A method for calculating a number of physical bits of a 5G NR network SSB

Abstract

The application discloses a method and system for calculating the physical bit number of SSB of a 5G NR network, and belongs to the technical field of mobile communication. The method comprises the following steps: determining the time domain distribution pattern and the possible position of the starting time domain symbol of SSB according to the subcarrier spacing, carrier frequency, duplex mode and spectrum sharing access scene of SSB, then determining the number of candidate SSB indexes, and combining the high-level protocol parameter ssb-PositionsInBurst to calculate the number of time domain symbols occupied by the actual transmission of SSB; determining the number of frequency domain subcarriers occupied by SSB according to the offset of the starting subcarrier of SSB and the starting subcarrier of the common resource block 0; and finally calculating the total number of time-frequency resource elements and multiplying the modulation order to obtain the physical bit number of SSB. The application can quickly and accurately calculate the physical bit number of SSB based on the physical layer parameters without implementing a complex protocol signal processing algorithm, and significantly improves the efficiency of SSB data generation and test work.

Description

Technical Field

[0001] This invention belongs to the field of mobile communication technology, specifically relating to a method and system for calculating the number of physical bits of SSB in a 5G NR network. Background Technology

[0002] The Synchronization Signal Block (SSB), composed of the Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH), and its carried Demodulation Reference Signal (DMRS), is a crucial resource for mobile communication terminals accessing 5G NR networks. Correct reception and processing of the SSB is a key foundation for achieving high-speed data transmission in 5G NR networks. The 3GPP protocol standard describes the radio parameters determining the time-frequency domain resources occupied by the SSB, laying a foundation for mobile communication terminals to demodulate the SSB. To flexibly and efficiently test the performance of mobile terminals demodulating the SSB, it is necessary to build SSB signal simulation capabilities. Researching the calculation method for the physical number of SSB bits is an important means to ensure and verify the fidelity of SSB signal simulation, which can improve the effectiveness and accuracy of SSB signal simulation results.

[0003] Existing methods for calculating the physical bit count of SSBs in 5G NR networks mainly fall into two categories. One category follows the 3GPP protocol series standards to describe the time-domain and frequency-domain resources of SSBs and determine the SSB time-frequency resource mapping method. This type of method involves cross-analysis of numerous physical layer parameters, failing to clarify the complex relationships between these parameters and the quantity of SSB time-domain and frequency-domain resources. It cannot accurately identify the parameters directly affecting the physical bit count of SSBs, nor does it provide a method for calculating the physical bit count based on physical layer parameters. Therefore, this type of method cannot be directly used for calculating the physical bit count of SSBs.

[0004] Another approach is based on physical layer protocol data processing algorithms. This involves inputting 3GPP protocol physical layer parameters, running the algorithm, and then outputting the number of SSB physical bits. In this type of method, the calculation of the SSB physical bit count is a black box. Although the SSB physical bit count can be calculated, the complex data processing algorithm takes a considerable amount of time to complete, and it doesn't provide an intuitive or explicit explanation of the process and method for calculating the SSB physical bit count based on the physical layer parameters.

[0005] Analysis of existing methods reveals the following shortcomings in current methods for calculating the physical bit count of SSBs: 1) The relationship between physical layer parameters and the time-domain and frequency-domain resource locations of SSBs is unclear, failing to clarify the complex interrelationships between parameters; 2) The calculation of the physical bit count of SSBs becomes a black box, making the calculation process difficult to visualize; 3) It requires a significant amount of time to run complex communication protocol physical layer data processing algorithms; 4) It suffers from poor scalability and flexibility. As 3GPP protocols evolve and the number of physical layer parameters gradually increases, the interrelationships between parameters become more complex, making existing solutions unable to flexibly address these challenges. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for calculating the number of physical SSB bits in a 5G NR network. By providing the specific relationship between physical layer parameters and the number of physical SSB bits, the number of physical SSB bits can be calculated directly and explicitly without implementing complex and time-consuming protocol signal processing algorithms. This improves the efficiency and accuracy of SSB data generation and has good scalability and flexibility.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for calculating the number of physical bits for a 5G NR network SSB includes the following steps: Step 1: Based on the SSB subcarrier spacing, carrier frequency, duplex mode, and whether it is in a spectrum sharing access scenario, determine the SSB time-domain distribution pattern and the possible position of the starting time-domain symbol, and then determine the maximum number of candidate SSB indices within a half-frame. The actual number of SSB indices transmitted is determined based on the higher-layer protocol parameter ssb-PositionsInBurst. This allows us to calculate the number of time-domain symbols occupied by the SSB. ; Step 2: Based on the offset between the starting subcarrier of the SSB and the starting subcarrier of common resource block 0 Determine the number of frequency domain subcarriers occupied by the SSB. :when hour, ;when hour, ; Step 3: Based on the number of time-domain symbols occupied by the SSB Number of frequency domain subcarriers Calculate the total number of time-frequency resource elements occupied by the SSB. Then multiply by the corresponding modulation order Obtain the number of physical bits of SSB. .

[0008] Preferably, the SSB time-domain distribution pattern in step 1 includes Case A to Case G, which correspond to different subcarrier intervals and starting time-domain symbol positions, respectively: When the subcarrier spacing is 15kHz, Case A is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 70; When the subcarrier spacing is 30kHz, either Case B or Case C is used. The starting time-domain symbol position of Case B is... The initial time-domain sign position of Case C is The number of symbols in each half-frame is 140; When the subcarrier spacing is 120kHz, Case D is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 560; When the subcarrier spacing is 240kHz, Case E is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 1120; When the subcarrier spacing is 480kHz, Case F is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 2240; When the subcarrier spacing is 960kHz, Case G is used, and the number of symbols per half frame is 4480.

[0009] Preferably, the variable The value range is determined based on the communication scenario and physical layer parameter configuration: For Case A: In the case of no spectrum sharing access, if the carrier frequency is ≤3GHz, then If the carrier frequency is >3GHz and belongs to FR1, then When accessing the spectrum sharing network ; For Case B: When the carrier frequency is ≤3GHz When the carrier frequency is >3GHz and belongs to FR1 ; For Case C: No spectrum sharing access, if it is FDD and the carrier frequency is ≤3GHz, then If the carrier frequency is >3GHz, then If it is TDD and the carrier frequency is <1.88GHz, then If the carrier frequency is ≥1.88GHz, then When accessing the spectrum sharing network ; For Case D: Used in the FR2 and FR2-NTN bands ; For Case E: Used in the FR2-1 and FR2-NTN bands ; For Case F: Used in the FR2-2 band .

[0010] Preferably, the possible positions of the SSB start time-domain symbol in step 1 are from... arrive Number them, and these numbers are respectively associated with Each candidate SSB index corresponds to; among them For variables The number of possible values; Maximum number of SSB indexes in a cell and a half-frame and The relationship is: For scenarios where the carrier frequency bands are FR1 and FR2 and there is no spectrum sharing access, or where the carrier frequency band is FR2-2 and there is spectrum sharing access, ; For a spectrum-sharing access scenario with carrier frequency band FR1, when the SSB subcarrier spacing is 15kHz and Or the SSB subcarrier spacing is 30kHz and hour, .

[0011] Preferably, the higher-layer protocol parameter ssb-PositionsInBurst includes The SSB index is 0, where the most significant bit corresponds to SSB index 0. If a bit is 0, the SSB with the corresponding index is not transmitted; if a bit is 1, the SSB with the corresponding index is transmitted. The actual number of SSB indices transmitted is determined based on this parameter. .

[0012] Preferably, the offset in step 2 The range is no more than one resource block; when At this time, the SSB occupies 252 subcarriers. Data in resource blocks overlapping with the SSB's frequency domain resources are all set to 0 and cannot be used for data transmission on other channels. At that time, the number of subcarriers occupied by the SSB is 240.

[0013] Furthermore, this invention also mentions a system for calculating the physical number of SSBs in a 5G NR network, used to perform the method for calculating the physical number of SSBs in a 5G NR network as described above, characterized in that it includes: The time-domain resource calculation module is used to determine the number of time-domain symbols occupied by the SSB based on the subcarrier spacing, carrier frequency, duplex mode, spectrum sharing access scenario, and higher-layer protocol parameter ssb-PositionsInBurst. The frequency domain resource calculation module is used to determine the number of frequency domain subcarriers occupied by the SSB based on the offset between the starting subcarrier of the SSB and the starting subcarrier of the common resource block 0. The physical bit count calculation module is used to calculate the total number of time-frequency resource elements based on the number of time-domain symbols and the number of frequency-domain subcarriers, and multiply it by the modulation order to output the physical bit count of SSB.

[0014] The beneficial technical effects of this invention are as follows: 1. This invention proposes a closed-loop calculation method for the physical number of SSB bits. By combining key protocol parameters of 5G NR networks, the physical number of SSB bits can be calculated efficiently and easily. It supports the calculation of the physical number of SSB bits under different subcarrier spacings and SSB patterns. At the same time, it explains the impact of higher-layer protocol parameters and SSB starting subcarrier offset on SSB transmission and the occupation of time and frequency domain resources. It is highly operable, effectively improves the efficiency of SSB data generation, and provides a means of testing and verifying the integrity and accuracy of SSB data.

[0015] 2. It does not rely on complex protocol processes and algorithm implementations. The number of physical bits can be quickly calculated through network protocol parameters, which greatly improves the efficiency of communication data generation and related testing work.

[0016] 3. A detailed analysis was conducted on the method for calculating SSB time-domain resources based on subcarrier spacing, spectrum sharing access, higher-layer protocol parameter SSB-PositionsInBurst, and other key protocol parameters. The corresponding calculation formulas were clearly given, eliminating the ambiguity and complexity of traditional methods and effectively improving the efficiency of PDSCH and DMRS data simulation and generation.

[0017] 4. The relationship between the offset between the starting subcarrier of the SSB and the starting subcarrier of common resource block 0 and the frequency domain resources of DMRS is analyzed in detail. The calculation formula of SSB frequency domain resources is given in a concise and clear manner, which can effectively guide the simulation and generation of SSB data. Attached Figure Description

[0018] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: In 5G NR networks, SSBs are transmitted in burst sets within a certain period. A burst set consists of several SSBs and is transmitted in either the first or second half of a frame (when the period is 5ms, it is transmitted in both the first and second half of the frame). Therefore, this application focuses on calculating the physical number of SSBs in a burst set. The process is as follows: Figure 1 As shown.

[0020] 1. Time-domain resources occupied by SSB; Depending on the different SSB subcarrier spacing parameters, the time-domain distribution of the SSB has seven patterns, A to G. The possible positions of the starting time-domain symbol of the SSB are different in each case, as shown in Table 1.

[0021] Table 1: SSB temporal distribution patterns and available symbol locations; .

[0022] According to the TS38.101 protocol, if the subcarrier spacing of the SSB is not given by the higher-layer protocol parameter `ssbSubcarrierSpacing`, the available SSB pattern is related to the corresponding carrier frequency band. If the SSB subcarrier spacing is given by the higher-layer protocol parameter `ssbSubcarrierSpacing`, for the frequency band of the SSB with only a 15kHz subcarrier spacing, the SSB pattern is Case B. For the frequency band of the SSB with a 30kHz subcarrier spacing, and for the SSB with both 15kHz and 30kHz subcarrier spacings, the pattern defined for the 30kHz subcarrier spacing SSB (Case B or Case C) is used. Regarding the variables in the table above... Depending on the different communication scenarios and physical layer parameter configurations, the values ​​have different ranges, as shown in Table 2.

[0023] Table 2: Explanation of variable n; .

[0024] The possible positions of the SSB start time domain symbol in Table 1 are from 0 to... Number them, among which For the variables in Table 2 The number of possible values, and the corresponding numbers are respectively associated with... Each candidate SSB index corresponds to one of the following. The maximum number of SSB indices within a cell and a half-frame is denoted as . , and The following relationship exists between them: For scenarios where the carrier frequency bands are FR1 and FR2 and there is no spectrum sharing access, or where the carrier frequency band is FR2-2 and there is spectrum sharing access, ; For a spectrum-sharing access scenario with carrier frequency band FR1, when the SSB subcarrier spacing is 15kHz and Or the SSB subcarrier spacing is 30kHz and hour, .

[0025] SSB transmission in the time domain is also affected by the higher-layer protocol parameter ssb-PositionsInBurst, which includes Each bit has an index of 0, with the leftmost / most significant bit corresponding to SSB index 0, and so on. When a bit is 0, the SSB with the corresponding index is not transmitted; when a bit is 1, the SSB with the corresponding index is transmitted.

[0026] The number of SSB indices determined according to the above method is denoted as . Since the SSB occupies four consecutive symbols starting from its start symbol, the actual number of time-domain symbols occupied by the SSB is [number missing]. .

[0027] 2. Frequency domain resources occupied by SSB A Service-Side Bus (SSB) occupies 240 consecutive subcarriers in the frequency domain. Normally, there is no offset between the starting subcarrier of the SSB and the starting subcarrier of common resource block 0. However, to increase flexibility, 5G NR networks may allow a certain frequency offset between them, with the relative offset not exceeding one resource block. In this case, the SSB does not occupy an integer number of resource blocks. According to the 5G NR network protocol, the data in the resource blocks overlapping with the SSB's frequency domain resources are all set to 0, meaning they cannot be used for data transmission on other channels. Let the offset between the starting subcarrier of the SSB and the starting subcarrier of common resource block 0 be denoted as... Then the number of subcarriers occupied by the SSB is: ; Combining the above two conclusions, we can deduce that the number of time-frequency domain resources occupied by the SSB is: Then multiply by the corresponding modulation order Then the number of physical bits of SSB is .

[0028] Example 1: FR1 band, 15kHz subcarrier spacing, no spectrum sharing access scenario; Assuming a carrier frequency of 2GHz (≤3GHz), an SSB subcarrier spacing of 15kHz, no spectrum sharing access, and using Case A. Referring to Table 2, n=0,1. Therefore, the possible positions of the initial time-domain symbol are: {2,8} when n=0; {16,22} when n=1. The number of candidate SSB indices L1=4. Since FR1 has no spectrum sharing access, L2=L1=4. Let the higher-layer protocol parameter ssb-PositionsInBurst be "1110", indicating SSB transmission for indices 0, 1, and 2, and no transmission for index 3. Then... =3. The number of time-domain symbols S = 4 × 3 = 12.

[0029] Assuming the starting subcarrier of the SSB has no offset from the starting subcarrier of common resource block 0, i.e., Δ=0, then =240. Total number of time-frequency resource elements N=12×240=2880. Modulation order Q=2, number of physical SSB bits B=2880×2=5760 bits.

[0030] Example 2: FR2 band, 120kHz subcarrier spacing scenario; Assuming the carrier frequency band is FR2, the SSB subcarrier spacing is 120kHz, and Case D pattern is adopted. Referring to Table 2, n takes the values: 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, a total of 16 values. The starting time-domain symbol position is {4, 8, 16, 20} + 28·n. The number of candidate SSB indices L1 = 16. According to the FR2 no-spectrum-sharing access rule, L2 = L1 = 16. Let ssb-PositionsInBurst be all 1s, i.e. =16. Number of time-domain symbols S = 4 × 16 = 64.

[0031] Assuming Δ>0, then =252. N=64×252=16128, B=16128×2=32256 bits.

[0032] The above embodiments demonstrate that the present invention can directly calculate the number of physical bits of SSB based on different combinations of protocol parameters. The process is clear, the computation is small, and there is no need to call the complete protocol stack processing algorithm, which significantly improves the computational efficiency.

[0033] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for calculating the number of physical bits for a 5G NR network's SSB, characterized in that, Includes the following steps: Step 1: Based on the SSB subcarrier spacing, carrier frequency, duplex mode, and whether it is in a spectrum sharing access scenario, determine the SSB time-domain distribution pattern and the possible position of the starting time-domain symbol, and then determine the maximum number of candidate SSB indices within a half-frame. The actual number of SSB indices transmitted is determined based on the higher-layer protocol parameter ssb-PositionsInBurst. This allows us to calculate the number of time-domain symbols occupied by the SSB. ; Step 2: Based on the offset between the starting subcarrier of the SSB and the starting subcarrier of common resource block 0 Determine the number of frequency domain subcarriers occupied by the SSB. :when hour, ;when hour, ; Step 3: Based on the number of time-domain symbols occupied by the SSB Number of frequency domain subcarriers Calculate the total number of time-frequency resource elements occupied by the SSB. Then multiply by the corresponding modulation order Obtain the number of physical bits of SSB. .

2. The method for calculating the number of physical bits of a 5G NR network SSB according to claim 1, characterized in that, The SSB time-domain distribution patterns mentioned in step 1 include Case A to Case G, which correspond to different subcarrier spacings and starting time-domain symbol positions, respectively: When the subcarrier spacing is 15kHz, Case A is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 70; When the subcarrier spacing is 30kHz, either Case B or Case C is used. The starting time-domain symbol position of Case B is... The initial time-domain sign position of Case C is The number of symbols in each half-frame is 140; When the subcarrier spacing is 120kHz, Case D is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 560; When the subcarrier spacing is 240kHz, Case E is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 1120; When the subcarrier spacing is 480kHz, Case F is used, and the starting time-domain symbol position is... The number of symbols in each half-frame is 2240; When the subcarrier spacing is 960kHz, Case G is used, and the number of symbols per half frame is 4480.

3. The method for calculating the number of physical bits of a 5G NR network SSB according to claim 2, characterized in that, The variable The value range is determined based on the communication scenario and physical layer parameter configuration: For Case A: In the case of no spectrum sharing access, if the carrier frequency is ≤3GHz, then If the carrier frequency is >3GHz and belongs to FR1, then When accessing the spectrum sharing network ; For Case B: When the carrier frequency is ≤3GHz When the carrier frequency is >3GHz and belongs to FR1 ; For Case C: No spectrum sharing access, if it is FDD and the carrier frequency is ≤3GHz, then If the carrier frequency is >3GHz, then ; If it is TDD and the carrier frequency is <1.88GHz, then If the carrier frequency is ≥1.88GHz, then When accessing the spectrum sharing network ; For Case D: Used in the FR2 and FR2-NTN bands ; For Case E: Used in the FR2-1 and FR2-NTN bands ; For Case F: Used in the FR2-2 band .

4. The method for calculating the number of physical bits of a 5G NR network SSB according to claim 3, characterized in that, The possible positions of the SSB start time domain symbol mentioned in step 1 are from arrive Number them, and these numbers are respectively associated with Each candidate SSB index corresponds to; among them For variables The number of possible values; Maximum number of SSB indexes in a cell and a half-frame and The relationship is: For scenarios where the carrier frequency bands are FR1 and FR2 and there is no spectrum sharing access, or where the carrier frequency band is FR2-2 and there is spectrum sharing access, ; For a spectrum-sharing access scenario with carrier frequency band FR1, when the SSB subcarrier spacing is 15kHz and Or the SSB subcarrier spacing is 30kHz and hour, .

5. The method for calculating the number of physical bits of a 5G NR network SSB according to claim 4, characterized in that, The higher-level protocol parameter ssb-PositionsInBurst includes 1 bit, of which the highest bit corresponds to SSB index 0; If a bit is 0, the SSB with the corresponding index is not transmitted; if a bit is 1, the SSB with the corresponding index is transmitted; the number of SSB indices actually transmitted is determined based on this parameter. .

6. The method for calculating the number of physical bits of a 5G NR network SSB according to claim 1, characterized in that, The offset mentioned in step 2 The range is no more than one resource block; when At this time, the SSB occupies 252 subcarriers. Data in resource blocks overlapping with the SSB's frequency domain resources are all set to 0 and cannot be used for data transmission on other channels. At that time, the number of subcarriers occupied by the SSB is 240.

7. A system for calculating the number of physical bits for a 5G NR network SSB, used to perform the method for calculating the number of physical bits for a 5G NR network SSB as described in any one of claims 1 to 6, characterized in that, include: The time-domain resource calculation module is used to determine the number of time-domain symbols occupied by the SSB based on the subcarrier spacing, carrier frequency, duplex mode, spectrum sharing access scenario, and higher-layer protocol parameter ssb-PositionsInBurst. The frequency domain resource calculation module is used to determine the number of frequency domain subcarriers occupied by the SSB based on the offset between the starting subcarrier of the SSB and the starting subcarrier of the common resource block 0. The physical bit count calculation module is used to calculate the total number of time-frequency resource elements based on the number of time-domain symbols and the number of frequency-domain subcarriers, and multiply it by the modulation order to output the physical bit count of SSB.

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