Power wireless private network physical layer frame structure definition and synchronization block mapping method

Abstract

The invention relates to a power wireless private network physical layer frame structure definition and synchronization block mapping method, and belongs to the technical field of wireless communication. The method comprises the following steps: firstly, subdividing a sub-band in a 230MHz frequency band into 2.5 kHz sub-carriers, generating a sub-carrier attribute table, and recording available and unavailable sub-carriers; secondly, defining a frame structure of the power wireless private network, which comprises parameters such as frame length, subframes, time slots, OFDM symbols and cyclic prefixes; and finally, mapping the 5GNR standard SSB block into a power wireless private network frame structure, selecting a maximum continuous available subcarrier region for mapping, and considering the protection of subcarriers to avoid interference. Simulation results show that the method effectively improves the spectrum utilization efficiency and the system anti-interference capability, enhances the synchronization reliability, and meets the efficient and stable communication requirements of the power wireless private network in the low-frequency narrow-band environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications and relates to a physical layer frame structure definition and synchronization block mapping method for a power wireless private network. Background Art

[0002] The 230MHz band belongs to the ISM band, which is the industrial, scientific and medical band. In my country, the 230MHz band is widely used in power wireless private network communications. The bandwidth of this band is relatively narrow, generally around 10MHz, and is often shared by multiple industries, such as Figure 1 As shown, in the power industry, the frequency band distribution is discontinuous and easily interfered by signals from other industries, and each sub-band bandwidth is only 25KHz. For the special application scenarios of the power private network, the subcarrier bandwidth in the standard frame structure of the fifth generation mobile communication (abbreviated as: 5GNR) is an integer multiple of 15KHz, which is not completely suitable for deploying 5GNR in the 230MHz frequency band. In addition, the 5G standard design is mainly for higher frequency bands and dedicated spectrum design, while the 230MHz frequency band in the power wireless private network has limited bandwidth and sharing characteristics, and the spectrum is discrete, which makes it impossible for the 5GNR system to be directly deployed and used in the 230MHz frequency band.

[0003] In actual projects, there are the following technical challenges in deploying 5G NR systems on the 230 MHz frequency band.

[0004] First: Choose a reasonable subcarrier spacing and FFT points

[0005] In the 5GNR system, the subcarrier spacing is mainly based on integer multiples of 15KHz, such as 15kHz, 30kHz, and 60kHz. In the 230MHz frequency band, the bandwidth of each subband is only 25KHz, and the out-of-band leakage of each subband needs to be considered. Therefore, the 5GNR system should require more detailed spectrum planning in the power wireless private network. For example, the subcarrier spacing is set to 2KHz or 2.5kHz to obtain higher spectrum resolution, but this requires a higher FFT (Fast Fourier Transform) point number, which increases the calculation load to a certain extent. In addition, unreasonable subcarrier spacing and FFT point number design will directly affect the 230MHz spectrum utilization rate, and it is also not conducive to the reuse of existing mature 5GNR engineering technologies. Therefore, it is necessary to design a frame structure based on the 230MHz frequency band, select a reasonable subcarrier spacing and match the appropriate 5GNR system FFT point number, so that the system can achieve effective bandwidth scheduling and resource allocation under the premise of ensuring spectrum utilization.

[0006] Second: Redefine the 5GNR frame structure

[0007] In the 5GNR system, the frame structure design directly affects communication delay, spectrum utilization and reuse of existing technologies. The traditional 5GNR frame structure design uses larger subcarrier spacings such as 15kHz and 30kHz. However, for the 230MHz frequency band, each subband is 25KHz, and it is impossible to use a 15KHz subcarrier spacing. Therefore, only a narrower subcarrier spacing can be selected to meet the 230MHz frequency band usage rules. The selection of different subcarrier spacings leads to the need to redesign the frame structure of the 5GNR system. The 5GNR frame structure needs to be redesigned to meet the requirements of this special frequency band in terms of bandwidth, subcarrier spacing, FFT points, cyclic prefix (CP for short), etc.

[0008] 3. Synchronous signal block (SSB) mapping requirements

[0009] The SSB block in 5GNR is used for initial downlink synchronization between the network and the user equipment (UE), mainly providing cell identification information and preliminary synchronization information. In the traditional 5GNR frequency band, the SSB block occupies 4 OFDM symbols and 240 consecutive subcarrier resources. However, in the 230MHz frequency band, due to the discontinuity of spectrum bandwidth and resource distribution, the SSB block cannot be directly mapped to the 230MHz frequency band with 240 consecutive subcarriers. Secondly, the power industry's private network communications have high requirements for reliability. When mapping resources, the interference caused by other systems in the shared frequency band must be considered to ensure the terminal's search and interpretation of SSB block performance.

[0010] In general, deploying the power wireless private network in the 230MHz frequency band requires redesigning the frame structure and SSB block mapping rules to solve the problem of discontinuous spectrum resources. In the design, it is necessary to consider the reuse of existing 5GNR technology and meet the problem of discontinuous 230MHz spectrum. Summary of the invention

[0011] In view of this, the object of the present invention is to provide a physical layer frame structure definition and synchronization block mapping method for a power wireless private network.

[0012] In order to achieve the above object, the present invention provides the following technical solutions:

[0013] In order to solve the above problems when the 5GNR system is deployed in the 230MHz shared frequency band, the present invention proposes a frame structure based on the 230MHz frequency band and a 5GNR SSB block mapping method. It mainly includes the following aspects:

[0014] The system of the present invention comprises four modules, namely, a subcarrier definition module, a subcarrier mapping module, a frame structure parameter definition module, and an SSB block mapping module. Figure 2 shown.

[0015] Subcarrier definition module: The subband bandwidth of the 230MHz frequency band is 25KHz, with a total of 480 independent frequency points. The power wireless private network subdivides the 25KHz subband into 10 5GNR subcarriers, each subcarrier is spaced 2.5kHz, and a total of 4800 subcarriers are recorded in a table, that is, the attributes of each subcarrier belong to the power system, light industry and construction, light industry and earthquake, military and earthquake, and idle subbands. The 5GNR system can only use subcarriers corresponding to the power system and idle subbands.

[0016] Subcarrier mapping module: Among the 4800 subcarriers, since multiple systems share the subband, the available subcarriers are discrete. The power wireless private network selects more than 12 consecutive subcarriers as available subcarriers, and the available subcarriers can only be an integer multiple of 12. If the number of consecutive subcarriers is not an integer multiple of 12, the remaining subcarriers on the edge are used as protection intervals.

[0017] Frame structure parameter definition module: The 5GNR system in the 230MHz frequency band can use 4800 subcarriers, and the power wireless private network chooses to use 4096 subcarriers. The subcarrier spacing is 2.5KHz, and the bandwidth is 10.24MHz. By changing the center frequency band position, the 4800 subcarrier resources can be flexibly used. In order to reuse the 5GNR design, the frame structure length is defined as 10ms, divided into 10 subframes, and each subframe contains 2 OFDM symbols.

[0018] SSB block mapping module: The SSB block in a normal 5GNR system occupies 240 subcarrier positions. The power wireless private network selects the frequency band with the most continuous subcarriers among the available subcarriers to carry SSB transmission. The power wireless private network gives priority to ensuring the normal transmission of the SSB block.

[0019] The present invention provides a method for defining a physical layer frame structure and a synchronization block mapping method for a power wireless private network, comprising the following steps:

[0020] Process 1: Generation process of available subcarrier attribute table of power wireless private network, such as Figure 3 shown.

[0021] Step 1: According to the definition of 230MHz frequency band subband, each subband has a bandwidth of 25KHz, and there are 480 subbands in total. The power wireless private network re-divides the 480 subbands in the 230MHz frequency band into 4800 subcarriers (480x10=4800) according to the subcarrier spacing of 2.5kHz, that is, each subband is subdivided into 10 subcarriers. Figure 3 Middle 1 step.

[0022] Step 2: Classify the subcarrier identification. Among the 4800 subcarriers, identify the subcarrier corresponding to the idle subband as 0, and record the subcarrier number in the index_0 array; the subcarrier corresponding to the subbands for light industry and construction, light industry and earthquake, and military and earthquake is identified as 1, and the subcarrier number is recorded in the index_1 array; the subcarrier corresponding to the subband dedicated to the power system is identified as 2, and the subcarrier number is recorded in the index_2 array. Figure 3 Middle 2 steps.

[0023] Step 3: In the classification of 4800 subcarrier frequency domain resources, the subcarriers corresponding to the idle subbands and power system subbands are defined as available subcarriers for the power wireless private network, and the remaining subcarriers are defined as unavailable subcarriers for the power wireless private network. The subcarrier attribute table is used to record the subcarrier attributes to facilitate the allocation and use of subcarriers for the power wireless private network. Figure 3 Middle 3 steps.

[0024] Step 4: The power wireless private network uses 12 subcarriers as the minimum basic unit of frequency domain resources. The power wireless private network supports the allocation of frequency resources of multiple basic units, but it must ensure that the basic unit of 12 subcarriers occupies continuous subcarriers. That is, the subcarriers that can be used by the power wireless private network must be continuous subcarriers, and the number of continuous subcarriers must be an integer multiple of 12. Figure 3 Middle 4 steps.

[0025] Step 5: Re-update the identifier of the 4800 subcarrier number. The numbers of the subcarriers that can be occupied are recorded in the as_index array, and the numbers of the subcarriers that cannot be occupied are recorded in the ns_index array. Figure 3 5 steps in.

[0026] Step 6: The power wireless private network frame structure resource grid can use 4096 subcarriers at a time, and the selected fast Fourier transform (FFT) point number is 4096. The power wireless private network selects 4096 consecutive subcarriers from 4800 subcarriers and arranges them from low frequency to high frequency. Figure 3 Middle 6 steps.

[0027] Process 2: Subcarrier resource determination process, such as Figure 4 shown.

[0028] According to the subcarrier attribute table, the power wireless private network can only use the subcarriers marked as available, and the subcarriers can only be allocated and used in integer multiples of the basic unit. In the 230MHz frequency band, each subband is 25KHz, which is divided into 10 2.5KHz subcarriers. 12 consecutive subcarrier resources cannot be used as protection subcarriers.

[0029] Assuming that there are m continuous 25KHz sub-bands available, there are a total of M (M = 10*m) sub-carriers, and the number of sub-carriers available for the power wireless private network is 12*K (K = M%12), where "%" indicates modulo calculation and "*" indicates multiplication calculation. The number of sub-carriers that cannot be used is S (S = 10*m-12*K).

[0030] Among the M subcarriers, the first ceil (S / 2) subcarriers and the last S-ceil (S / 2) subcarriers cannot be used and can only exist as protection subcarriers. The ceil () is calculated by taking the minimum integer.

[0031] Process 3: Power wireless private network frame structure definition, such as Figure 5 shown.

[0032] The power wireless private network defines a frame length of 10 milliseconds (10ms). Each frame is divided into 10 subframes. Each subframe consists of 1 time slot. Each time slot consists of two OFDM symbols. Each OFDM symbol consists of an OFDM prefix (abbreviated as: CP) and an OFDM data part, where the OFDM prefix is ​​1024 points and the OFDM data part is 4096 points.

[0033] The design process of the frame structure parameters of the power wireless private network, such as Figure 6 shown.

[0034] Step 1: Sampling rate definition: Based on the subcarrier spacing (SCS) of 2.5kHz and the number of FFT points of 4096, the frame structure clock rate is defined as 10240000, also known as the sampling rate, recorded as SampleRate. Figure 6 Step 1.

[0035] SampleRate = subcarrier spacing x FFT points = 2.5KHz x 4096 = 10240000

[0036] Step 2: Frame length definition: Define a wireless frame T f The length is 10ms, including 10 subframes, each subframe T sf According to the defined sampling rate, the total number of sampling points per frame is N. f and the number of subframe sampling points N sf .like Figure 6 Step 2.

[0037] N f =SampleRate×T f =102400

[0038] N sf =SampleRate×T sf =10240

[0039] Step 3: Definition of OFDM symbol number: Determine the number of OFDM symbols in a time slot. The FFT point number used in the power wireless private network is 4096, and the number of symbols Symbols must satisfy the total number of samples Symbols×FFT≤N sf , so the maximum number of symbols is That is, one subframe consists of 2 OFDM symbols. Figure 6 Step 3.

[0040] Step 4: Time slot definition: Each time slot in the design contains 2 OFDM symbols, and one subframe contains one time slot, that is, like Figure 6 Step 4.

[0041] Step 5: Cyclic prefix definition: The cyclic prefix length (CPLength) meets the frame structure length requirement, that is, 2×(CPLength+FFT)=N sf , then the calculation method of the cyclic prefix length CPLength is defined as follows.

[0042]

[0043] like Figure 6 Step 5.

[0044] The frame structure parameters of the power wireless private network, such as Figure 7 shown.

[0045] Process 4: Implementation process of mapping SSB block to 230MH band

[0046] Step 1: Generate SSB blocks using the standard 5GNR standard. The SSB consists of 4 OFDM symbols and 240 subcarriers. The definition of the SSB block of the power wireless private network complies with the 5GNR standard definition. Figure 8 Middle 1 step.

[0047] Step 2: Determine the OFDM symbol position occupied by the SSB block. According to the 5GNR frame structure and SSB time slot position definition, it is defined that one wireless frame of the power wireless private network can carry two SSB blocks, which are placed at the second OFDM symbol and the eighth OFDM symbol of the frame structure respectively, and are recorded as the starting symbol position of the SSB block in the wireless frame {2,8}. Figure 8 Middle 2 steps.

[0048] Step 3: Determine the frequency domain mapping of the SSB block. In the power wireless private network frame structure resource grid, based on the record of the subcarrier numbers that can be occupied, search for the largest continuous subcarrier area that can be used, map the 240 continuous subcarriers of the SSB block to this available subcarrier number, and mark the corresponding subcarrier number position as ssbUsedCarrier. Figure 8 Middle 3 steps.

[0049] The beneficial effects of the present invention are:

[0050] Aiming at the special needs of the 230MHz shared frequency band, the present invention proposes a time-frequency resource allocation method adapted to the 5GNR system. By redesigning the frame structure, optimizing the subcarrier resource table and improving the SSB synchronization signal mapping, the sharing and spectrum discontinuity problems of the frequency band are solved. This method effectively improves the spectrum utilization efficiency and the anti-interference ability of the system, while enhancing the synchronization reliability, and meets the needs of the power wireless private network for efficient and stable communication in a low-frequency narrowband environment. The specific points are as follows.

[0051] First: Aiming at the requirement of deploying the 5GNR system of the power wireless private network to the 230MHz frequency band, the present invention redesigns the existing 5GNR frame structure to be compatible with the 5GNR standard to the greatest extent possible while meeting its transmission requirements on the 230MHz frequency band.

[0052] Second: In view of the characteristics of the 230MHz shared spectrum, the 25KHz sub-band is subdivided into 2.5KHz subcarrier bandwidth. By redefining the frame structure resource grid and subcarrier mapping method of the power wireless private network, a subcarrier table for the power wireless private network is generated to record the subcarrier availability of the 230MHz frequency band.

[0053] Third: According to the resource grid of the power wireless private network frame structure, search for reliable subcarrier areas to carry SSB blocks, so as to maintain the best synchronization performance when the spectrum resources are discontinuous.

[0054] Fourth: In the definition of the resource grid of the power wireless private network frame structure, only 12 integer multiples of available continuous subcarrier areas are used. If there are scattered subcarriers in two segments of the available subcarrier area, they are used as protection subcarriers to avoid interference between different systems.

[0055] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0057] Figure 1 This is a schematic diagram of the division of frequencies in the 230MHz frequency band;

[0058] Figure 2 A framework for deploying the 230MHz band for 5G NR systems;

[0059] Figure 3 It is the sub-band subdivision process of 230MHz frequency band;

[0060] Figure 4 To define the allocation method of available subcarriers;

[0061] Figure 5 Define a schematic diagram for the frame structure;

[0062] Figure 6 Define a process diagram for the frame structure;

[0063] Figure 7 Define the frame structure for the power wireless private network;

[0064] Figure 8 It is the SSB block mapping process;

[0065] Fig. 9 The occupancy of each user's subcarrier;

[0066] Fig.10 A schematic diagram of calculating the available subcarrier positions;

[0067] Fig.11 Update flow chart for subcarrier occupancy;

[0068] Fig.12 A diagram of discrete subcarriers available for power wireless private networks;

[0069] Fig.13 NR 230 subcarrier grid and subband table; Fig.13 (a) Available subcarriers for power wireless private networks; Fig.13 (b) The subcarriers occupied by the power wireless private network in the time-frequency resource diagram;

[0070] Fig.14 Verify the block diagram for the SSB simulation link;

[0071] Fig.15 Map resource graph for SSB; Fig.15 (a) is a continuous 240x4 SSB time-frequency resource diagram; Fig.15 (b) is the SSB discrete time-frequency resource diagram;

[0072] Fig.16 Remap resource map for SSB; Fig.16 (a) is the SSB discrete time-frequency resource diagram; Fig.16 (b) is a continuous 240×4 SSB time-frequency resource diagram

[0073] Fig.17 It is the time-frequency resource diagram of the transmitting and receiving ends without interference; Fig.17 (a) is the continuous time-frequency resource diagram of the transmitter; Fig.17 (b) is the discrete time-frequency resource diagram of the transmitter; Fig.17 (c) is the discrete time-frequency resource diagram at the receiving end; Fig.17 (d) is the continuous time-frequency resource map at the receiving end; Fig.17 (e) is the continuous SSB time-frequency resource diagram at the receiving end;

[0074] Fig.18 The spectrum resource diagram for the transmitting and receiving ends without interference; Fig.18 (a) is the discrete time-frequency resource diagram of the transmitter (txAnt1); Fig.18 (b) is the discrete time-frequency resource diagram of the transmitter (txAnt2); Fig.18 (c) is the discrete time-frequency resource diagram of the receiving end (txAnt1); Fig.18 (d) is the discrete time-frequency resource diagram of the receiving end (txAnt2);

[0075] Fig.19 This is the SSB demodulation diagram without interference: SNR = 20dB; Fig.19 (a) is the PSS demodulation constellation diagram; Fig.19 (b) is the SSS demodulation constellation diagram; Fig.19 (c) is the unbalanced PBCH demodulation constellation diagram; Fig.19 (d) is the PSS signal detection result; Fig.19 (e) is the SSS signal detection result; Fig.19 (f) is the PBCH demodulation constellation diagram after equalization; Fig.19 (g) is the ibar_SSB detection result; Fig.19 (h) is the PBCH amplitude after equalization; Fig.19 (i) is the PBCH phase after equalization;

[0076] Fig. 20 This is the SSB demodulation performance diagram without interference; Fig. 20 (a) is a schematic diagram of PSS signal threshold; Fig. 20 (b) is the PSS signal detection result; Fig. 20 (c) is a schematic diagram of the SSS signal threshold; Fig. 20 (d) is the SSS signal detection result; Fig. 20 (e) is the PBCH detection bit error rate;

[0077] Fig.21 The block diagram of the SSB simulation link for chirp interference;

[0078] Fig. 22 It is the time-frequency resource diagram of the transmitting and receiving ends of the chirp interference; Fig. 22 (a) is the continuous time-frequency resource diagram of the transmitter; Fig. 22 (b) is the discrete time-frequency resource diagram of the transmitter; Fig. 22 (c) is the discrete time-frequency resource diagram at the receiving end; Fig. 22 (d) is the continuous time-frequency resource map at the receiving end; Fig. 22 (e) is the continuous SSB time-frequency resource diagram at the receiving end;

[0079] Fig.23 Spectrum resource diagram for the transmitter and receiver of chirp interference; Fig.23 (a) is the discrete time-frequency resource diagram of the transmitter (txAnt1); Fig.23 (b) is the discrete time-frequency resource diagram of the transmitter (txAnt2); Fig.23 (c) is the discrete time-frequency resource diagram of the receiving end (txAnt1); Fig.23 (d) is the discrete time-frequency resource diagram of the receiving end (txAnt2);

[0080] Fig.24 This is the SSB demodulation diagram of chirp interference; Fig.24 (a) is the PSS demodulation constellation diagram; Fig.24 (b) is the SSS demodulation constellation diagram; Fig.24 (c) is the unbalanced PBCH demodulation constellation diagram; Fig.24 (d) is the PSS signal detection result; Fig.24 (e) is the SSS signal detection result; Fig.24 (f) is the PBCH demodulation constellation diagram after equalization; Fig.24 (g) is the ibar_SSB detection result; Fig.24 (h) is the PBCH amplitude after equalization; Fig.24 (i) is the PBCH phase after equalization;

[0081] Fig.25 The SSB demodulation performance diagram for chirp interference is as follows: Fig.25 (a) is a schematic diagram of PSS signal threshold; Fig.25 (b) is the PSS signal detection result; Fig.25 (c) is a schematic diagram of the SSS signal threshold; Fig.25 (d) is the SSS signal detection result; Fig.25 (e) is the PBCH detection bit error rate;

[0082] Fig.26It is the time-frequency resource diagram of the transmitting and receiving ends of the chirp interference of the unoccupied SSB subcarrier; Fig.26 (a) is the continuous time-frequency resource diagram of the transmitter; Fig.26 (b) is the discrete time-frequency resource diagram of the transmitter; Fig.26 (c) is the discrete time-frequency resource diagram at the receiving end; Fig.26 (d) is the continuous time-frequency resource map at the receiving end; Fig.26 (e) is the continuous SSB time-frequency resource diagram at the receiving end;

[0083] Fig. 27 The spectrum resource diagram of the transmitting and receiving ends of the chirp interference of the unoccupied SSB subcarrier; Fig. 27 (a) is the discrete time-frequency resource diagram of the transmitter (txAnt1); Fig. 27 (b) is the discrete time-frequency resource diagram of the transmitter (txAnt2); Fig. 27 (c) is the discrete time-frequency resource diagram of the receiving end (txAnt1); Fig. 27 (d) is the discrete time-frequency resource diagram of the receiving end (txAnt2);

[0084] Fig.28 is the SSB demodulation diagram of chirp interference on unoccupied SSB subcarriers; Fig.28 (a) is the PSS demodulation constellation diagram; Fig.28 (b) is the SSS demodulation constellation diagram; Fig.28 (c) is the unbalanced PBCH demodulation constellation diagram; Fig.28 (d) is the PSS signal detection result; Fig.28 (e) is the SSS signal detection result; Fig.28 (f) is the PBCH demodulation constellation diagram after equalization; Fig.28 (g) is the ibar_SSB detection result; Fig.28 (h) is the PBCH amplitude after equalization; Fig.28 (i) is the PBCH phase after equalization;

[0085] Fig.29 is the SSB demodulation performance diagram of chirp interference on unoccupied SSB subcarriers; Fig.29 (a) is a schematic diagram of PSS signal threshold; Fig.29 (b) is the PSS signal detection result; Fig.29 (c) is a schematic diagram of the SSS signal threshold; Fig.29 (d) is the SSS signal detection result; Fig.29 (e) is the PBCH detection bit error rate. DETAILED DESCRIPTION

[0086] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0087] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0088] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0089] In order to clearly illustrate the specific meaning and usage of the present invention, this embodiment will use a MATLAB simulation embodiment to further illustrate the application method of the present invention in a power wireless private network.

[0090] Process 1: Subdivision of 25KHz sub-band in 230MH frequency band. Fig. 9 shown.

[0091] First, for the 480 sub-bands in the 230MHz shared frequency band, each sub-band 25KHz frequency point is divided into 10 2.5KHz sub-carriers, generating a total of 4800 sub-carrier resources.

[0092] According to the different attributes of the 230MHz sub-band, refer to the "Notice of the Ministry of Industry and Information Technology on Adjusting the Frequency Usage Planning of Wireless Data Transmission Systems in the 223-235MHz Frequency Band", the sub-band allocation rules are as follows: Figure 1The power wireless private network identifies the subcarrier resources corresponding to each 25KHz subband according to its attributes: the subcarriers of idle subbands are marked as 0, the subcarriers of non-power authorized subbands are marked as 1, and the subcarriers of power system subbands are marked as 2, generating a complete subcarrier resource table containing various subbands, also known as a subcarrier attribute table, as shown in Fig. 9 This process completes the subdivision of the 25KHz subband numbering of the 230MHz shared frequency band into subcarrier numbers of 2.5KHz subcarrier bandwidth, totaling 4800 subcarriers.

[0093] The specific process is as follows.

[0094] Step 1: In the power wireless private network, create a subcarrier attribute table. You can use the subcarriers of the idle subband and the subcarriers of the power system subband, that is, Fig. 9 In the example, the subcarriers whose attributeFlag is 2 and 0. However, not all subcarriers in idle subbands and subcarriers in power system subbands can be used in power wireless private networks. Fig.11 Middle 1 step.

[0095] Step 2: In the subcarrier attribute table of 4800 subcarriers, calculate the number of resource blocks (RBs) in the continuous subcarrier area. The minimum resource block contains 12 continuous subcarriers. Assuming that a continuous M available subcarriers are searched among 4800 subcarriers, the length is recorded as a_length, and the starting subcarrier number is recorded as start_idx, then the power wireless private network can use 12*K (K=M%12) subcarriers. K is the number of unit resource blocks, recorded as num_blocks. The "%" is calculated modulo. num_blocks=a_length%12, such as Fig.11 Step 2,3.

[0096] Fig.12 Diagram of available discrete subcarriers for power wireless private networks.

[0097] In this embodiment,

[0098] Fig.12 In the first row, two consecutive 25KHz subbands are subdivided into 20 subcarriers, so the resource block that can be used is 20% 12=1, that is, only 12 of the subcarriers can be used by the power wireless private network.

[0099] Fig.12 In the second row, three consecutive 25KHz subbands are subdivided into 30 subcarriers, so the resource block that can be used is 30% 12=2, that is, only 24 of the subcarriers can be used by the power wireless private network.

[0100] Fig.12In the third row, four consecutive 25KHz subbands are subdivided into 40 subcarriers, so the resource block that can be used is 40% 12=3, that is, only 36 of the subcarriers can be used by the power wireless private network.

[0101] Fig.12 In the fourth row, five consecutive 25KHz subbands are subdivided into 50 subcarriers, so the resource block that can be used is 50% 12=4, that is, only 48 of the subcarriers can be used by the power wireless private network.

[0102] All other situations can be calculated in the same way.

[0103] Step 3: Calculate the number of subcarriers that can be occupied in the continuous subcarrier block, based on the resource block number num_blocks calculated in step 1. The number of valid subcarriers that can actually be used in the power wireless private network is 12*K, recorded as valid_length, valid_length = num_blocks × 12. Fig.11 Middle 4 steps.

[0104] In this embodiment,

[0105] Fig.12 In the first row, the power wireless private network uses 12 subcarriers.

[0106] Fig.12 In the second row, the power wireless private network uses 24 subcarriers.

[0107] Fig.12 In the third row, the power wireless private network uses 36 subcarriers.

[0108] Fig.12 In the fourth row, the power wireless private network uses 48 subcarriers.

[0109] All other situations can be calculated in the same way.

[0110] Step 4: Update the starting position of the continuous subcarrier block in the subcarrier attribute table. Fig.11 Middle 4 steps.

[0111] start_keep=start_idx+(a_length-valid_length) / 2

[0112] Among them, a_length indicates the size of the subcarrier area that can be used continuously in the subcarrier attribute table; valid_length indicates the subcarrier that can be directly used by the power wireless private network; start_idx indicates the starting position of the subcarrier area size; start_keep indicates the starting number of the subcarrier that can be used by the power wireless private network. Fig.10 shown.

[0113] Step 5: Update the end position of the continuous subcarrier block in the subcarrier attribute table, such as Fig.10 shown.

[0114] end_keep=start_keep+valid_length-1.

[0115] Among them, end_keep indicates the end number of the subcarrier that can be used in the power wireless private network.

[0116] Step 6: Record the occupied subcarrier positions after the subcarrier attribute table is updated in the burst_OccupiedSubcarriers array to provide a mark for subsequent frequency domain resource scheduling and data transmission. Fig.11 5 steps in.

[0117] Fig.13 The NR 230 subcarrier grid and subband table. The updated subcarrier attribute table occupancy is as follows: Fig.13 As shown in (a), "1" indicates the position of the subcarrier that can be occupied, while "0" indicates the position of the subcarrier that cannot be occupied.

[0118] also, Fig.13 (b) shows the distribution of the corresponding subcarriers after the update in the time-frequency resource grid (an OFDM symbol), which intuitively reflects the availability of the subcarriers.

[0119] Process 2: Mapping and verification process of SSB blocks on the time-frequency resource grid of the power wireless private network.

[0120] The MATLAB simulation platform is used to verify the transmission of the SSB block on the wireless resources of the power wireless private network. In this embodiment, the power wireless private network first subdivides the 230MHz shared frequency band into 4800 subcarriers through process 1 in this embodiment, and records the subcarrier attribute table. From the 4800 subcarriers, the 4096 consecutive subcarriers are specifically numbered from 1 to 4096 to form the resource grid of the power wireless private network.

[0121] This embodiment will verify the newly defined power wireless private network frame structure and the method of mapping SSB to 230MHz discrete spectrum. First, MATLAB is used to simulate one frame (10ms) of data.

[0122] According to the content of the present invention, the parameters of the simulation settings in this embodiment include: the FFT point number is set to 4096; the subcarrier spacing (SCS) is 2.5kHz; the sampling rate is 10240000; the signal-to-noise ratio is 5dB, denoted as snr; and the cell identifier (NCellID) is set to 102.

[0123] Specific verification link block diagram, such as Fig.14 shown.

[0124] according to Fig.14 The simulation link structure shown in the figure is as follows:

[0125] Step 1: Prepare the resource grid of the power wireless private network. According to the subcarrier attribute table in the process 1 of this embodiment, generate the resource grid of the power wireless private network. The resource grid of the power wireless private network occupies 4096 subcarriers, and the subcarrier bandwidth is 2.5KHz.

[0126] Note: Not all subcarriers in the resource grid of the power wireless private network can be used.

[0127] Step 2: Generate SSB time-frequency data blocks. Fig.16 The SSB remapping resource map is shown in Figure 2. In this embodiment, the 5GNRToolbox toolbox is used to generate a 240x4 SSB time-frequency data block to ensure that the SSB block used in the power wireless private network meets the 5GNR standard specification requirements, which is recorded as tx_ssb_resourceGrid. Then the SSB is mapped to the corresponding OFDM symbol position in the wireless frame. According to the present invention, it can be mapped to the starting position of the {2,8} OFDM symbol. In this embodiment, it starts from 2 OFDM. Fig.16 (a). Step 3: Fig.15 The SSB block is remapped to the updated power wireless private network resource grid, and the subcarrier positions that can be occupied in the updated 4096×20 time-frequency resource table are mapped. Fig.15 The SSB block in (a) is remapped to the power wireless private network resource grid, denoted as tx_resourceGrid, as shown in Fig.15 (b) as shown.

[0128] Step 4: OFDM modulation. Perform OFDM modulation on tx_resourceGrid, perform 4096-point inverse fast Fourier transform (IFFT) on each OFDM symbol in the power wireless private network resource grid, obtain a 4096-point OFDM symbol data area, and add a 1024-point cyclic prefix to the head to form a complete OFDM symbol time domain data, a total of 20 OFDM symbols, so a time domain signal with a wireless frame (10ms) length is generated, a total of 102400 points of data, recorded as a_tx_waveform.

[0129] Step 5: The time domain signal of the power wireless private network passes through the simulation channel. That is, the time domain signal a_tx_waveform is simulated through the NR channel (CDL) and AWGN, and the received signal a_rx_waveform is output. In this embodiment, the channel model provided by MATLAB is used. The channel model sampling clock selects the power wireless private network sampling frequency 10240000 defined in the present invention. Different signal-to-noise ratios can be selected in the simulation to evaluate the SSB demodulation performance.

[0130] Step 6: OFDM demodulation. Perform OFDM demodulation on the received time domain signal a_rx_waveform to obtain a 4096×20 time-frequency resource grid rx_resourceGrid, as shown in Fig.16 In this embodiment, the simulation is performed under the assumption of perfect timing and frequency offset synchronization.

[0131] Step 7: Remap the discrete SSB blocks in the power wireless private network resource grid. According to the occupied position of SSB, the discrete SSB signal is remapped into a continuous 240×4 time-frequency resource grid rx_ssb_resourceGrid, such as Fig.16 (a) shown.

[0132] Step 8: Extract PSS data according to the position of PSS in SSB block, record it as pssRx, and use conventional search algorithm to solve it

[0133] Step 9: Extract the SSS data according to the position of SSS in the SSB block, record it as sssRx, and use the conventional search algorithm to solve it

[0134] Step 10: Extract DMRS data according to the position of DMRS in the SSB block, record dmrsRx, and blindly detect the signal strength ibar_SSB.

[0135] Step 11: Use dmrsRx data and occupied subcarrier positions to perform channel estimation and equalization to complete the equalization processing of PBCH channel data.

[0136] Step 13: Parse the PBCH data to obtain the MIB bit data stream carrying CRC. First, use CRC detection to evaluate the impact of CRC detection on system performance, and then calculate the MIB block bit error rate.

[0137] Step 14: Count the PSS, SSS, MIB false detection rate, and MIB data block bit error rate.

[0138] In this embodiment, the above-mentioned SSB simulation link is used to evaluate different simulation scenarios.

[0139] Scenario 1: Impact on SSB synchronization when the available spectrum in the power wireless private network resource grid is not occupied by other systems

[0140] In scenario 1, it is assumed that the spectrum resources available in the power wireless private network resource grid are not occupied by other systems, so the impact on the SSB (synchronization signal and broadcast signal) synchronization performance in this scenario is relatively small. Table 1 shows the detailed parameter configuration of scenario 1.

[0141] In this scenario, the subcarriers of the SSB (synchronization signal block) signal are spectrally distributed in a discrete manner in the power wireless private network resource grid, and these subcarriers strictly follow the spectrum resource configuration defined by the power wireless private network. Importantly, no interference from any other signal occurs at the allocated subcarrier position, ensuring the purity and reliability of the SSB signal during transmission. To clearly illustrate this process, the following legend uses "Antx" to represent the antenna, where "Ant" represents the antenna and "x" identifies the specific antenna number.

[0142] Fig.17 It is the time-frequency resource diagram of the transmitting and receiving ends without interference; Fig.17 (a) is the continuous time-frequency resource diagram of the transmitter; Fig.17 (b) is the discrete time-frequency resource diagram of the transmitter; Fig.17 (c) is the discrete time-frequency resource diagram at the receiving end; Fig.17 (d) is the continuous time-frequency resource map at the receiving end; Fig.17 (e) is the continuous SSB time-frequency resource diagram at the receiving end. Fig.17 The figure shows the occupancy of antenna 1 at the transmitting end and the receiving end in the continuous and discrete time-frequency resource grids. Specifically, the figure shows how the SSB synchronization signal is converted from the continuous time-frequency resource grid to the subcarrier occupancy in the power wireless private network resource grid through a specific mapping algorithm, and the corresponding OFDM symbols are generated accordingly. At the same time, the figure further shows how to remap these subcarrier information back to the continuous time-frequency resource grid to ensure the effectiveness of resource allocation and stable signal transmission. This process highlights the mapping characteristics of the SSB signal from the continuous resource grid to the discrete resource grid, as well as the allocation of subcarriers and the position of OFDM symbols in this process.

[0143] Fig.18 The spectrum resource diagram for the transmitting and receiving ends without interference; Fig.18 (a) is the discrete time-frequency resource diagram of the transmitter (txAnt1); Fig.18 (b) is the discrete time-frequency resource diagram of the transmitter (txAnt2); Fig.18 (c) is the discrete time-frequency resource diagram of the receiving end (txAnt1); Fig.18 (d) is the discrete time-frequency resource diagram of the receiving end (txAnt2). Fig.18It further demonstrates the distribution of time-frequency resources at the transmitter and receiver ends within the power wireless private network resource grid in an interference-free environment. In particular, Fig.18 The time-frequency resource allocation relationship between antenna 1 of the transmitter and antenna 1 of the receiver, and between antenna 2 of the transmitter and antenna 2 of the receiver are shown in FIG. This figure shows the influence of the channel on the transmission characteristics of the SSB synchronization signal, and provides the occupancy of the signal in the time-frequency resource grid and the possible signal attenuation effect under interference-free conditions.

[0144] from Fig.17 and Fig.18 It can be observed that the subcarrier position of the SSB synchronization information block has a discrete distribution characteristic, and all spectrum resources of the power wireless private network resource grid are not occupied or interfered by other systems.

[0145] Table 1

[0146]

[0147] Fig.19 The figure is a demodulation diagram of SSB without interference: SNR = 20dB. In an ideal environment, assuming that the spectrum resources of the SSB synchronization block are not occupied by other systems and the system signal-to-noise ratio (SNR) is 20dB, SSB synchronization and demodulation tests are performed. Fig.19 (a) shows the constellation diagram after PSS demodulation; Fig.19 (b) shows the constellation diagram after SSS demodulation; Fig.19 (c) shows the un-equalized PBCH demodulation constellation; Fig.19 (d) shows the detection results of PSS signal; Fig.19 (e) shows the detection results of SSS signal; Fig.19 (f) shows the demodulation constellation of PBCH after equalization; Fig.19 (g) shows the detection results of ibar_SSB; Fig.19 (h) shows the PBCH amplitude after equalization; Fig.19 (i) shows the PBCH phase after equalization. It can be seen that under ideal conditions where no other system occupies the SSB block subcarrier position, the system can accurately detect and And SSB signal with cell identifier ID 374.

[0148] Furthermore, by extracting the DMRS data and frequency domain PBCH data of the PBCH from the SSB signal, the DMRS signal is used for channel estimation, and then the equalization and demodulation operations of the PBCH channel are completed. In this process, the PBCH signal is successfully restored through equalization processing, and the MIB information of the system is accurately demodulated. Finally, all demodulation operations are successfully completed, and the downlink synchronization process proceeds smoothly, verifying that the system's synchronization mechanism and signal processing method can efficiently and accurately complete signal synchronization and demodulation without other interference.

[0149] In order to illustrate the impact of different signal-to-noise ratios on SSB demodulation performance when the available spectrum in the power wireless private network resource grid is not occupied by other systems, Monte Carlo simulation is used to verify the simulation, and the number of simulations is 1000.

[0150] Fig. 20 The figure is a non-interfered SSB demodulation performance diagram. In an ideal environment, it is assumed that the spectrum resources of SSB (synchronization signal block) are not occupied by other systems, and the SSB synchronization and demodulation performance are tested under different signal-to-noise ratio (SNR) conditions. Fig. 20 (a) shows a schematic diagram of the PSS signal threshold; Fig. 20 (b) shows the PSS signal detection results; Fig. 20 (c) shows a schematic diagram of the SSS signal threshold; Fig. 20 (d) shows the SSS signal detection result. The threshold calculation formula is: From the results shown in the figure, it can be observed that when the subcarrier position of the SSB block is not occupied by other systems, the detection accuracy of the PSS and SSS signals gradually increases with the improvement of the signal-to-noise ratio. This shows that in a high signal-to-noise ratio environment, the SSB synchronization signal can be more accurately detected and demodulated, thereby improving the synchronization performance of the system. Furthermore, the DMRS data and frequency domain PBCH data of the PBCH are extracted from the SSB synchronization block, and accurate channel estimation is performed through the DMRS signal, thereby realizing the equalization and demodulation operation of the PBCH channel. Fig. 20 (e) shows the bit error rate (BER) variation trend of PBCH signals under different signal-to-noise ratio conditions. The results show that as the signal-to-noise ratio increases, the PBCH bit error rate gradually decreases, indicating that channel equalization and demodulation operations are more effective in an environment with a high signal-to-noise ratio, and the signal recovery accuracy is significantly improved.

[0151] In this embodiment, the above simulation verifies the correctness of the design of this solution in a non-interference environment.

[0152] Scenario 2: Impact of other chirp systems occupying valid subcarriers of the SSB block on SSB resolution performance

[0153] 230MHz shared frequency band, part of which is 25KHz sub-band used by other systems. In this embodiment, the main purpose is to verify the impact of other system interference on SSB performance. In this embodiment, chirp signals are used to simulate other systems. The chirp bandwidth generated by simulation is 25KHz, and the sampling rate of the generated chirp time domain signal is the same as the sampling rate of the power wireless private network, so that the time domain signals can be directly added and merged during the simulation process. Link as Fig.21 shown.

[0154] The parameter configuration in scenario 2 is shown in Table 2. In this scenario, the Chirp signal occupies specific spectrum resources. This embodiment assumes that the Chirp signal occupies the SSB (synchronization signal block) subcarrier positions in the power wireless private network resource grid. These positions include: 210, 211, 212, 213, 214, 215, 216, 217, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229 (the Chirp signal bandwidth is 50kHz). These subcarriers are within the available subcarrier range (4096×20) of the power wireless private network, and the subcarrier positions occupied by the Chirp signal overlap with the SSB signal, thereby interfering with the PSS, SSS and PBCH signals. This configuration is used to accurately evaluate the impact of the Chirp signal on the SSB signal.

[0155] Fig. 22 The time-frequency resource distribution of antenna 1 at the transmitting and receiving ends is shown. Specifically, Fig. 22 (a)~ Fig. 22 (b) shows the mapping process of SSB signals from continuous time-frequency resource grids to power wireless private network resource grids, and presents the occupancy of subcarriers of SSB signals in power wireless private network resource grids; Fig. 22 (c)~ Fig. 22 (e) shows in detail the effective subcarrier positions of the SSB block occupied by the Chirp signal, and how the Chirp signal affects the corresponding positions of consecutive subcarriers of the SSB block after remapping, further revealing the impact of the Chirp signal on the occupancy of the SSB resource grid.

[0156] Fig.23 Spectrum resource diagram for the transmitter and receiver of chirp interference; Fig.23 (a) is the discrete time-frequency resource diagram of the transmitter (txAnt1); Fig.23 (b) is the discrete time-frequency resource diagram of the transmitter (txAnt2); Fig.23 (c) is the discrete time-frequency resource diagram of the receiving end (txAnt1); Fig.23 (d) is the discrete time-frequency resource diagram of the receiving end (txAnt2). Fig.23The time-frequency resource distribution of transmitter antenna 1 and receiver antenna 1, transmitter antenna 2 and receiver antenna 2 is shown, highlighting the situation where the Chirp signal occupies the spectrum resources of the SSB block. This figure can effectively reflect the impact on the resolution performance of the SSB signal when the Chirp signal occupies the effective subcarrier position of the SSB block. Through the analysis of this time-frequency resource diagram, the interference characteristics of the Chirp signal in the power wireless private network spectrum can be further evaluated.

[0157] Table 2

[0158] Parameters Numeric Subcarrier spacing 2.5KHz FFT points 4096 CP length 1024 Number of SSBs 2 SSB starting position 2、8 Number of OFDM symbols 20 Channel Model CDL、AWGN SNR(dB) -20-20 Cell Identifier ID 374 Chirp Type Linear MIMO 2×2

[0159] Fig.24 The figure is a SSB demodulation diagram with chirp interference. In an environment where some subcarrier positions of the SSB (synchronization signal block) spectrum resource are occupied by chirp signals, the system performs SSB synchronization and demodulation tests under the condition of an SNR of 20dB. Fig.24 (a) shows the demodulated constellation diagram of the PSS signal; Fig.24 (b) shows the demodulated constellation diagram of the SSS signal; Fig.24 (c) shows the demodulation constellation diagram of the unequalized PBCH signal; Fig.24 (f) shows the demodulation constellation of PBCH after equalization. Fig.19 (a)~ Fig.19 (c) and Fig.19 Compared with the demodulation result in (f), Fig.24 (a)~ Fig.24 (c) and Fig.24 The demodulated constellation diagram in (f) shows that the Chirp signal has a certain impact on the phase of PSS, SSS and PBCH signals. Fig.24 (h) is the PBCH amplitude after equalization; Fig.24 (i) is the PBCH phase after equalization.

[0160] Fig.24 (d) shows the detection results of PSS signal; Fig.24 (e) shows the detection results of SSS signal; Fig.24 (g) shows the detection result of ibar_SSB. The test results show that when the Chirp signal occupies part of the spectrum resources of the SSB block, the system can still successfully detect the PSS and SSS signals of the cell identifier ID 374. However, compared with the case where the SSB block spectrum resources are not occupied in scenario 1, the peak value of the signal is significantly reduced, showing the impact of the Chirp signal on the synchronization performance.

[0161] Furthermore, the DMRS data and frequency domain PBCH data of PBCH are extracted from the SSB signal, and the DMRS signal is used for channel estimation, thereby completing the equalization and demodulation operations of the PBCH channel. In the environment of Chirp signal interference, the demodulation result of PBCH is still correct, which verifies the effectiveness of the channel equalization and demodulation process. However, compared with the interference-free environment in scenario 1, the demodulation peak value is slightly reduced, which indicates that the Chirp signal has a certain degree of influence on the signal processing effect under the condition of SSB block spectrum resource occupancy.

[0162] In order to illustrate the influence of chirp signal on SSB demodulation performance of power wireless private network resource grid under different signal-to-noise ratio conditions, Monte Carlo simulation was used to verify the simulation, and the number of simulations was 1000.

[0163] Fig.25 The figure is a SSB demodulation performance diagram with chirp interference. In an environment where part of the SSB (synchronization signal block) spectrum resources are occupied by chirp signals, the system tests the SSB synchronization and demodulation performance under different signal-to-noise ratio (SNR) conditions. Fig.25 (a) shows the threshold diagram of PSS signal; Fig.25 (b) shows the detection results of PSS signal; Fig.25 (c) shows the threshold diagram of SSS signal; Fig.25 (d) shows the detection result of the SSS signal. It can be seen from the test results that when the Chirp signal occupies part of the spectrum resources of the SSB block, the detection accuracy of PSS and SSS does not change significantly. This phenomenon is closely related to the high anti-interference ability of the PSS and SSS signals, which are essentially M sequences (maximum length sequences). The M sequence has excellent anti-interference ability and can resist interference from the Chirp signal to a certain extent. However, it can be seen from the threshold calculation results that the presence of the Chirp signal leads to a decrease in the judgment threshold, which further affects the detection performance of the signal, especially when the signal-to-noise ratio is low, the interference of the Chirp signal is more significant.

[0164] In addition, the DMRS data and frequency domain PBCH data of the PBCH are extracted from the SSB signal, and the DMRS is used to perform channel estimation, thereby realizing the equalization and demodulation operations of the PBCH channel. Fig.25 (e) shows the PBCH bit error rate (BER) performance under different signal-to-noise ratio conditions. The results show that under the same signal-to-noise ratio conditions, the PBCH bit error rate under chirp signal interference increases compared to the case where the SSB block spectrum resources are not occupied in scenario 1. This shows that although the system maintains synchronization performance to a certain extent, the interference of chirp signals affects the accuracy of channel equalization and demodulation, resulting in a relatively high bit error rate.

[0165] Scenario 3: Impact of other chirp systems occupying non-valid subcarriers in the SSB block on SSB resolution performance

[0166] The parameter configuration in scenario 3 is shown in Table 3. In this scenario, the Chirp signal is configured to occupy specific spectrum resources, including light industry and construction, light industry and earthquake, and military and earthquake sub-bands. In this embodiment, it is assumed that the Chirp signal occupies the non-valid subcarrier positions of SSB (synchronization signal block) in these sub-bands. These subcarrier positions are: 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 (the Chirp signal bandwidth is 50kHz), and are located within the available subcarrier range (4096×20) of the power wireless private network. The subcarrier positions occupied by the Chirp signal do not interfere with the PSS, SSS and PBCH signals. Therefore, this scenario is used to accurately evaluate the impact of the Chirp system occupying the non-valid subcarrier positions of the SSB block on the SSB resolution performance.

[0167] Fig.26 The continuous and discrete time-frequency resource diagrams corresponding to the transmitting and receiving antennas 1 are shown. Specifically, Fig.26 (a)~ Fig.26 (b) shows the mapping process of SSB signals from continuous time-frequency resource grids to power wireless private network resource grids, and presents the occupancy of subcarriers of SSB signals in power wireless private network resource grids; Fig.26 (c)~ Fig.26 (e) clearly shows the corresponding subcarrier positions of the Chirp signal occupying specific spectrum resources, and after remapping, shows the corresponding positions of consecutive subcarriers of the SSB block.

[0168] Fig. 27 (a)~ Fig. 27 (b) shows the discrete SSB block time-frequency resource diagram of antenna 1 and antenna 2 at the transmitting end without interference, as a comparison diagram; Fig. 27 (c)~ Fig. 27 (d) shows the corresponding time-frequency resource diagram when the chirp signal occupies the spectrum resources of the light industry and construction, light industry and earthquake, and military and earthquake sub-bands in antenna 1 and antenna 2 at the receiving end.

[0169] Table 3

[0170] Parameters Numeric Subcarrier spacing 2.5KHz FFT points 4096 CP length 1024 Number of SSBs 2 SSB starting position 2、8 Number of OFDM symbols 20 Channel Model CDL、AWGN SNR(dB) -20-20 Cell Identifier ID 374 Chirp Type Linear MIMO 2×2

[0171] In an environment where chirp signals occupy specific spectrum resources (including light industry and construction, light industry and seismic, military and seismic sub-bands), the system performed SSB (synchronization signal block) synchronization and demodulation tests under an SNR of 20dB. Fig.28 This is the SSB demodulation diagram of chirp interference on unoccupied SSB subcarriers. Fig.28 (a) shows the demodulated constellation diagram of the PSS signal;

[0172] Fig.28 (b) shows the demodulated constellation diagram of the SSS signal; Fig.28 (c) shows the un-equalized PBCH demodulation constellation diagram; Fig.28 (f) shows the demodulation constellation diagram of PBCH after equalization. Compared with the test results in scenario 1, Fig.28 (a)-(c) and Fig.28 The demodulation results in (f) show that the Chirp signal has little effect on the phase of the PSS, SSS and PBCH signals, indicating that the Chirp signal has limited interference with the synchronization signal. Fig.28 (d) shows the detection results of PSS signal; Fig.28 (e) shows the detection results of SSS signal; Fig.28 (g) shows the detection result of ibar_SSB. It can be concluded that compared with scenario 1, the SSB resolution performance is less affected in the scenario where the Chirp signal occupies the non-valid subcarriers of the SSB block. Specifically, the system can accurately detect the PSS and SSS signals with the cell identifier ID 374, and there are no significant errors in the synchronization process. In addition, the system extracts the DMRS data and frequency domain PBCH data of the PBCH from the SSB signal, uses the DMRS signal for channel estimation, and successfully completes the equalization and demodulation operations of the PBCH channel. The experimental results show that although the Chirp signal occupies the non-valid subcarrier resources of some SSB blocks, the demodulation of the PBCH signal is still accurate, indicating that the system can effectively equalize and demodulate the signal in this environment.

[0173] In summary, although the Chirp signal occupies a part of the spectrum resources of the SSB block, especially the non-valid subcarrier position, its impact on the SSB synchronization and demodulation performance is relatively small.

[0174] In order to illustrate the influence of chirp signal occupying specific spectrum resources (light industry and construction, light industry and earthquake, military and earthquake sub-bands) on SSB demodulation performance under different signal-to-noise ratios, Monte Carlo simulation was used to verify the simulation with 1000 simulations.

[0175] In the scenario where the chirp signal occupies non-valid subcarriers of the SSB block, the system performs SSB synchronization and demodulation tests under different signal-to-noise ratio (SNR) conditions. Fig.29 (a) Schematic diagram showing the PSS threshold; Fig.29 (b) shows the detection results of PSS signal; Fig.29 (c) Schematic diagram showing the SSS threshold; Fig.29 (d) shows the detection result of the SSS signal. The experimental results show that compared with scenario 1, when the Chirp signal occupies the non-valid subcarriers of the SSB block, the detection accuracy of the PSS and SSS signals is not significantly affected, and the detection thresholds corresponding to the PSS and SSS signals remain stable, indicating that the Chirp signal has little interference with the detection performance of the PSS and SSS signals.

[0176] Furthermore, the system extracts the DMRS (demodulation reference signal) data and frequency domain PBCH data of the PBCH (physical broadcast channel) from the SSB signal, and uses the DMRS signal for channel estimation. Through this process, the system successfully completes the equalization and demodulation operations of the PBCH channel. Fig.29 (e) shows the bit error rate (BER) results of the PBCH signal under different signal-to-noise ratio conditions. The results show that under the same signal-to-noise ratio conditions, the chirp signal has little effect on the bit error rate of the PBCH signal, which indicates that the system can still stably demodulate the PBCH signal when the chirp signal occupies the non-valid subcarriers of the SSB block.

[0177] In summary, although the Chirp signal occupies some non-valid subcarrier positions of the SSB block, its impact on the synchronization and demodulation performance of the PSS, SSS and PBCH signals is relatively small.

[0178] It can be known from the simulation of the embodiment of the present invention that when an interference signal occupies a valid subcarrier position of an SSB block, the SSB block needs to be remapped to other subcarrier positions that can be occupied.

[0179] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for defining a physical layer frame structure and a synchronization block mapping method for a power wireless private network, characterized in that: The method comprises the following steps: Process 1: Generation process of available subcarrier attribute table of power wireless private network; Step 1: According to the definition of 230MHz frequency band sub-band, each sub-band has a bandwidth of 25KHz, and there are 480 sub-bands in total; the power wireless private network re-divides the 480 sub-bands in the 230MHz frequency band into 4800 sub-carriers according to the sub-carrier interval of 2.5kHz, that is, each sub-band is subdivided into 10 sub-carriers; Step 2: Classify the subcarrier identification. Among the 4800 subcarriers, identify the subcarrier corresponding to the idle subband as 0, and record the subcarrier number in the index_0 array; the subcarrier corresponding to the subbands for light industry and construction, light industry and earthquake, military and earthquake is identified as 1, and the subcarrier number is recorded in the index_1 array; the subcarrier corresponding to the subband dedicated to the power system is identified as 2, and the subcarrier number is recorded in the index_2 array; Step 3: In the classification of 4800 subcarrier frequency domain resources, the subcarriers corresponding to the idle subbands and power system subbands are defined as available subcarriers for the power wireless private network, and the remaining subcarriers are defined as unavailable subcarriers for the power wireless private network. The subcarrier attribute table is used to record the subcarrier attributes to facilitate the allocation and use of subcarriers for the power wireless private network. Step 4: The power wireless private network uses 12 subcarriers as the minimum basic unit of frequency domain resources. The power wireless private network supports the allocation of frequency resources of multiple basic units to ensure that the basic unit of 12 subcarriers occupies continuous subcarriers; that is, the subcarriers that can be used by the power wireless private network are continuous subcarriers, and the number of continuous subcarriers is an integer multiple of 12; Step 5: Re-update the identifier of the 4800 subcarrier number. The numbers of the subcarriers that can be occupied are recorded in the as_index array, and the numbers of the subcarriers that cannot be occupied are recorded in the ns_index array. Step 6: The power wireless private network frame structure resource grid can use 4096 subcarriers each time, and the selected fast Fourier transform (FFT) point number is 4096; the power wireless private network selects 4096 consecutive subcarriers from 4800 subcarriers and arranges them from low frequency to high frequency; Process 2: Subcarrier resource determination process; According to the subcarrier attribute table, the power wireless private network can only use the subcarriers marked as available, and the subcarriers can only be allocated and used in integer multiples of the basic unit. In the 230MHz frequency band, each subband is 25KHz, which is divided into 10 2.5KHz subcarriers; 12 consecutive subcarrier resources cannot be used as protection subcarriers; Assume that there are m continuous 25KHz subbands available, with a total of M subcarriers, M = 10*m, and the number of subcarriers available for the power wireless private network is 12*K, K = M%12, % represents modulo calculation, * represents multiplication calculation; the number of subcarriers that cannot be used is S, S = 10*m-12*K; Among the M subcarriers, the first ceil(S / 2) subcarriers and the last S-ceil(S / 2) subcarriers cannot be used and exist as protection subcarriers; where ceil() is calculated by taking the minimum integer; Process 3: Power wireless private network frame structure definition; The power wireless private network defines a frame length of 10 milliseconds. Each frame is divided into 10 subframes. Each subframe consists of 1 time slot. Each time slot consists of two orthogonal frequency division multiplexing (OFDM) symbols. Each OFDM symbol consists of an OFDM prefix, called a cyclic prefix (CP), and an OFDM data part. The OFDM prefix is ​​1024 points and the OFDM data part is 4096 points. Process 4: Implementation process of mapping SSB block to 230MH band Step 41: Generate a synchronization signal block (SSB) block using the standard fifth generation mobile communication technology (5G New Radio, 5GNR) standard; the SSB block consists of 4 OFDM symbols and 240 subcarriers; define the power wireless private network SSB block to comply with the 5GNR standard definition; Step 42: Determine the OFDM symbol position occupied by the SSB block; according to the 5GNR frame structure and the SSB time slot position definition, define that one wireless frame of the power wireless private network can carry two SSB blocks, which are placed at the second OFDM symbol and the eighth OFDM symbol of the frame structure respectively, and are recorded as the starting symbol position of the SSB block in the wireless frame {2,8}; Step 43: Determine the frequency domain mapping of the SSB block; in the power wireless private network frame structure resource grid, search for the largest available continuous subcarrier area based on the recorded occupied subcarrier numbers, map the 240 continuous subcarriers of the SSB block to this available subcarrier number, and mark the corresponding subcarrier number position as ssbUsedCarrier.

2. A method for defining a physical layer frame structure and a synchronization block mapping method for a power wireless private network according to claim 1, characterized in that: The parameter design of the power wireless private network frame structure includes the following steps: Step 11: Sampling rate definition: Based on the subcarrier spacing (SCS) of 2.5kHz and the FFT point number of 4096, the frame structure clock rate is defined as 10240000, also known as the sampling rate, denoted as SampleRate; SampleRate = subcarrier spacing × FFT points = 2.5KHz x 4096 = 10240000 Step 12: Frame length definition: Define a wireless frame T f The length is 10ms, including 10 subframes, each subframe T sf is 1ms; according to the defined sampling rate, the total number of sampling points corresponding to each frame is N f and the number of subframe sampling points N sf ; N f =SampleRate×T f =102400 N sf =SampleRate×T sf =10240 Step 13: Definition of OFDM symbol number: Determine the number of OFDM symbols in the time slot; the number of Fast Fourier Transform (FFT) points used in the power wireless private network is 4096, and the number of symbols Symbols must satisfy the total number of samples Symbols×FFT≤N sf , maximum number of symbols That is, one subframe consists of 2 OFDM symbols; Step 14: Time slot definition: Each time slot in the design contains 2 OFDM symbols, and one subframe contains one time slot, that is, Step 15: Cyclic prefix definition: The cyclic prefix length CPLength meets the frame structure length requirement, that is, 2×(CPLength+FFT)=N sf , then the calculation method of the cyclic prefix length CPLength is defined as follows;

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