of the first SSB;

[0168] time domain resources of the first SSB;

[0169] a cell identity (ID) corresponding to the first SSB;

[0170] synchronization sequence related information in the first SSB;

[0171] a broadcast message in the first SSB;

[0172] The first SSB contains the signal.

[0173] In some specific embodiments, the synchronization sequence related information in the first SSB may include but is not limited to at least one of the following:

[0174] Number of synchronization sequences;

[0175] Initialization parameters of the synchronization sequence;

[0176] The frequency domain starting position of the synchronization sequence;

[0177] The time domain starting position of the synchronization sequence;

[0178] The length of the synchronization sequence;

[0179] The type of synchronization sequence.

[0180] In some specific embodiments, the broadcast message in the first SSB may include first indication information, and the first indication information is used to indicate whether time and frequency synchronization is performed based on the first signal.

[0181] That is, the network side device can carry indication information in the broadcast message of the first SSB to indicate whether to perform time and frequency synchronization based on the first signal.

[0182] For example, the MIB or layer 1 payload (L1-payload) in the broadcast message carries a first indication field for indicating whether to perform time-frequency synchronization based on the first signal. Different values ​​of the first indication field are used to instruct the terminal to perform or not perform time-frequency synchronization based on the first signal.

[0183] In some embodiments, the terminal may determine whether to perform time-frequency synchronization based on the first signal based on the signal composition included in the first SSB. For example, when the first SSB does not include PBCH, the terminal cannot obtain cell information from PBCH and cannot initiate random access. The terminal needs to continue to receive signals to obtain cell information. In this case, the terminal may determine to perform time-frequency synchronization based on the first signal to obtain more accurate time-frequency synchronization results, and receive PBCH based on the first signal to obtain cell information, thereby initiating random access. Optionally, when the first SSB includes PBCH, time-frequency synchronization based on the first signal may be performed to obtain more accurate time-frequency synchronization results, thereby improving the reception performance of PBCH or the subsequent random access success rate. Alternatively, time-frequency synchronization based on the first signal may not be performed. In this way, the terminal can quickly initiate random access, thereby reducing the random access delay.

[0184] In some embodiments, the capabilities of the terminal include at least one of the following:

[0185] A first capability, used to indicate whether the terminal supports time-frequency synchronization based on the first signal;

[0186] A second capability, used to indicate whether the terminal supports completing time-frequency synchronization based on the first signal within a first time window;

[0187] The third capability is used to indicate whether the terminal supports time-frequency synchronization based on the first signal after a second time window.

[0188] In some embodiments, the first time window is used by the terminal to perform time-frequency synchronization based on the first signal. Optionally, the length of the first time window may be predefined, or configured by a network-side device, or determined according to the capabilities of the terminal.

[0189] Optionally, the first time window is from after the terminal receives the first SSB (or, after performing time-frequency synchronization based on the first SSB) to before the terminal sends the PRACH. The first time window is designed to achieve a balance between obtaining time-frequency synchronization accuracy and random access efficiency.

[0190] For example, if the terminal supports completing time and frequency synchronization based on the first signal within the first time window, it can be understood that the random access delay caused by the terminal performing time and frequency synchronization based on the first signal can be tolerated, or in other words, the terminal has a strong processing capability for time and frequency synchronization based on the first signal. After completing the time and frequency synchronization based on the first signal, random access is initiated based on the time and frequency synchronization result of the first signal, which has little effect on the speed of the initial random access. In this case, the terminal can perform time and frequency synchronization based on the first signal, and then initiate random access based on the time and frequency synchronization result of the first signal, which is conducive to improving the performance of random access.

[0191] For another example, if the terminal does not support the completion of time-frequency synchronization based on the first signal within the first time window, it can be understood that the random access delay caused by the terminal performing time-frequency synchronization based on the first signal is large, or in other words, the terminal's processing capability for time-frequency synchronization based on the first signal is weak. In this case, if after completing the time-frequency synchronization based on the first signal, random access is initiated based on the time-frequency synchronization result of the first signal, it will have a greater impact on the speed of the initial random access. Therefore, the terminal may not perform time-frequency synchronization based on the first signal.

[0192] In some embodiments, the second time window is used by the terminal to perform time-frequency synchronization based on the first SSB. Optionally, the length of the second time window can be predefined, or configured by a network-side device, or determined according to the capabilities of the terminal.

[0193] Optionally, the second time window is after the terminal receives the first SSB, and the length of the second time window is related to the processing capability of the terminal for time and frequency synchronization based on the first SSB.

[0194] For example, for a terminal with limited processing capabilities, time and frequency synchronization based on the first signal cannot be performed within the second time window after receiving the first SSB and / or the first signal. In this case, the terminal may support time and frequency synchronization based on the first signal after the second time window. If the terminal supports time and frequency synchronization based on the first signal after the second time window, the terminal may perform time and frequency synchronization based on the first signal after the second time window, or may not perform time and frequency synchronization based on the first signal. Alternatively, if the terminal does not support time and frequency synchronization based on the first signal after the second time window, the terminal may perform time and frequency synchronization based on the first signal within the second time window after receiving the first SSB, or may not perform time and frequency synchronization based on the first signal.

[0195] In some embodiments, at least one of the first capability, the second capability, and the third capability is related to a first resource, wherein the first resource can also be understood as a signal.

[0196] Therefore, the terminal can implicitly indicate the capabilities of the terminal through the first resource. Correspondingly, the network-side device can obtain the capabilities of the terminal based on the first resource used by the terminal.

[0197] In some embodiments, the first resource includes but is not limited to at least one of the following:

[0198] Random access preamble or preamble set;

[0199] Random access channel transmission opportunity (RO) or a set of random access channel transmission opportunities;

[0200] Channel State Information Reference Signal (CSI-RS), such as at least one of a CSI-RS time domain resource, a frequency domain resource, a code domain resource, a CSI-RS index, and an index of a CSI-RS set;

[0201] Sounding Reference Signal (SRS), such as at least one of an SRS time domain resource, a frequency domain resource, a code domain resource SRS index, and an SRS set index;

[0202] Message A or message 3 in the random access process, such as time domain resources, frequency domain resources, code domain resources of message A or message 3, and at least one of the information carried in message A or message 3.

[0203] Optionally, the CSI-RS is associated with a PRACH resource. Optionally, the PRACH resource includes a preamble code and / or a random access channel transmission opportunity corresponding to the PRACH.

[0204] For example, the first CSI-RS (for example, CSI-RS resource #1) is associated with the first capability, the second CSI-RS (for example, CSI-RS resource #2) is associated with the second capability, the first CSI-RS is associated with the first PRACH resource (for example, preamble #1), and the second CSI-RS is associated with the second PRACH resource (for example, preamble #2). Then, when the terminal has the first capability, random access can be initiated through the first PRACH resource (for example, preamble #1) associated with the first CSI-RS associated with the first capability. Thus, the network side device can determine that the terminal has the first capability based on the PRACH resource used by the terminal.

[0205] Optionally, SRS is associated with PRACH resources.

[0206] For example, the first SRS (for example, SRS resource #1) is associated with the first capability, the second SRS (for example, SRS resource #2) is associated with the second capability, the first SRS is associated with the first PRACH resource (for example, preamble #1), and the second SRS is associated with the second PRACH resource (for example, preamble #2). Then, when the terminal has the first capability, random access can be initiated through the first PRACH resource (for example, preamble #1) associated with the first SRS associated with the first capability. Thus, the network side device can determine that the terminal has the first capability based on the PRACH resource used by the terminal.

[0207] In some embodiments, the terminal determines, based on the first information, whether to receive the first signal, including:

[0208] When a first condition is met, receiving a first signal;

[0209] The first condition includes but is not limited to at least one of the following:

[0210] a first parameter obtained based on the first SSB measurement does not meet a specific threshold;

[0211] A change in the first parameter obtained based on multiple measurements of the first SSB is greater than or equal to a change threshold;

[0212] The number of failures of the PRACH associated with the first SSB is greater than or equal to a first number threshold;

[0213] The number of retransmissions of the random access response message associated with the first SSB is greater than or equal to a second number threshold;

[0214] The BLER corresponding to the PBCH in the first SSB is greater than or equal to the BLER threshold;

[0215] The BLER corresponding to the random access response message associated with the first SSB is greater than or equal to a BLER threshold;

[0216] The frequency domain resources of the first SSB are specific frequency domain resources;

[0217] The time domain resource of the first SSB is a specific time domain resource;

[0218] The cell identifier corresponding to the first SSB is a specific time domain resource;

[0219] The broadcast message in the first SSB includes first indication information, where the first indication information is used to instruct time-frequency synchronization based on the first signal;

[0220] The first SSB does not include a PBCH;

[0221] The terminal has a first capability;

[0222] The terminal has a second capability;

[0223] The terminal has a third capability.

[0224] In some embodiments, the first parameter obtained based on the first SSB measurement satisfies a specific threshold, including at least one of the following:

[0225] The timing parameter exceeds a timing threshold;

[0226] The frequency deviation parameter exceeds a frequency deviation threshold;

[0227] The measurement result does not reach the measurement result threshold, for example, RSRP does not reach the RSRP threshold;

[0228] The EVM of the PBCH in the first SSB exceeds the EVM threshold.

[0229] In some embodiments of the present application, the time-frequency synchronization result based on the first signal can be used for subsequent uplink transmission and / or downlink transmission. For example, based on the completion time of the time-frequency synchronization based on the first signal, it can be determined which uplink transmission or downlink transmission the time-frequency synchronization result based on the first signal is used for, thereby improving the performance of the subsequent uplink transmission or downlink transmission.

[0230] Optionally, the completion time of the time-frequency synchronization based on the first signal may be determined according to the transmission time of the first signal, or according to the transmission time of the first signal and the terminal processing time, where the terminal processing time may include at least one time unit, which may be a symbol, a time slot, or a subframe. The terminal processing time may be predefined or indicated by a network-side device.

[0231] In some embodiments of the present application, the completion time of the time-frequency synchronization based on the first signal may include at least one of the following situations:

[0232] Case 1: The terminal completes the time-frequency synchronization based on the first signal before the terminal sends the PRACH or message A.

[0233] Case 1-1: If the PRACH or message A sent by the terminal is associated with the first SSB.

[0234] Optionally, the association relationship between PRACH or message A and the first SSB may be configured by the network side device or predefined.

[0235] In this case, the PRACH in the random access process or the downlink message after message A (for example, Msg2 / Msg4 / MsgB) is associated with the first SSB.

[0236] Optionally, associating the downlink message with the first SSB may include:

[0237] The QCL reference of the downlink message is the first SSB, or in other words, the spatial reception reference of the downlink message is the same as the spatial reception parameter of the first SSB; and / or,

[0238] The reception reference of the downlink message is based on the time-frequency synchronization result of the first SSB.

[0239] Optionally, in case 1-1, it is assumed that the terminal measures the RSRP of the first signal, for example, the first signal is the second SSB, and the target second SSB is selected as SSB#2, but the terminal fails to perform time-frequency synchronization based on the second SSB. In this case, the terminal can fall back to initiating random access using the time-frequency synchronization result based on the first SSB, for example, a first SSB with better RSRP (for example, SSB#1).

[0240] Case 1-2: The PRACH or message A sent by the terminal is associated with the first signal.

[0241] In this case, the PRACH in the random access process or the downlink message after message A (eg, Msg2 / Msg4 / MsgB) is associated with the first signal.

[0242] Optionally, associating the downlink message with the first signal may include:

[0243] The QCL reference of the downlink message is the first signal, or in other words, the spatial reception reference of the downlink message is the same as the spatial reception parameter of the first signal; and / or,

[0244] The reception reference of the downlink message is based on the time-frequency synchronization result of the first signal.

[0245] Optionally, in case 1-2, assuming that the terminal selects the target first SSB as SSB#1, if the terminal uses the time-frequency synchronization result of the first signal associated with SSB#1 to initiate random access, but cannot access successfully, for example, the number of failures of the PRACH associated with the first signal reaches a threshold, or the number of retransmissions of the random access response message associated with the first signal reaches a threshold, or the BLER associated with the first signal reaches a threshold, etc., in this case, the terminal can reselect an SSB (for example, the third SSB) to initiate random access.

[0246] Case 2: The time and frequency synchronization of the terminal based on the first signal is completed after the terminal sends the PRACH and before the terminal receives Message 2 or Message B.

[0247] In this case, the message 2 or message B is associated with the first signal, or a combination of the first SSB and the first signal.

[0248] Optionally, associating the message 2 or the message B with the first signal may include:

[0249] The QCL reference of message 2 or message B is the first signal, or in other words, the spatial reception reference of message 2 or message B is the same as the spatial reception parameter of the first signal; and / or,

[0250] The reception reference of message 2 or message B is based on the time-frequency synchronization result of the first signal.

[0251] Optionally, the message 2 or message B associating the first SSB with the combination of the first signal may include:

[0252] The QCL reference of message 2 or message B is a combination of the first SSB and the first signal, or in other words, the spatial reception reference of message 2 or message B is the same as the spatial reception parameter of the combination of the first SSB and the first signal; and / or

[0253] The reception reference of message 2 or message B is based on the time-frequency synchronization result of the combination of the first SSB and the first signal.

[0254] Case 3: The completion time of the time and frequency synchronization of the terminal based on the first signal is after the terminal receives message 2 or message B and before the terminal receives message 3.

[0255] In this case, the transmission of the message 3 is associated with the first signal.

[0256] For example, the transmission of message 3 being associated with the first signal may include: the transmission reference of message 3 is based on the time-frequency synchronization result of the first signal.

[0257] Case 4: The completion time of the time and frequency synchronization of the terminal based on the first signal is after the terminal sends message 3 and before the terminal receives message 4.

[0258] In this case, the message 4 is associated with the first signal, or a combination of the first SSB and the first signal.

[0259] Optionally, the message 4 associating the first signal may include:

[0260] The QCL reference of message 4 is the first signal, or in other words, the spatial reception reference of message 4 is the same as the spatial reception parameter of the first signal; and / or,

[0261] The reception reference of message 4 is based on the time-frequency synchronization result of the first signal.

[0262] Optionally, the message 4 associating the first SSB with the first signal may include:

[0263] The QCL reference of message 4 is a combination of the first SSB and the first signal, or in other words, the spatial reception reference of message 4 is the same as the spatial reception parameter of the combination of the first SSB and the first signal; and / or,

[0264] The reception reference of message 4 is based on the time-frequency synchronization result of the combination of the first SSB and the first signal.

[0265] Therefore, in an embodiment of the application, if time-frequency synchronization based on a first signal is completed before a signal is transmitted during a random access process, the signal can be transmitted based on the time-frequency synchronization result based on the first signal, thereby improving the performance of the signal transmission.

[0266] In some embodiments, for the terminal, the time-frequency synchronization result based on the first signal takes effect after the third time window of receiving the first signal. For the network-side device, the time-frequency synchronization result based on the first signal takes effect after the third time window of sending the first signal. That is, the terminal and the network device can determine the effective time of the time-frequency synchronization result based on the first signal according to consistent rules, thereby ensuring the scheduling performance of subsequent transmissions.

[0267] Optionally, the length of the third time window may be predefined or configured by a network-side device.

[0268] Optionally, after the third time window, it can be considered that the terminal has completed time and frequency synchronization based on the first signal.

[0269] In some embodiments, the first signal is associated with a second resource, and the second resource can also be understood as a signal.

[0270] The second resource includes at least one of the following:

[0271] A preamble or a set of preambles for random access;

[0272] A random access channel transmission opportunity or a set of random access channel transmission opportunities;

[0273] Channel State Information Reference Signal (CSI-RS), such as at least one of a CSI-RS time domain resource, a frequency domain resource, a code domain resource, a CSI-RS index, and an index of a CSI-RS set;

[0274] Sounding reference signal SRS, such as at least one of the time domain resource, frequency domain resource, code domain resource SRS index, and SRS set index of the SRS;

[0275] Message A or message 3 in the random access process, such as time domain resources, frequency domain resources, code domain resources of message A or message 3, and at least one of the information carried in message A or message 3.

[0276] Therefore, the terminal can implicitly indicate to the network side device through the second resource that the terminal receives the first signal, or performs time-frequency synchronization based on the first signal. Correspondingly, the network side device can know that the terminal receives the first signal, or performs time-frequency synchronization based on the first signal based on the second resource used by the terminal.

[0277] In some cases, the first signal is associated with a preamble code or a preamble code set, and the network side device can determine whether the terminal has performed time and frequency synchronization based on the first signal according to the preamble code used by the terminal.

[0278] In some specific embodiments, the first SSB and the first signal are associated with different preamble code sets. When the terminal has performed time-frequency synchronization based on the first signal, the terminal can use the preamble code in the preamble code set associated with the first signal when initiating random access. The network side device can determine that the terminal has performed time-frequency synchronization based on the first signal based on the preamble code used by the terminal; or, when the terminal has not performed time-frequency synchronization based on the first signal, the terminal can use the preamble code in the preamble code set associated with the first SSB when initiating random access. The network side device can determine that the terminal has not performed time-frequency synchronization based on the first signal based on the preamble code used by the terminal.

[0279] In some cases, the first signal is associated with a random access channel transmission opportunity or a random access channel transmission opportunity set. The network side device can determine whether the terminal has performed time and frequency synchronization based on the first signal according to the random access channel transmission opportunity where the PRACH sent by the terminal is located.

[0280] In some specific embodiments, the first SSB and the first signal are associated with different random access channel transmission opportunity sets. When the terminal has performed time-frequency synchronization based on the first signal, when the terminal initiates random access, it can send PRACH on the random access channel transmission opportunity in the random access channel transmission opportunity set associated with the first signal. The network side device can determine that the terminal has performed time-frequency synchronization based on the first signal based on the random access channel transmission opportunity where the received PRACH is located; or, when the terminal has not performed time-frequency synchronization based on the first signal, when the terminal initiates random access, it can send PRACH on the random access channel transmission opportunity in the random access channel transmission opportunity set associated with the first SSB. The network side device can determine that the terminal has not performed time-frequency synchronization based on the first signal based on the random access channel transmission opportunity where the received PRACH is located.

[0281] In some embodiments, the first signal is associated with message A or message 3 in the random access process, and the network side device can determine whether the terminal has performed time and frequency synchronization based on the first signal according to message A or message 3 sent by the terminal.

[0282] In some specific embodiments, the first SSB and the first signal are associated with different messages A or messages 3, for example, different information in message A or message 3 is associated. Then, when the terminal performs time-frequency synchronization based on the first signal, when the terminal sends message A or message 3, the information associated with the first signal can be carried in message A or message 3. Then the network side device can determine that the terminal has performed time-frequency synchronization based on the first signal based on the information carried in the received message A or message 3; or, when the terminal does not perform time-frequency synchronization based on the first signal, when the terminal sends message A or message 3, the information associated with the first SSB or the information associated with the first signal can be carried in message A or message 3. Then the network side device can determine that the terminal has not performed time-frequency synchronization based on the first signal based on the information carried in the received message A or message 3.

[0283] Optionally, the CSI-RS is associated with PRACH resources, where the PRACH resources include a preamble code corresponding to the PRACH, a random access channel transmission opportunity, etc.

[0284] In some specific embodiments, the first SSB and the first signal are associated with different CSI-RSs, and the different CSI-RSs are associated with different PRACH resources (for example, preamble codes and / or random access channel transmission opportunities). When the terminal performs time-frequency synchronization based on the first signal, when the terminal sends PRACH, it can use the PRACH resources associated with the CSI-RS associated with the first signal to send PRACH, then the network side device can determine that the terminal has performed time-frequency synchronization based on the first signal based on the PRACH resources used by the received PRACH; or, when the terminal does not perform time-frequency synchronization based on the first signal, when the terminal sends PRACH, it can use the PRACH resources associated with the CSI-RS associated with the first SSB to send PRACH, then the network side device can determine that the terminal has not performed time-frequency synchronization based on the first signal based on the PRACH resources used by the received PRACH.

[0285] Optionally, SRS is associated with PRACH resources.

[0286] In some specific embodiments, the first SSB and the first signal are associated with different SRSs, and the different SRSs are associated with different PRACH resources. When the terminal performs time-frequency synchronization based on the first signal, when the terminal sends PRACH, it can use the PRACH resources associated with the SRS associated with the first signal to send PRACH, then the network side device can determine that the terminal has performed time-frequency synchronization based on the first signal based on the PRACH resources used by the received PRACH; or, when the terminal does not perform time-frequency synchronization based on the first signal, when the terminal sends PRACH, it can use the PRACH resources associated with the SRS associated with the first SSB to send PRACH, then the network side device can determine that the terminal has not performed time-frequency synchronization based on the first signal based on the PRACH resources used by the received PRACH.

[0287] In some embodiments of the present application, the method 500 further includes:

[0288] The network-side device determines, according to whether the terminal performs time and frequency synchronization of the first signal, transmission parameters of a random access response message (e.g., Msg2 / Msg4 / MsgB);

[0289] The network side device sends the random access response message according to the transmission parameter;

[0290] The transmission parameters include at least one of the following:

[0291] Quasi-co-sited QCL information;

[0292] Modulation order;

[0293] Bit rate;

[0294] Transport block size;

[0295] Transmission power;

[0296] Time-frequency resources.

[0297] Optionally, the QCL information may include spatial filter information or beam information.

[0298] Therefore, in an embodiment of the present application, the network side device can use corresponding transmission parameters to send a random access response message according to whether the terminal performs time-frequency synchronization based on the first signal, which is conducive to improving transmission performance and efficiency.

[0299] For example, when the terminal performs time-frequency synchronization based on the first signal, the network-side device can determine that the time-frequency synchronization accuracy of the terminal is high, and therefore can support scheduling with higher complexity or greater throughput.

[0300] For example, the network side device can determine the beam corresponding to the random access response message based on whether the terminal performs time-frequency synchronization based on the first signal. For example, when time-frequency synchronization of the first signal is performed, it can be determined that the beam of the random access response message is associated with the first signal, or, when time-frequency synchronization of the first signal is not performed, it can be determined that the beam of the random access response message is associated with the first SSB.

[0301] For another example, the network side device can determine the data transmission size of the random access response message based on whether the terminal performs time-frequency synchronization based on the first signal. For example, when time-frequency synchronization of the first signal is performed, it can be determined that the random access response message includes a larger transmission block size, or, when time-frequency synchronization of the first signal is not performed, it can be determined that the random access response message includes a smaller transmission block size.

[0302] For another example, the network side device can determine the modulation order of the random access response message based on whether the terminal performs time-frequency synchronization based on the first signal. For example, when time-frequency synchronization of the first signal is performed, it can be determined that the random access response message uses a higher modulation order, or, when time-frequency synchronization of the first signal is not performed, it can be determined that the random access response message uses a lower modulation order.

[0303] For another example, the network side device can determine the code rate of the random access response message based on whether the terminal performs time-frequency synchronization based on the first signal. For example, when time-frequency synchronization of the first signal is performed, it can be determined that the random access response message uses a higher code rate, or, when time-frequency synchronization of the first signal is not performed, it can be determined that the random access response message uses a lower code rate.

[0304] For another example, the network side device can determine the transmission power of the random access response message based on whether the terminal performs time-frequency synchronization based on the first signal. For example, when time-frequency synchronization of the first signal is performed, it can be determined that the random access response message uses a lower power, or, when time-frequency synchronization of the first signal is not performed, it can be determined that the random access response message uses a higher power.

[0305] For another example, the network side device can determine the time-frequency resources of the random access response message based on whether the terminal performs time-frequency synchronization based on the first signal. For example, when time-frequency synchronization of the first signal is performed, it can be determined that the random access response message uses larger time-frequency resources, or, when time-frequency synchronization of the first signal is not performed, it can be determined that the random access response message uses smaller time-frequency resources.

[0306] In summary, in an embodiment of the present application, the terminal can first receive the first SSB, perform time-frequency synchronization based on the first SSB, obtain a preliminary time-frequency synchronization result, further receive the first signal, and perform further time-frequency synchronization based on the first signal, which is conducive to obtaining more accurate time-frequency synchronization results, thereby improving the signal transmission performance during the initial access process and enhancing the overall performance and efficiency of the initial access.

[0307] The above text, in conjunction with Figure 5, describes in detail the method embodiment of the present application. The following text, in conjunction with Figures 6 to 10, describes in detail the device embodiment of the present application. It should be understood that the device embodiment and the method embodiment correspond to each other, and similar descriptions can refer to the method embodiment.

[0308] The initial access method provided in the embodiment of the present application may be performed by an initial access device. In the embodiment of the present application, the initial access device provided in the embodiment of the present application is described by taking the initial access method performed by the initial access device as an example.

[0309] FIG6 shows a schematic block diagram of an initial access device 600 according to an embodiment of the present application. As shown in FIG6 , the device 600 includes:

[0310] The communication unit 610 is configured to receive a first synchronization signal block SSB;

[0311] A processing unit 620 is configured to perform time and frequency synchronization according to the first SSB;

[0312] The communication unit 610 is further configured to: receive a first signal;

[0313] The processing unit 620 is further configured to perform time-frequency synchronization according to the first signal.

[0314] In some embodiments, the first SSB satisfies at least one of the following:

[0315] The frequency domain resources of the first SSB are predefined frequency domain resources;

[0316] The time domain resource of the first SSB is a predefined time domain resource;

[0317] The first SSB carries a physical broadcast channel PBCH;

[0318] The first SSB is transmitted on the initial bandwidth part BWP.

[0319] In some embodiments, the first signal includes at least one of the following:

[0320] a repetitive signal of the first SSB;

[0321] an extended signal of the first SSB;

[0322] Second SSB;

[0323] Other reference signals besides SSB for time and frequency synchronization.

[0324] In some embodiments, the time-frequency resources of the second SSB are different from the time-frequency resources of the first SSB.

[0325] In some embodiments, the first signal includes an extended signal of the first SSB, and the processing unit 620 is further configured to:

[0326] Performing time-frequency synchronization according to the extended signal of the first SSB; or

[0327] Time and frequency synchronization is performed according to a second signal, wherein the second signal includes the first SSB and an extended signal of the first SSB.

[0328] In some embodiments, the first SSB is associated with at least one of the first signals.

[0329] In some embodiments, the processing unit 620 is further configured to:

[0330] determining, according to the first information, whether to receive the first signal;

[0331] The first information includes at least one of the following:

[0332] a reception result of the first SSB;

[0333] Associating the random access result of the first SSB;

[0334] parameters of the first SSB;

[0335] The capabilities of the terminal.

[0336] In some embodiments, the reception result of the first SSB includes at least one of the following:

[0337] a first parameter obtained based on the first SSB measurement;

[0338] a change in a first parameter obtained based on multiple measurements of the first SSB;

[0339] The BLER corresponding to the PBCH in the first SSB.

[0340] In some embodiments, the first parameter obtained based on the first SSB measurement includes at least one of the following:

[0341] Timing parameters;

[0342] Frequency deviation parameters;

[0343] a result related to the reception quality of the first SSB;

[0344] The error vector magnitude (EVM) of the PBCH in the first SSB.

[0345] In some embodiments, the random access result associated with the first SSB includes at least one of the following:

[0346] The number of failed attempts to associate the physical random access channel (PRACH) of the first SSB;

[0347] The number of retransmissions of the random access response message associated with the first SSB;

[0348] Associate the BLER corresponding to the random access response message of the first SSB.

[0349] In some embodiments, the parameters of the first SSB include at least one of the following:

[0350] frequency domain resources of the first SSB;

[0351] time domain resources of the first SSB;

[0352] a cell identifier corresponding to the first SSB;

[0353] synchronization sequence related information in the first SSB;

[0354] a broadcast message in the first SSB;

[0355] The first SSB contains the signal.

[0356] In some embodiments, the broadcast message in the first SSB includes first indication information, and the first indication information is used to indicate whether time and frequency synchronization is performed based on the first signal.

[0357] In some embodiments, the capabilities of the terminal include at least one of the following:

[0358] A first capability, used to indicate whether the terminal supports time-frequency synchronization based on the first signal;

[0359] A second capability, used to indicate whether the terminal supports completing time-frequency synchronization based on the first signal within a first time window;

[0360] a third capability, used to indicate whether the terminal supports time-frequency synchronization based on the first signal after a second time window;

[0361] Among them, the first time window is used by the terminal to perform time and frequency synchronization based on the first signal; the second time window is used by the terminal to perform time and frequency synchronization based on the first SSB.

[0362] In some embodiments, at least one of the first capability, the second capability, and the third capability is related to a first resource, wherein the first resource includes at least one of the following:

[0363] A preamble or a set of preambles for random access;

[0364] A random access channel transmission opportunity or a set of random access channel transmission opportunities;

[0365] Channel State Information Reference Signal CSI-RS;

[0366] Sounding reference signal SRS;

[0367] Message A or Message 3 in the random access process.

[0368] In some embodiments, if the completion time of the time-frequency synchronization of the terminal based on the first signal is before the terminal sends the PRACH or message A, and the PRACH or message A sent by the terminal is associated with the first SSB, then the downlink message after the PRACH or message A in the random access process is associated with the first SSB; or

[0369] If the completion time of the time-frequency synchronization of the terminal based on the first signal is before the terminal sends the PRACH or message A, and the PRACH or message A sent by the terminal is associated with the first signal, then the downlink message after the PRACH or message A in the random access process is associated with the first signal; or

[0370] If the completion time of the time-frequency synchronization of the terminal based on the first signal is after the terminal sends the PRACH and before receiving message 2 or message B, the message 2 or message B is associated with the first signal, or a combination of the first SSB and the first signal; or

[0371] If the completion time of the time-frequency synchronization of the terminal based on the first signal is after the terminal receives message 2 or message B and before the terminal receives message 3, the transmission of message 3 is associated with the first signal; or

[0372] If the completion time of the time and frequency synchronization of the terminal based on the first signal is after the terminal sends message 3 and before the terminal receives message 4, then the message 4 is associated with the first signal, or the combination of the first SSB and the first signal.

[0373] In some embodiments, after a third time window of receiving the first signal, a time-frequency synchronization result based on the first signal takes effect.

[0374] In some embodiments, the first signal is associated with a second resource, and the second resource includes at least one of the following:

[0375] A preamble or a set of preambles for random access;

[0376] A random access channel transmission opportunity or a set of random access channel transmission opportunities;

[0377] Channel State Information Reference Signal CSI-RS;

[0378] Sounding reference signal SRS;

[0379] Message A or Message 3 in the random access process.

[0380] In some embodiments, the communication unit 610 is further configured to:

[0381] receiving a random access response message, where a transmission parameter of the random access response message is determined by whether the terminal performs time-frequency synchronization according to the first signal;

[0382] The transmission parameters include at least one of the following:

[0383] Quasi-co-sited QCL information;

[0384] Modulation order;

[0385] Bit rate;

[0386] Transport block size;

[0387] Transmission power;

[0388] Time-frequency resources.

[0389] Alternatively, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip. The processing unit may be one or more processors.

[0390] It should be understood that the device 600 according to the embodiment of the present application may correspond to the terminal in the method embodiment of the present application, and the above-mentioned and other operations and / or functions of each unit in the device 600 are respectively for realizing the corresponding processes of the terminal in the method embodiment shown in Figure 5 and achieving the same technical effect. To avoid repetition, they will not be repeated here.

[0391] FIG7 shows a schematic block diagram of an initial access device 700 according to an embodiment of the present application. As shown in FIG7 , the device 700 includes:

[0392] The communication unit 710 is configured to send a first synchronization signal block SSB, where the first SSB is used for the terminal to perform time and frequency synchronization;

[0393] A first signal is sent, where the first signal is used for the terminal to perform time and frequency synchronization.

[0394] In some embodiments, the first SSB satisfies at least one of the following:

[0395] The frequency domain resources of the first SSB are predefined frequency domain resources;

[0396] The time domain resource of the first SSB is a predefined time domain resource;

[0397] The first SSB carries a physical broadcast channel PBCH;

[0398] The first SSB is transmitted on the initial bandwidth part BWP.

[0399] In some embodiments, the first signal includes at least one of the following:

[0400] a repetitive signal of the first SSB;

[0401] an extended signal of the first SSB;

[0402] Second SSB;

[0403] Other reference signals besides SSB for time and frequency synchronization.

[0404] In some embodiments, the time-frequency resources of the second SSB are different from the time-frequency resources of the first SSB.

[0405] In some embodiments, the first SSB is associated with at least one of the first signals.

[0406] In some embodiments, the first signal is associated with a second resource, wherein the second resource includes at least one of the following:

[0407] A preamble or a set of preambles for random access;

[0408] A random access channel transmission opportunity or a set of random access channel transmission opportunities;

[0409] Channel State Information Reference Signal CSI-RS;

[0410] Sounding reference signal SRS;

[0411] Message A or Message 3 in the random access process.

[0412] In some embodiments, the positioning device 700 further includes:

[0413] a processing unit, configured to determine a transmission parameter of a random access response message according to whether the terminal performs time and frequency synchronization of the first signal;

[0414] The communication unit 710 is further configured to: send the random access response message according to the transmission parameter;

[0415] The transmission parameters include at least one of the following:

[0416] Quasi-co-sited QCL information;

[0417] Modulation order;

[0418] Bit rate;

[0419] Transport block size;

[0420] Transmission power;

[0421] Time-frequency resources.

[0422] In some embodiments, after a third time window of sending the first signal, a time-frequency synchronization result based on the first signal takes effect.

[0423] Alternatively, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip. The processing unit may be one or more processors.

[0424] It should be understood that the initial access device 700 according to the embodiment of the present application may correspond to the network side device in the method embodiment of the present application, and the above-mentioned and other operations and / or functions of each unit in the device 700 are respectively for realizing the corresponding processes of the network side device in the method embodiment shown in Figure 5 and achieving the same technical effect. To avoid repetition, they will not be repeated here.

[0425] In some embodiments, the initial access device 600 and the initial access device 700 in the embodiments of the present application can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or chip. The electronic device can be a terminal or other device other than a terminal. For example, the terminal can include but is not limited to the types of terminals 11 listed above, and other devices can be servers, network attached storage (NAS), etc., which are not specifically limited in the embodiments of the present application.

[0426] As shown in Figure 8, an embodiment of the present application further provides a communication device 800, including a processor 801 and a memory 802. The memory 802 stores a program or instruction that can be run on the processor 801. For example, when the communication device 800 is a terminal, the program or instruction, when executed by the processor 801, implements the steps performed by the terminal in the above-mentioned initial access method embodiment, and can achieve the same technical effect. When the communication device 800 is a network-side device, the program or instruction, when executed by the processor 801, implements the various steps performed by the network-side device in the above-mentioned initial access method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0427] The present application also provides a terminal including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the method embodiment shown in FIG5 . This terminal embodiment corresponds to the aforementioned terminal-side method embodiment, and each implementation process and implementation method of the aforementioned method embodiment is applicable to this terminal embodiment and can achieve the same technical effects. Specifically, FIG9 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of the present application.

[0428] The terminal 900 includes but is not limited to: a radio frequency unit 901, a network module 902, an audio output unit 903, an input unit 904, a sensor 905, a display unit 906, a user input unit 907, an interface unit 908, a memory 909 and at least some of the components of the processor 910.

[0429] Those skilled in the art will appreciate that the terminal 900 may also include a power supply (such as a battery) to power various components. The power supply may be logically connected to the processor 910 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The terminal structure shown in FIG9 does not limit the terminal. The terminal may include more or fewer components than shown, or may combine certain components, or have different component arrangements, which will not be described in detail here.

[0430] It should be understood that in an embodiment of the present application, the input unit 904 may include a graphics processing unit (GPU) 9041 and a microphone 9042, and the graphics processor 9041 processes the image data of a static picture or video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 906 may include a display panel 9061, and the display panel 9061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 907 includes a touch panel 9071 and at least one of other input devices 9072. The touch panel 9071 is also called a touch screen. The touch panel 9071 may include two parts: a touch detection device and a touch controller. Other input devices 9072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and an operating stick, which will not be repeated here.

[0431] In the embodiment of the present application, after receiving downlink data from a network-side device, the RF unit 901 may transmit the data to the processor 910 for processing. Furthermore, the RF unit 901 may send uplink data to the network-side device. Typically, the RF unit 901 includes, but is not limited to, an antenna, an amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, and the like.

[0432] The memory 909 can be used to store software programs or instructions and various data. The memory 909 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, applications or instructions required for at least one function (such as a sound playback function, an image playback function, etc.). In addition, the memory 909 may include a volatile memory or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DRRAM). The memory 909 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0433] Processor 910 may include one or more processing units. Optionally, processor 910 integrates an application processor and a modem processor. The application processor primarily handles operations related to the operating system, user interface, and application programs, while the modem processor primarily processes wireless communication signals, such as a baseband processor. It is understood that the modem processor may not be integrated into processor 910.

[0434] It can be understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description in the method embodiment and achieve the same or corresponding technical effects. To avoid repetition, it will not be repeated here.

[0435] The present application also provides a network-side device, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the method embodiment shown in FIG5 . This network-side device embodiment corresponds to the aforementioned network-side device method embodiment, and each implementation process and implementation method of the aforementioned method embodiment are applicable to this network-side device embodiment and can achieve the same technical effects.

[0436] Specifically, an embodiment of the present application also provides a network-side device. As shown in Figure 10, the network-side device 1000 includes: an antenna 1001, a radio frequency device 1002, a baseband device 1003, a processor 1004, and a memory 1005. Antenna 1001 is connected to radio frequency device 1002. In the uplink direction, radio frequency device 1002 receives information via antenna 1001 and sends the received information to baseband device 1003 for processing. In the downlink direction, baseband device 1003 processes the information to be transmitted and sends it to radio frequency device 1002. Radio frequency device 1002 processes the received information and sends it through antenna 1001.

[0437] The method executed by the network-side device in the above embodiment may be implemented in the baseband device 1003 , which includes a baseband processor.

[0438] The baseband device 1003 may include, for example, at least one baseband board, on which multiple chips are arranged, as shown in Figure 10, one of which is, for example, a baseband processor, which is connected to the memory 1005 through a bus interface to call the program in the memory 1005 and execute the network side device operations shown in the above method embodiment.

[0439] The network side device may further include a network interface 1006, which is, for example, a Common Public Radio Interface (CPRI).

[0440] Specifically, the network side device 1000 of the embodiment of the present application also includes: instructions or programs stored in the memory 1005 and executable on the processor 1004. The processor 1004 calls the instructions or programs in the memory 1005 to execute the method of execution of each module shown in Figure 7 and achieve the same technical effect. To avoid repetition, it will not be described here.

[0441] The processors mentioned in the embodiments of the present application may include general-purpose processors, special-purpose processors, etc., such as a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), an artificial intelligence (AI) processor, a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a network processor (NP), a field programmable gate array (FPGA), or other programmable logic devices, gate circuits, transistors, discrete hardware components, etc.

[0442] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned initial access method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0443] The processor is the processor in the terminal or network-side device described in the above embodiments. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0444] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned initial access method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0445] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0446] An embodiment of the present application further provides a computer program / program product, which is stored in a storage medium. The computer program / program product is executed by at least one processor to implement the various processes of the above-mentioned initial access method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0447] An embodiment of the present application also provides a communication system, including: a terminal and a network-side device, wherein the terminal can be used to execute the steps of the initial access method as described above, and the network-side device can be used to execute the steps of the initial access method as described above.

[0448] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0449] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general-purpose hardware platform, or of course, by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes a number of instructions for enabling a terminal or network-side device to execute the methods described in each embodiment of the present application.

[0450] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of this application and the scope of protection of the claims. These implementation methods are all within the protection of this application.

Claims

1. An initial access method, wherein: include: The terminal receives a first synchronization signal block SSB and performs time and frequency synchronization according to the first SSB; The terminal receives a first signal and performs time-frequency synchronization according to the first signal.

2. The method according to claim 1, wherein The first SSB satisfies at least one of the following: The frequency domain resources of the first SSB are predefined frequency domain resources; The time domain resource of the first SSB is a predefined time domain resource; The first SSB carries a physical broadcast channel PBCH; The first SSB is transmitted on the initial bandwidth part BWP.

3. The method according to claim 1 or 2, wherein: The first signal includes at least one of the following: a repetitive signal of the first SSB; an extended signal of the first SSB; Second SSB; Other reference signals besides SSB for time and frequency synchronization.

4. The method according to claim 3, wherein: The time-frequency resources of the second SSB are different from the time-frequency resources of the first SSB.

5. The method according to claim 3, wherein The first signal includes an extended signal of the first SSB, and performing time-frequency synchronization according to the first signal includes: Performing time-frequency synchronization according to the extended signal of the first SSB; or Time and frequency synchronization is performed according to a second signal, wherein the second signal includes the first SSB and an extended signal of the first SSB.

6. The method according to any one of claims 1 to 5, wherein The first SSB is associated with at least one of the first signals.

7. The method according to any one of claims 1 to 6, wherein The method further comprises: determining, according to the first information, whether to receive the first signal; The first information includes at least one of the following: a reception result of the first SSB; Associating the random access result of the first SSB; parameters of the first SSB; The capabilities of the terminal.

8. The method according to claim 7, wherein: The reception result of the first SSB includes at least one of the following: a first parameter obtained based on the first SSB measurement; a change in a first parameter obtained based on multiple measurements of the first SSB; The BLER corresponding to the PBCH in the first SSB.

9. The method according to claim 8, wherein The first parameter obtained based on the first SSB measurement includes at least one of the following: Timing parameters; Frequency deviation parameters; a result related to the reception quality of the first SSB; The error vector magnitude (EVM) of the PBCH in the first SSB.

10. The method according to any one of claims 7 to 9, wherein: The random access result associated with the first SSB includes at least one of the following: The number of failed attempts to associate the physical random access channel (PRACH) of the first SSB; The number of retransmissions of the random access response message associated with the first SSB; Associate the BLER corresponding to the random access response message of the first SSB.

11. The method according to any one of claims 7 to 10, wherein: The parameters of the first SSB include at least one of the following: frequency domain resources of the first SSB; time domain resources of the first SSB; a cell identifier corresponding to the first SSB; synchronization sequence related information in the first SSB; a broadcast message in the first SSB; The first SSB contains the signal.

12. The method according to claim 11, wherein The broadcast message in the first SSB includes first indication information, and the first indication information is used to indicate whether time and frequency synchronization is performed based on the first signal.

13. The method according to any one of claims 7 to 12, wherein: The terminal's capabilities include at least one of the following: A first capability, used to indicate whether the terminal supports time-frequency synchronization based on the first signal; A second capability, used to indicate whether the terminal supports completing time-frequency synchronization based on the first signal within a first time window; a third capability, used to indicate whether the terminal supports time-frequency synchronization based on the first signal after a second time window; Among them, the first time window is used by the terminal to perform time and frequency synchronization based on the first signal; the second time window is used by the terminal to perform time and frequency synchronization based on the first SSB.

14. The method according to claim 13, wherein At least one of the first capability, the second capability, and the third capability is related to a first resource, wherein the first resource includes at least one of the following: A preamble or a set of preambles for random access; A random access channel transmission opportunity or a set of random access channel transmission opportunities; Channel State Information Reference Signal CSI-RS; Sounding reference signal SRS; Message A or Message 3 in the random access process.

15. The method according to any one of claims 1 to 14, wherein If the completion time of the time-frequency synchronization of the terminal based on the first signal is before the terminal sends the PRACH or message A, and the PRACH or message A sent by the terminal is associated with the first SSB, then the downlink message after the PRACH or message A in the random access process is associated with the first SSB; or If the completion time of the time-frequency synchronization of the terminal based on the first signal is before the terminal sends the PRACH or message A, and the PRACH or message A sent by the terminal is associated with the first signal, then the downlink message after the PRACH or message A in the random access process is associated with the first signal; or If the completion time of the time and frequency synchronization of the terminal based on the first signal is after the terminal sends the PRACH and before receiving message 2 or message B, the message 2 or message B is associated with the first signal, or a combination of the first SSB and the first signal; or If the completion time of the time-frequency synchronization of the terminal based on the first signal is after the terminal receives message 2 or message B and before the terminal receives message 3, the transmission of message 3 is associated with the first signal; or If the completion time of the time and frequency synchronization of the terminal based on the first signal is after the terminal sends message 3 and before the terminal receives message 4, then the message 4 is associated with the first signal, or the combination of the first SSB and the first signal.

16. The method according to any one of claims 1 to 15, wherein The method further comprises: After receiving the third time window of the first signal, the time-frequency synchronization result based on the first signal takes effect.

17. The method according to any one of claims 1 to 16, wherein: The first signal is associated with a second resource, where the second resource includes at least one of the following: A preamble or a set of preambles for random access; A random access channel transmission opportunity or a set of random access channel transmission opportunities; Channel State Information Reference Signal CSI-RS; Sounding reference signal SRS; Message A or Message 3 in the random access process.

18. The method according to any one of claims 1 to 17, wherein The method further comprises: receiving, by the terminal, a random access response message, where a transmission parameter of the random access response message is determined by whether the terminal performs time-frequency synchronization according to the first signal; The transmission parameters include at least one of the following: Quasi-co-sited QCL information; Modulation order; Bit rate; Transport block size; Transmission power; Time-frequency resources.

19. An initial access method, wherein: include: The network side device sends a first synchronization signal block SSB, where the first SSB is used for the terminal to perform time and frequency synchronization; The network side device sends a first signal, where the first signal is used for the terminal to perform time and frequency synchronization.

20. The method according to claim 19, wherein The first SSB satisfies at least one of the following: The frequency domain resources of the first SSB are predefined frequency domain resources; The time domain resource of the first SSB is a predefined time domain resource; The first SSB carries a physical broadcast channel PBCH; The first SSB is transmitted on the initial bandwidth part BWP.

21. The method according to claim 19 or 20, wherein The first signal includes at least one of the following: a repetitive signal of the first SSB; an extended signal of the first SSB; Second SSB; Other reference signals besides SSB for time and frequency synchronization.

22. The method according to claim 21, wherein The time-frequency resources of the second SSB are different from the time-frequency resources of the first SSB.

23. The method according to any one of claims 19 to 22, wherein: The first SSB is associated with at least one of the first signals.

24. The method according to any one of claims 19 to 23, wherein: The first signal is associated with a second resource, wherein the second resource includes at least one of the following: A preamble or a set of preambles for random access; A random access channel transmission opportunity or a set of random access channel transmission opportunities; Channel State Information Reference Signal CSI-RS; Sounding reference signal SRS; Message A or Message 3 in random access.

25. The method according to any one of claims 19 to 24, wherein: The method further comprises: The network-side device determines, according to whether the terminal performs time and frequency synchronization of the first signal, a transmission parameter of the random access response message; The network side device sends the random access response message according to the transmission parameter; The transmission parameters include at least one of the following: Quasi-co-sited QCL information; Modulation order; Bit rate; Transport block size; Transmission power; Time-frequency resources.

26. The method according to any one of claims 19 to 25, wherein: The method further comprises: After the third time window of sending the first signal, the time-frequency synchronization result based on the first signal takes effect.

27. An initial access device, wherein: include: A receiving unit, configured to receive a first synchronization signal block SSB; a processing unit, configured to perform time and frequency synchronization according to the first SSB; The receiving unit is further configured to: when a first condition is met, the terminal receives a first signal; The processing unit is further configured to perform time-frequency synchronization according to the first signal.

28. The apparatus according to claim 27, wherein The first SSB satisfies at least one of the following: The frequency domain resources of the first SSB are predefined frequency domain resources; The time domain resource of the first SSB is a predefined time domain resource; The first SSB carries a physical broadcast channel PBCH; The first SSB is transmitted on the initial bandwidth part BWP.

29. The device according to claim 27 or 28, wherein The first signal includes at least one of the following: a repetitive signal of the first SSB; an extended signal of the first SSB; Second SSB; Other reference signals besides SSB for time and frequency synchronization.

30. The device according to any one of claims 27 to 29, wherein The processing unit is further configured to: determining, according to the first information, whether to receive the first signal; The first information includes at least one of the following: a reception result of the first SSB; Associating the random access result of the first SSB; parameters of the first SSB; The capabilities of the terminal.

31. The device according to any one of claims 27 to 30, wherein The first signal is associated with a second resource, wherein the second resource includes at least one of the following: A preamble or a set of preambles for random access; A random access channel transmission opportunity or a set of random access channel transmission opportunities; Channel State Information Reference Signal CSI-RS; Sounding reference signal SRS; Message A or Message 3 in the random access process.

32. An initial access device, wherein: include: A sending unit, configured to send a first synchronization signal block SSB, where the first SSB is used for time and frequency synchronization of the terminal; A first signal is sent, where the first signal is used for the terminal to perform time and frequency synchronization.

33. The apparatus according to claim 32, wherein The first SSB satisfies at least one of the following: The frequency domain resources of the first SSB are predefined frequency domain resources; The time domain resource of the first SSB is a predefined time domain resource; The first SSB carries a physical broadcast channel PBCH; The first SSB is transmitted on the initial bandwidth part BWP.

34. The apparatus according to claim 32 or 33, wherein: The first signal includes at least one of the following: a repetitive signal of the first SSB; an extended signal of the first SSB; Second SSB; Other reference signals besides SSB for time and frequency synchronization.

35. The device according to any one of claims 32 to 34, wherein The device further comprises: a processing unit, configured to determine a transmission parameter of a random access response message according to whether the terminal performs time and frequency synchronization of the first signal; The transmission parameters include at least one of the following: Quasi-co-sited QCL information; Modulation order; Bit rate; Transport block size; Transmission power; Time-frequency resources.

36. The device according to any one of claims 32 to 35, wherein The first signal is associated with a second resource, wherein the second resource includes at least one of the following: A preamble or a set of preambles for random access; A random access channel transmission opportunity or a set of random access channel transmission opportunities; Channel State Information Reference Signal CSI-RS; Sounding reference signal SRS; Message A or Message 3 in the random access process.

37. A communication device, wherein: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 18 and the steps of the method according to any one of claims 19 to 26 are implemented.

38. A readable storage medium, wherein: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, it implements the method according to any one of claims 1 to 18, or implements the steps of the method according to any one of claims 19 to 26.

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