5G base station single-cell frequency domain multi-SSB random access method

Abstract

The invention discloses a 5G base station single-cell frequency domain multi-SSB random access method, which comprises the following steps: when user equipment searches a plurality of SSB frequency points corresponding to a cell, respectively acquiring SIB1 messages associated with the plurality of SSB frequency points; the frequency band broadband of each cell is divided into a plurality of SSB frequency points; the user equipment initiates random access to any SSB frequency point corresponding to the cell according to the RACH parameter of the SIB1 message; when the RRC connection is established between the user equipment and the wireless network, if the SINR value of the SSB frequency point accessed by the user equipment is smaller than a preset threshold value, the SSB frequency point with the larger SINR value is selected from a plurality of SSB frequency points through pilot frequency measurement, and redirection is triggered to enable the user equipment to access the SSB frequency point with the larger SINR value. According to the invention, the anti-interference capability of the cell is improved.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a random access method for multiple SSBs in the frequency domain of a single cell of a 5G base station. Background Art

[0002] SSB (Synchronization Signal and PBCH block) is one of the most important pilot channels of 5G. Its role is related to many aspects of user equipment accessing the cell, such as cell search, beam measurement, beam selection, beam recovery, etc. Its main function is to allow the terminal to obtain the PCI (Physical Cell Identifier) ​​of the cell, achieve downlink synchronization with the cell, and obtain the signal quality of the cell in the air interface.

[0003] The composition of SSB: SSB occupies 4 OFDM symbols in the time domain and 20 RBs (Resource Blocks) in the frequency domain. It contains three types of information: primary synchronization signal (PSS), secondary synchronization signal (SSS) and physical broadcast channel (PBCH).

[0004] When a user device accesses the 5G system, it will first search for the SSB of the 5GNR cell on the global synchronization grid before initiating subsequent random access.

[0005] Cell search: Cell search is the process by which the user equipment obtains time and frequency domain synchronization with a cell and detects the physical cell identifier of the cell. After the user equipment searches for the SSB on the global synchronization grid, it obtains the PCI through the PSS and SSS, decodes the MIB (Master Information Block) and DMRS (Demodulation Reference Signal) on the PBCH to obtain the cell system frame number, and then obtains the slot number and symbol of the SSB through the SSB index in the PBCH DMRS to achieve downlink time slot synchronization.

[0006] System message block SIB1 reception: When the user equipment obtains the SIB1 related parameters of the MIB signaling content of the PBCH on the SSB, it searches for the SIB1 message of the cell. The frequency domain position of the physical channel of SIB1 can be configured in the MIB signaling, which is strongly related to the position of the SSB. SIB1 contains the necessary information for the user equipment to subsequently initiate RACH (Random Access Channel) random access.

[0007] Random access: The random access process is used by the user equipment to obtain uplink synchronization. After the random access is completed, the user equipment can communicate uplink with the base station. The frequency domain position of the common search space used for uplink and downlink signaling interaction between the base station and the user equipment during the random access process must be included in the frequency domain position of the physical channel where SIB1 is located according to the 3GPP protocol requirements.

[0008] The frequency domain position of SSB in the 5G cell bandwidth: Since the bandwidth of the 5G system is as high as 100MHz, and even reaches 400MHz at high frequencies, the bandwidth of SSB is only fixed at 240 subcarriers. Depending on the subcarrier spacing, the bandwidth of SSB ranges from 3.6MHz to 57.6MHz. In the current 5G commonly used frequency and bandwidth range, the frequency band range of SSB is generally smaller than the cell bandwidth. Taking a 30kHz subcarrier as an example, in a 5G cell with a bandwidth of 100MHz, the frequency band of SSB only occupies 7.2MHz.

[0009] From this, we can see that although the frequency domain position of SSB only occupies a small part of the cell bandwidth, it has a considerable impact on the access capability of the cell. Once the frequency domain of the SSB on the cell bandwidth is interfered with, it will affect the access capability of the entire cell bandwidth and the stability of subsequent traffic services. Summary of the invention

[0010] In view of this, the present application provides a random access method for multiple SSBs in the frequency domain of a single cell of a 5G base station to improve the anti-interference capability of cell access.

[0011] The present application discloses a random access method for multiple SSBs in a frequency domain of a single cell of a 5G base station, which includes:

[0012] After the user equipment searches for multiple SSB frequency points corresponding to the cell, it obtains SIB1 messages associated with the multiple SSB frequency points respectively; the frequency bandwidth of each cell is divided into multiple SSB frequency points;

[0013] The user equipment initiates random access to any SSB frequency corresponding to the cell according to the RACH parameters of the SIB1 message;

[0014] When an RRC connection is established between a user device and a wireless network, if the SINR value of the SSB frequency accessed by the user device is less than a preset threshold value, an SSB frequency with a larger SINR value is selected from multiple SSB frequencies through heterodyne measurement, triggering redirection so that the user device accesses the SSB frequency with a larger SINR value.

[0015] Further, the frequency domain position of the common search space corresponding to each of the multiple SSB frequency points does not overlap within the cell bandwidth; each of the multiple SSB frequency points has a common physical cell identifier;

[0016] Each of the multiple SSB frequency points is associated with a SIB1 message, the frequency domain position of the physical channel of each SIB1 message is independent of each other, and the RACH parameters of each SIB1 message are different, which are used for the cell to identify the SSB frequency point accessed by the user equipment;

[0017] The NR cell identifier NCGI of all SIB1 messages corresponding to the multiple SSB frequency points is the same, and each SIB1 message corresponds to an independent random access RACH resource configuration and common search space configuration.

[0018] Further, the RACH resource configuration includes MSG1 time domain resources and frequency domain resources sent when the user equipment initiates random access;

[0019] Among them, the frequency domain resource is a parameter of the frequency domain starting position of MSG1, which is used to indicate the starting RB position of MSG1; the time domain resource is a RACH time domain resource set index, which corresponds to a RACH time domain resource set. The frequency domain of MSG1 configured by each RACH resource in each RACH time domain resource set falls within the common search space corresponding to the relevant SSB frequency point as much as possible, and the time domain resources configured by each RACH resource are independent of each other in the time domain and do not overlap with each other.

[0020] Furthermore, it also includes:

[0021] The cell allocates a corresponding public search space to the user equipment based on the SSB frequency point accessed by the user equipment; the frequency domain position of the public search space overlaps with the frequency domain position of the SIB1 message, and the public search space is used to schedule the wireless resources for random access. During the access process, the corresponding PUSCH and PDSCH RB frequency domain positions are within the public search space.

[0022] Furthermore, the common search space corresponding to each of the SSB frequency points is used for the transmission of the SIB1 message and the uplink and downlink scheduling of the RACH, and the common search spaces are independent of each other in the frequency domain and do not overlap each other;

[0023] After the user equipment successfully accesses the SSB frequency, the frequency domain range of the dedicated search space allocated by the cell to each user equipment is the same, and the user equipment that accesses the same SSB frequency can use the same dedicated resources for scheduling.

[0024] Furthermore, it also includes:

[0025] When air interface signal interference occurs in the frequency band around the SSB frequency point to be accessed by the user equipment, and the user equipment has not established an RRC connection with the wireless network, the user equipment selects an available SSB frequency point for access or residence according to the cell selection S criterion or the cell reselection R criterion;

[0026] If the user equipment selects an SSB frequency that is interfered with, and the access success rate of the SSB frequency counted by the cell is lower than a preset value, the SSB frequency will be stopped from being scheduled for a period of time, allowing the user equipment to select an available SSB frequency to initiate access.

[0027] Furthermore, it also includes:

[0028] After the cell recognizes that the SSB frequency on part of the bandwidth is interfered with, after the user equipment randomly accesses, the cell identifies the SSB frequency accessed by the user equipment. When other non-access SSB frequency locations are interfered with, the cell allocates a dedicated search space and PDCCH candidate positions and PDSCH / PUSCH resources corresponding to the access SSB frequency location to the user equipment, or switches the user equipment to the bandwidth BWP corresponding to the SSB frequency location.

[0029] Further, the cell identifies the SSB frequency point accessed by the user equipment, including:

[0030] The cell identifies the SSB frequency point selected by the user equipment for access by judging the frequency domain starting position or PRACH opportunity at which the user equipment sends MSG1; wherein each SSB frequency point is associated with a SIB1 signaling, and the RACH parameters in each SIB1 signaling are different; the different RACH parameters include different time-frequency domain positions of MSG1 for initiating random access; the frequency domain position of MSG1 of the RACH resource corresponding to each SSB frequency point, within the common search space corresponding to the SSB frequency point, the time domain position is determined according to the PRACH opportunity.

[0031] Further, if the SINR value of the SSB frequency point accessed by the user equipment is less than the preset threshold value, a SSB frequency point with a larger SINR value is selected from multiple SSB frequency points through inter-frequency measurement, and redirection is triggered to enable the user equipment to access the SSB frequency point with a larger SINR value, including:

[0032] For each user equipment accessed by the SSB frequency point, the measurement object of the corresponding SSB frequency point is configured in the measurement configuration to ensure that the user equipment measures the SSB frequency point when accessed; the measurement report carries the SINR information of the user equipment accessing the SSB frequency point, so that the cell can judge the wireless air interface quality of the SSB frequency point, and the measurement report is configured as an event trigger, the event type is A2 event, and the trigger threshold type is SINR;

[0033] When the user equipment reports an A2 event in which the SINR value is lower than the set threshold, the cell sends an inter-frequency measurement configuration, the inter-frequency measurement object is other SSB frequency points in the cell, the measurement configuration is an A3 event trigger type or an A4 event trigger type, and the measurement parameter type is SINR, so that the base station obtains an SSB frequency point with a larger SINR value; after the user equipment receives the inter-frequency measurement configuration sent by the cell, it starts to measure the RSRP, RSRQ, and SINR of the SSB frequency point of the cell, and configures the A2 event of SINR; the user equipment uses a dedicated search space for scheduling;

[0034] After the user equipment reports an SSB frequency with a larger SINR value through inter-frequency measurement, the redirection process is triggered, that is, the redirection carrier information is carried in the RRC release signaling, which carries an absolute wireless frequency channel number of NR to indicate the SSB frequency so that the user equipment can access.

[0035] Furthermore, it also includes an interference frequency band identification mechanism; the interference frequency band identification mechanism includes:

[0036] The base station determines the air interface quality environment and interference conditions around multiple SSB frequency points of the cell bandwidth through the access success rate of the user equipment for any SSB frequency point and the reported SINR value.

[0037] Due to the adoption of the above technical solution, the present application has the following advantages:

[0038] The present application can improve the access success rate in the case of partial interference in the cell bandwidth. A cell can be configured with multiple SSB frequencies, and the user equipment can initiate random access through multiple SSB frequencies respectively. During the initial access, the scheduled bandwidth is the bandwidth of the public search space, which can avoid interference from other locations on the bandwidth. Compared with the situation where the usual 5G cell has only one SSB frequency, the access anti-interference situation is greatly improved. At the same time, when the base station scheduling strategy is implemented, avoiding the interfered frequency band can ensure the stability and reliability of the subsequent services of the user equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is a schematic diagram of describing multiple SSB frequency points on a carrier in the 3GPP protocol in the prior art;

[0041] Figure 2 This is a schematic diagram of multiple SSB frequencies in the frequency domain of a single cell according to an embodiment of the present application;

[0042] Figure 3 This is a schematic diagram of processing interference in a part of the frequency band of a cell according to an embodiment of the present application;

[0043] Figure 4 This is a schematic diagram of MSG1 associated with each SSB frequency point of a single-cell multiple SSB frequency points in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of the connection state measurement and redirection process of an embodiment of the present application;

[0045] Figure 6 This is a schematic diagram of the process of UE selecting SSB frequency access according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] The present application is further described in conjunction with the accompanying drawings and embodiments, and the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.

[0047] When there is signal interference in the frequency domain of the SSB on the cell bandwidth, it will affect the access capability of the entire cell bandwidth and the stability of subsequent traffic services. In order to meet the requirements of the base station's anti-interference capability, multiple cells can be configured in the base station, and each cell has a different SSB frequency. When the SSB frequency interferes, another cell can also be accessed, but this will cause a waste of system resources.

[0048] Therefore, for the design of multiple SSB frequencies in the frequency domain of a single cell, when one SSB frequency in the cell is interfered with, other SSB frequencies can also be accessed normally. At the same time, the cell can subsequently allocate physical channel resources in the corresponding frequency domain according to the SSB frequency accessed by the user equipment, avoid the frequency band that receives interference, and improve the cell's anti-interference ability.

[0049] The embodiment of the present application provides a random access method for multiple SSBs in the frequency domain of a single cell of a 5G base station. Taking the currently most used 5G base station scenario as an example, under the SSB with a subcarrier spacing of 30kHz and a cell bandwidth of 100M with a subcarrier spacing of 30kHz, multiple SSB frequency points can effectively improve the anti-interference capability of the cell. Its main features are as follows:

[0050] Feature 1: A 5GNR (5G New Radio, a global 5G standard based on OFDM's new air interface design) cell can support the configuration of multiple SSB frequencies in the frequency domain. Each SSB has the same PCI but different frequencies, and each is evenly distributed within the 100M bandwidth.

[0051] Feature 2: Each SSB frequency corresponds to a SIB1 (System Information Block 1) message. The frequency domain position of each SIB1 physical channel (PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel)) is also independent. At the same time, the RACH parameters of each SIB1 message are different, which are used to identify the SSB frequency accessed by the UE (User Equipment) in the cell.

[0052] Feature 3: The cell can allocate the corresponding public search space according to the SSB frequency point accessed by the UE. The frequency domain position of the search space overlaps with the frequency domain position of SIB1. The public search space is used to schedule the wireless resources for random access. The corresponding PUSCH (Physical Uplink Shared Channel) and PDSCH RB (resource block) frequency domain positions during the access process are also within the public search space.

[0053] Feature 4: After the UE completes random access, the cell can dynamically allocate PDCCH candidate positions and PDSCH / PUSCH resources corresponding to the access SSB frequency position in the UE-specific search space, or switch the UE to the BWP (bandwidth part) corresponding to the SSB frequency position, based on the SSB frequency point accessed by the UE, when interference is received at other non-access SSB frequency points.

[0054] Feature 5: The serving cell can determine which SSB frequency point has interference based on different SSB random access success rates or the SINR measured and reported after the UE accesses, and thus stop scheduling and sending the SSB with interference. By redirecting, the UE can initiate random access through other SSBs that are not interfered with, while avoiding scheduling uplink and downlink resources in the interfering frequency band.

[0055] See also Figure 5 and Figure 6 , the embodiment of the present application includes the following steps:

[0056] After the user equipment searches for multiple SSB frequency points corresponding to the cell, it obtains SIB1 messages associated with the multiple SSB frequency points respectively; the frequency bandwidth of each cell is divided into multiple SSB frequency points;

[0057] The user equipment initiates random access to any SSB frequency corresponding to the cell according to the RACH parameters of the SIB1 message;

[0058] When an RRC connection is established between a user device and a wireless network (a wireless network generally refers to a base station and a core network, and here it mainly refers to a base station), if the SINR (Signal to Interference plus Noise Ratio) value of the SSB frequency accessed by the user device is less than a preset threshold value, an SSB frequency with a larger SINR value is selected from multiple SSB frequencies through heterodyne measurement, triggering redirection so that the user device accesses the SSB frequency with a larger SINR value.

[0059] Optionally, the frequency domain position of the common search space corresponding to each of the multiple SSB frequency points does not overlap within the cell bandwidth; each of the multiple SSB frequency points has a common physical cell identifier;

[0060] Each of the multiple SSB frequency points is associated with a SIB1 message, the frequency domain position of the physical channel of each SIB1 message is independent of each other, and the RACH parameters of each SIB1 message are different, which are used for the cell to identify the SSB frequency point accessed by the user equipment;

[0061] The NR cell identifier NCGI (NR Cell Global Identifier, cell global identifier) ​​of all SIB1 messages corresponding to the multiple SSB frequency points is the same, and each SIB1 message corresponds to an independent random access RACH resource configuration and common search space configuration.

[0062] Optionally, the RACH resource configuration includes time domain resources and frequency domain resources of MSG1 (a random access request message sent by the UE during network access) sent when the user equipment initiates random access;

[0063] The frequency domain resource is a parameter of the frequency domain starting position of MSG1, which is used to indicate the starting RB position of MSG1; the time domain resource is a RACH time domain resource set index, which corresponds to a RACH time domain resource set, see Figure 4 The frequency domain of MSG1 configured by each RACH resource in each RACH time domain resource set falls within the common search space corresponding to the relevant SSB frequency point as much as possible, and the time domain resources configured by each RACH resource are independent of each other in the time domain and do not overlap with each other.

[0064] Optionally, it also includes:

[0065] The cell allocates a corresponding public search space to the user equipment based on the SSB frequency point accessed by the user equipment; the frequency domain position of the public search space overlaps with the frequency domain position of the SIB1 message, and the public search space is used to schedule the wireless resources for random access. During the access process, the corresponding PUSCH and PDSCH RB frequency domain positions are within the public search space.

[0066] Optionally, the common search space corresponding to each of the SSB frequency points is used for transmission of SIB1 messages and uplink and downlink scheduling of RACH, and the common search spaces are independent of each other in the frequency domain and do not overlap each other;

[0067] After the user equipment successfully accesses the SSB frequency, the frequency domain range of the dedicated search space allocated by the cell to each user equipment is the same, and the user equipment that accesses the same SSB frequency can use the same dedicated resources for scheduling.

[0068] Alternatively, see Figure 3 , also includes:

[0069] When air interface signal interference occurs in the frequency band around the SSB frequency point (such as SSB1 frequency point and SSB2 frequency point) to be accessed by the user equipment, and the user equipment has not established an RRC connection with the wireless network, the user equipment selects an available SSB frequency point for access or residence through the cell selection S criterion or the cell reselection R criterion; wherein the S criterion is the cell selection criterion, and its calculation formula is:

[0070] Srxlev>0AND Squal>0

[0071] Srxlev=Qrxlevmeas–(Qrxlevmin+Qrxlevminoffset)–Pcompensation-Qoffsettemp

[0072] Squal=Qqualmeas–(Qqualmin+Qqualminoffset)-Qoffsettemp

[0073] Among them, Srxlev is the calculation result of the cell received power value, Squal is the calculation result of the cell signal quality value, Qrxlevmeas is the actual received power RSRP (Reference Signal Receiving Power) of the cell measured by the UE, Qrxlevmin is the minimum received power of the cell, Qrxlevminoffset is the minimum received power offset value of the cell, Pcompensation is the additional power compensation supported by the UE, Qoffsettemp is the cell-specific temporary offset value, Qqualmeas is the actual received signal quality RSRQ of the cell measured by the UE, Qqualmin is the minimum received signal quality of the cell, and Qqualminoffset is the minimum received signal quality offset value of the cell.

[0074] The S criterion is a cell selection criterion for cell selection on the UE side. The UE will select the cell only if the RSRP and RSRQ calculated by the cell measurement meet certain thresholds.

[0075] The R criterion is used by the user equipment to reselect a cell in the RRC_IDLE (Radio Resource Control Idle) state, which enables the user equipment to choose to reside in a cell with stronger signal quality. R criterion: Rs = Qmeas,s + Qhyst-Qoffsettemp, Rn = Qmeas,n-Qoffset-Qoffsettemp, where: Qmeas,s is the measured value of the received signal power of the serving cell, i.e. RSRP; Qmeas,n is the measured value of the received signal power of the adjacent cell; Qhyst is the cell reselection delay; Qoffset is the difference in the received signal power requirements of the two cells, and Qoffsettemp is a temporary offset value dedicated to the neighboring cell.

[0076] If the user equipment selects an SSB frequency that is interfered with, and the access success rate of the SSB frequency counted by the cell is lower than a preset value, the SSB frequency will be stopped from being scheduled for a period of time, allowing the user equipment to select an available SSB frequency to initiate access.

[0077] Optionally, it also includes:

[0078] After the cell recognizes that the SSB frequency on part of the bandwidth is interfered with, after the user equipment randomly accesses, the cell identifies the SSB frequency accessed by the user equipment. When other non-access SSB frequency locations are interfered with, the cell allocates a dedicated search space and PDCCH candidate positions and PDSCH / PUSCH resources corresponding to the access SSB frequency location to the user equipment, or switches the user equipment to the bandwidth BWP corresponding to the SSB frequency location.

[0079] Alternatively, see Figure 4, the cell identifies the SSB frequency point accessed by the user equipment, wherein, it includes:

[0080] The cell identifies the SSB frequency point selected by the user equipment for access by determining the frequency domain starting position or PRACH opportunity at which the user equipment sends MSG1; wherein each SSB frequency point is associated with a SIB1 signaling, and the RACH parameters in each SIB1 signaling are different; the different RACH parameters include different time-frequency domain positions of MSG1 for initiating random access; the frequency domain position of MSG1 of the RACH resource corresponding to each SSB frequency point, within the common search space corresponding to the SSB frequency point, the time domain position can be determined according to the 4 PRACH opportunities specified in the 3GPP protocol.

[0081] Optionally, if the SINR value of the SSB frequency point accessed by the user equipment is less than a preset threshold value, selecting an SSB frequency point with a larger SINR value from multiple SSB frequency points through inter-frequency measurement, triggering redirection so that the user equipment accesses the SSB frequency point with a larger SINR value, including:

[0082] For each user equipment accessed by the SSB frequency point, the measurement object of the corresponding SSB frequency point is configured in the measurement configuration to ensure that the user equipment measures the SSB frequency point when accessed; the measurement report carries the SINR information of the user equipment accessing the SSB frequency point, so that the cell can judge the wireless air interface quality of the SSB frequency point, and the measurement report is configured as an event trigger, the event type is A2 event (the SINR value of the SSB frequency point of the serving cell accessed by the user equipment is less than the preset threshold value), and the trigger threshold type is SINR;

[0083] When the user equipment reports an A2 event in which the SINR value is lower than the set threshold, the cell sends an inter-frequency measurement configuration. The inter-frequency measurement object is other SSB frequency points in the cell. The measurement configuration is an A3 event (the neighboring cell is higher than the bias of the main service cell) trigger type or an A4 event (the neighboring cell is higher than the threshold value) trigger type. The measurement parameter type is SINR, so that the base station can obtain an SSB frequency point with a larger SINR value. After the user equipment receives the inter-frequency measurement configuration sent by the cell, it starts to measure the RSRP, RSRQ, and SINR of the SSB frequency point of the cell and configures the A2 event of SINR. The user equipment uses a dedicated search space for scheduling.

[0084] After the user equipment reports an SSB frequency with a larger SINR value through inter-frequency measurement, the redirection process is triggered, that is, the redirection carrier information is carried in the RRC release signaling, which carries an absolute wireless frequency channel number of NR to indicate the SSB frequency so that the user equipment can access.

[0085] Optionally, an interference frequency band identification mechanism is further included; the interference frequency band identification mechanism includes:

[0086] The base station determines the air interface quality environment and interference conditions around multiple SSB frequency points of the cell bandwidth through the access success rate of the user equipment for any SSB frequency point and the reported SINR value.

[0087] For example, Figure 1 Indicates the scenario of multiple SSB frequencies on one carrier in the existing 3GPP protocol standard, which is multiple cells with multiple SSB frequencies: when the UE is in the RRC_CONNECTED (radio resource control connection) state, within the same carrier range, the BWP configured by the UE in the serving cell is likely to overlap with the BWP configured by the UE in other cells in the frequency domain. Under the current protocol design, each cell is associated with at most one SSB frequency. When the UE accesses, it will only select one cell in one of the SSBs for access. Figure 1 In the example, two different cells with RMSI (Remaining Minimum System Information) (the cell with NCGI=5 is associated with SSB1 frequency, and the cell with NCGI=6 is associated with SSB3 frequency) have overlapping BWP positions in the frequency domain. At the same time, the measurement configuration of radio resource management (RRM) allows the UE to perform measurements on each available SSB frequency, namely SSB1 frequency, SSB2 frequency, SSB3 frequency, and SSB4 frequency.

[0088] Figure 2 It indicates that there is only one cell (cell with NCGI=5) with 4 SSB frequencies in the frequency domain of a single cell designed in the embodiment of the present application, and its 100MHz bandwidth has 4 SSB frequencies. Each SSB of the cell can allow the UE to initiate random access individually. The common search space corresponding to each SSB is used for the transmission of SIB1 and the uplink and downlink scheduling during RACH. These common search spaces are independent of each other in the frequency domain and do not overlap. After the UE successfully accesses, the frequency domain range of the UE-specific search space allocated by the serving cell to the UE is the same. UEs accessed through each SSB can be scheduled with the same dedicated resources, maintaining the old multi-UE scheduling design.

[0089] Figure 2 In the calculation of multiple SSB frequency points allocated to a cell: According to the 3GPP Release 15 protocol definition, the frequency point of SSB is the global synchronization channel number (GSCN), which needs to meet the synchronization grid. The frequency point range of SSB is within the cell frequency band bandwidth, and it is required that the frequency domain position of the public search space corresponding to SSB can not overlap within the cell bandwidth.

[0090] The present application designs multiple SSB frequency points in the NR single-cell frequency domain; it has a multiple SSB frequency point identification mechanism, that is, by associating different RACH parameters to identify the SSB selected by the UE; it also has a multiple SSB measurement and redirection mechanism within the cell, that is, the UE's measurement event report triggers its redirection selection of each SSB in the cell; it also has a jamming band identification mechanism, that is, the interfered frequency band is determined by the access success rate of a certain SSB and the measurement report SINR of the UE; it also has an interference band avoidance scheduling strategy, that is, avoiding interference bands in scheduling resources.

[0091] The embodiments of the present application can improve the access success rate in the case of partial interference of the cell bandwidth. Figure 2 As shown, on a 100M bandwidth, a cell can be configured with four SSB frequencies, each SSB is evenly distributed within the 100MHz bandwidth, and the UE can initiate random access through four SSBs respectively. During the initial access, the scheduled bandwidth is the bandwidth of the public search space, which can avoid interference from other locations on the bandwidth. Compared with the usual 5G cell with only one SSB frequency, the access anti-interference situation is greatly improved. At the same time, when the base station scheduling strategy is implemented, avoiding the interfered frequency band can ensure the stability and reliability of the UE's subsequent services.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. A random access method for multiple SSBs in the frequency domain of a single cell of a 5G base station, characterized in that: include: When the user equipment searches for multiple SSB frequency points corresponding to the cell, it obtains SIB1 messages associated with the multiple SSB frequency points respectively; The frequency bandwidth of each cell is divided into multiple SSB frequencies; The user equipment initiates random access to any SSB frequency corresponding to the cell according to the RACH parameters of the SIB1 message; When an RRC connection is established between a user device and a wireless network, if the SINR value of the SSB frequency accessed by the user device is less than a preset threshold value, an SSB frequency with a larger SINR value is selected from multiple SSB frequencies through heterodyne measurement, triggering redirection so that the user device accesses the SSB frequency with a larger SINR value.

2. The random access method of frequency domain multi-SSB of a single cell of a 5G base station according to claim 1, characterized in that: The frequency domain position of the common search space corresponding to each SSB frequency point of the multiple SSB frequency points does not overlap within the cell bandwidth; Each of the multiple SSB frequencies has a common physical cell identifier; Each of the multiple SSB frequency points is associated with a SIB1 message, the frequency domain position of the physical channel of each SIB1 message is independent of each other, and the RACH parameters of each SIB1 message are different, which are used for the cell to identify the SSB frequency point accessed by the user equipment; The NR cell identifier NCGI of all SIB1 messages corresponding to the multiple SSB frequency points is the same, and each SIB1 message corresponds to an independent random access RACH resource configuration and common search space configuration.

3. The random access method of frequency domain multi-SSB of a single cell of a 5G base station according to claim 2 is characterized in that: The RACH resource configuration includes MSG1 time domain resources and frequency domain resources sent when the user equipment initiates random access; Among them, the frequency domain resource is a parameter of the frequency domain starting position of MSG1, which is used to indicate the starting RB position of MSG1; the time domain resource is a RACH time domain resource set index, which corresponds to a RACH time domain resource set. The frequency domain of MSG1 configured by each RACH resource in each RACH time domain resource set falls within the common search space corresponding to the relevant SSB frequency point as much as possible, and the time domain resources configured by each RACH resource are independent of each other in the time domain and do not overlap with each other.

4. The random access method for multiple SSBs in the frequency domain of a single cell of a 5G base station according to any one of claims 1 to 3, characterized in that: Also includes: The cell allocates a corresponding public search space to the user equipment according to the SSB frequency point accessed by the user equipment; The frequency domain position of the common search space overlaps with the frequency domain position of the SIB1 message. The common search space is used to schedule the radio resources for random access. During the access process, the corresponding RB frequency domain positions of PUSCH and PDSCH are within the common search space.

5. The random access method of multiple SSB in frequency domain of a single cell of a 5G base station according to any one of claims 1 to 3, characterized in that: The common search space corresponding to each of the SSB frequency points is used for the transmission of the SIB1 message and the uplink and downlink scheduling of the RACH, and the common search spaces are independent of each other in the frequency domain and do not overlap each other; After the user equipment successfully accesses the SSB frequency, the frequency domain range of the dedicated search space allocated by the cell to each user equipment is the same, and the user equipment that accesses the same SSB frequency can use the same dedicated resources for scheduling.

6. The random access method of frequency domain multi-SSB of a single cell of a 5G base station according to any one of claims 1 to 3, characterized in that: Also includes: When air interface signal interference occurs in the frequency band around the SSB frequency point to be accessed by the user equipment, and the user equipment has not established an RRC connection with the wireless network, the user equipment selects an available SSB frequency point for access or residence according to the cell selection S criterion or the cell reselection R criterion; If the user equipment selects an SSB frequency that is interfered with, and the access success rate of the SSB frequency counted by the cell is lower than a preset value, the SSB frequency will be stopped from being scheduled for a period of time, allowing the user equipment to select an available SSB frequency to initiate access.

7. The random access method for multiple SSBs in the frequency domain of a single cell of a 5G base station according to any one of claims 1 to 3, characterized in that: Also includes: After the cell recognizes that the SSB frequency on part of the bandwidth is interfered with, after the user equipment randomly accesses, the cell identifies the SSB frequency accessed by the user equipment. When other non-access SSB frequency locations are interfered with, the cell allocates a dedicated search space and PDCCH candidate positions and PDSCH / PUSCH resources corresponding to the access SSB frequency location to the user equipment, or switches the user equipment to the bandwidth BWP corresponding to the SSB frequency location.

8. The random access method of frequency domain multi-SSB of a single cell of a 5G base station according to claim 7, characterized in that: The cell identifies the SSB frequency point accessed by the user equipment, and includes: The cell identifies the SSB frequency point selected by the user equipment for access by judging the frequency domain starting position or PRACH opportunity at which the user equipment sends MSG1; wherein each SSB frequency point is associated with a SIB1 signaling, and the RACH parameters in each SIB1 signaling are different; the different RACH parameters include different time-frequency domain positions of MSG1 for initiating random access; the frequency domain position of MSG1 of the RACH resource corresponding to each SSB frequency point, within the common search space corresponding to the SSB frequency point, the time domain position is determined according to the PRACH opportunity.

9. The random access method of frequency domain multi-SSB of a single cell of a 5G base station according to claim 1, characterized in that: If the SINR value of the SSB frequency point accessed by the user equipment is less than the preset threshold value, a SSB frequency point with a larger SINR value is selected from multiple SSB frequency points through inter-frequency measurement, and redirection is triggered to enable the user equipment to access the SSB frequency point with a larger SINR value, including: For each user equipment accessed by the SSB frequency point, the measurement object of the corresponding SSB frequency point is configured in the measurement configuration to ensure that the user equipment measures the SSB frequency point when accessed; the measurement report carries the SINR information of the user equipment accessing the SSB frequency point, so that the cell can judge the wireless air interface quality of the SSB frequency point, and the measurement report is configured as an event trigger, the event type is A2 event, and the trigger threshold type is SINR; When the user equipment reports an A2 event in which the SINR value is lower than the set threshold, the cell sends an inter-frequency measurement configuration, the inter-frequency measurement object is other SSB frequency points in the cell, the measurement configuration is an A3 event trigger type or an A4 event trigger type, and the measurement parameter type is SINR, so that the base station obtains an SSB frequency point with a larger SINR value; after the user equipment receives the inter-frequency measurement configuration sent by the cell, it starts to measure the RSRP, RSRQ, and SINR of the SSB frequency point of the cell, and configures the A2 event of SINR; the user equipment uses a dedicated search space for scheduling; After the user equipment reports an SSB frequency with a larger SINR value through inter-frequency measurement, the redirection process is triggered, that is, the redirection carrier information is carried in the RRC release signaling, which carries an absolute wireless frequency channel number of NR to indicate the SSB frequency so that the user equipment can access.

10. The random access method of frequency domain multi-SSB of a single cell of a 5G base station according to any one of claims 1 to 3, characterized in that: It also includes an interference frequency band identification mechanism; the interference frequency band identification mechanism includes: The base station determines the air interface quality environment and interference conditions around multiple SSB frequency points of the cell bandwidth through the access success rate of the user equipment for any SSB frequency point and the reported SINR value.

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