5GNR-based random access method and device, baseband processing equipment and storage medium

Abstract

The invention discloses a 5GNR-based random access method and device, baseband processing equipment and a storage medium, and relates to the technical field of communication. The method comprises the following steps: receiving a random access signal, and carrying out CP removal processing and FFT conversion on the random access signal to obtain a target frequency domain signal corresponding to each symbol in the random access signal; sequentially executing a peak detection process on the target frequency domain signal of each symbol according to the index of the symbol until a peak detection result of the symbol is that a PRACH signal exists or the symbol is greater than a preset value, taking the symbol as a target symbol under the condition that the peak detection result of the symbol is that the PRACH signal exists, and determining a measurement time delay corresponding to the target symbol; and determining a first target time delay, a second target time delay and a third target time delay based on the measurement time delay, the FFT point number and the target symbol, and sending the first target time delay, the second target time delay and the third target time delay to the terminal. Therefore, the success rate of random access of the remote terminal is improved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a random access method, apparatus, baseband processing device and storage medium based on 5G NR. Background Technology

[0002] In 5G NR systems, uplink synchronization is crucial for ensuring uplink coverage. Its core lies in the base station estimating the transmission delay of the coverage distance using random access signals and then calibrating the terminal's transmission timing accordingly. Existing technologies primarily rely on fixed-format preamble sequences defined by 3GPP for distance estimation. Longer sequences naturally support long-distance coverage, while shorter sequences enhance signal strength through symbol repetition.

[0003] However, existing preamble detection methods have significant drawbacks: First, the fixed length of the cyclic prefix specified by the protocol limits the maximum coverage distance of the PRACH format, failing to meet the access requirements for longer distances; second, although existing detection methods attempt to expand coverage using repeating symbols, they heavily rely on preset thresholds, resulting in unstable accuracy of delay measurements in complex channel environments; third, existing methods fail to effectively utilize the multi-symbol coherent combining gain, leading to limited improvement in the received signal-to-noise ratio, ultimately restricting the detection success rate in long-distance scenarios. Summary of the Invention

[0004] The main objective of this application is to provide a random access method, apparatus, baseband processing device, and storage medium based on 5G NR, so as to improve the success rate of random access for long-distance terminals.

[0005] To achieve the above objectives, this application provides a random access method based on 5G NR, applied to a base station, the method comprising: Receive random access signals, and perform CP removal processing and FFT transformation on the random access signals to obtain the target frequency domain signals corresponding to each symbol in the random access signals; According to the index of the symbol, the peak detection process is performed on the target frequency domain signal of each symbol in sequence until the peak detection result of the symbol is that a PRACH signal exists or the symbol is greater than a preset value. If the peak detection result of the symbol is that a PRACH signal exists, the symbol is taken as the target symbol and the measurement delay corresponding to the target symbol is determined. Based on the measurement delay, the FFT points, and the target symbol, a first target delay, a second target delay, and a third target delay are determined, and the first target delay, the second target delay, and the third target delay are sent to the terminal.

[0006] Optionally, determining the first target delay, the second target delay, and the third target delay based on the measurement delay, the FFT points, and the target symbol includes: determining the first target delay using the following formula (1) and based on the measurement delay, the FFT points, and the target symbol: (1); In the formula, The measurement delay; The number of points in the FFT; The target symbol; The first target delay is defined as follows: the second target delay is defined as the sum of the first target delay and the number of FFT points; the third target delay is defined as the difference between the first target delay and the number of FFT points.

[0007] Optionally, the step of performing peak detection on the target frequency domain signal of each symbol sequentially according to the symbol index includes: each time the peak detection process is performed on the target frequency domain signal of the symbol, the steps include: determining whether the symbol is less than or equal to the preset value; if the symbol is less than or equal to the preset value, determining the correlation coefficients between the target frequency domain signal of the symbol and all symbols preceding the symbol and the local sequence, and coherently combining each correlation coefficient to obtain the coherent combining coefficient of the symbol, and performing peak detection on the coherent combining coefficient of the symbol.

[0008] Optionally, determining the correlation coefficients between the target frequency domain signal of the symbol and all symbols preceding the symbol and the local sequence, and coherently combining each correlation coefficient to obtain the coherent combining coefficient of the symbol, includes: determining the correlation coefficients between the target frequency domain signal of the symbol and the local sequence using the following formula (2): (2); The correlation coefficients are coherently combined using the following formula (3) to obtain the coherent combination coefficient of the symbols: (3); In the formula, For symbols l The correlation coefficient, iSymbol is the total number of the symbols; For the first l Target frequency domain signal; The local sequence; N_FFT is the smallest positive integer that is greater than the length of the preamble sequence of the random access signal and is an integer power of 2. For symbols l The coherence merging coefficient.

[0009] Optionally, after performing peak detection on the coherent combining coefficients of the symbol, the method further includes: if the peak detection result of the symbol indicates that there is no PRACH signal, then performing a peak detection process on the target frequency domain signal of the next symbol.

[0010] Optionally, the step of performing CP removal processing and FFT transformation on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal includes: performing CP removal processing on the random access signal to obtain an initial access signal; dividing the initial access signal into L parts, where L is equal to the total number of symbols and equal to the preset value, and each part of the initial access signal corresponds one-to-one with each of the symbols; performing FFT transformation on the initial access signal corresponding to each symbol to obtain the frequency domain signal corresponding to each symbol; and using a preset frequency domain resource index to extract the frequency domain signal corresponding to each symbol to obtain the target frequency domain signal corresponding to each symbol.

[0011] Furthermore, to achieve the above objectives, this application also provides a random access method based on 5G NR, applied to a terminal. The method includes: sending a random access signal to a base station; receiving a first target delay, a second target delay, and a third target delay sent by the base station; wherein the first target delay, the second target delay, and the third target delay are determined based on a measurement delay, FFT points, and a target symbol. The target symbol is determined by the base station sequentially performing a peak detection process on the target frequency domain signal of each symbol according to the symbol index, until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol is greater than a preset value. If the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is determined as a target symbol. The measurement delay corresponds to the target symbol. A connection establishment request is initiated to the base station based on the first target delay, the second target delay, and the third target delay, respectively.

[0012] This application also provides a random access device based on 5G NR, comprising: a preprocessing module, configured to receive a random access signal and perform CP removal processing and FFT transformation on the random access signal to obtain a target frequency domain signal corresponding to each symbol in the random access signal; a detection module, configured to perform a peak detection process on the target frequency domain signal of each symbol sequentially according to the index of the symbol, until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol is greater than a preset value, and if the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is taken as a target symbol and the measurement delay corresponding to the target symbol is determined; and a delay determination module, configured to determine a first target delay, a second target delay, and a third target delay based on the measurement delay, the number of FFT points, and the target symbol, and send the first target delay, the second target delay, and the third target delay to a terminal.

[0013] This application also provides a baseband processing device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the random access method based on 5G NR as described above.

[0014] This application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the 5GNR-based random access method as described above.

[0015] The random access method based on 5G NR in this application expands the coverage distance of random access by a factor of L by utilizing the multi-symbol transmission characteristic of random access signals. Furthermore, by calculating and sending the three possible delays—the first target delay, the second target delay, and the third target delay—to the terminal, the terminal can attempt to access the base station with these three delays, eliminating the ambiguity of the measurement delay obtained from peak measurement and thus effectively improving the access success rate. Attached Figure Description

[0016] Figure 1 This is a scenario example of a random access method based on 5G NR according to an embodiment of this application; Figure 2 This is one of the flowcharts of a random access method based on 5G NR according to an embodiment of this application; Figure 3 This is a second flowchart of a random access method based on 5G NR according to an embodiment of this application; Figure 4 This is the third flowchart of a random access method based on 5G NR according to an embodiment of this application; Figure 5 This is a graph showing the results of peak detection of the coherent merging coefficients of symbol 1, an example of this application; Figure 6 This is a graph showing the results of peak detection of the coherent merging coefficients of symbol 2, an example of this application; Figure 7 This is a graph showing the results of peak detection of the coherent merging coefficients of symbol 3, an example of this application; Figure 8 This is a flowchart of another embodiment of the random access method based on 5G NR in this application; Figure 9 This is a schematic diagram of a 5GNR-based random access device according to an embodiment of this application; Figure 10 An example is a schematic diagram of the physical structure of a baseband processing device; In the diagram, 110 is the base station; 120 is the terminal; 900 is the random access device; 910 is the preprocessing module; 920 is the detection module; 930 is the delay determination module; 1010 is the processor; 1020 is the communication interface; 1030 is the memory; and 1040 is the communication bus.

[0017] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In 5G NR systems, the key to uplink coverage capability lies in achieving precise uplink synchronization. This process relies on the base station estimating the transmission delay equivalent to the corresponding coverage distance by receiving the initial random access signal sent by the terminal, and then sending this delay information as a timing advance to the terminal to ensure the synchronous transmission of the terminal's uplink signal.

[0020] In existing technologies, the 3GPP specifications define various preamble sequence formats, including short sequences and long sequences. Among them, the long sequence format, with its smaller subcarrier spacing and longer transmission time resources, is mainly designed to meet the needs of long-distance coverage; while the short sequence format supports a multi-symbol repetition mechanism, which aims to combat large-scale fading during signal propagation by utilizing multi-symbol merging, thereby enhancing the strength of random access signals.

[0021] However, existing technologies have significant limitations in achieving these goals. First, the cyclic prefix length defined by the 3GPP specifications for different PRACH formats is fixed, which fundamentally limits the maximum coverage distance that each format can support. Therefore, for systems using short-sequence formats, existing detection methods cannot effectively handle coverage needs that exceed the protocol's specified range.

[0022] Secondly, although existing technologies employ detection schemes that utilize the characteristic of repeated transmission of multiple symbols in PRACH signals, attempting to extend coverage distance by combining a multi-symbol search window with a preset threshold to correct measurement delay, the measurement delay results of this method heavily depend on the accuracy of the preset threshold. In real-world, complex, and variable wireless channel environments, a fixed preset threshold is difficult to adjust adaptively, leading to unstable accuracy in delay measurement and impacting access reliability. Furthermore, this type of technology fails to achieve true multi-symbol coherent combining during preamble sequence detection, failing to obtain the necessary combining gain, resulting in limited improvement in the received signal-to-noise ratio, ultimately hindering further improvements in detection success rate.

[0023] To address this, this application provides a random access method, apparatus, baseband processing device, and storage medium based on 5G NR. By coherently combining the correlation coefficients of multiple symbols and then using the combined coherent combining technology for peak detection, the detection accuracy is effectively improved. Furthermore, by sending all possible delay advances to the terminal, the terminal can attempt to access the base station based on these delay advances, completely avoiding access failures caused by delay measurement errors, improving the success rate of random access for long-distance terminals, and with low implementation complexity.

[0024] For ease of understanding, this specification provides a scenario example of a random access method based on 5G NR, which is applied in situations such as... Figure 1 In the application environment shown, the scenario example includes a base station 110 and several terminals 120. The base station 110 integrates a high-performance baseband processing device, which can be used to execute the 5GNR-based random access method provided in the embodiments of this application.

[0025] In this scenario example, terminal 120 can be any user equipment or machine that needs to establish a communication connection with base station 110 via a wireless link and receive network services. For example, terminal 120 can be a smartphone, computer, vehicle terminal, industrial terminal, IoT terminal, etc. No specific limitation is made to terminal 120 here.

[0026] When terminal 120 needs to access the network, it can initiate a connection establishment request to base station 110 using a short sequence format with multiple symbol repetitions, i.e., send a random access signal to base station 110. After receiving the random access signal, the baseband processing device in base station 110 measures the preamble sequence of the random access signal, and can calculate the transmission delay between terminal 120 and base station 110 based on the preamble sequence. After calculating the transmission delay, the baseband processing device can send a timing advance to terminal 120 based on the transmission delay, so that terminal 120 can successfully access the network and complete uplink synchronization based on the timing advance.

[0027] Referring to the scenario examples of the random access method based on 5GNR in the foregoing embodiments, the random access method based on 5GNR in this application embodiment will be described in detail below.

[0028] Figure 2 This is one of the flowcharts of a 5GNR-based random access method according to an embodiment of this application. This 5GNR-based random access method can be executed by the baseband processing device in the foregoing embodiments, such as... Figure 2 As shown, the 5G NR-based random access method may include the following steps: Step 210: Receive the random access signal, and perform CP removal and FFT transformation on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal.

[0029] Step 220: Perform peak detection on the target frequency domain signal of each symbol according to the symbol index, until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol is greater than a preset value. If the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is taken as the target symbol, and the measurement delay corresponding to the target symbol is determined.

[0030] Step 230: Determine the first target delay, the second target delay, and the third target delay based on the measurement delay, the number of FFT points, and the target symbol, and send the first target delay, the second target delay, and the third target delay to the terminal.

[0031] It should be noted that the random access method in the embodiments of this application mainly focuses on the processing of random access signals in the format of short sequence with multiple symbol repetition (i.e., PRACH signals), that is, the terminal sends random access signals to the base station in the format of enhanced short sequence with multiple symbol repetition.

[0032] In this embodiment, when the base station receives a random access signal in a short sequence format with multiple symbol repetitions sent by the terminal, the baseband processing equipment in the base station can preprocess the random access signal to separate the useful parts of the random access signal for subsequent measurement. Specifically, the baseband processing equipment can first perform CP removal processing on the random access signal. It can be understood that the random access signal mainly consists of two parts: a cyclic prefix (CP) and a preamble. The cyclic prefix is ​​a protective interval formed by copying a segment of signal from the end of the preamble and adding it to the beginning of the symbol. Therefore, performing CP removal processing on the random access signal first can remove the CP part containing transmission interference, thereby obtaining a clean and complete symbol body (i.e., the preamble).

[0033] Furthermore, the baseband processing equipment performs an FFT transform on the random access signal after CP removal to obtain the target frequency domain signal corresponding to each symbol in the random access signal. It is understandable that the random access signal sent by the terminal is a time-domain signal; therefore, the baseband processing equipment needs to convert the time-domain signal into a frequency-domain signal to facilitate subsequent processing and detection. This necessitates performing an FFT transform on the random access signal.

[0034] It should be noted that the random access signal sent by the terminal adopts a multi-symbol short sequence format, that is, the terminal will continuously send the complete symbol structure containing a cyclic prefix and a preamble sequence L times. In this embodiment, the random access signal is composed of these L consecutive complete symbols, and each symbol carries a copy of the same preamble sequence.

[0035] Figure 3 This is a second flowchart of a random access method based on 5G NR according to an embodiment of this application. Figure 3 As shown, in some embodiments, step 210 performs CP removal processing and FFT transformation on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal, which may include the following steps: Step 310: Perform CP removal processing on the random access signal to obtain the initial access signal.

[0036] Step 320: Divide the initial access signal into L parts, where L is equal to the total number of symbols and equal to a preset value, and each part of the initial access signal corresponds one-to-one with each symbol.

[0037] Step 330: Perform FFT transformation on the initial access signal corresponding to each symbol to obtain the frequency domain signal corresponding to each symbol.

[0038] Step 340: Using a preset frequency domain resource index, extract the frequency domain signal corresponding to each symbol to obtain the target frequency domain signal corresponding to each symbol.

[0039] Specifically, after receiving the random access signal, the baseband processing device first performs CP removal processing on the random access signal, that is, removes the cyclic prefix of the random access signal to obtain the initial access signal. In this embodiment, the received random access signal is denoted as... The initial access signal is denoted as Then, the random access signal can be de-CP processed according to the following formula (4): (4); In the formula, The CP length of the random access signal; The length of the preamble sequence for the random access signal.

[0040] After obtaining the initial access signal, it is further divided into L parts. It should be noted that L is the number of times the symbol structure is repeatedly transmitted, and therefore also the total number of symbols; in this embodiment, each initial access signal is described as corresponding to each symbol one by one for ease of description, but in fact, each initial access signal can be directly regarded as each symbol. After dividing the initial access signal into L parts, FFT transformation is performed on each initial access signal to obtain the frequency domain signal corresponding to each symbol. Specifically, the frequency domain signal corresponding to each symbol can be obtained using the following formula (5): (5); In the formula, For symbols l The frequency domain signal.

[0041] Furthermore, the preset frequency domain resource index is utilized. The frequency domain signal corresponding to each symbol is extracted, and the useful part of the obtained frequency domain signal is extracted based on the standard frequency domain signal, so that the useful part can be used in the subsequent detection process. It should be noted that the preset frequency domain resource index is a number or identifier used to indicate or locate the specific position of a particular channel or signal on the frequency axis.

[0042] Specifically, the frequency domain signal corresponding to each symbol can be extracted using the following formula (6) to obtain the target frequency domain signal corresponding to each symbol: (6); In the formula, For symbols l The corresponding target frequency domain signal; This is a preset frequency domain resource index.

[0043] In step 220, after obtaining the target frequency domain signal corresponding to each symbol, the peak detection process can be performed on the target frequency domain signal of each symbol sequentially according to the symbol index until a certain symbol can detect the PRACH signal, or the target frequency domain signals corresponding to all symbols have been detected, at which point the peak detection process stops. If the target frequency domain signal of a certain symbol can detect the PRACH signal, then that symbol is taken as the target symbol, and the measurement delay corresponding to that target symbol is measured.

[0044] Figure 4 This is the third flowchart of a random access method based on 5G NR according to an embodiment of this application. Figure 4 As shown, in some embodiments, step 220, which sequentially performs peak detection on the target frequency domain signal of each symbol according to the symbol index, may include: each time the peak detection process is performed on the target frequency domain signal of a symbol, the following steps are taken: determining whether the symbol is less than or equal to a preset value; if the symbol is less than or equal to the preset value, determining the correlation coefficients between the target frequency domain signal of the symbol and all symbols preceding the symbol and the local sequence, and coherently combining the correlation coefficients to obtain the coherent combining coefficients of the symbol, and performing peak detection on the coherent combining coefficients of the symbol.

[0045] In this embodiment, the symbols can be numbered sequentially, i.e., the symbols... Where 1, 2, 3, ..., iSymbol is the symbol number (i.e., index), and iSymbol is the total number of symbols. It should be noted that the preset value described in this embodiment is equal to the total number of symbols. For example, if the total number of symbols is 12, then the preset value is also 12.

[0046] During the peak detection process, peak detection can be performed sequentially on the target frequency domain signal of each symbol, starting with symbol 1. Specifically, it is first determined whether symbol 1 is less than or equal to a preset value. If symbol 1 is less than or equal to the preset value, the correlation coefficient between the target frequency domain signal corresponding to symbol 1 and the local sequence is calculated. It should be noted that this correlation coefficient is used to characterize the correlation between the target frequency domain signal and the local sequence, which is the local root frequency domain sequence. , , The length of the preamble sequence of the randomly accessed signal is given. The purpose of calculating the correlation coefficient is to find the time delay position where the received signal best matches the ideal signal.

[0047] In some implementations, the correlation coefficient between the target frequency domain signal of the symbol and the local sequence can be determined using the following formula (2): (2); In the formula, For symbols lThe correlation coefficient, iSymbol represents the total number of symbols; For the first l Target frequency domain signal; Local sequence; N_FFT is the smallest positive integer that is a power of 2 greater than the length of the preamble sequence of the randomly accessed signal. It should be noted that the target frequency domain signal of all symbols can be represented by a matrix, where the rows are denoted by k. , list l express, .

[0048] Furthermore, after calculating the correlation coefficient of symbol 1 using formula (2), since there are no other symbols before symbol 1, there is no need to perform coherent merging of the correlation coefficients. Therefore, the coherent merging coefficient of symbol 1 is equal to the correlation coefficient of symbol 1. It should be noted that the correlation coefficient and coherent merging coefficient described in this embodiment are both in sequence form.

[0049] Furthermore, peak detection is performed on the coherent combining coefficients of symbol 1. If the coherent combining coefficients of symbol 1 can detect the PRACH signal, then symbol 1 is taken as the target symbol, and the time delay of the coherent combining coefficients of symbol 1 is measured to obtain the required measurement time delay. If the coherent combining coefficients of symbol 1 cannot detect the PRACH signal, that is, the peak detection result of symbol 1 indicates that there is no PRACH signal, then the symbol is incremented by one, that is, the peak detection process is performed on the target frequency domain signal of the next symbol (symbol 2).

[0050] Specifically, first determine whether symbol 2 is less than or equal to a preset value. If symbol 2 is less than or equal to the preset value, then calculate the correlation coefficient between the target frequency domain signal corresponding to symbol 2 and all preceding symbols and the local sequence. Here, the symbols preceding the symbol are determined according to their numbering order. For example, the symbols preceding symbol 2 include symbol 1. Therefore, it is necessary to calculate the correlation coefficient between the target frequency domain signal corresponding to symbol 2 and symbol 1 and the local sequence. Specifically, the correlation coefficient between symbol 2 and symbol 1 can be calculated using the above formula (2), which will not be elaborated here.

[0051] Furthermore, after calculating the correlation coefficients of symbol 2 and symbol 1 using formula (2), it is necessary to coherently combine the correlation coefficients of symbol 2 and symbol 1. In some embodiments, the correlation coefficients can be coherently combined using the following formula (3) to obtain the coherent combination coefficients of the symbols: (3); In the formula, For symbols lThe coherent merging coefficient. Since the coherent merging coefficient of symbol 2 is being calculated, iSymbol in formula (3) is equal to 2.

[0052] Furthermore, peak detection is performed on the coherent combining coefficients of symbol 2. If the coherent combining coefficients of symbol 2 can detect the PRACH signal, then symbol 2 is taken as the target symbol, and the time delay of the coherent combining coefficients of symbol 2 is measured to obtain the required measurement time delay. If the coherent combining coefficients of symbol 2 cannot detect the PRACH signal, that is, the peak detection result of symbol 2 is that there is no PRACH signal, then the symbol is incremented by one, that is, the peak detection process is performed on the target frequency domain signal of the next symbol (symbol 3).

[0053] It should be noted that time delay measurement can be directly achieved using existing equipment, which will not be elaborated here.

[0054] Therefore, as Figure 4 As shown, the peak detection process is repeated until the peak detection result of a certain symbol indicates the presence of a PRACH signal, or all symbols have undergone peak detection, at which point the peak detection process ends.

[0055] In step 230, after obtaining the measurement delay corresponding to the target symbol, the first target delay, the second target delay, and the third target delay can be determined based on the measurement delay, the number of FFT points, and the target symbol. The base station then sends the first target delay, the second target delay, and the third target delay as timing advance to the terminal.

[0056] In some implementations, the first target delay can be determined using the following formula (1) and based on the measurement delay, the number of FFT points, and the target symbol: (1); In the formula, For measuring time delay; The number of FFT points; For target symbols; This represents the first target latency. It should be noted that the first target latency is the final corrected measurement latency for long-distance coverage scenarios.

[0057] The second objective delay equals the first objective delay plus the FFT points (i.e., ... + The third objective delay is equal to the first objective delay minus the number of FFT points (i.e., - ).

[0058] As an example, if the FFT number is 2048, that is, the length of one symbol corresponds to 2048 sampling points, and the actual round-trip time of the random access signal sent by the terminal is 3000 sampling points; the baseband processing device will search for the signal in the detection window of the first symbol and find that the peak appears at the position of 3000 - 2048 = 952. However, since the detection window only has 2048 sampling points, the baseband processing device cannot distinguish whether the peak appearing at this 952 point comes from the near terminal (i.e., the actual delay is 952) or from the far terminal (i.e., the actual delay is 952 + 2048 = 3000).

[0059] Based on this, this embodiment sends all possible delays as timing advances to the terminal, enabling the terminal to access the network based on each timing advance until random access is successful or the maximum number of random access attempts is reached. This eliminates ambiguity in the measured delay value, improves the access success rate, and achieves uplink synchronization. Furthermore, the random access method in this embodiment expands the coverage distance of the random access signal by a factor of L, where L is the number of times the random access signal is repeatedly transmitted, thereby effectively increasing the coverage distance of the random access signal.

[0060] To facilitate understanding, the random access method based on 5G NR of this application embodiment will be further described below through a specific example.

[0061] In this example, the system bandwidth is 100MHz, PRACH format is B4, subcarrier spacing is 30kHz, and the PRACH Configuration Index (Random Access Resource Index) is configured to be 147. In this 5G NR communication system, the start symbol of the random access signal... It occupies 12 symbols consecutively. The normal coverage distance of this random access signal is 5km. In this example, a terminal 12km away from the base station initiates random access.

[0062] The specific access process is as follows: First, the baseband processing equipment uses the above formula (4) to perform CP removal processing on the random access signal to obtain the initial access signal. In formula (4), , .

[0063] Furthermore, since the random access signal repeats 12 times, the initial access signal after CP removal is divided into 12 parts and each part is subjected to FFT transformation to obtain the frequency domain signal corresponding to each symbol. Then, using formula (6), the frequency domain signal corresponding to each symbol is extracted to obtain the target frequency domain signal corresponding to each symbol.

[0064]

[0065] Furthermore, before calculation The correlation coefficients of each symbol are combined to obtain the coherent combined coefficients corresponding to each symbol, and peak search is performed on the coherent combined coefficients corresponding to the symbols. The initial value is 1. If the peak detection result of the symbol is a detected PRACH signal, the peak detection process ends; otherwise, And repeat the peak detection process.

[0066] Before calculation When the correlation coefficient of each symbol is given, the local sequence is... , The preamble sequence length of the random access signal is 139. The correlation coefficient between the target frequency domain signal and the local sequence is calculated using formula (2): (2); ; in, The N_FFT is set to 256 because the smallest positive integer that is greater than the length of the preceding sequence 139 and is an integer power of 2 is 256.

[0067] when When the first symbol is merged, the coherent merging coefficient is calculated and a peak search is performed. Figure 5 This is a result graph of the peak detection of the coherent merging coefficients of symbol 1 in this application, as shown below. Figure 5 As shown, no PRACH signal was detected in the coherent merging coefficient of symbol 1.

[0068] when When the first two symbols are combined, the coherence merging coefficient is calculated and a peak search is performed. Figure 6 This is a result graph of the peak detection of the coherent merging coefficients of symbol 2 in an example of this application, as shown below. Figure 6 As shown, no PRACH signal was detected in the coherent merging coefficients of symbol 2.

[0069] when If the first three symbols are combined, the coherence merging coefficient is calculated and a peak search is performed. Figure 7 This is a result graph of the peak detection of the coherent merging coefficients of symbol 3 in an example of this application, as shown below. Figure 7 As shown, the coherent combining coefficient of symbol 3 detected the PRACH signal. At this time, the delay of the first target is:

[0070] In this example, the number of FFT points Therefore, the delay for the second target is 10240 + 4096 = 14336, and the delay for the third target is 10240 - 4096 = 6144.

[0071] When the base station sends a PRACH response to the terminal, it can send the three timing advances mentioned above. The terminal first attempts to access the network with a timing advance of 10240. If the terminal's first access attempt is successful, the process ends. If the terminal's access attempt fails, it changes to the next timing advance and tries to access the network again.

[0072] Therefore, this embodiment utilizes the characteristic of multiple symbol repetition of the PRACH signal to increase the coverage distance of random access by a factor of L, where L is the number of times the PRACH signal is repetitively transmitted, while also improving the access success rate. This embodiment enhances the uplink coverage distance and has low implementation complexity.

[0073] Based on the above embodiments, this application also provides another random access method based on 5G NR. Figure 8 This is a flowchart of another embodiment of the random access method based on 5G NR in this application. This 5G NR-based random access method can be executed by a terminal, such as... Figure 8 As shown, the 5G NR-based random access method may include: sending a random access signal to the base station; receiving a first target delay, a second target delay, and a third target delay sent by the base station; and initiating a connection establishment request to the base station based on the first target delay, the second target delay, and the third target delay, respectively.

[0074] The first target delay, the second target delay, and the third target delay are determined based on the measurement delay, the number of FFT points, and the target symbol. The target symbol is determined by the base station performing peak detection on the target frequency domain signal of each symbol in sequence according to the symbol index, until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol is greater than a preset value. If the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is determined as the target symbol, and the measurement delay corresponds to the target symbol.

[0075] Specifically, the terminal first sends a random access signal to the base station, and the base station responds to the random access signal by executing the first 5GNR-based random access method provided in this application embodiment to obtain a first target delay, a second target delay, and a third target delay. The base station then sends the first target delay, the second target delay, and the third target delay to the terminal in turn.

[0076] Furthermore, the terminal can first initiate a connection establishment request to the base station with a first target delay. If the request succeeds, the base station and the terminal establish a connection. If the request fails, the base station then sends a second target delay, and the terminal initiates a connection establishment request to the base station with the second target delay. If the request succeeds, the base station and the terminal establish a connection. If the request fails, the base station then sends a third target delay, and the terminal initiates a connection establishment request to the base station with the third target delay, until random access is successful or the maximum number of random access attempts is reached.

[0077] It should be noted that for details not disclosed in the second 5GNR-based random access method of this embodiment, please refer to the details disclosed in the embodiment of the first 5GNR-based random access method in this specification, which will not be repeated here.

[0078] Based on the above embodiments, this application also provides a random access device based on 5G NR. Figure 9 This is a schematic diagram of a 5G NR-based random access device according to an embodiment of this application. Figure 9 As shown, the 5GNR-based random access device 900 may include a preprocessing module 910, a detection module 920, and a delay determination module 930 connected in sequence.

[0079] The preprocessing module 910 receives the random access signal and performs CP removal and FFT transformation on it to obtain the target frequency domain signal corresponding to each symbol in the random access signal. The detection module 920 performs peak detection on the target frequency domain signal of each symbol sequentially according to its index until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol's peak value exceeds a preset value. If the peak detection result indicates the presence of a PRACH signal, the symbol is designated as the target symbol, and the measurement delay corresponding to the target symbol is determined. The delay determination module 930 determines a first target delay, a second target delay, and a third target delay based on the measurement delay, the number of FFT points, and the target symbol, and sends these three delays to the terminal.

[0080] In some implementations, the delay determination module 930 is specifically used to: determine a first target delay using the following formula (1) and based on the measurement delay, the number of FFT points, and the target symbol: (1); In the formula, For measuring time delay; The number of FFT points; For target symbols; The first target delay is the sum of the first target delay and the number of FFT points; the third target delay is the difference between the first target delay and the number of FFT points.

[0081] In some implementations, the detection module 920 is specifically used to: each time a peak detection process is performed on the target frequency domain signal of a symbol, include: determining whether the symbol is less than or equal to a preset value; if the symbol is less than or equal to the preset value, determining the correlation coefficients between the target frequency domain signal of the symbol and all symbols preceding the symbol and the local sequence, coherently combining each correlation coefficient to obtain the coherent combining coefficient of the symbol, and performing peak detection on the coherent combining coefficient of the symbol.

[0082] In some implementations, the detection module 920 is specifically used to: determine the correlation coefficient between the target frequency domain signal of the symbol and the local sequence using the following formula (2): (2); The correlation coefficients are coherently combined using the following formula (3) to obtain the coherent combination coefficient of the symbols: (3); In the formula, For symbols l The correlation coefficient, iSymbol represents the total number of symbols; For the first l Target frequency domain signal; Local sequence; N_FFT is the smallest positive integer that is greater than the length of the preamble sequence of the random access signal and is an integer power of 2. For symbols l The coherence merging coefficient.

[0083] In some implementations, the detection module 920 is further specifically used to: perform a peak detection process on the target frequency domain signal of the next symbol if the peak detection result of the symbol indicates that there is no PRACH signal.

[0084] In some implementations, the preprocessing module 910 is specifically used to perform CP removal processing on the random access signal to obtain an initial access signal; divide the initial access signal into L parts, where L is equal to the total number of symbols and equal to a preset value, and each part of the initial access signal corresponds to each symbol; perform FFT transformation on the initial access signal corresponding to each symbol to obtain the frequency domain signal corresponding to each symbol; and extract the frequency domain signal corresponding to each symbol using a preset frequency domain resource index to obtain the target frequency domain signal corresponding to each symbol.

[0085] It should be noted that for details not disclosed in the 5GNR-based random access device of this embodiment, please refer to the details disclosed in the embodiment of the first 5GNR-based random access method in this specification, which will not be repeated here.

[0086] Based on the above embodiments, this application also provides a baseband processing device. Figure 10 An example is a schematic diagram of the physical structure of a baseband processing device, such as... Figure 10 As shown, the baseband processing device may include a processor 1010, a communication interface 1020, a memory 1030, and a communication bus 1040. The processor 1010, communication interface 1020, and memory 1030 communicate with each other via the communication bus 1040. The processor 1010 can call logic instructions in the memory 1030 to execute a 5G NR-based random access method. This method includes: receiving a random access signal and performing CP removal processing and FFT transformation on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal; sequentially performing a peak detection process on the target frequency domain signal of each symbol according to the symbol index until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol is greater than a preset value; if the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is taken as the target symbol, and the measurement delay corresponding to the target symbol is determined; based on the measurement delay, the number of FFT points, and the target symbol, a first target delay, a second target delay, and a third target delay are determined, and the first target delay, the second target delay, and the third target delay are sent to the terminal.

[0087] Furthermore, the logical instructions in the aforementioned memory 1030 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0088] Based on the above embodiments, in another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it implements the random access method based on 5G NR provided by the above methods. The method includes: receiving a random access signal and performing CP removal processing and FFT transformation on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal; performing a peak detection process on the target frequency domain signal of each symbol sequentially according to the symbol index until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol is greater than a preset value; if the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is taken as the target symbol, and the measurement delay corresponding to the target symbol is determined; determining a first target delay, a second target delay, and a third target delay based on the measurement delay, the number of FFT points, and the target symbol, and sending the first target delay, the second target delay, and the third target delay to the terminal.

[0089] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0090] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A random access method based on 5G NR, characterized in that, Applied to a base station, the method includes: Receive random access signals, and perform CP removal processing and FFT transformation on the random access signals to obtain the target frequency domain signals corresponding to each symbol in the random access signals; According to the index of the symbol, the peak detection process is performed on the target frequency domain signal of each symbol in sequence until the peak detection result of the symbol is that a PRACH signal exists or the symbol is greater than a preset value. If the peak detection result of the symbol is that a PRACH signal exists, the symbol is taken as the target symbol and the measurement delay corresponding to the target symbol is determined. Based on the measurement delay, FFT points, and target symbol, a first target delay, a second target delay, and a third target delay are determined, and the first target delay, the second target delay, and the third target delay are sent to the terminal.

2. The random access method based on 5G NR according to claim 1, characterized in that, The determination of the first target delay, the second target delay, and the third target delay based on the measurement delay, the FFT point count, and the target symbol includes: The first target delay is determined using the following formula (1) and based on the measurement delay, the number of FFT points, and the target symbol: （1）; In the formula, The measurement delay; The number of points in the FFT; The target symbol; The delay is the time delay for the first target. The second target delay is the sum of the first target delay and the number of FFT points; The third target delay is the difference between the first target delay and the number of FFT points.

3. The random access method based on 5G NR according to claim 1, characterized in that, The step of performing peak detection on the target frequency domain signal of each symbol sequentially according to the symbol index includes: Each time a peak detection process is performed on the target frequency domain signal of the symbol, the process includes: determining whether the symbol is less than or equal to the preset value; if the symbol is less than or equal to the preset value, determining the correlation coefficients between the target frequency domain signal of the symbol and all symbols preceding the symbol and the local sequence, and coherently combining each correlation coefficient to obtain the coherent combining coefficient of the symbol, and performing peak detection on the coherent combining coefficient of the symbol.

4. The random access method based on 5G NR according to claim 3, characterized in that, The step of determining the correlation coefficients between the target frequency domain signal and the local sequence of the symbol and all symbols preceding the symbol, and coherently combining each correlation coefficient to obtain the coherent combining coefficient of the symbol, includes: The correlation coefficient between the target frequency domain signal of the symbol and the local sequence is determined using the following formula (2): （2）； The correlation coefficients are coherently combined using the following formula (3) to obtain the coherent combination coefficient of the symbols: （3）； In the formula, For symbols l The correlation coefficient, iSymbol is the total number of the symbols; For the first l Target frequency domain signal; The local sequence; N_FFT is the smallest positive integer that is greater than the length of the preamble sequence of the random access signal and is an integer power of 2. For symbols l The coherence merging coefficient.

5. The random access method based on 5G NR according to claim 3, characterized in that, After performing peak detection on the coherent combining coefficients of the symbols, the method further includes: If the peak detection result of the symbol is that there is no PRACH signal, then the peak detection process is performed on the target frequency domain signal of the next symbol.

6. The random access method based on 5G NR according to any one of claims 1 to 5, characterized in that, The step of performing CP removal processing and FFT transform on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal includes: The random access signal is subjected to CP removal processing to obtain the initial access signal; The initial access signal is divided into L parts, where L is equal to the total number of symbols and equal to the preset value, and each part of the initial access signal corresponds one-to-one with each of the symbols; Perform FFT transformation on the initial access signal corresponding to each symbol to obtain the frequency domain signal corresponding to each symbol; Using a preset frequency domain resource index, the frequency domain signal corresponding to each symbol is extracted to obtain the target frequency domain signal corresponding to each symbol.

7. A random access method based on 5G NR, characterized in that, Applied to a terminal, the method includes: Send random access signals to the base station; The system receives a first target delay, a second target delay, and a third target delay sent by the base station. The first target delay, the second target delay, and the third target delay are determined based on measurement delay, FFT points, and target symbols. The target symbols are determined by the base station sequentially performing peak detection on the target frequency domain signals of each symbol according to its index, until the peak detection result of the symbol indicates the presence of a PRACH signal or the symbol exceeds a preset value. If the peak detection result of the symbol indicates the presence of a PRACH signal, the symbol is determined as the target symbol. The measurement delay corresponds to the target symbol. A connection establishment request is initiated to the base station based on the first target latency, the second target latency, and the third target latency, respectively.

8. A random access device based on 5G NR, characterized in that, include: The preprocessing module is used to receive the random access signal and perform CP removal and FFT transformation on the random access signal to obtain the target frequency domain signal corresponding to each symbol in the random access signal; The detection module is used to perform peak detection on the target frequency domain signal of each symbol sequentially according to the index of the symbol, until the peak detection result of the symbol is that a PRACH signal exists or the symbol is greater than a preset value. If the peak detection result of the symbol is that a PRACH signal exists, the symbol is taken as the target symbol and the measurement delay corresponding to the target symbol is determined. The delay determination module is used to determine a first target delay, a second target delay, and a third target delay based on the measured delay, the number of FFT points, and the target symbol, and send the first target delay, the second target delay, and the third target delay to the terminal.

9. A baseband processing device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the 5GNR-based random access method as described in any one of claims 1 to 6.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the 5GNR-based random access method as described in any one of claims 1 to 6.

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