Base station, terminal and random access preamble detection and random access channel configuration method

Abstract

Provided are a base station, a terminal, and a random access preamble detection and random access channel configuration method. The random access channel time-frequency resource acquisition and determination device in the terminal includes: a downlink measurement module, used to determine the synchronization signal block through the downlink measurement result; a configuration information reading module, used to read the random access channel configuration information from the synchronization signal block; a random access opportunity time-frequency resource determination module, used to determine the time-frequency resource position of the random access opportunity according to the random access channel configuration and binding information; a preamble sequence sending module, which sends the preamble sequence at the random access opportunity, wherein the random access opportunity time-frequency resource determination module determines the time-frequency resource position of the random access opportunity through the random access channel configuration method.

Description

[0001] This application is a divisional application of an invention patent application with an application date of January 11, 2018, application number 201810027605.8, and invention name “Base station, terminal and random access preamble detection, random access channel configuration method”. Technical Field

[0002] The present application relates to a method for configuring a random access channel in the field of wireless communication technology, and in particular to a base station and a random access preamble sequence detection method, a terminal and a random access channel configuration method. Background Art

[0003] With the rapid development of the information industry, especially the growing demand from mobile Internet and Internet of Things (IoT), future mobile communication technology has brought unprecedented challenges. For example, according to the report ITU-R M.[IMT.BEYOND 2020.TRAFFIC] of the International Telecommunication Union, it can be expected that by 2020, the growth of mobile business volume will increase by nearly 1,000 times compared with 2010 (4G era), and the number of user device connections will exceed 17 billion. As a large number of IoT devices gradually penetrate into mobile communication networks, the number of connected devices will be even more amazing. In order to cope with this unprecedented challenge, the communications industry and academia have launched extensive research on the fifth generation mobile communication technology (5G) for the 2020s. At present, the framework and overall goals of the future 5G are being discussed in the ITU report ITU-RM.[IMT.VISION], which provides a detailed description of the demand outlook, application scenarios and various important performance indicators of 5G. In response to new requirements in 5G, the ITU report ITU-R M.[IMT.FUTURE TECHNOLOGY TRENDS] provides information on technology trends for 5G, aiming to address issues such as significant improvement in system throughput, consistency in user experience, scalability to support IoT, latency, energy efficiency, cost, network flexibility, emerging services and flexible spectrum utilization.

[0004] The random access process is an important way for terminals in the system to establish a connection with the base station. In LTE, whether it is a contention-based random access process or not, it is necessary to send a preamble sequence in the Physical Random Access Channel (PRACH). PRACH is configured and notified through PRACH configuration information. Specifically, the PRACH configuration is defined by a lookup table, including the corresponding preamble format of PRACH, as well as available subframes, time domain density, and frequency domain mapping information.

[0005] In LTE, for different frame structures (FDD frequency division duplex or TDD time division duplex), the content of PRACH configuration information is different. For FDD, the PRACH configuration includes the preamble sequence format and the available subframe index; for TDD, the PRACH configuration includes the preamble sequence format, time domain PRACH density and version index. At the same time, for the TDD frame structure, the protocol specifies the PRACH time domain and frequency domain resource mapping method corresponding to each PRACH configuration index and uplink / downlink configuration. The PRACH configuration methods in LTE are all given in the form of a lookup table. The terminal reads the PRACH configuration information from the Master Information Block (MIB) in the physical broadcast channel or the System Information Block (SIB) indicated by the MIB, so as to know the time and frequency resource location of the PRACH.

[0006] The PRACH structure in LTE is relatively simple, and the terminal can directly obtain the time-frequency resource location of PRACH through the PRACH configuration information. In the 5G high-frequency band system, multi-beam operation is required to compensate for the large path loss in the high-frequency band channel through beamforming gain. For the random access process under multi-beam operation, each beam needs to determine the corresponding PRACH configuration (i.e., random access channel configuration). If the PRACH configuration information method in LTE is still used, the required signaling overhead will increase significantly, which will reduce the operating efficiency of the system. Therefore, for the PRACH configuration method in the 5G system (i.e., the random access channel configuration corresponding to the PRACH configuration method in LTE), a new method needs to be adopted to improve the operating efficiency of the system. Summary of the invention

[0007] The problem addressed by the present invention is that the random access channel configuration method similar to the PRACH configuration of LTE in 5G will cause large signaling overhead and is not conducive to improving system efficiency. For possible multi-beam operating systems in 5G, it is necessary to optimize the random access channel configuration method and configuration content similar to the PRACH configuration of LTE, but there is currently no public document or method to solve this problem.

[0008] According to one aspect of the present invention, a random access channel configuration method is provided, comprising the steps of: a terminal determining a preferred synchronization signal block according to a downlink measurement result; the terminal acquiring a random access channel configuration index and preamble sequence resource pool information based on the preferred synchronization signal block; the terminal determining a time-frequency resource position of a corresponding random access opportunity according to a binding relationship between the synchronization signal block and the random access channel resource and / or a read random access channel configuration index; the terminal selecting a preamble sequence from the preamble sequence resource pool; and sending the selected preamble sequence at the determined time-frequency resource position of the random access opportunity, wherein the random access channel configuration index comprises a physical random access channel configuration index, the physical random access channel configuration index comprises: a random access preamble sequence format, random access channel time-frequency resource information, the number of random access opportunities included in the random access channel, the number of random access opportunities included in the random access channel in the time domain, or wherein the physical random access channel configuration index further comprises at least one of the number of synchronization signal blocks bound to the same random access opportunity, the available time unit of the random access opportunity, the number of random access channels in a unit time unit in the time domain, and the number of random access opportunities included in the random access channel in the frequency domain.

[0009] The binding relationship between the synchronization signal block and the random access channel resource includes a one-to-one mapping relationship between the synchronization signal block and the random access opportunity, wherein the main information block on the broadcast signal in the synchronization signal block, or the system information block indicated by the main information block carries the random access channel configuration information, and the random access channel configuration information indicated by different synchronization signal blocks is the same.

[0010] The terminal determines the time-frequency resource position of the corresponding random access opportunity including: when the random access opportunities in the random access channel are arranged continuously in the time domain and the frequency domain, and are mapped and bound based on the time domain priority principle, the number of random access opportunities in the random access channel in the time domain and the frequency domain determined by the terminal according to the random access channel configuration information is M respectively. RO With N RO , the number of random access opportunities in the random access channel is M RO N RO , the number of synchronization channel blocks is N SS =M RO N RO , and the synchronization channel block index selected by the terminal according to the measurement result is n SS , the index range is 0 to N SS -1, the index of the random access opportunity selected by the terminal in the time domain is:

[0011] m RO =mod(n SS , M RO )

[0012] The index of the random access opportunity selected by the terminal in the frequency domain is:

[0013]

[0014] The operation mod(·) represents modulo, and the operation Indicates rounding down.

[0015] The terminal determines the time-frequency resource position of the corresponding random access opportunity by: the terminal determines the preamble sequence format according to the random access channel configuration, and obtains the number of time units occupied by the complete preamble sequence as t msg1 and the random access opportunity bandwidth w expressed in the number of physical resource blocks msg1 , where the time domain starting position of the random access opportunity is t+t msg1 m RO time units, where parameter t is the time-frequency resource location information carried by the random access channel configuration; where the frequency domain starting position of the random access opportunity is the n+Wth msg1 n RO , where n is the time-frequency resource location information carried by the random access channel configuration.

[0016] The terminal determines the time-frequency resource position of the corresponding random access opportunity including: when the random access opportunities in the random access channel are distributed at equal intervals and mapped and bound according to the time domain priority principle, if there is a time unit interval of k between two random access opportunities adjacent to each other in the time domain, then the synchronization signal block n SS The time domain starting position of the bound random access opportunity is t+(t msg1 +k)m RO time units; if the interval between two adjacent random access opportunities in the frequency domain is s physical resource blocks, then the synchronization signal block n SS The frequency domain starting position of the bound random access opportunity is n+(w msg1 +s)n RO physical resource block.

[0017] The terminal determines the time-frequency resource position of the corresponding random access opportunity including: when the random access opportunities in the random access channel are distributed at equal intervals and bound according to the frequency domain priority criterion, if the synchronization channel block index selected by the terminal according to the measurement result is n SS , the index range is 0 to N SS -1, the index of the random access opportunity selected by the terminal in the time domain is:

[0018] m RO =mod(n SS , N RO )

[0019] The index of the random access opportunity selected by the terminal in the frequency domain is:

[0020]

[0021] Among them, N RO is the number of random access opportunities in the frequency domain.

[0022] The indexes of the consecutively arranged random access opportunities in the random access channel meet the criteria of time domain priority or frequency domain priority; or the indexes of the random access opportunities distributed at equal intervals in the random access channel meet the criteria of time domain priority or frequency domain priority. The indexes that meet the criteria of time domain priority are consecutive indexes of random access opportunities on the same frequency domain resources; the indexes that meet the criteria of frequency domain priority are consecutive indexes of random access opportunities on the same time domain resources.

[0023] The terminal determines the time-frequency resource position of the corresponding random access opportunity, including: mapping the random access opportunity onto all available uplink time units.

[0024] The terminal determines the time-frequency resource position of the corresponding random access opportunity by: when a random access opportunity occupies k m When there are k time units, a random access opportunity is mapped to the bound adjacent k m For an uplink time unit, an uplink time unit adjacent to a downlink time unit that cannot be bound with other uplink time units is excluded and no binding and mapping operations are performed.

[0025] The terminal determines the time-frequency resource position of the corresponding random access opportunity by: when a random access opportunity occupies k m When there are k time units, a random access opportunity is mapped to the bound adjacent k m Uplink time unit.

[0026] The terminal determines the time and frequency resource position of the corresponding random access opportunity, including: the terminal also determines the time and frequency position of the random access opportunity according to the available time unit information of the random access opportunity in the random access channel configuration information.

[0027] The terminal determines the time-frequency resource position of the corresponding random access opportunity including: if the available time unit is used up but the mapping of the random access opportunity is still not completed, then use the adjacent frequency band and the same available time unit to map the random access opportunity.

[0028] Random access opportunities in different time units use different frequency resources.

[0029] The binding relationship between the synchronization signal block and the random access channel resources includes a mapping relationship between multiple synchronization signal blocks and a random access opportunity, wherein the main information block on the broadcast signal in the synchronization signal block, or the system information block indicated by the main information block carries the random access channel configuration information, and the random access channel configuration information indicated by different synchronization signal blocks is the same.

[0030] The terminal determines the time-frequency resource position of the corresponding random access opportunity including: if the number of synchronization signal blocks bound to the same random access opportunity is S, and the random access opportunity is allocated based on the time domain priority principle, the index of the synchronization signal block starts from 0, and the number of random access opportunities available in the time domain is M RO , then with synchronization signal block n SS The bound random access opportunity time domain index is calculated as:

[0031]

[0032] With synchronization signal block n Ss The frequency domain index of the bound random access opportunity is calculated as:

[0033]

[0034] After the terminal obtains the time domain or frequency domain index of the random access opportunity in the random access channel, it can obtain the time-frequency position of the random access opportunity.

[0035] The terminal determines the time-frequency resource position of the corresponding random access opportunity including: if the number of synchronization signal blocks bound to the same random access opportunity is S, and the random access opportunity is allocated based on the frequency domain priority principle, the index of the synchronization signal block starts from 0, and the number of random access opportunities available in the frequency domain is N RO , then with synchronization signal block n SS The bound random access opportunity time domain index is calculated as:

[0036]

[0037] With synchronization signal block n Ss The frequency domain index of the bound random access opportunity is calculated as:

[0038]

[0039] After obtaining the time domain or frequency domain index of the random access opportunity in the random access channel, the terminal determines the time-frequency position of the random access opportunity according to the above method.

[0040] The terminal determines the time-frequency resource position of the corresponding random access opportunity, including: the terminal also determines the time-frequency position of the random access opportunity according to the above method based on the number information of synchronization signal blocks bound to the same random access opportunity in the random access channel configuration information.

[0041] Among them, when the random access channel configuration information carried by the main information block on the broadcast signal in each synchronization signal block, or the system information block indicated by the main information block, is the same, the synchronization signal block carries the offset of the random access opportunity time-frequency resource position bound to the synchronization signal block relative to the time-frequency position information provided in the random access channel configuration. Among them, when the random access channel configuration carried by the main information block on the broadcast signal in different synchronization signal blocks, or the system information block indicated by the main information block, is different, the time-frequency resource information in the random access channel configuration directly represents the random access opportunity time-frequency resource position information bound to the synchronization signal block.

[0042] The terminal determines the time-frequency resource position of the corresponding random access opportunity by: if the time-frequency resource information provided in the random access channel configuration information is (t, n), and at the same time, the synchronization signal block n SS The offset information carried in is t SS With n SS , then with synchronization signal block n SS The time domain position of the bound random access opportunity is t+t SS , the frequency domain position is n+n SS .

[0043] According to another aspect of the present invention, a random access preamble sequence detection method for a base station is provided, comprising the steps of: sending a synchronization signal block including a primary synchronization signal, a secondary synchronization signal and a broadcast channel; detecting each random access opportunity in a random access channel; if the sending of a preamble sequence is detected, determining a downlink transmission beam for sending a random access response based on the time-frequency resources of the random access opportunity and / or the detected random access preamble sequence; and sending a random access response using the determined downlink transmission beam, wherein the detected preamble sequence is sent on the time-frequency resources of the random access opportunity determined by the above method of the terminal.

[0044] According to another aspect of the present invention, there is provided a device for acquiring and determining time-frequency resources of a random access channel of a terminal, comprising: a downlink measurement module, used to determine a synchronization signal block through a downlink measurement result; a configuration information reading module, used to read the random access channel configuration information from the synchronization signal block; a random access opportunity time-frequency resource determination module, used to determine the time-frequency resource position of the random access opportunity according to the random access channel configuration and binding information, etc.; a preamble sequence sending module, which sends a preamble sequence at the random access opportunity, wherein the random access opportunity time-frequency resource determination module determines the time-frequency resource position of the random access opportunity through the above method.

[0045] According to another aspect of the present invention, there is provided a preamble sequence detection device of a base station, comprising: a synchronization signal block sending module, which sends a synchronization signal block; a preamble sequence detection module, which detects a preamble sequence in each random access opportunity of a random access channel; a downlink beam determination module, which determines a downlink beam according to the time-frequency resources of the random access opportunity and the preamble sequence; and a random access response sending module, which uses the determined downlink beam to send a random access response, wherein the preamble sequence detected in the preamble sequence detection module is sent by the terminal on the time-frequency resources of the random access opportunity determined by the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and / or other aspects will become apparent and more readily understood through the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0047] Figure 1 A flowchart of a method for determining time-frequency resources of a random access channel by a terminal according to the present invention;

[0048] Figure 2 Schematic diagram of the binding relationship between the synchronization signal block and the random access opportunity according to the first embodiment of the present invention, wherein there is a one-to-one mapping relationship between the synchronization signal block and the random access opportunity;

[0049] Figure 3 A schematic diagram of a method for determining a random access opportunity in a random access channel according to a first embodiment of the present invention;

[0050] Figure 4 A method for determining a random access opportunity sending position in a time division multiplexing frame structure according to the first embodiment of the present invention;

[0051] Figure 5 Another method for determining a random access opportunity sending position in a time division multiplexing frame structure according to the first embodiment of the present invention;

[0052] Figure 6 A method for determining a random access opportunity sending position in a time division multiplexing frame structure according to the first embodiment of the present invention;

[0053] Figure 7 A schematic diagram of a method for determining a random access opportunity time index according to a first embodiment of the present invention;

[0054] Figure 8 A schematic diagram of another method for determining a random access opportunity time index according to the first embodiment of the present invention;

[0055] Fig. 9It is a schematic diagram of binding multiple synchronization signal blocks to the same random access opportunity according to the second embodiment of the present invention, wherein a mapping relationship exists between the multiple synchronization signal blocks and one random access opportunity.

[0056] Fig.10 It is a TDD frame structure;

[0057] Fig.11 A first start time calculation method according to the seventh embodiment of the present invention;

[0058] Fig.12 A start time calculation method when the start symbol index is not 0 according to the seventh embodiment of the present invention;

[0059] Fig.13 A second start time calculation method according to the seventh embodiment of the present invention;

[0060] Fig.14 A second random access channel starting position determination method according to the seventh embodiment of the present invention;

[0061] Fig.15 It is a schematic diagram of a random access preamble sequence detection method at a base station side according to the present invention.

[0062] Fig.16 A random access channel time-frequency resource acquisition and determination device included in a terminal according to the present invention.

[0063] Fig.17 A preamble sequence detection device is included in a base station according to the present invention.

[0064] Fig.18 This is an index configuration method under a certain downlink / uplink configuration according to the present invention. DETAILED DESCRIPTION

[0065] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0066] In view of the random access channel configuration problem under multi-beam operation in 5G, the present invention provides a random access channel configuration method. Specifically, see Figure 1 , Figure 1 The present invention is a flow chart of a method for determining time-frequency resources of a random access channel according to the present invention.

[0067] Figure 1In step S110, the terminal determines the optimal synchronization signal block according to the downlink measurement result. In step S120, the terminal reads the index of the optimal synchronization signal block, and reads the random access channel configuration index and the preamble sequence resource pool information from the master information block (MIB) in the broadcast channel or the system information block (SIB) indicated by the master information block. In step S130, the terminal determines the time-frequency resource position of the corresponding random access channel according to the binding relationship between the synchronization signal block and the random access channel resource predefined or notified in the MIB or SIB and the read random access channel configuration index information. In step S140, the terminal selects a preamble sequence from the preamble sequence resource pool, and sends the selected preamble sequence on the random access channel time-frequency resource determined in step S140.

[0068] Compared with the prior art, the method provided by the present invention can use less signaling to complete the notification of random access channel time-frequency resources, save signaling overhead, and improve the efficiency and performance of system notification.

[0069] First embodiment

[0070] In this embodiment, a notification method for physical random access channel configuration information will be introduced in combination with a specific system. In this embodiment, the system operates in a high frequency band, and adopts multi-beam operation and beamforming to counteract the significant path loss in the high frequency band through beamforming gain. In order to complete the synchronization of multiple downlink beams, the synchronization channel of the system is composed of multiple synchronization signal blocks (Synchronization Signal Block, SS block), and each synchronization signal block is composed of a primary synchronization signal (Primary Synchronization Signal, PSS), a secondary synchronization signal block (Secondary Synchronization Signal, SSS) and a physical broadcast channel. Different synchronization signal blocks are sent using the same or different downlink transmit beams. This embodiment assumes that different synchronization signal blocks use different downlink transmit beams.

[0071] In order to facilitate the base station to determine the optimal transmission beam, a binding relationship is established between the synchronization signal block and the physical random access channel. In this embodiment, it is assumed that the binding relationship is implemented in a pre-set manner, that is, the binding relationship is known to both the base station and the terminal, and the terminal can determine the corresponding random access channel time-frequency resources through the physical random access channel configuration information and the corresponding indication information.

[0072] In this embodiment, the assumption of the random access channel is as follows: the random access channel is composed of multiple random access opportunities, and one random access opportunity is used to transmit a preamble sequence defined by a random access preamble sequence format. At the same time, as a binding relationship between a synchronization signal block and a physical random access channel, a mapping relationship is established between a synchronization signal block and a random access opportunity, such as Figure 2 shown. Figure 2 The figure illustrates the binding relationship between the synchronization signal block and the random access opportunity according to the first embodiment of the present invention, wherein there is a one-to-one mapping relationship between the synchronization signal block and the random access opportunity.

[0073] It should be noted that in the following description of the second embodiment Fig. 9 The situation in which multiple synchronization signal blocks are bound to the same random access opportunity will be described.

[0074] In the first embodiment, Figure 1 As described above, when the terminal attempts to access, it first determines the optimal synchronization signal block according to the downlink measurement result. The measurement result includes the reference signal received power (RSRP) of the PSS and / or the reference signal received power of the SSS. The terminal selects one or more synchronization signal blocks with the best measurement result (for example, the maximum RSRP) and reads the information therein. If multiple synchronization signal blocks are selected, the terminal selects the synchronization signal block with a measurement result higher than a preset threshold. When reading the information in the synchronization signal block, according to the preset rules, for example, the information is read from the synchronization signal block with the largest RSRP, or the information is read from multiple synchronization signal blocks with equal probability. It should be noted that reading information from the synchronization signal block means determining the index of the synchronization signal block from the selected synchronization signal block, reading the master information block (MIB) in its broadcast channel and the corresponding remaining minimum system information (RMSI) indicated by the master information block. Reading information from multiple synchronization signal blocks with equal probability should be understood as selecting a synchronization signal block from multiple synchronization signal blocks with equal probability and reading its information.

[0075] The above-mentioned process and criteria for determining the synchronization signal block, as well as the method for determining the random access channel configuration, are also applicable to the process of random access retry when the random access process fails. Specifically, if the random access process fails, when the terminal performs power ramping and initiates a random access process retry, the random access opportunity time-frequency resources used are determined based on the most recent downlink signal measurement result. If the selection criterion for the downlink signal is to select the synchronization signal block with the largest RSRP, then when initiating a random access retry, the terminal still selects the synchronization signal block with the largest RSRP and selects the random access opportunity bound thereto to retry the random access process; if the selection criterion for the downlink signal is to select a synchronization signal block from multiple synchronization signal blocks that are higher than a preset threshold with equal probability, then when the terminal initiates a random access retry, it first confirms whether the RSRP of the synchronization signal block bound to the current random access opportunity is still above the threshold. If it is above the threshold, the current random access opportunity time-frequency resources are still used to retry the random access process. If it is not above the threshold, multiple synchronization signal blocks that are higher than the preset threshold are selected from the most recent measurement results, one of which is randomly selected with equal probability, the random access timing is determined according to the binding relationship, and the random access process is initiated and retried.

[0076] The terminal reads information from the optimal synchronization signal block determined above, including determining the index of the synchronization signal block through the PSS, SSS, and / or the master information block in the broadcast channel; reading the random access channel configuration information and the random access preamble sequence pool information from the master information block in the broadcast channel or the system information block indicated by the master information block; and reading other information necessary for access.

[0077] The terminal determines the time-frequency resource position of the random access channel according to the read random access channel configuration information and the pre-set binding relationship between the synchronization signal block and the random access channel resource. The terminal selects a preamble sequence from the preamble sequence resource pool and sends the selected preamble sequence at the determined time-frequency resource position of the random access channel.

[0078] Among them, in the terminal determining the time-frequency resource position of the random access channel according to the read random access channel configuration information and the pre-set binding relationship between the synchronization signal block and the random access channel resource, a possible method for determining the time-frequency resource of the random access channel is as follows:

[0079] First, regarding the random access channel configuration information read, the random access channel configuration information includes a physical random access channel configuration index. The content indicated by the physical random access channel configuration index includes the following content: random access preamble sequence format, random access channel time-frequency resource information, the number of random access channels in a unit time unit in the time domain, the number of random access opportunities contained in the random access channel, and the number of random access opportunities contained in the random access channel in the time domain. The random access channel configuration index is given in the form of an index table, and both the base station and the terminal save the index table. The terminal obtains the random access channel configuration through the random access channel configuration index. An example of the above random access channel configuration method can be given by Table 1.

[0080] The random access channel configuration information also includes other information related to the time-frequency resource position of the random access opportunity.

[0081] Table 1: Example of random access channel configuration index table

[0082]

[0083]

[0084] It should be noted that the aforementioned unit time unit can be expressed in absolute time, such as the number of random access channels within 1 millisecond; or in radio frames, subframes or time slots, such as the number of random access channels within a radio frame. The content indicated by the random access channel density in Table 1 has the same meaning as the number of random access channels within the unit time unit. Among them, 0.5 means that there is one random access channel in every two time units, 1 means that there is one random access channel in each time unit, and 2 means that there are 2 random access channels in each time unit. The time-frequency resource information in Table 1 is given in the form of a combination of time index and frequency index, where the time index can be given by an index of unit time, such as a subframe index, a time slot index, or a symbol index; the frequency index can be given as a physical resource block index.

[0085] In the representation of other configuration methods of random access channel configuration information, the time-frequency resources can be separated and represented, for example, the time-frequency resource information in the table is removed, and the time domain index and frequency domain index content are added, where the time domain index is given as an index per unit time, such as a subframe index, a time slot index, or a symbol index; the frequency index can be given as a physical resource block index. In this method, the time domain index can also give a time index available per unit time, for example, a subframe index in which a random access channel may exist within a wireless frame, or a time slot index or symbol index in which a random access channel may exist within a subframe, or a symbol index in which a random access channel may exist within a time slot. In other configuration methods, the time-frequency position information can also be notified separately, without being included in the physical random access channel configuration index.

[0086] In the description of the configuration method of the aforementioned Table 1, the number of random access opportunities and the number of random access opportunities in the time domain are used to determine the distribution of each random access opportunity in the random access channel in the time domain and the frequency domain. In the aforementioned example, by knowing the number of random access opportunities in the random access channel and the number of random access opportunities in the time domain, the distribution of random access opportunities in the random access channel in the time domain and the frequency domain can be inferred. That is, the number of random access opportunities in the frequency domain can be obtained by dividing the number of random access opportunities by the number of random access opportunities in the time domain.

[0087] In other configuration methods of random access channel configuration information, the number of random access opportunities in the time domain and the number of random access opportunities in the frequency domain can be notified to replace the above-mentioned number of random access opportunities and the number of random access opportunities in the time domain; or the number of random access opportunities and the number of random access opportunities in the frequency domain are notified, and the terminal obtains the number of random access opportunities in the time domain by calculation.

[0088] It should be noted that in this embodiment, the random access channel configuration information carried by the master information block on the broadcast signal in each synchronization signal block or the system information block indicated by the master information block is the same. Among them, the time-frequency resource information is the time-frequency resource position of the first random access opportunity of the random access channel. The aforementioned first random access opportunity represents the random access opportunity with the smallest time index and the smallest frequency index.

[0089] In addition, in the configuration of Table 1, the random access channel density, or the number of random access channels per unit time unit, is used to characterize the number of random access channels available per unit time unit in the time domain. Similarly, there may be multiple available random access channels in the frequency domain, which can also be obtained by adding corresponding parameters in the random access channel configuration information.

[0090] After the terminal obtains the random access channel configuration information, it determines the random access opportunity time-frequency position corresponding to the synchronization signal block selected by the terminal based on the binding relationship between the aforementioned synchronization signal block and the random access channel, wherein the binding relationship is implemented through a predetermined criterion.

[0091] One possible binding relationship is that there is a one-to-one mapping relationship between the synchronization signal block and the random access opportunity (such as Figure 2As shown in FIG. 1 , that is, different synchronization signal blocks are bound to different random access opportunity time-frequency resources. The predetermined criterion is to number and index the random access opportunities in the random access channel according to the time domain priority (or frequency domain priority) criterion; the criterion also includes the interval between the random access opportunities adjacent to the time domain and the frequency domain. Among them, the time domain priority criterion is to number the time domain resources first and then the frequency domain resources when numbering; the frequency domain priority criterion is to number the frequency domain resources first and then the time domain resources when numbering.

[0092] Figure 3 FIG. 1 is a schematic diagram of a method for determining a random access opportunity in a random access channel according to the first embodiment of the present invention.

[0093] Specifically, the description of determining the time-frequency position of the random access opportunity corresponding to the synchronization signal block selected by the terminal is as follows.

[0094] Case 1:

[0095] Pre-setting: random access opportunities in the random access channel are arranged continuously in both the time domain and the frequency domain, and are mapped and bound based on the principle of time domain priority. This example is suitable for the structure of frequency division multiplexing, that is, the situation where the uplink frame structure is continuous.

[0096] The terminal receives the random access channel configuration information and determines the time-frequency resource position of the random access channel (i.e., the time-frequency resource position of the first random access opportunity in the random access channel) according to the information. The number of random access opportunities in the random access channel determined by the terminal according to the random access channel configuration information in the time domain and in the frequency domain is M respectively. RO With N RO , the number of random access opportunities in the random access channel is M RO N RO Considering the one-to-one binding relationship between synchronization channel blocks and random access opportunities, the number of synchronization channel blocks is N SS =M RO N RO .

[0097] The synchronization channel block index selected by the terminal according to the measurement result is n SS (The index range is 0 to N SS -1), the index of the random access opportunity selected by the terminal in the time domain is:

[0098] m RO =mod(n SS , M RO )

[0099] The index of the random access opportunity selected by the terminal in the frequency domain is:

[0100]

[0101] Among them, the operation mod() represents modulus, and the operation The above rule indicates that the synchronization signal block index obtained by the terminal according to the measurement result is n SS , then the random access opportunity bound to it is the mth in the time domain RO The nth RO random access opportunity. That is, the synchronization signal block index n SS The time domain index of the bound random access opportunity is m RO , synchronization signal block index n SS The frequency domain index of the bound random access opportunity is n RO .

[0102] The terminal determines the preamble format according to the random access channel configuration, and obtains the number of time units occupied by the complete preamble sequence as t msg1 and the random access opportunity bandwidth w expressed in the number of physical resource blocks msg1 After obtaining this information, combined with the index of the random access opportunity in the time domain and frequency domain, the time-frequency resource position of the random access opportunity can be calculated. Specifically, the time domain starting position of the random access opportunity is the t+t msg1 m RO time units, where parameter t is the time-frequency resource location information carried by the random access channel configuration; the frequency domain starting position of the random access opportunity is the n+wth msg1 n RO , where n is the time-frequency resource location information carried by the random access channel configuration.

[0103] Case 2:

[0104] Pre-setting: The random access opportunities in the random access channel are distributed at equal intervals. At the same time, they are mapped and bound based on the principle of time domain priority.

[0105] For example, if there is a time interval of k units between two random access opportunities that are adjacent in the time domain, then the synchronization signal block n SS The time domain starting position of the bound random access opportunity is t+(t msg1 +k)m RO time unit.

[0106] If there are s physical resource blocks between two adjacent random access opportunities in the frequency domain, then the synchronization signal block n SS The frequency domain starting position of the bound random access opportunity is n+(w msg1 +s)n RO physical resource block.

[0107] It should be noted that the above description is also applicable to the method of binding based on the frequency domain priority criterion. Specifically, if the synchronization channel block index selected by the terminal according to the measurement result is n SS (The index range is 0 to N SS -1), the index of the random access opportunity selected by the terminal in the time domain is:

[0108] m RO =mod(n SS , N RO )

[0109] The index of the random access opportunity selected by the terminal in the frequency domain is:

[0110]

[0111] Among them, N RO is the number of random access opportunities in the frequency domain.

[0112] The example of Case 1 above is more suitable for determining the time-frequency position of the random access opportunity corresponding to the synchronization signal block selected by the terminal in a frequency division multiplexing structure (ie, a case where the uplink frame structure is continuous).

[0113] For determining the time-frequency position of the random access opportunity corresponding to the synchronization signal block selected by the terminal in the time division multiplexing structure (i.e., the case where the uplink frame structure is discontinuous), the above example description may be modified. Figure 4 , 5 , 6 for explanation.

[0114] For the time division multiplexing frame structure, the synchronization signal block index n is still calculated according to the above process. SS The time domain index m of the bound random access opportunity RO With frequency domain index n RO The terminal receives the preamble format information contained in the random access configuration, or the number of time units k required for the complete preamble and the bandwidth s measured in physical resource blocks.

[0115] To determine the time index of the random access opportunity under the time division multiplexing frame structure, the index of the starting time unit in the available uplink time unit is calculated according to the above process, and the sending time position of the random access opportunity is determined according to the current uplink / downlink configuration.

[0116] Figure 4 This is a method for determining a random access opportunity transmission position in a time division multiplexing frame structure according to the first embodiment of the present invention.

[0117] Figure 4 In the time division multiplexing frame structure, downlink subframes, uplink subframes and special subframes are formed. Among them, the special subframe is used for the conversion from downlink transmission to uplink transmission. Figure 4 In the example, it is assumed that one random access opportunity occupies one subframe and is only mapped onto all available uplink subframes.

[0118] Figure 5 Another method for determining a random access opportunity sending position in a time division multiplexing frame structure according to the first embodiment of the present invention; Figure 6 This is another method for determining a random access opportunity sending position in a time division multiplexing frame structure according to the first embodiment of the present invention.

[0119] exist Figure 5 , 6 In the example shown, one random access opportunity may occupy multiple time units.

[0120] Figure 5 The processing method is as follows: If a random access opportunity occupies k m time units, then the adjacent k m Uplink time units are bound and mapped, and uplink time units adjacent to downlink time units that cannot be bound with other uplink time units are excluded and not bound and mapped.

[0121] Figure 5 In the example shown, one random access opportunity needs to occupy two subframes. Among all available uplink subframes, two temporally adjacent subframes are bundled and paired to transmit one random access opportunity. For subframe 4 and subframe 9 (index range is 0 to 9), since their adjacent subframes are downlink subframes, they cannot be paired and are therefore not used for the transmission of random access opportunities.

[0122] It should be noted that Figure 4 and Figure 5 In the example shown, the time units are all subframes. In other possible embodiments, the time units may be time slots or symbols.

[0123] Figure 6 The processing method is as follows: If a random access opportunity occupies k m time units, then the adjacent k m The difference from the above method is that this method only considers the uplink time unit and does not consider the downlink time unit, which has higher resource utilization efficiency, but there is a risk that the leading sequence is interrupted by the downlink time unit.

[0124] Figure 6 In the example shown, each random access opportunity requires two subframes, so every two uplink subframes are used for transmission of one random access opportunity. Figure 6 In the embodiment, the second random access opportunity is mapped to two subframes separated in time for transmission.

[0125] It should be noted that Figure 6 In the example, the time unit used is a subframe. In other methods, the time unit that can be used includes a time slot, a symbol, etc.

[0126] The above methods describe the methods applicable to frequency division multiplexing ( Figure 3 ) and time division multiplexing ( Figure 4 , 5 , 6) A method for determining time-frequency resources for random access timing.

[0127] Another method for determining the random access opportunity time index is to add the time unit index available for random access opportunities in the random access channel to the random access channel configuration index table. This method is applicable to both frequency division multiplexing and time division multiplexing frame structures.

[0128] Figure 7 A schematic diagram of a method for determining a random access opportunity time index according to a first embodiment of the present invention; Figure 8 It is a schematic diagram of another method for determining a random access opportunity time index according to the first embodiment of the present invention.

[0129] For example, in the random access channel configuration index, the available time unit index of the random access opportunity is added. A possible representation method is shown in Table 2.

[0130] Table 2: Another example of random access channel configuration index table

[0131]

[0132] In Table 2, a parameter for characterizing the available time unit of random access opportunities is added. The available number of random access opportunities in the time domain is directly obtained from the available time unit of random access opportunities. In the above table, the time unit offset relative to the first random access opportunity in the random access channel is used as the characterization of the available time unit. For example, the available time unit of random access opportunity in index 0 is (1, 2, 3, 5), which means that relative to the first random access opportunity of the random access channel, the available time unit of the random access opportunity is the 1st, 2nd, 3rd, and 5th time unit. Figure 7 shown.

[0133] In the above example, the first time unit is the time unit position indicated in the random access channel configuration information. The available time units for random access opportunities in the index table are calculated starting from the first time unit, and the index starting number, that is, the index of the first time unit is 1. In another possible manner, the first time unit index may start from 0.

[0134] In the above method, the available time unit is a relative value, that is, a time unit index relative to the first time unit of the random access channel. In other possible ways, the time unit absolute value can also be represented, for example, using a possible subframe, time slot or symbol index as the time index of the available random access opportunity.

[0135] After receiving the random access channel configuration information, the terminal calculates the random access opportunity time-frequency index bound to the selected synchronization signal block index, and then needs to determine the time position of the random access opportunity. The terminal determines the time and frequency position of the random access opportunity based on the available time unit information of the random access opportunity in the random access channel configuration information and the pre-set mapping rules.

[0136] A possible pre-set rule is to map random access opportunities according to the time priority principle. If the available time unit is used up, but the random access opportunity mapping is still not completed, the adjacent frequency band and the same available time unit are used to map the random access opportunity. A simple example is Figure 8 shown.

[0137] Figure 8 In the example, there are 8 random access opportunities that need to be mapped, and the available random access opportunity time units are subframes 1, 2, 3, and 5. The mapping method is as follows: Figure 8 As shown. The random access opportunity with index 0 is mapped to subframe 1 of a frequency band, the random access opportunity with index 1 is mapped to subframe 2 of the frequency band, the random access opportunity with index 2 is mapped to subframe 3 of the frequency band, the random access opportunity with index 3 is mapped to subframe 5 of the frequency band, the random access opportunity with index 4 is mapped to subframe 1 of the next adjacent frequency band, the random access opportunity with index 5 is mapped to subframe 2 of the next adjacent frequency band, the random access opportunity with index 6 is mapped to subframe 3 of the next adjacent frequency band, and the random access opportunity with index 7 is mapped to subframe 5 of the next adjacent frequency band.

[0138] It should be noted that the available time unit for random access opportunity in the above manner should be understood as the first time unit index of the random access opportunity. In the actual preamble sequence format adopted, a single complete preamble sequence may occupy multiple time units. The time unit may be a subframe, a time slot, a mini time slot, or a symbol.

[0139] In the above description, the frequency domain mapping adopts a continuous mapping method.

[0140] In other possible ways, frequency domain mapping can be performed by frequency hopping. For example, the physical resource block index n of the wth available frequency band is specified. w for:

[0141]

[0142] Among them, N UL The number of physical resource blocks included in the allocated uplink bandwidth. The uplink bandwidth can be the entire available uplink bandwidth or the available bandwidth specifically used to transmit the random access channel.

[0143] It should be noted that the meanings of the density and the number of available random access channels in the frequency domain in the random access channel configuration information are as follows.

[0144] The terminal determines multiple random access channels in the time domain (each random access channel contains multiple random access opportunities) based on the time-frequency resource information and density in the random access channel configuration information, that is, one synchronization channel block binds multiple random access opportunities in different random access channels. The terminal selects a random access opportunity from them to send the preamble sequence according to a predetermined criterion. One possible criterion is to select the random access opportunity with the smallest delay to send the preamble sequence; another possible criterion is to select a random access opportunity with equal probability for transmission in the current wireless frame, or subframe, or time slot.

[0145] The terminal determines multiple random access channels in the frequency domain (each random access channel includes multiple random access opportunities) according to the time-frequency resource information in the random access channel configuration information and the number of available random access channels in the frequency domain, that is, one synchronization channel block is bound to multiple random access opportunities in different random access channels. The terminal selects a random access opportunity from them to send a preamble sequence according to a predetermined criterion. In one possible criterion, the terminal selects a random access opportunity with equal probability to send a preamble sequence.

[0146] Second embodiment

[0147] In this embodiment, a notification method for physical random access channel configuration information will be introduced in combination with a specific system. The assumptions of this embodiment are the same as those of the first embodiment. That is, it is assumed that different synchronization signal blocks use different downlink transmission beams; it is assumed that the binding relationship is implemented in a pre-set manner, that is, the binding relationship is known to both the base station and the terminal; it is assumed that the random access channel consists of multiple random access opportunities, and one random access opportunity is used to transmit a leading sequence defined by a random access leading sequence format.

[0148] In the first embodiment ( Figure 2-8 ), which stipulates that there is a one-to-one binding and corresponding relationship between the synchronization signal block and the random access opportunity. In this embodiment, multiple synchronization signal blocks can be mapped to multiple identical or different random access opportunities. For the case where multiple synchronization signal blocks are bound to the same random access opportunity, the binding method example at this time can be as follows Fig. 9 shown. Fig. 9A schematic diagram of binding multiple synchronization signal blocks to a same random access opportunity according to a second embodiment of the present invention, wherein a mapping relationship exists between the multiple synchronization signal blocks and a random access opportunity

[0149] Fig. 9 In the scheme, every two synchronization signal blocks are bound to one random access opportunity.

[0150] In this embodiment, the terminal obtains the random access channel configuration in a manner similar to that of the first embodiment. The terminal first obtains the optimal synchronization signal block according to the downlink measurement result; the terminal reads the index of the synchronization signal block, as well as the random access channel configuration information and the preamble sequence resource pool information carried therein; the terminal selects a preamble sequence from the preamble sequence resource pool, and determines the time-frequency resource position of the random access opportunity according to the binding relationship between the random access channel configuration information, the synchronization signal block, and the random access opportunity.

[0151] In this embodiment, the random access channel configuration information transmitted in each synchronization signal block is the same, that is, the master information block in the broadcast channel and the system information block indicated by the master information block both transmit the same content.

[0152] If the binding relationship between the synchronization signal block and the random access opportunity is determined in a predetermined manner, the number of synchronization signal blocks bound to the same random access opportunity is specified as S, and the random access opportunity is allocated based on the time domain priority principle. If the index of the synchronization signal block starts from 0, and the number of random access opportunities available in the time domain is M RO , then with synchronization signal block n SS The bound random access opportunity time domain index is calculated as:

[0153]

[0154] With synchronization signal block n SS The frequency domain index of the bound random access opportunity is calculated as:

[0155]

[0156] In another method of determining random access opportunities, random access opportunities are allocated based on the frequency domain priority criterion. If the index of the synchronization signal block starts from 0 and the number of random access opportunities available in the frequency domain is N RO , then with synchronization signal block n SS The bound random access opportunity time domain index is calculated as:

[0157]

[0158] With synchronization signal block n SS The frequency domain index of the bound random access opportunity is calculated as:

[0159]

[0160] After the terminal obtains the index of the random access opportunity in the random access channel, it can obtain the time-frequency position of the random access opportunity. The specific method can refer to the method provided in the first embodiment.

[0161] If the binding relationship between the synchronization signal block and the random access opportunity is determined by configuration, the number of synchronization signal blocks bound to the same random access opportunity is added to the random access channel configuration information. The random access channel configuration index table using this method is shown in Table 3.

[0162] Table 3: Another example of random access channel configuration index table

[0163]

[0164] In the example shown in Table 3, the parameter of the number of synchronization signal blocks is added. This parameter should be understood as the number of synchronization signal blocks bound to the same random access opportunity.

[0165] In this case, the terminal can obtain the parameters for determining the time-frequency resources of the random access opportunity according to the random access channel configuration, and obtain the time-frequency position of the random access opportunity according to the above process.

[0166] Third embodiment

[0167] In this embodiment, a notification method for physical random access channel configuration information will be introduced in combination with a specific system. The assumptions of this embodiment are the same as those of the first embodiment. That is: it is assumed that different synchronization signal blocks use different downlink transmission beams; it is assumed that the binding relationship is implemented in a pre-set manner, that is, the binding relationship is known to both the base station and the terminal; it is assumed that the random access channel consists of multiple random access opportunities, and a random access opportunity is used to transmit a leading sequence defined in a random access leading sequence format; it is assumed that, as a binding relationship between a synchronization signal block and a physical random access channel, a mapping relationship is established between a synchronization signal block and a random access opportunity.

[0168] In this embodiment, the terminal obtains the random access channel configuration in a manner similar to that in the first embodiment. The terminal first obtains the optimal synchronization signal block according to the downlink measurement result; the terminal reads the index n of the synchronization signal block. SS , and the random access channel configuration information and preamble sequence resource pool information carried therein; the terminal selects a preamble sequence from the preamble sequence resource pool, and determines the time-frequency resource position of the random access opportunity according to the binding relationship between the random access channel configuration information, the synchronization signal block and the random access opportunity.

[0169] In this embodiment, the information transmitted in each synchronization signal block may be different. In the first implementation of this embodiment, the information provided by the random access channel configuration information includes the random access preamble sequence format supported by the random access channel configuration, the random access channel time-frequency resource information, and the like. The random access channel configuration information is the same in all synchronization signal blocks. That is, the same system uses the same random access channel configuration information.

[0170] In addition to the random access channel configuration information, the synchronization signal block carries the offset of the random access opportunity time-frequency resource position bound to the synchronization signal block relative to the time-frequency position information provided in the random access channel configuration. Specifically, the offset of the time-frequency resource position can be represented by the number of time units and the number of physical resource blocks. For example, the synchronization signal block n SS The information carried in the random access channel includes: random access channel configuration information, random access preamble sequence resource pool information, and synchronization signal block n SS The time-frequency offset of the bound random access opportunity is carried by a master information block in a broadcast channel or a system information block indicated by the master information block.

[0171] A simple example is as follows: if the time-frequency resource information provided in the random access channel configuration information is (t, n), and the synchronization signal block n SS The offset information carried in is t SS With n SS , then with synchronization signal block n SS The time domain position of the bound random access opportunity is t+t SS , the frequency domain position is n+n SS It should be noted that the time domain position of the random access opportunity should be understood as the time unit index of the first time unit of the random access opportunity; the frequency domain position should be understood as the physical resource block index.

[0172] The terminal reads the random access channel configuration information and the corresponding offset information from the synchronization signal block, determines the time-frequency resource position of the random access opportunity bound to the synchronization signal block, selects a preamble sequence from the preamble sequence resource pool read from the synchronization signal block, generates a preamble sequence according to the preamble sequence format in the random access channel configuration information, and transmits it in the corresponding random access opportunity.

[0173] In a second implementation scenario of this embodiment, the random access channel configurations carried in different synchronization signal blocks are different, and the time-frequency resource information in the random access channel configuration directly represents the time-frequency resource position information of the random access opportunity bound to the synchronization signal block.

[0174] After the terminal reads the random access channel configuration, it can directly obtain the random access opportunity time-frequency resource position information bound to the synchronization signal block, and send a preamble sequence on the time-frequency resource.

[0175] In this case, the content in the random access channel configuration information should at least include the random access preamble sequence format, random access opportunity time-frequency position information, and random access opportunity density.

[0176] It should be noted that the above random access channel configurations are all given in the form of a lookup table, and only the index of the corresponding configuration is notified during notification. Another notification method is to directly notify the content of the random access channel configuration in a signaling manner.

[0177] Fourth embodiment

[0178] In this embodiment, a notification method of physical random access channel configuration information will be introduced in combination with a specific system. In this embodiment, it is assumed that the random access channel configuration information is transmitted on the remaining minimum system information (RMSI), and the RMSI content on different downlink signals (corresponding to different downlink beams) is the same.

[0179] In the foregoing embodiment, it is briefly described that the binding relationship between the downlink signal (such as the downlink synchronization block) and the random access opportunity is configured in a pre-set manner. This embodiment uses a display notification method to notify the relevant binding relationship. At the same time, the binding relationship can be used as part of the random access channel configuration (for example, adding a new field to indicate the binding relationship between the downlink signal index and the random access opportunity), or as an independent signaling, and notified together with the random access channel configuration information. There is no essential difference between the above two notification methods. In this embodiment, the first method, that is, the method of carrying the binding relationship indication in the random access channel configuration information, will be used for explanation.

[0180] In this embodiment, the random access opportunity information bound to each synchronization signal block is displayed and notified. The random access opportunity information is a resource index of the random access opportunity, which is configured in a predefined manner or determined according to a predetermined criterion. The random access opportunity information may also include a subframe index and a PRB index of the random access opportunity, through which the time-frequency resources of the available random access opportunity can be determined.

[0181] A possible display notification method is to establish a lookup table as shown in Table 4, and obtain corresponding random access timing information through a downlink signal index (such as a synchronization signal block index or a possible CSI-RS index).

[0182] Table 4: Relationship between downlink signal index and random access opportunity information

[0183] Downlink signal index Random access timing information 0 Information 0 1 Information 1 2 Information 2 ... ...

[0184] The above table can be notified in the form of a binary, that is, the notification form is (n SS , n PRACH ), where n SS is the downlink signal index, n PRACH In another notification method, the random access opportunity information sequence is directly notified, the number of elements in the sequence is the same as the number of synchronization signal blocks, and each element represents the time-frequency resource information of the random access opportunity corresponding to the corresponding synchronization signal block.

[0185] Another possible notification method is to use a bit-map method to notify. For each random access channel configuration, the number of random access opportunities is fixed. When notifying the binding relationship between the synchronization signal block and the random access opportunity, each synchronization signal block establishes a 0, 1 bit sequence with a length equal to the number of random access opportunities, where each element indicates whether the synchronization signal block corresponds to the corresponding random access opportunity. If the element is 1, it indicates that the random access opportunity of the corresponding index is bound to the synchronization signal block, otherwise it is bound. For example, for a certain random access channel configuration information, the number of available random access opportunities is M, then for each synchronization signal block, the length of the bit sequence used to configure and notify the corresponding random access opportunity is M, which contains M-1 0s and 1 1, and the position of the 1 represents the index of the random access opportunity. When configuring and notifying the binding relationship in this way, each synchronization signal block needs to establish a bit sequence of length M, and the total overhead is proportional to the product of the number of synchronization signal blocks N and the number of random access opportunities M.

[0186] When a bit map is used, another method is to establish a 0 and 1 bit sequence with a length equal to the number of synchronization signal blocks for each random access opportunity, wherein the elements represent whether the synchronization signal block with the corresponding index is bound to the random access opportunity. If it is 1, it indicates that the synchronization signal block with the corresponding index at this position is bound to the random access opportunity, otherwise it is bound. For example, for a system containing N synchronization signal blocks, a bit sequence with a length of N is established for each random access opportunity, wherein 0 and 1 indicate whether the synchronization signal block at the corresponding position is bound to the random access opportunity. For example, a bit sequence with a length of 8 [0 1 100 0 0 0] indicates that there are 8 synchronization signal blocks in total, and the elements at positions 1 and 2 in the bit sequence are 1, indicating that the synchronization signal blocks with synchronization signal block indexes 1 and 2 are bound to the random access opportunity. When notifying using this bit map method, a bit sequence with a length of N needs to be established for each random access opportunity, so the total overhead is proportional to the product of the number of synchronization signal blocks N and the number of random access opportunities M.

[0187] Another method of notifying the binding relationship between the downlink signal index and the random access opportunity by using a bit map is to directly notify the time domain and frequency domain resource index of the random access opportunity bound to the downlink signal by using a bit map. For example, the symbol index starting with the random access opportunity bound to the downlink signal in the subframe is indicated by a bit map method; at the same time, the index of the starting PRB of the random access opportunity is indicated by a bit map method. For a subframe structure containing 7 or 14 symbols, for each downlink signal (such as a synchronization signal block or CSI-RS), a bit sequence of length 7 or 14 is established, wherein the value of each bit represents whether the symbol at the corresponding position is the starting symbol of the random access opportunity bound to the downlink signal. If the bit is 1, it is the starting symbol of the random access opportunity, otherwise it is not. At the same time, a bit sequence of length equal to the number of PRBs available for random access is established, wherein the element indicates whether the symbol at the corresponding position is the starting PRB of the random access opportunity bound to the downlink signal. If it is 1, the PRB at the corresponding position is the starting PRB, otherwise it is not.

[0188] In another configuration method, the time domain index is notified and configured in a bit map manner, and the frequency domain index directly notifies the PRB index.

[0189] After adding the notification of the aforementioned binding relationship, the format of the random access channel configuration information is:

[0190] {Preamble sequence format, random access channel time-frequency resource information, synchronization signal block and random access opportunity binding relationship}

[0191] The above-mentioned format is numbered by an index and sent to the terminal in the form of a number. When the binding relationship between the synchronization signal block and the random access opportunity is notified by the random access channel configuration index, there will be many possible indexes. Another notification method is that the random access channel configuration only notifies the preamble sequence format and the random access channel time-frequency resource information, and the binding relationship between the synchronization signal block and the random access opportunity is notified separately outside the random access channel configuration index. This notification method can more flexibly establish the binding relationship between the synchronization signal block and the random access opportunity. It should be noted that the aforementioned random access channel time-frequency resource information includes the implementation method of the random access channel time-frequency resource information in the aforementioned embodiment.

[0192] Fifth embodiment

[0193] In this embodiment, a notification method for physical random access channel configuration information will be introduced. In this embodiment, it is assumed that the base station adopts multi-beam or single-beam operation. For multi-beam operation, multiple synchronization signal blocks are used to send downlink synchronization signals and broadcast channels. Among them, each synchronization signal block is sent using a downlink transmission beam, and the downlink transmission beams used by different synchronization signal blocks can be the same or different. For single-beam operation, a synchronization signal block or a periodic repetition of a synchronization signal block is used to complete the transmission of the downlink synchronization signal and the broadcast channel. Each synchronization signal block includes a primary synchronization signal, a secondary synchronization signal, and a broadcast channel carrying a main information block. Other necessary information for the access system is transmitted in the remaining minimum system information (RMSI). The content of the RMSI indicated and transmitted by different synchronization signal blocks is the same.

[0194] The method provided in this embodiment is applicable to the base stations using single beam operation and multi-beam operation, providing a certain flexibility for the system without introducing obvious redundant signaling. The basic idea of ​​the solution provided in this embodiment is to adjust the random access channel configuration information sent according to the number of synchronization signal blocks actually transmitted, so that the method provided in this embodiment can be applicable to both the system using single beam operation and the multi-beam operation system in which the number of synchronization signal blocks actually transmitted varies.

[0195] A possible implementation is that the physical random access channel configuration information is not notified by an index of a lookup table, but directly notifies possible configurations. At the same time, the random access channel configuration information of different synchronization signal blocks may be different and notified by enumeration. The random access channel configuration information of each synchronization signal block includes:

[0196] -Random access preamble sequence format information;

[0197] -Random access opportunity time domain index;

[0198] -Random access opportunity time domain density / period;

[0199] - Random access opportunity frequency domain index;

[0200] -Number of random access opportunities in frequency domain.

[0201] The meaning of each parameter in the above random access channel configuration information is: the preamble sequence format determines the subcarrier spacing of the random access channel, the number of sequence repetitions or sequences of the preamble sequence used, and the cyclic prefix length. Based on this information, the terminal can know the time domain duration and frequency domain bandwidth of the random access opportunity.

[0202] The random access time domain index can be notified by the time unit index starting from the random access opportunity, such as the subframe index starting from the random access opportunity, or the time slot index, or the mini-time slot index, or the symbol index. The random access opportunity time domain density / period specifies the frequency domain in which the random access opportunity bound to the synchronization signal block appears in the time domain. This parameter can be configured as follows: the number of random access opportunities appearing in a time unit set, or the number of time units between two adjacent random access opportunities bound to the synchronization signal block. Among them, the time unit set is a set of multiple continuous time units. For example, if the time unit is a symbol, the time unit set is a time slot or a mini-time slot; if the time unit is a time slot or a mini-time slot, the time unit is a subframe; if the time unit is a subframe, the time unit is a radio frame.

[0203] The frequency domain index of the random access opportunity can be notified by the random access opportunity starting physical resource block index. The frequency domain number of random access opportunities is used to notify the number of random access opportunities in the frequency band used for uplink random access. This parameter can be replaced by the number of physical resource blocks between two adjacent random access opportunities in the frequency domain.

[0204] The above series of parameters can determine the structure and time-frequency resource position of the random access opportunity bound to the synchronization signal block. After the terminal learns the above parameters, it can fully learn the time-frequency resource position of the random access opportunity.

[0205] The parameters for determining the random access opportunity time-frequency resources mentioned above may be replaced by the following other parameters: the time domain parameters (including the random access opportunity time domain index and the random access opportunity density / period) may be replaced by the available time units in the time unit set. For example, if the time unit is a subframe, the available subframe index in the unit radio frame is notified; if the time unit is a time slot / mini time slot, the available time slot or mini time slot in the unit subframe is notified; if the time unit is a symbol, the available symbol in the unit time slot is notified. There are one or more available time units in the time unit set, which are indicated by vectors or sequences.

[0206] The frequency domain parameters (including the frequency domain index of the random access opportunity and the number of random access opportunities in the frequency domain) can be determined in the following manner. One manner is to notify the first physical resource block index of the available random access opportunity, and notify and configure it in the form of an index sequence. Or notify the number of physical resource blocks between two adjacent random access opportunities, etc. Another manner is to determine the frequency domain resources according to a predetermined rule. For example, it is pre-specified that resource mapping is prioritized in the time domain, and the number of physical resource blocks between two adjacent random access opportunities in the frequency domain is specified or notified, and the number of available random access opportunities in the time unit set and the available time unit index in the time unit set are notified. After receiving the above information, the terminal first maps in the time domain according to the given frequency domain index. If the number of available time unit indexes is less than the number of random access opportunities, after the indexing of the time domain unit is completed, the next available frequency domain position is determined according to the available frequency domain index or the frequency domain physical resource block interval of the adjacent random access opportunity, and the time domain mapping is performed at the frequency domain position until the time-frequency resource positions can be determined for all random access opportunities.

[0207] The above parameters need to be configured and notified for each synchronization signal block. The random access channel configuration information includes the following parameters:

[0208] - Sync signal block index;

[0209] -Preamble format;

[0210] - Information related to random access opportunity time and frequency resources.

[0211] The random access opportunity time-frequency resource related information includes the parameters for determining the random access opportunity time-frequency resource. The random access access channel configuration information can be notified in the following manner:

[0212] The number of synchronization signal blocks N;

[0213] {synchronization signal block index 0, preamble sequence format, random access opportunity time-frequency resource information};

[0214] {synchronization signal block index 1, preamble sequence format, random access opportunity time-frequency resource information};

[0215] {Synchronization signal block index N-1, preamble sequence format, random access opportunity time-frequency resource information}.

[0216] That is, the configuration information of the random access opportunities corresponding to the N synchronization signal blocks is notified in the form of enumeration. In addition, the number of synchronization signal blocks N is the number of synchronization signal blocks actually transmitted, which can be transmitted separately or in the main information block.

[0217] When there are many synchronization signal blocks, the above configuration and notification method require a large overhead. An effective way to reduce the overhead is to propose the common part. If the random access opportunities corresponding to different synchronization signal blocks use the same preamble sequence format, the notification can be performed in the following way:

[0218] The number of synchronization signal blocks N;

[0219] Preamble sequence format;

[0220] {Synchronization signal block index 0, random access opportunity time-frequency resource information};

[0221] {Synchronization signal block index 1, random access opportunity time-frequency resource information};

[0222] {Synchronization signal block index N-1, random access opportunity time-frequency resource information}.

[0223] Among them, the number of synchronization signal blocks N is the number of synchronization signal blocks actually transmitted, which can be transmitted separately or in the main information block.

[0224] If the time-frequency resource information of the random access opportunities corresponding to different asynchronous signal blocks has a common part, it can also be proposed to save signaling. For example, if the random access opportunities corresponding to different synchronization signal blocks use the same frequency domain resources, the notification method is as follows:

[0225] The number of synchronization signal blocks N;

[0226] Preamble sequence format;

[0227] Frequency domain index;

[0228] The number of random access opportunities in the frequency domain;

[0229] {Synchronization signal block index 0, random access opportunity time domain position information};

[0230] {Synchronization signal block index 1, random access opportunity time domain position information};

[0231] {Synchronization signal block index N-1, random access opportunity time domain position information}.

[0232] Among them, the number of synchronization signal blocks N is the number of synchronization signal blocks actually transmitted, which can be transmitted separately or in the main information block. The frequency domain index and the number of frequency domains of random access opportunities are used to determine the frequency domain position of the random access opportunity, which can be replaced by the other alternative methods mentioned above. In addition, the above example assumes that the random access opportunities corresponding to different synchronization signal blocks use the same preamble sequence format, so they can be notified separately. Similarly, the above method is also applicable to the situation where different random access opportunities use the same or different preamble sequence formats. In this case, the preamble sequence format should not be notified and configured separately.

[0233] If the random access opportunities corresponding to different synchronization signal blocks use the same density, the notification and configuration can be performed in the following manner:

[0234] The number of synchronization signal blocks N;

[0235] Preamble sequence format;

[0236] Random access opportunity time domain density / period indication;

[0237] {Synchronization signal block index 0, random access opportunity time domain position information};

[0238] {Synchronization signal block index 1, random access opportunity time domain position information};

[0239] {Synchronization signal block index N-1, random access opportunity time domain position information}.

[0240] The number of synchronization signal blocks N is the number of synchronization signal blocks actually transmitted, which can be transmitted separately or in a master information block. The above notification method is also applicable to the case where different synchronization signal blocks use the same or different preamble sequence formats.

[0241] When the above notification and configuration method is adopted, the terminal determines the synchronization signal block according to the measurement results at the time of initial access, and obtains the configuration information of the corresponding random access opportunity according to the synchronization signal block index (for example, the logical index of the synchronization signal block, or the time domain index of the synchronization signal block, which is obtained through the primary synchronization signal, the secondary synchronization signal and the information read in the main information block at the time of initial access) and the random access channel configuration information read in the RMSI, and sends a preamble sequence on it.

[0242] In the above configuration, the time-frequency resources of the random access opportunity are configured with the synchronization signal block as the index. This method is more suitable for the case where there is a one-to-one mapping relationship between the synchronization signal block and the random access opportunity, that is, different synchronization signal blocks are mapped to non-overlapping random access opportunities. For the case where multiple synchronization signal blocks are mapped to the same random access opportunity, the above configuration method can also be used, but some redundant signaling will be introduced.

[0243] Another notification method is to use the random access opportunity as an index for configuration and notification. In this configuration and notification method, the signaling content that needs to be configured is:

[0244] {Random access opportunity time-frequency resource location information 0, preamble sequence format, corresponding synchronization signal block index};

[0245] {Random access opportunity time-frequency resource location information 1, preamble sequence format, corresponding synchronization signal block index};

[0246] {Random access opportunity time-frequency resource location information M-1, preamble sequence format, corresponding synchronization signal block index}.

[0247] Among them, in the above configuration, each random access opportunity is configured with corresponding time-frequency resource location information and corresponding preamble sequence format information. At the same time, the synchronization signal block index corresponding to the random access opportunity is also configured. For the case where a random access opportunity is bound to multiple synchronization signal blocks, the synchronization signal block index sequence can be notified. At the same time, for the case where different random access opportunities have the same parameters (such as the same preamble sequence format, etc.), the common parameters can be proposed for separate notification and configuration.

[0248] The above notification method adopts the method of notifying the actual configuration information. Another possible method is to list the possible configuration methods into an index table, and the information contained in the index table includes the preamble sequence format and the aforementioned random access timing configuration information. When notifying and configuring the random access channel configuration information, the notification method is:

[0249] The number of synchronization signal blocks N;

[0250] {synchronization signal block index 0, random access opportunity configuration index 0};

[0251] {synchronization signal block index 1, random access opportunity configuration index 1};

[0252] {synchronization signal block index N-1, random access opportunity configuration index N-1};

[0253] Among them, the number of synchronization signal blocks N is the number of synchronization signal blocks actually transmitted, which can be transmitted separately or in the main information block.

[0254] The random access opportunity configuration index table may be described by an index table in the following table.

[0255] Table 5: An example of a possible random access opportunity configuration index table

[0256] index Preamble format Time-frequency resource allocation 0 Format Index 0 Configuration 0 1 Format Index 1 Configuration 1 ... ... ... K Format Index K Configuring K

[0257] It should be noted that the above table only lists the parameters that may appear in the random access opportunity configuration index table, and the corresponding format indexes in different indexes may be the same, that is, different indexes may use the same preamble sequence format.

[0258] To further reduce the overhead of random access channel configuration, different available index ranges are defined when the number of synchronization signal blocks actually sent is different. A simple example is that if the number of synchronization signal blocks actually sent is not greater than K1, the available random access timing configuration index range is 1 to M1; if the number of synchronization signal blocks actually sent is greater than K1 but not greater than K2, the available random access timing configuration index range is 1 to M2; if the number of synchronization signal blocks sent at a certain time is greater than K2, the available random access timing configuration index range is 1 to M3. And so on, until the maximum number of synchronization signal blocks that can be transmitted is reached.

[0259] In the above configuration methods, no relevant information of the preamble sequence resource pool is configured. In the case where multiple synchronization signal blocks correspond to the same random access opportunity, in order to facilitate the base station to determine the downlink transmission beam used to send the random access response, it is necessary to group the preamble sequence and notify the base station of the appropriate downlink transmission beam in a grouping manner. The preamble sequence grouping information needs to be notified together with the corresponding random access opportunity configuration information, that is, the random access opportunity configuration information includes the preamble sequence grouping information in addition to the time-frequency resource configuration information. The notification method of the grouping information can be the following:

[0260] In each random access opportunity configuration information, a preamble sequence start index and an end index are added; or a preamble sequence start index and the number of preamble sequences;

[0261] First, configure each preamble sequence group. One possible way is to configure the number of preamble sequence groups and the number of preamble sequences in each group.

[0262] If the total number of preamble sequences is determined (for example, the total number of preamble sequences is predetermined, or the total number of preamble sequences is notified in the RMSI), it is only necessary to notify and configure the number of groups (number of groups) in the random access configuration information. At the same time, the corresponding preamble group index is notified in the random access opportunity configuration information. The terminal determines the index of the preamble sequence in each group based on the total number of preamble sequences and the number of groups. The terminal determines the preamble resource pool information to be used based on the preamble group index in the corresponding random access opportunity configuration information;

[0263] The above method is suitable for the case where the number of preamble sequences contained in different random access preamble sequence groups is the same. For the case where the number of preamble sequences contained in different groups is different, the number of preamble sequences in each group can be indicated by directly notifying. For example, one possible method is to use the preamble sequence number vector for configuration and notification. A simple example is that the total available preamble sequences are divided into S groups, where the number of preamble sequences contained in the i-th group is s i , then the notification method is the notification vector [s 0,…,s S-1 ]. At the same time, the corresponding preamble sequence grouping index is added to the random access opportunity configuration. The terminal determines the preamble sequence resource to be used according to the grouping information in the random access opportunity configuration information and the grouping index;

[0264] If the preamble sequences of different groups are distinguished by means of covering codes (orthogonal or non-orthogonal), it is only necessary to add the covering code index to be used at the random access opportunity to the random access configuration information.

[0265] Sixth embodiment

[0266] In this embodiment, a notification method for physical random access channel configuration information will be introduced. In this embodiment, the system can operate in frequency division duplex (FDD) mode or time division duplex (TDD) mode. For FDD mode, the frequency bands used for uplink and downlink are separated, and all uplink time-frequency resources are considered available when configuring the random access channel; while for TDD mode, uplink and downlink share the frequency band, and all uplink time-frequency resources cannot be considered available when configuring the random access channel. Therefore, for these two different duplex modes, different configuration methods need to be adopted, or different optimization processing should be performed for the same configuration method.

[0267] First, for the FDD mode system, the configuration method of the random access channel is briefly described. In this embodiment, the configuration of the random access channel is notified and configured by means of a random access channel configuration index table. Specifically, the random access channel configuration index table includes: a physical random access channel configuration index, a preamble sequence format index, a radio frame index (or a random access channel period), a time slot index, and other possible parameters.

[0268] Among them, when notifying the random access channel configuration information, the base station only notifies the physical random access channel configuration index, and the terminal determines the configuration information based on the index; the preamble sequence format index is used to determine the preamble sequence format, thereby determining the time-frequency domain structure of the random access opportunity; the wireless frame index is used to determine the period of the random access channel; the time slot index is used to determine the time slot index in which the random access channel can be within a random access channel period.

[0269] The present invention determines the available time slot index of the random access channel within a random access channel cycle in a formulaic manner. The available subcarrier spacing of the random access channel is an integer multiple of 15kHz, which is expressed in the following manner: SCS = 15*2 u kHz, where u=0,1,2,…is an integer not less than 0.

[0270] In the method provided by the present invention, the reference subcarrier spacing is first determined as an available time slot index, and then the corresponding time slot index under other subcarrier spacing is determined according to the relationship between other subcarrier spacing and the reference subcarrier spacing. For example, taking 15kHz as the reference subcarrier spacing, if the time slot index under a certain physical random access channel index is (a, b, c), that is, time slot a, time slot b, and time slot c can be used for transmission of the random access channel, then other subcarrier spacings (15*2 u kHz) under the same physical random access channel index: (a,b,c)+10*i,i=0,…,2 u .

[0271] The above methods can be unified as follows: For a certain physical random access channel index, the available time slot index in a cycle is (a, b, c) + 10*i, i = 0, ..., 2 u .

[0272] When the time slots within the first k milliseconds are not available for the random access process, the available time slot index quantized according to the subcarrier spacing can be used as follows: Taking 15kHz as the reference subcarrier spacing, if the time slot index is (a,b,c) under a physical random access channel index, that is, time slot a, time slot b, and time slot c can be used for random access channel transmission, then the other subcarrier spacings (15*2 u kHz) under the same physical random access channel index: (a,b,c)*u+10*i,i=0,…,2 u -1.

[0273] Available random access channel periods include: 10ms, 20ms, 40ms, 80ms and 160ms. For periods greater than 10ms, only the position of the 10ms frame used to transmit the random access channel can be specified. For example, for a period of 20ms, the 10ms frame used to transmit the random access channel in 20ms can be configured by specifying the available frame index as an odd number or an even number; for other available periods, one possible way is to determine the frame index in the following way:

[0274] For 40ms, the available frame index is mod(Nf,4)=k, where Nf is the frame index and k is an integer from 0 to 3. By determining k, the available frame index can be determined;

[0275] For 80ms, the available frame index is mod(Nf,8)=k, where Nf is the frame index and k is an integer from 0 to 7. By determining k, the available frame index can be determined;

[0276] For 160 ms, the available frame index is mod(Nf, 16) = k, where Nf is the frame index and k is an integer from 0 to 15. By determining k, the available frame index can be determined.

[0277] For a period of 20 ms, the above method can also be used to summarize, that is, the available frame index is mod(Nf, 2) = k, where Nf is the frame index and k is an integer from 0 to 1. By determining k, the available frame index can be determined.

[0278] That is, the random access channel period and the available frame index may be determined in the above manner by predetermining the parameter k.

[0279] Another possible way is to determine the available frame index within the period by a predefined method, and only notify the period in the random access channel configuration index. For example, one possible way is to only specify that the transmission of random access opportunities is completed within the first 10ms of a period. In this case, only the actual random access channel period needs to be notified.

[0280] The above description is for the random access configuration method of the FDD mode. For the TDD mode, the random access configuration method designed for the FDD mode can be reused, but it needs to be explained and modified. Specifically, when a certain downlink / uplink configuration method is configured, the time slot index is determined for the available uplink time-frequency resources to obtain a continuous virtual index of the available uplink time slot. For example, the downlink / uplink configuration is Fig.18 As shown in FIG. 1 , the actual indexes of the uplink time slots are {2, 3, 4, 7, 8, 9}. The virtual indexes of these 6 time slots are {0, 1, 2, 3, 4, 5}.

[0281] The time slot index of the physical random access channel in the downlink / uplink configuration is determined according to the virtual index and the available time slot index in the physical random access channel configuration.

[0282] It should also be noted that the physical random access channel configuration index table used can be shared by FDD and TDD modes, but the FDD mode can use some of the configuration indexes, while the TDD mode can use other configuration indexes. By adopting the above-mentioned virtual time slot index method, the physical random access channel configuration of the FDD mode and the TDD mode is completed. For the special time slot in the TDD mode (used for switching from downlink to uplink), the processing methods include the following two:

[0283] 1. Special subframes are not considered to be uplink time slots available for random access channels;

[0284] 2. The special subframe is considered to be an uplink time slot in which a random access channel is available, but a limit is set on the starting symbol position thereof. For example, the starting position of the random access channel in the special time slot is fixed to start from symbol 2.

[0285] The above parameters can determine the time slot resources that can be used by the random access channel, but the symbol position where the random access channel starts within the time slot still needs to be additionally specified. A simple way is to determine the starting symbol position in each available time slot in a predetermined manner. For example, the starting symbol position in each available time slot is specified to be 0, then in the available time slots of all random access channels, the random access channels are arranged starting from the 0th symbol; or, for FDD mode and TDD mode, the starting symbol positions of the two modes are determined in a predefined manner, and different starting symbol positions are used in different modes. For example, for the FDD mode, the starting symbol position in each available time slot is specified to be 0; for the TDD mode, the starting symbol position of each available time slot is specified to be 2.

[0286] To support a more flexible starting symbol position, the starting symbol position in the available time slot may be configured and notified by a lookup table. For example, the starting symbol position in the available time slot may be defined by a lookup table as shown in Table 6.

[0287] Table 6: Definition of starting symbol position

[0288] index Starting symbol position 0 0 1 2 2 (0，2) ... ...

[0289] In the above table, the starting position of the tuple indicates that there are multiple positions in a time slot that can be used for random access channel transmission.

[0290] The configuration and notification of the above-mentioned starting symbol position can be performed by adding an index to the physical random access channel configuration index table, and configuring the starting symbol position in the available time slot together with the physical random access channel configuration index; in another method, the starting symbol position configuration is configured and notified using a separate parameter.

[0291] It should be noted that for the random access configuration method with multiple available time slots, the same or different starting symbol positions can be configured for each available time slot. For the method of configuring different starting symbol positions for different time slots, the configuration and notification are performed in the form of index combination. For the TDD mode, the starting symbol position can be configured separately for the special time slot. That is, for other uplink time slots except the special time slot, the same starting symbol position is used, and for the special time slot, the starting symbol position that conforms to its uplink and downlink symbol distribution is configured. Or for the special time slot, a predetermined starting symbol position configuration is used instead of the notified starting symbol configuration.

[0292] Seventh embodiment

[0293] This embodiment will describe the method of configuring a random access channel for a system operating in TDD mode. Fig.10 As shown, it is assumed that the system operates in the following TDD frame structure.

[0294] Fig.10 In the , a downlink-uplink transmission cycle contains multiple time slots, among which there are X1 uplink time slots and Y1 downlink time slots, and the remaining time slots contain X2 uplink symbols and Y2 downlink symbols. The remaining symbols are flexible symbols, and the sending direction of these symbols is determined by the base station configuration. In data transmission, the base station completely determines the frame structure of TDD in data transmission by configuring the parameters downlink-uplink transmission cycle, X1, X2, Y1, and Y2.

[0295] In this embodiment, the following information can be obtained through the random access channel configuration index: preamble sequence format, including the cyclic prefix length, sequence length, number of sequence repetitions, etc. of the preamble sequence; the configuration period of the random access channel, including options such as 10 milliseconds, 20 milliseconds, 40 milliseconds, and 80 milliseconds; the time slot index in which the random access channel can appear, which can be a single index or an index combination; the system frame in which the random access channel can be configured within the random access configuration period, obtained by the system frame number modulo 1 (for a 10 millisecond period), or modulo 2 (for a 20 millisecond period), or modulo 4 (for a 40 millisecond period), or modulo 8 (for an 80 millisecond period), and the same applies to other configuration periods; the starting symbol index in the time slot; the number of time slots in which the random access channel can be configured; and the number of random access opportunities in a random access time slot (related to the random access preamble sequence format).

[0296] For random access, since the terminal is not connected to the network, it is impossible to determine how Fig.10 The frame structure shown in FIG. 1 also makes it difficult to ensure that the random access channel does not conflict with the downlink channel. To solve this problem, this embodiment proposes the following possible solutions:

[0297] 1. For Fig.10 The TDD frame structure shown in FIG. 1 configures and notifies the downlink-uplink transmission period in the system information or the remaining minimum system information (RMSI), and makes the following provisions for the time-frequency resource mapping of the random access channel:

[0298] Take the end point of each available uplink time slot in the random access channel as the reference time, and push forward the time K according to the random access configuration information and the preamble sequence format RA , as the starting point for sending random access opportunities.

[0299] Time K RAYou can do this in the following ways.

[0300] 1a. Consider the cyclic prefix length, sequence length, and number of random access opportunities in the random access slot specified in the random access preamble sequence format to calculate the parameter K RA Specifically, the parameter K RA The calculation is as follows:

[0301] K RA =(N CP +N Seq )*N RO

[0302] Among them, N CP is the cyclic prefix length, N Seq is the sequence length, N RO is the number of random access opportunities in the random access slot.

[0303] The above method can be Fig.11 describe.

[0304] Fig.11 In the example shown, the random access slot includes three random access opportunities, and the time domain length of each random access opportunity is specified by the cyclic prefix length and the sequence length. The terminal uses the end point of the uplink slot as the reference time and calculates the starting point of sending the random access channel based on the reference time.

[0305] In the case where there are multiple random access time slots in the uplink time slot, the start time of the random access channel can be calculated forward for each random access time slot in the above manner, using the end point of the random access time slot as the reference time.

[0306] For the random access channel configuration, the random access start symbol index is N start In the case of N, the symbols in the uplink time slot are numbered from back to front, with index N start The random access channel start time is calculated from the symbol end point forward, such as Fig.12 shown.

[0307] Fig.12 In the example, the starting symbol index is 2, then the symbols in the random access slot are numbered from the back to the front, and the start time of the random access channel is calculated from the end point of symbol 2. Another way is to determine the end point of the random access channel as follows: for the N sym The uplink time slot of symbols is sym -1-N start The start point of the random access channel is calculated forward from the end point. For example, in the above example, for sym = 14 symbols, N start=2, the start point of the random access channel is calculated from the end point of symbol 11.

[0308] For random access time slots combined with multiple preamble sequence formats, the time domain starting point of the random access channel is calculated forward from the end point of the random access uplink time slot or according to the start symbol index in the following manner:

[0309] K RA =∑(N CPi +N Seqi )*N ROi

[0310] Among them, N CPi is the cyclic prefix length of the i-th preamble format, N Seqi is the length of the sequence of the i-th leading sequence format, N ROi is the number of random access opportunities of the i-th preamble format. The parameter i is counted from 1 to the preamble type.

[0311] For example, for the combination of preamble format A1 and B1, if a random access slot includes 6 random access opportunities, the first 5 of which use preamble format A1 and the last one uses preamble format B1, the start time is calculated as:

[0312] K RA =(N CP_A1 +N Seq_A1 )*5+(N CP_B1 +N Seq_B1 )

[0313] 1b. Consider the cyclic prefix length, sequence length, number of random access opportunities contained in the random access time slot, and the guard time calculation parameter K specified in the random access preamble sequence format. RA Specifically, the parameter K RA The calculation is as follows:

[0314] K RA =(N CP +N Seq )*N RO +N GT

[0315] Among them, N CP is the cyclic prefix length, N Seq is the sequence length, N RO is the number of random access opportunities in the random access slot, N GT To protect the length of time.

[0316] The above method can be Fig.13 describe.

[0317] Since the current preamble sequence format and random access channel configuration information do not include the guard time length, if the random access channel start time is calculated in the manner described in this embodiment, the guard time length may be obtained in the following possible manners:

[0318] The base station adds the notification and configuration of the protection time in the random access channel configuration information or the preamble sequence format;

[0319] The terminal calculates the guard time based on the data structure of the data channel and the random access channel. For example, the guard time length is calculated based on the channel structure of the initial uplink channel including the random access channel (including subcarrier spacing, data channel cyclic prefix length, symbol length, etc.) and the preamble format.

[0320] After the above parameters are known, the start time of the random access channel is calculated based on the end point of the uplink time slot, the above parameters, and the start symbol index.

[0321] If multiple preamble sequence formats can be transmitted in the random access time slot, the start time of the random access channel can be calculated according to the number of each preamble sequence format, as shown in the following formula:

[0322] K RA =∑(N CPi +N Seqi )*N ROi +N GT

[0323] Among them, N CPi is the cyclic prefix length of the i-th preamble format, N Seqi is the length of the sequence of the i-th leading sequence format, N ROi is the number of random access opportunities of the i-th preamble format. The parameter i is counted from 1 to the number of preamble types, N GT To protect the length of time.

[0324] In the above method, if the timing advance and / or timing advance offset used for random access is not zero, the timing advance and / or timing advance offset can be used as the time domain transmission starting point of the random access channel based on the above starting position.

[0325] For example, if both the timing advance and the timing advance offset are non-zero, then

[0326] T RA =K RA +N TA +N TA-offset

[0327] Among them, N TA is the timing advance for random access, N TA-offSetis the timing advance offset used for the random access process. TA and N TA-offset Both can be zero.

[0328] 2. For Fig.10 The TDD frame structure shown in the figure configures and notifies the downlink-uplink transmission period and the number of uplink time slots X1 in the system information or the remaining minimum system information (RMSI). Based on these parameters, the terminal can know the starting position of the uplink time slot. Taking the starting position as the starting point, the time-frequency resource selection and mapping of the random access channel are performed. Fig.14 shown.

[0329] In the case of multiple available random access time slots, the starting point of each random access time slot is used as the time domain starting point of the random access channel.

[0330] Specifically, the method uses the starting point of each available uplink time slot as the starting position of the random access channel.

[0331] In the above method, if the timing advance and / or timing advance offset used for random access is not zero, the timing advance and / or timing advance offset can be used as the time domain transmission starting point of the random access channel based on the above starting position.

[0332] 3. A combination of the first two methods. The base station configures and notifies the downlink-uplink transmission cycle and the number of uplink time slots X1 in the system information or RMSI. The terminal obtains the starting position of the uplink time slot based on the cycle information and the number of uplink time slots. For the first uplink time slot in the downlink-uplink transmission cycle, the method for determining the starting position of the random access channel in method 1 is adopted, that is, the end point of the uplink time slot is used as the reference time, and the starting position of the random access channel is calculated forward according to the random access channel configuration information and the preamble sequence format; for other uplink time slots, the method for determining the starting position of the random access channel in method 2 is adopted, that is, the starting point of the uplink time slot is used as the starting position of the random access channel.

[0333] Or, for the first M uplink time slots in the downlink-uplink transmission period, the method for determining the starting position of the random access channel in method 1 is adopted; for the remaining uplink time slots, the method for determining the starting position of the random access channel in method 2 is adopted. The parameter M may be configured and notified by the base station in the system information or RMSI, or may be configured in a predetermined manner.

[0334] It should be noted that this embodiment does not use Fig.10 The X2 uplink symbols in the frame structure shown are used for random access channel configuration.

[0335] It may be specified that the uplink symbols in the special subframe are not used for transmission of the random access preamble sequence.

[0336] Through the method provided in this embodiment, it is possible to avoid interference to the random access channel caused by downlink-uplink conversion and interference between base stations in the TDD system, thereby improving the performance of the random access process in the TDD system.

[0337] Eighth embodiment

[0338] In the above embodiments, all of them are for the configuration of random access channels in the initial access bandwidth. Although the above configuration method is also applicable to other random access application scenarios other than the initial random access, such as the sending of scheduling requests, the random access process triggered by the downlink control channel, etc., it is still necessary to configure random access channels in other bandwidth parts (Bandwidth Part, BWP) to reduce terminal access delay and avoid frequent switching between different BWPs. This embodiment will discuss the configuration method of random access channels on other BWPs.

[0339] In this embodiment, the base station configures the random access channel on the initial access BWP through random access configuration information in the RMSI, wherein the random access channel configuration is used to configure the time domain resources of the random access channel, and the frequency domain resources are notified and configured by the offset relative to the starting physical resource block of the initial access BWP. For the random access channel configuration of other BWPs, the following methods can be used:

[0340] 1. It is stipulated that the same random access channel configuration information is used in all BWPs, and notification and configuration are performed through cell-common or terminal-specific high-level signaling or physical layer signaling. Among them, the random access configuration information, including random access channel configuration and frequency domain offset, can use the same configuration information as the initial access BWP. In this case, no additional signaling is required for configuration and notification; the same random access channel configuration information as the initial access BWP can be used, but with a different frequency domain offset. In this case, the frequency domain offset needs to be configured for other BWPs. Other BWPs can use the same frequency domain offset; the same frequency domain offset as the initial access BWP can be used, but with different random access channel configuration information. In this case, random access channel configuration information needs to be configured for other BWPs. Other BWPs can use the same random access channel configuration information; or other BWPs use different random access channel configuration information and frequency domain offset from the initial access BWP, and the base station configures through high-level signaling or physical downlink control channels.

[0341] 2. Use terminal-specific signaling to configure random access channels on other BWPs. For other BWPs except the initial access BWP, use the same random access configuration information as on the initial access BWP, and notify the index or index group of the BWP that can be used for random access in the terminal-specific signaling. The signaling can be high-level signaling or physical layer signaling, such as downlink control information in the downlink control channel.

[0342] The terminal obtains the index or index group of the BWP that can be used for random access through high-layer signaling or physical layer signaling, and determines the time-frequency resources of the random access channel in the BWP that can be used for random access through the random access configuration information transmitted in the RMSI.

[0343] Specifically, the time domain resources of the random access channel can be known through the random access channel configuration; and the frequency domain offset of the random access channel should be understood as an offset relative to the starting physical resource block of the BWP that can be used for random access.

[0344] 3. Use terminal-specific signaling to configure random access channels on other BWPs. The base station configures the index or index group of the BWP that can be used for random access, and configures the random access channel frequency domain offset for the BWP that can be used for the random access channel. The frequency domain offset can be configured uniformly for all BWPs that can be used for random access channels, that is, using the same frequency domain offset; or different BWPs can be configured with separate frequency domain offsets.

[0345] For the method of using uniform frequency domain offset, the corresponding signaling is:

[0346] {B 1 , …, B K}, f RA

[0347] Among them, {B 1 , ..., B K} is the BWP index group that can be used for random access, f RA is the frequency domain offset, which is the frequency domain offset relative to the BWP starting physical resource block.

[0348] For frequency domain offset using separate configuration, the corresponding signaling is:

[0349] {B 1 , ..., B K}, {f RA1 , ..., f RAK}

[0350] Among them, {f RA1 , ..., f RAK} is the frequency domain offset of the random access channel for each BWP.

[0351] The random access channel configuration information of other BWPs uses the random access channel configuration information of the initial access BWP.

[0352] 4. Use terminal-specific signaling to configure random access channels on other BWPs. The base station configures the index or index group of the BWP that can be used for random access, and configures the random access channel configuration for the BWP that can be used for random access. Other BWPs that can be used for random access use the same frequency domain offset configuration as the initial access BWP.

[0353] 5. Use terminal-specific signaling to configure random access channels on other BWPs. The base station configures the index or index group of the BWP that can be used for random access, and configures the random access channel configuration and frequency domain offset configuration for the BWP that can be used for random access channels.

[0354] If the terminal has been configured by the base station to transmit data with a BWP other than the initial access BWP and needs to perform random access, the random access channel time-frequency resources and the preamble sequence are selected according to the random access configuration information on the BWP, and the selected or base station-configured preamble sequence is sent on the random access channel on the BWP.

[0355] If there is no random access configuration information on the configured BWP, the terminal needs to initiate a BWP switching process, switch to the initial access bandwidth or a BWP with a random access channel, and perform a random access process.

[0356] If the random access process is triggered by the base station (for example, a random access process triggered by a downlink control channel), and there is no random access channel on the BWP currently configured for the terminal, the base station first schedules the terminal to the initial access BWP or the BWP with a random access channel, and then triggers the random access process.

[0357] Fig.15 It is a schematic diagram of a random access preamble sequence detection method at a base station side according to the present invention.

[0358] according to Fig.15 The present invention provides a random access detection method, which is briefly described as follows: Step S1010: Send a synchronization signal block including a primary synchronization signal, a secondary synchronization signal and a broadcast channel. Step S1020: Detect each random access opportunity in the random access channel. Step S1030: If the transmission of a preamble sequence is detected, determine a downlink transmission beam for sending a random access response based on the random access opportunity time-frequency resources and / or the detected random access preamble sequence. Step S1040: Send a random access response using the downlink transmission beam determined in step S1030. Fig.15The flowchart is a behavior flow chart of the base station side. The preamble sequence detected in step S1030 is sent by the terminal on the time-frequency resource of the random access opportunity determined in the methods described in the first to third embodiments above.

[0359] Fig.16 A random access channel time-frequency resource acquisition and determination device included in a terminal according to the present invention.

[0360] The present invention provides a random access channel time-frequency resource acquisition and determination device, such as Fig.16 As shown, it is composed of the following modules: a downlink measurement module 1110, which is used to determine the synchronization signal block through the downlink measurement result. A configuration information reading module 1120, which is used to read the random access channel configuration information from the synchronization signal block. A random access opportunity time-frequency resource determination module 1130, which is used to determine the time-frequency resource position of the random access opportunity according to the random access channel configuration and binding information. A preamble sequence sending module 1140, which sends a preamble sequence at the random access opportunity. Among them, the random access opportunity time-frequency resource determination module 1130 determines the time-frequency resource position of the random access opportunity by the methods described in the first to third embodiments above.

[0361] Fig.17 A preamble sequence detection device included in a base station according to the present invention. The present invention provides a preamble sequence detection device, such as Fig.17 As shown, it is composed of the following modules: a synchronization signal block sending module 1210, which sends a synchronization signal block. A preamble sequence detection module 1220, which detects the preamble sequence in each random access opportunity of the random access channel. A downlink beam determination module 1230, which determines the downlink beam according to the random access opportunity time-frequency resources and the preamble sequence. A random access response sending module 1240, which uses the determined downlink beam to send a random access response. Among them, the preamble sequence detected in the preamble sequence detection module 1220 is sent by the terminal on the time-frequency resources of the random access opportunity determined in the method described in the first to third embodiments above.

[0362] The present invention provides a method for obtaining and determining the position of random access channel time-frequency resources in a multi-beam operating system. By adopting the method provided by the present invention, the system can configure the random access opportunity time-frequency resources corresponding to different beams at a lower signaling overhead cost. At the same time, the terminal can also obtain the information of the random access opportunity more quickly, thereby improving the overall performance and operation efficiency of the system.

[0363] To facilitate understanding of the exemplary embodiments, some exemplary embodiments of the acquisition and determination of the time-frequency resource position of the random access channel in the multi-beam operation system according to the present invention have been described and shown in the accompanying drawings. However, it should be understood that these exemplary embodiments are only intended to illustrate the exemplary embodiments, rather than to limit the exemplary embodiments. It should also be understood that the exemplary embodiments are not limited to the exemplary embodiments shown and described. A person of ordinary skill in the art may make various modifications to the exemplary embodiments.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving at least one synchronization signal block SSB from a base station; receiving random access channel RACH configuration information from the base station, the RACH configuration information including information about the number S of SSBs associated with one RACH opportunity; determining a RACH timing corresponding to an SSB in at least one SSB based on the RACH configuration information; Sending a random access preamble based on the determined RACH opportunity; Wherein, according to the frequency domain priority criterion, based on the frequency resource of at least one RACH opportunity and the time resource of at least one RACH opportunity, S SSBs are mapped to one RACH opportunity, and Wherein, based on the frequency domain priority criterion, the frequency resources of the at least one RACH opportunity are used before the time resources of the at least one RACH opportunity to map the S SSBs to the one RACH opportunity.

2. The method according to claim 1, in, The periodicity of the RACH opportunity is configured to be one of 10ms, 20ms, 40ms, 80ms and 160ms; and Wherein, an SSB is selected from the at least one SSB based on a threshold.

3. The method according to claim 1, in, The RACH configuration information also includes an index indicating a preamble sequence format.

4. The method according to claim 3, in, The random access preamble code is obtained based on the preamble sequence format.

5. The method according to claim 1, in, An SSB among the at least one SSB is selected by the terminal, and each of the at least one SSB corresponds to a different transmission beam of the base station.

6. A method performed by a base station in a wireless communication system, the method comprising: Sending at least one synchronization signal block SSB to the terminal; Sending random access channel RACH configuration information to the terminal, wherein the RACH configuration information includes information about the number S of SSBs associated with one RACH opportunity; as well as receiving a random access preamble on a RACH opportunity corresponding to an SSB in at least one SSB, Wherein, according to the frequency domain priority criterion, based on the frequency resource of at least one RACH opportunity and the time resource of at least one RACH opportunity, S SSBs are mapped to one RACH opportunity; and Wherein, based on the frequency domain priority criterion, the frequency resources of the at least one RACH opportunity are used before the time resources of the at least one RACH opportunity to map the S SSBs to the one RACH opportunity.

7. The method according to claim 6, in, The periodicity of the RACH opportunity is configured to be one of 10ms, 20ms, 40ms, 80ms and 160ms.

8. The method according to claim 6, in, The RACH configuration information also includes an index indicating a preamble sequence format.

9. The method according to claim 8, in, The random access preamble code is obtained based on the preamble sequence format.

10. The method according to claim 6, in, An SSB among the at least one SSB is selected by the terminal, and each of the at least one SSB corresponds to a different transmission beam of the base station.

11. A terminal in a wireless communication system, the terminal being configured to: receiving at least one synchronization signal block SSB from a base station; receiving random access channel RACH configuration information from a base station, the RACH configuration information including information about the number S of SSBs associated with one RACH opportunity; determining a RACH timing corresponding to an SSB in at least one SSB based on the RACH configuration information; Sending a random access preamble based on the determined RACH opportunity; Wherein, according to the frequency domain priority criterion, based on the frequency resource of at least one RACH opportunity and the time resource of at least one RACH opportunity, S SSBs are mapped to one RACH opportunity; and Wherein, based on the frequency domain priority criterion, the frequency resources of the at least one RACH opportunity are used before the time resources of the at least one RACH opportunity to map the S SSBs to the one RACH opportunity.

12. The terminal according to claim 11, in, The periodicity of the RACH opportunity is configured to be one of 10ms, 20ms, 40ms, 80ms and 160ms; and Wherein, an SSB is selected from the at least one SSB based on a threshold.

13. The terminal according to claim 11, in, The RACH configuration information also includes an index indicating a preamble sequence format.

14. The terminal according to claim 13, in, The random access preamble code is obtained based on the preamble sequence format.

15. The terminal according to claim 11, in, An SSB among the at least one SSB is selected by the terminal, and each of the at least one SSB corresponds to a different transmission beam of the base station.

16. A base station in a wireless communication system, the base station being configured to: Sending at least one synchronization signal block SSB to the terminal; Sending random access channel RACH configuration information to the terminal, wherein the RACH configuration information includes information about the number S of SSBs associated with one RACH opportunity; as well as receiving a random access preamble on a RACH opportunity corresponding to an SSB in at least one SSB; Wherein, according to the frequency domain priority criterion, based on the frequency resource of at least one RACH opportunity and the time resource of at least one RACH opportunity, S SSBs are mapped to one RACH opportunity; and Wherein, based on the frequency domain priority criterion, the frequency resources of the at least one RACH opportunity are used before the time resources of the at least one RACH opportunity to map the S SSBs to the one RACH opportunity.

17. The base station according to claim 16, in, The periodicity of the RACH opportunity is configured to be one of 10ms, 20ms, 40ms, 80ms and 160ms.

18. The base station according to claim 16, in, The RACH configuration information also includes an index indicating a preamble sequence format.

19. The base station according to claim 18, in, The random access preamble code is obtained based on the preamble sequence format.

20. The base station according to claim 16, in, An SSB among the at least one SSB is selected by the terminal, and each of the at least one SSB corresponds to a different transmission beam of the base station.

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