Communication frequency selection method and device, equipment, storage medium and program product
By dividing the entire frequency band spectrum of the UHF system into sub-channel groups and sending ZC sequence groups with good cross-correlation performance to the slave stations, the problem of long time consumption in traditional frequency selection schemes is solved, and efficient frequency selection and channel characteristic detection are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-03-13
AI Technical Summary
Traditional frequency selection schemes are time-consuming in high-precision, high-bandwidth scenarios, resulting in low frequency selection efficiency.
The entire frequency band spectrum of the VHF system is divided into sub-channel groups, and ZC sequence groups with good cross-correlation performance are sent to the slave stations. The optimal communication frequency is determined by iterative processing of signal-to-noise ratio estimation and channel response values.
It effectively reduces the detection time at each frequency point in the full-band spectrum, improves frequency selection efficiency, and obtains better detection accuracy through channel estimation.
Smart Images
Figure CN121665339A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of communication technology, and in particular to a communication frequency selection method, apparatus, device, storage medium, and program product. Background Technology
[0002] The transmission characteristics of wireless communication channels are complexly affected by various environmental factors such as temperature, climate, season, and monthly variations, easily leading to various types of signal fading, including flat fading and frequency-selective fading, which severely restricts the reliability and communication quality of communication links. Among these issues, frequency-selective fading in the VHF band (30-300 MHz) is particularly prominent. This band not only suffers from frequency-selective fading due to multipath propagation but also exhibits significant differences in natural environmental interference, meaning that the noise floor levels at different frequencies in nature vary considerably (up to 20 dB or more). This inherent channel characteristic makes precise frequency selection in VHF communication systems to avoid deep fading and strong interference a crucial step in improving system performance.
[0003] Current frequency selection schemes use frequency sweeping to probe channel characteristics and then select suitable high-quality frequencies for communication. Specifically, this involves point-by-point frequency sweeping, where the communication device sequentially switches between preset frequency sequences, sending a probe signal and receiving a response at each frequency. The channel condition at each frequency is evaluated by analyzing the quality parameters of the received signal. After traversing all the frequencies to be probed, the evaluation results of each frequency are compared, and one or more optimal frequencies are ultimately selected for establishing or switching communication links.
[0004] However, in high-precision, high-bandwidth scenarios, the frequency selection method using frequency sweeping takes a long time due to the long full-band sweeping cycle, resulting in low frequency selection efficiency. Summary of the Invention
[0005] This application aims to address at least one of the technical problems existing in the related art. To this end, this application proposes a communication frequency selection method, apparatus, device, storage medium, and program product to solve the problem of long processing time in traditional frequency selection schemes, thereby improving frequency selection efficiency.
[0006] The communication frequency selection method according to the first aspect of this application includes: The full-band spectrum of the VHF system is divided into at least one sub-channel group; each sub-channel group includes at least one frequency point; For each sub-channel group, a set of ZC sequences is sent to the connected slave station; wherein, the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. Receive the detection signals returned by the slave station based on each group of ZC sequences; For each detection signal, the signal-to-noise ratio (SNR) of each frequency point is estimated based on each ZC sequence in the corresponding group of ZC sequences, and the SNR estimate value of each frequency point is obtained. Based on the signal-to-noise ratio estimates, the frequency points used for communication with the slave station are determined from all frequency points in each sub-channel group.
[0007] According to one embodiment of this application, determining the frequency point for communication with the slave station from all frequency points of each sub-channel group based on each signal-to-noise ratio estimate includes: Compare the various signal-to-noise ratio estimates; The frequency point corresponding to at least one optimal signal-to-noise ratio estimate is determined as the frequency point for communication with the slave station.
[0008] According to one embodiment of this application, determining the frequency point for communication with the slave station from all frequency points of each sub-channel group based on each signal-to-noise ratio estimate further includes: For the signal-to-noise ratio (SNR) estimate of each frequency point corresponding to each sub-channel group, the ZC sequence of the corresponding group is sorted. For each sorted ZC sequence, the channel response value of the corresponding frequency point of each ZC sequence is determined by combining the corresponding detection signal; Based on the response values of each channel, the frequency points used for communication with the slave station are determined from all frequency points of each sub-channel group.
[0009] According to one embodiment of this application, when determining the channel response value of each frequency point corresponding to each sorted ZC sequence in combination with the corresponding detection signal, the following operations are performed for each sorted ZC sequence: Channel estimation is performed by combining the first ZC sequence in the current group of ZC sequences and the detection signal corresponding to the current group of ZC sequences to obtain the channel response value of the frequency point corresponding to the first ZC sequence and the component of the first ZC sequence in the detection signal corresponding to the current group of ZC sequences. In the detection signal corresponding to the first ZC sequence in the current group of ZC sequences, the component corresponding to the first ZC sequence is separated to obtain the separated detection signal; By combining the second ZC sequence in the current ZC sequence group and the separated probe signal, channel estimation is performed to obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current ZC sequence group. In the separated detection signal, the component corresponding to the second ZC sequence is separated to obtain a new separated detection signal; After taking the third ZC sequence in the current group of ZC sequences as the new second ZC sequence, return to the step of combining the second ZC sequence in the current group of ZC sequences and the separated probe signal to perform channel estimation, obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current group of ZC sequences, until the channel response values of the frequency points corresponding to all ZC sequences in the current group of ZC sequences are obtained.
[0010] According to one embodiment of this application, after determining the channel response value of each frequency point corresponding to each sorted ZC sequence in conjunction with the corresponding detection signal, the method further includes: Based on the channel response value corresponding to each ZC sequence in each sorted ZC sequence group and the component corresponding to each ZC sequence in each sorted ZC sequence group, iterative channel estimation is performed until the number of iterations reaches a preset threshold or the value of the preset cost function during the iteration process is less than a preset value. Based on the channel response value of each frequency point obtained from the last channel estimation, the frequency point used for communication with the slave station is determined from all frequency points of each sub-channel group.
[0011] According to one embodiment of this application, the value of the preset cost function is determined based on the estimation error of the channel response value at the corresponding frequency point of each ZC sequence.
[0012] A communication frequency selection device according to a second aspect embodiment of this application includes: The partitioning module is used to divide the full-band spectrum of the VHF system into at least one sub-channel group; each sub-channel group includes at least one frequency point. The transmitting module is used to transmit a set of ZC sequences to the connected slave stations for each sub-channel group; wherein the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. The receiving module is used to receive the detection signals returned by the slave station based on each group of ZC sequences; The estimation module is used to estimate the signal-to-noise ratio (SNR) of each frequency point for each probe signal based on each ZC sequence in the corresponding group of ZC sequences, and obtain the SNR estimate value of each frequency point. The determination module is used to determine the frequency points for communication with the slave station from all frequency points of each sub-channel group based on each signal-to-noise ratio estimate.
[0013] An electronic device according to a third aspect of this application includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the communication frequency selection method as described above.
[0014] According to a fourth aspect of the present application, the storage medium is a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the communication frequency selection method as described above.
[0015] A computer program product according to a fifth aspect of this application includes a computer program that, when executed by a processor, implements the communication frequency selection method as described above.
[0016] The above-described one or more technical solutions in the embodiments of this application have at least the following technical effects: By dividing the entire frequency band spectrum of an ultra-shortwave system into one or more sub-channel groups, and then sending a set of ZC sequences to the connected slave stations for each sub-channel group, the number of ZC sequences in each group is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any group is lower than a preset threshold. Then, after receiving the probe signals returned by the slave stations based on each group of ZC sequences, the signal-to-noise ratio (SNR) of each frequency point can be estimated based on each ZC sequence in the corresponding group for each probe signal, obtaining the SNR estimate value for each frequency point. Based on the SNR estimate values, the frequency point used for communication with the slave station can be determined from all frequency points in each sub-channel group. By simultaneously sending ZC sequences with good cross-correlation performance at multiple frequency points, the channel characteristics of probing multiple frequency points at once are achieved while avoiding mutual interference between ZC sequences. This effectively reduces the detection time of each frequency point in the entire frequency band spectrum, greatly reduces the time consumption of the frequency selection process, and thus improves the frequency selection efficiency.
[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a flowchart illustrating the communication frequency selection method provided in the embodiments of this application.
[0020] Figure 2 This is a frequency domain schematic diagram of the detection signal transmitted in the communication frequency selection method provided in the embodiments of this application.
[0021] Figure 3 This is one of the time-domain schematic diagrams of the detection signal transmitted in the communication frequency selection method provided in the embodiments of this application.
[0022] Figure 4 This is the second time-domain schematic diagram of the detection signal transmitted in the communication frequency selection method provided in the embodiments of this application.
[0023] Figure 5 This is a schematic diagram of the structure of the electronic device provided in this application. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0025] This application proposes a communication frequency selection method, apparatus, device, storage medium, and program product, which improves detection efficiency by simultaneously transmitting detection sequences at multiple frequency points, rather than detecting each frequency point one by one; and the time saved can be used to lengthen the sequence to obtain better detection accuracy.
[0026] It should be noted that all actions involving the acquisition of signals, information, or data in this application are carried out in compliance with the relevant data protection laws and regulations of the locality and with authorization from the owner of the relevant device.
[0027] Figure 1 This is one of the flowcharts illustrating the communication frequency selection method provided in the embodiments of this application, such as... Figure 1 As shown, the communication frequency selection method includes: Step 110: Divide the full-band spectrum of the VHF system into at least one sub-channel group; each sub-channel group includes at least one frequency point.
[0028] Step 120: For each sub-channel group, send a set of ZC sequences to the connected slave station; wherein the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold.
[0029] Step 130: Receive the probe signals returned by the slave station based on each group of ZC sequences.
[0030] Step 140: For each detection signal, the signal-to-noise ratio (SNR) of each frequency point is estimated based on each ZC sequence in the corresponding group of ZC sequences, and the SNR estimate value of each frequency point is obtained.
[0031] Step 150: Based on each signal-to-noise ratio estimate, determine the frequency points used for communication with slave stations from all frequency points in each sub-channel group.
[0032] It should be noted that the execution subject of the communication frequency selection method provided in this application embodiment can be a computer device, such as a mobile phone, tablet computer, laptop computer, handheld computer, vehicle-mounted electronic device, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA). For example, the execution subject can specifically be a computer device in a base station, where the base station can act as the master station in the communication scenario.
[0033] Correspondingly, a slave station can be a computer device that communicates with the master station, while for a base station acting as the master station, a slave station can be a user terminal.
[0034] Specifically, in this application, the master station can establish a connection with the slave station in advance. Furthermore, the entire frequency band spectrum of the VHF system can be divided into a specified number of sub-channels according to actual needs.
[0035] It should be noted that the division can be done in a uniform or non-uniform manner.
[0036] For example, the frequency band of an ultra-shortwave system between 30 MHz and 300 MHz can be divided into M sub-channels according to requirements, resulting in f1, f2, ..., f M Sub-channels.
[0037] Furthermore, every N sub-channels can be grouped into a sub-channel group, thus obtaining ceil(M / N) sub-channel groups (which can also be referred to as frequency groups in this application), [f1, f2, ..., f N ];[f N+1 ,f N+2 ...f 2N ];……[f M-N+1 ,f M-N+2 ...f M ]; where ceil is the floor function.
[0038] Based on this, the master station can inform the slave station of the frequency to be detected through the control channel, and send downlink detection signals to the slave station at the preset frequency.
[0039] Specifically, in this application, when the master station sends downlink detection signals, it sends a ZC sequence group [ZC1, ZC2...ZCN] composed of N cross-correlation ZC sequences at N frequency points corresponding to a sub-channel group each time, forming the transmit signal TX.
[0040] Among them, the ZC sequence, or Zadoff-Chu sequence, is a special type of complex numerical sequence.
[0041] By sending a group of ZC sequences consisting of N cross-correlation ZC sequences, the mutual interference between ZC sequences can be reduced, which helps to improve the accuracy of frequency selection results.
[0042] The quality of cross-correlation between two ZC sequences can be determined by comparing the maximum cross-correlation peak between the two ZC sequences with a preset threshold. This preset threshold can be a value lower than the autocorrelation peak, for example, 20 dB. Specifically, when the maximum cross-correlation peak between the two ZC sequences is 20 dB lower than the autocorrelation peak, the cross-correlation between the two ZC sequences is considered good; otherwise, the cross-correlation is considered poor.
[0043] It should be noted that the quality of cross-correlation can be judged by other methods, which are not specifically limited in this application.
[0044] After receiving the downlink probe signal, the slave station transmits the uplink probe signal at the corresponding frequency.
[0045] The master station can receive the uplink probe signal RX transmitted by the slave station based on each ZC sequence.
[0046] Furthermore, the uplink channel parameters can be calculated using the uplink probe signal RX.
[0047] Specifically, in one embodiment, the master station can calculate the uplink channel parameters for each probe signal RX using the ZC sequence group corresponding to the probe signal RX.
[0048] For example, the master station can use each ZC sequence in a set of locally stored ZC sequences [ZC1, ZC2...ZCN] to correlate with the probe signal RX, thereby obtaining the corresponding number of correlation peaks C1, C2...CN.
[0049] Furthermore, based on each correlation peak in this group, the signal-to-noise ratio (SNR) estimate for each frequency point in the corresponding sub-channel group can be determined. Specifically, the ratio of the peak power within the window of the correlation peak to the average power of the noise region outside the window can be used as the SNR estimate for the frequency point corresponding to the correlation peak.
[0050] After completing the ZC sequence group transmission and signal-to-noise ratio (SNR) estimation for all sub-channel groups, the SNR estimates for all frequency points can be obtained.
[0051] Furthermore, by comparing all the determined signal-to-noise ratio estimates, one or more frequency points can be determined from the corresponding number of frequency points as the frequency points for communication with the slave station, and the slave station can be informed of this via the control channel.
[0052] It should be noted that after receiving the downlink probe signal, the slave station can calculate the downlink channel parameters (i.e., determine the channel-related information of each frequency point for frequency point selection, such as the signal-to-noise ratio estimate, channel response value, etc., or directly determine one or more selectable frequency points) through the downlink probe signal signal, and report it to the master station through the control channel. The process of the slave station calculating the downlink channel parameters can refer to the process of the master station calculating the uplink channel parameters, and the process of the slave station calculating the downlink channel parameters is not described in detail in this application.
[0053] Furthermore, the master station, in conjunction with the uplink and downlink channel parameters or the optional frequency point information provided by the master and slave stations, selects one or more of the most suitable frequency points for communication and informs the slave station through the control channel.
[0054] Thus, the master station and the slave station can communicate at a high quality through negotiated frequency points.
[0055] According to the communication frequency selection method of this application embodiment, the full-band spectrum of the VHF system is divided into one or more sub-channel groups, and a set of ZC sequences is sent to the connected slave station for each sub-channel group. The number of ZC sequences in each group is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any group is lower than a preset threshold. Then, after receiving the detection signals returned by the slave station based on each group of ZC sequences, the signal-to-noise ratio (SNR) of each frequency point can be estimated based on each ZC sequence in the corresponding group for each detection signal, obtaining the SNR estimate value for each frequency point. Therefore, based on the SNR estimate values, the frequency point used for communication with the slave station can be determined from all frequency points in each sub-channel group. By simultaneously sending ZC sequences with good cross-correlation performance at multiple frequency points, the channel characteristics of multiple frequency points can be detected at once while avoiding mutual interference between ZC sequences. This effectively reduces the detection time of each frequency point in the full-band spectrum, greatly reduces the time consumption of the frequency selection process, and thus improves the frequency selection efficiency.
[0056] It should be noted that while polyphase filters can be used to scan multiple frequency points at once, they can only select frequency points at equal intervals, which can be very resource-intensive in high-precision, high-bandwidth scenarios.
[0057] In this application, after completing one or more frequency point selections of the entire frequency band spectrum, when selecting frequency points in subsequent frequency point selections, frequency point screening of the entire frequency band spectrum can be performed based on the historical channel estimation information of each frequency point. Specifically, frequency points that have been in the middle and lower range of all frequency points for a long time or in multiple evaluations can be eliminated, and then the remaining frequency points can be selected according to the above scheme.
[0058] Therefore, this application can detect multiple frequency points at once without using a multiphase filter, and all of these frequency points can be arbitrary. This makes the frequency point setting more flexible, thereby reducing resource pressure, avoiding resource consumption, and helping to save resources.
[0059] In one embodiment, determining the frequency points for communication with the slave station from all frequency points in each sub-channel group based on each signal-to-noise ratio estimate includes: Compare the various signal-to-noise ratio estimates; The frequency point corresponding to at least one optimal signal-to-noise ratio estimate is determined as the frequency point used for communication with the slave station.
[0060] Specifically, after obtaining the signal-to-noise ratio (SNR) estimates for all frequency points corresponding to each sub-channel group, this application can compare the SNR estimates to determine the magnitude relationship between them.
[0061] Therefore, the frequency point corresponding to the largest signal-to-noise ratio estimate, or the frequency point corresponding to multiple largest signal-to-noise ratio estimates, can be used as the frequency point for communication with the slave station.
[0062] If multiple frequency points are identified, the master station can communicate with the slave station using frequency hopping. Alternatively, it can perform a comprehensive analysis based on the multiple frequency points identified by both the master and slave stations to determine the final frequency point for communication. This application does not specify the particular method for selecting and using the final frequency point.
[0063] This application improves the quality of subsequent communication by selecting one or more frequency points with the best signal-to-noise ratio estimate as communication frequency points.
[0064] In one embodiment, determining the frequency points for communication with the slave station from all frequency points in each sub-channel group based on each signal-to-noise ratio estimate further includes: For the signal-to-noise ratio (SNR) estimate of each frequency point corresponding to each sub-channel group, the ZC sequence of the corresponding group is sorted. For each sorted ZC sequence, the channel response value of the corresponding frequency point of each ZC sequence is determined by combining the corresponding detection signal; Based on the response values of each channel, the frequency points used for communication with slave stations are determined from all frequency points in each sub-channel group.
[0065] Furthermore, when determining the channel response value of each frequency point corresponding to each sorted ZC sequence in conjunction with the corresponding detection signal, the following operations are performed for each sorted ZC sequence: Channel estimation is performed by combining the first ZC sequence in the current group of ZC sequences and the detection signal corresponding to the current group of ZC sequences to obtain the channel response value of the frequency point corresponding to the first ZC sequence and the component of the first ZC sequence in the detection signal corresponding to the current group of ZC sequences. In the detection signal corresponding to the first ZC sequence in the current group of ZC sequences, the component corresponding to the first ZC sequence is separated to obtain the separated detection signal; By combining the second ZC sequence in the current ZC sequence group and the separated probe signal, channel estimation is performed to obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current ZC sequence group. In the separated detection signal, the component corresponding to the second ZC sequence is separated to obtain a new separated detection signal; After taking the third ZC sequence in the current group as the new second ZC sequence, return to the step of combining the second ZC sequence in the current group and the separated probe signal to perform channel estimation, obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current group ZC sequence, until the channel response values of the frequency points corresponding to all ZC sequences in the current group ZC sequence are obtained.
[0066] It should be noted that after obtaining the signal-to-noise ratio estimates of all frequency points corresponding to each sub-channel group, this application may temporarily refrain from selecting frequency points and instead perform further channel estimation to obtain more channel information.
[0067] Specifically, step 150 above may include steps 1501-1507 as follows.
[0068] Step 1501: For the ZC sequence group corresponding to the current sub-channel group, determine the positions of ZC sequence 1 to ZC sequence N in the ZC sequence group according to the position of the correlation peak used when determining the signal-to-noise ratio estimation value of each frequency point.
[0069] Step 1502: Based on the position of each ZC sequence in the ZC sequence group, the time delay of each ZC sequence is determined. Then, based on the time delay of each ZC sequence, the first received ZC sequence can be found. Furthermore, based on the time delays of the remaining ZC sequences, the receiving order of the completed ZC sequences can be determined. Therefore, the ZC sequences in this group can be sorted. For each ZC sequence, this application can assume the receiving order is ZC sequence 1 to ZC sequence N.
[0070] Step 1503: Using the first ZC sequence (i.e., ZC1) of the group of ZC sequences stored locally and the probe signal RX, channel estimation is performed on ZC1 to obtain the channel response value H1 at the corresponding frequency point, and the component RZC of ZC1 in the probe signal RX (1). It should be noted that the channel estimation in this application can be implemented using common channel estimation methods such as least squares, maximum likelihood estimation, and compressed sensing, and no specific limitation is made in this application.
[0071] Step 1504: Separate the ZC1 component RZC(1) in the detection signal RX to obtain the separated detection signal RX': ; Step 1505: Using the second ZC sequence (i.e. ZC2) and RX' stored locally, channel estimation is performed on ZC2 to obtain the channel response value H2 at the corresponding frequency point, as well as the component RZC(2) of ZC2 in the probe signal.
[0072] Step 1506: Separate the ZC2 component RZC(2) in the separated detection signal RX' to obtain a new separated detection signal. .
[0073] Step 1507: Repeat steps S1505-1506 until channel estimation is completed for all N frequency points corresponding to the group of ZC sequences, obtaining the channel estimation values H1, H2...HN for each frequency point. That is, after taking the third ZC sequence in the group as the new second ZC sequence, repeat steps S1505-1506, and so on, until the channel response values for all frequency points corresponding to the ZC sequences in the group and the components of each ZC sequence in the probe signal RX are obtained.
[0074] By performing the above steps on the ZC sequence groups corresponding to each sub-channel group, the channel estimates of all frequency points corresponding to each sub-channel group and the components of each ZC sequence in the corresponding probe signal RX can be obtained.
[0075] Furthermore, based on the channel response values of all frequency points in each sub-channel group, the optimal frequency point or multiple relatively optimal frequency points can be selected from all frequency points as the frequency points for communication with the slave station.
[0076] For example, the channel response values of all frequency points can be compared, and the optimal frequency point (such as the one with the largest channel response value or multiple channel response values with relatively large values) can be selected as the frequency point for communication with the slave station.
[0077] After obtaining the signal-to-noise ratio (SNR) estimates for each frequency point, this application can further perform channel estimation to acquire more channel information, thereby enabling a more accurate assessment of the channel conditions at each frequency point. This results in a more accurate selection of the final frequency point and improved communication quality.
[0078] In one embodiment, after determining the channel response value of each frequency point corresponding to each sorted ZC sequence in conjunction with the corresponding detection signal, the method further includes: Based on the channel response value corresponding to each ZC sequence in each sorted ZC sequence and the component corresponding to each ZC sequence in each sorted ZC sequence, iterative channel estimation is performed until the number of iterations reaches a preset threshold or the value of the preset cost function during the iteration is less than a preset value. Based on the channel response value of each frequency point obtained from the last channel estimation, the frequency point used for communication with the slave station is determined from all frequency points of each sub-channel group.
[0079] It should be noted that after obtaining the channel response values at each frequency point and the components of the corresponding ZC sequence in the probe signal RX, this application can further employ a genetic algorithm to increase the accuracy of channel estimation.
[0080] Specifically, after obtaining the channel estimates H1, H2...HN for each group of frequency points and the estimates RZC(1), RZC(2)...RZC(N) for each component in the probe signal through steps 1501-1507 above, this application can improve the accuracy of the channel estimation by iterating through the following process: Step 1508, ERXN is the data of the detected signal RX minus all other estimated components. Taking ERX1 as an example, we have: ; Step 1509: Channel estimation is performed again using the first ZC sequence (i.e., ZC1) of each group of ZC sequences stored locally and the signal ERX1 to obtain new channel response values H1(2) and RZC'.
[0081] Step 1510, repeat step 1509 to obtain the channel estimates H1(2), H2(2)……HN(2) for each frequency point of the corresponding ZC sequence.
[0082] Step 1511, NRXN is the data of the detected signal RX minus the estimated component of its own frequency ZC sequence. Taking NRX1 as an example, we have: ; Step 1512, construct the following cost function J as the preset cost function, J n This represents the estimation error of the channel estimate HN at the frequency corresponding to ZCN. Taking J1 as an example, where corr is the correlation operation and max is the maximum value operation: ; ; It should be noted that J n Specifically, it can be the peak value of the correlation peak between NRXN and the ZCN of the locally stored ZC sequence. The higher the peak value, the higher the residual ZCN component in NRXN, and the worse the accuracy of HN estimation.
[0083] Step 1513: After obtaining two sets of channel estimation results (initial channel response values H(1): [H1(1), H2(1)……HN(1)]; channel response values H(2) after the first iteration: [H1(2), H2(2)……HN(2)]), a genetic algorithm crossover matrix HG can be constructed. HG is generated by randomly swapping ceil(k·N) data points from the two sets of channel estimation results H(1) and H(2). Here, k is the swapping coefficient, 0 ≤ k ≤ N ≤ 1. <k<1。
[0084] Step 1514: From this, we can obtain 3 sets of channel estimation results H(1), H(2), and HG. Based on the 3 sets of channel estimation results, we can obtain the values of 3 cost functions. We take the set of channel response values H with the lowest value, which is also the best channel estimation performance, and save it as HTEMP.
[0085] Step 1515: Using the channel response value HTEMP and the corresponding RZC', repeat step 1509 above to obtain the channel estimate H(3) after the new iteration; use H(3) and HTEMP to cross-reference to obtain HG for this iteration; further obtain the new HTEMP.
[0086] Step 1516: Repeat the iteration until the value of the cost function J is less than the preset threshold, or the number of iterations reaches the preset number.
[0087] It should be noted that for the local ZC sequence ZC1 and its corresponding received signal ERX1, the least squares solution for channel estimation is: ; in() H The operation represents the conjugate transpose of a matrix.
[0088] Other channel estimation processes can be implemented with reference to the above formulas, and will not be illustrated in detail in this application.
[0089] This application uses a genetic algorithm to iteratively perform the channel estimation process, which can improve the accuracy of channel estimation, thereby enabling a more accurate assessment of the channel conditions at each frequency point, resulting in a more accurate final selection of the frequency point and improved communication quality.
[0090] Based on the above embodiments, this application proposes a more efficient and higher-performance communication frequency selection method. It simultaneously transmits probe sequences at multiple frequency points, rather than probing each frequency point individually, thus improving detection efficiency. The time saved can be used to lengthen the sequences for better detection accuracy. Furthermore, it utilizes the cross-correlation characteristics of ZC sequences (the correlation between ZC sequences and their non-self signals is approximately 0, similar to noise correlation) and iterative genetic algorithms to reduce the mutual influence between sequences, instead of using polyphase filters. This allows for more flexible frequency point settings and less resource pressure.
[0091] Figure 2 This is a frequency domain schematic diagram of the detection signal transmitted in the communication frequency selection method provided in this application embodiment. Figure 3 This is one of the time-domain schematic diagrams of the detection signal transmitted in the communication frequency selection method provided in this application embodiment, such as... Figure 2 and Figure 3 As shown, in one embodiment, this application simultaneously transmits different ZC sequences for detection within the range of [-300 kHz, 300 kHz] at 100 kHz intervals at 35 MHz, 55 MHz, and 135 MHz frequency points. The bandwidth of the ZC sequence is the same as the bandwidth of the service signal, and the length of the ZC sequence is 2048 sampling points. There are a total of 21 frequency points, corresponding to ZC1 to ZC21.
[0092] The receiver at the master station uses the locally stored ZC sequences ZC1~ZC21 to correlate with the received probe signal RX, respectively, to obtain 21 correlation peaks. The correlation peaks corresponding to the frequency points are recorded and used for frequency selection decisions.
[0093] Figure 4 This is the second time-domain schematic diagram of the detection signal transmitted in the communication frequency selection method provided in this application embodiment, as shown below. Figure 4 As shown, in another embodiment, this application transmits different ZC sequences for detection within the [-300kHz, 300kHz] range at 35MHz, 55MHz, and 135MHz frequency points, with intervals of 100kHz. The start of each ZC sequence is spaced 10 symbols from the start of the previous ZC sequence to obtain better initial channel estimation. The bandwidth of the ZC sequence is 100kHz, and the length of the ZC sequence is 2048 sampling points. There are a total of 21 frequency points, corresponding to ZC1 to ZC21.
[0094] The receiver at the master station uses the locally stored ZC sequences ZC1~ZC21 to correlate with the received probe signal to obtain the starting position of the ZC sequence. First, the first 10 points of each ZC sequence are used to obtain the initial channel estimate for each frequency point. Then, the frequency selection algorithm is iterated 9 times, with the exchange coefficient k being 0.4. The final parameters such as frequency characteristics, time domain characteristics, and phase characteristics of each frequency band are obtained and recorded for frequency selection decision.
[0095] The communication frequency selection device provided in this application is described below. The communication frequency selection device described below can be referred to in correspondence with the communication frequency selection method described above.
[0096] Furthermore, this application also provides a communication frequency selection device.
[0097] The communication frequency selection device includes: The partitioning module is used to divide the full-band spectrum of the VHF system into at least one sub-channel group; each sub-channel group includes at least one frequency point. The transmitting module is used to transmit a set of ZC sequences to the connected slave stations for each sub-channel group; wherein the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. The receiving module is used to receive the detection signals returned by the slave station based on each group of ZC sequences; The estimation module is used to estimate the signal-to-noise ratio (SNR) of each frequency point for each probe signal based on each ZC sequence in the corresponding group of ZC sequences, and obtain the SNR estimate value of each frequency point. The determination module is used to determine the frequency points for communication with the slave station from all frequency points of each sub-channel group based on each signal-to-noise ratio estimate.
[0098] The communication frequency selection device of this application divides the full-band spectrum of an ultra-shortwave system into one or more sub-channel groups, and then sends a set of ZC sequences to the connected slave station for each sub-channel group. The number of ZC sequences in each group is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any group is lower than a preset threshold. Furthermore, after receiving the detection signals returned by the slave station based on each group of ZC sequences, the signal-to-noise ratio (SNR) of each frequency point can be estimated based on each ZC sequence in the corresponding group for each detection signal, obtaining the SNR estimate value for each frequency point. Therefore, based on the SNR estimate values, the frequency point used for communication with the slave station can be determined from all frequency points in each sub-channel group. By simultaneously sending ZC sequences with good cross-correlation performance at multiple frequency points, the channel characteristics of multiple frequency points can be detected at once while avoiding mutual interference between ZC sequences. This effectively reduces the detection time of each frequency point in the full-band spectrum, greatly reduces the time consumption of the frequency selection process, and thus improves the frequency selection efficiency.
[0099] In one embodiment, the determining module is specifically used for: Compare the various signal-to-noise ratio estimates; The frequency point corresponding to at least one optimal signal-to-noise ratio estimate is determined as the frequency point for communication with the slave station.
[0100] In one embodiment, the determining module is further configured to: For the signal-to-noise ratio (SNR) estimate of each frequency point corresponding to each sub-channel group, the ZC sequence of the corresponding group is sorted. For each sorted ZC sequence, the channel response value of the corresponding frequency point of each ZC sequence is determined by combining the corresponding detection signal; Based on the response values of each channel, the frequency points used for communication with the slave station are determined from all frequency points of each sub-channel group.
[0101] In one embodiment, the determining module is further configured to perform the following operations for each sorted ZC sequence when determining the channel response value of the corresponding frequency point of each ZC sequence in conjunction with the corresponding detection signal: Channel estimation is performed by combining the first ZC sequence in the current group of ZC sequences and the detection signal corresponding to the current group of ZC sequences to obtain the channel response value of the frequency point corresponding to the first ZC sequence and the component of the first ZC sequence in the detection signal corresponding to the current group of ZC sequences. In the detection signal corresponding to the first ZC sequence in the current group of ZC sequences, the component corresponding to the first ZC sequence is separated to obtain the separated detection signal; By combining the second ZC sequence in the current ZC sequence group and the separated probe signal, channel estimation is performed to obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current ZC sequence group. In the separated detection signal, the component corresponding to the second ZC sequence is separated to obtain a new separated detection signal; After taking the third ZC sequence in the current group of ZC sequences as the new second ZC sequence, return to the step of combining the second ZC sequence in the current group of ZC sequences and the separated probe signal to perform channel estimation, obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current group of ZC sequences, until the channel response values of the frequency points corresponding to all ZC sequences in the current group of ZC sequences are obtained.
[0102] In one embodiment, the determining module is further configured to: Based on the channel response value corresponding to each ZC sequence in each sorted ZC sequence group and the component corresponding to each ZC sequence in each sorted ZC sequence group, iterative channel estimation is performed until the number of iterations reaches a preset threshold or the value of the preset cost function during the iteration process is less than a preset value. Based on the channel response value of each frequency point obtained from the last channel estimation, the frequency point used for communication with the slave station is determined from all frequency points of each sub-channel group.
[0103] Figure 5 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 5 As shown, the electronic device may include a processor 510, a communications interface 520, a memory 530, and a communication bus 540, wherein the processor 510, communications interface 520, and memory 530 communicate with each other via the communication bus 540. The processor 510 can call logical instructions in the memory 530 to execute the following method: dividing the full-band spectrum of the VHF system into at least one sub-channel group; each sub-channel group includes at least one frequency point; For each sub-channel group, a set of ZC sequences is sent to the connected slave station; wherein, the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. Receive the detection signals returned by the slave station based on each group of ZC sequences; For each detection signal, the signal-to-noise ratio (SNR) of each frequency point is estimated based on each ZC sequence in the corresponding group of ZC sequences, and the SNR estimate value of each frequency point is obtained. Based on the signal-to-noise ratio estimates, the frequency points used for communication with the slave station are determined from all frequency points in each sub-channel group.
[0104] Furthermore, the logical instructions in the aforementioned memory 530 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0105] In another aspect, embodiments of this application also provide a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the methods provided in the above embodiments, such as: dividing the full-band spectrum of an ultra-shortwave system into at least one sub-channel group; each sub-channel group includes at least one frequency point; For each sub-channel group, a set of ZC sequences is sent to the connected slave station; wherein, the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. Receive the detection signals returned by the slave station based on each group of ZC sequences; For each detection signal, the signal-to-noise ratio (SNR) of each frequency point is estimated based on each ZC sequence in the corresponding group of ZC sequences, and the SNR estimate value of each frequency point is obtained. Based on the signal-to-noise ratio estimates, the frequency points used for communication with the slave station are determined from all frequency points in each sub-channel group.
[0106] In another aspect, embodiments of this application also provide a computer program product having a computer program stored thereon, which, when executed by a processor, is implemented to perform the methods provided in the above embodiments, such as: dividing the full-band spectrum of an ultra-shortwave system into at least one sub-channel group; each sub-channel group includes at least one frequency point; For each sub-channel group, a set of ZC sequences is sent to the connected slave station; wherein, the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. Receive the detection signals returned by the slave station based on each group of ZC sequences; For each detection signal, the signal-to-noise ratio (SNR) of each frequency point is estimated based on each ZC sequence in the corresponding group of ZC sequences, and the SNR estimate value of each frequency point is obtained. Based on the signal-to-noise ratio estimates, the frequency points used for communication with the slave station are determined from all frequency points in each sub-channel group.
[0107] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0108] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of software products. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.
[0109] Finally, it should be noted that the above embodiments are only used to illustrate this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application.
Claims
1. A communication frequency selection method, characterized in that, include: Divide the full-band spectrum of the VHF system into at least one sub-channel group; Each sub-channel group includes at least one frequency point; For each sub-channel group, a set of ZC sequences is sent to the connected slave station; wherein, the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. Receive the detection signals returned by the slave station based on each group of ZC sequences; For each detection signal, the signal-to-noise ratio (SNR) of each frequency point is estimated based on each ZC sequence in the corresponding group of ZC sequences, and the SNR estimate value of each frequency point is obtained. Based on the signal-to-noise ratio estimates, the frequency points used for communication with the slave station are determined from all frequency points in each sub-channel group.
2. The communication frequency selection method according to claim 1, characterized in that, The step of determining the frequency points for communication with the slave station from all frequency points in each sub-channel group based on each signal-to-noise ratio estimate includes: Compare the various signal-to-noise ratio estimates; The frequency point corresponding to at least one optimal signal-to-noise ratio estimate is determined as the frequency point for communication with the slave station.
3. The communication frequency selection method according to claim 1, characterized in that, The step of determining the frequency point for communication with the slave station from all frequency points of each sub-channel group based on each signal-to-noise ratio estimate also includes: For the signal-to-noise ratio (SNR) estimate of each frequency point corresponding to each sub-channel group, the ZC sequence of the corresponding group is sorted. For each sorted ZC sequence, the channel response value of the corresponding frequency point of each ZC sequence is determined by combining the corresponding detection signal; Based on the response values of each channel, the frequency points used for communication with the slave station are determined from all frequency points of each sub-channel group.
4. The communication frequency selection method according to claim 3, characterized in that, When determining the channel response value of each frequency point corresponding to each sorted ZC sequence in conjunction with the corresponding detection signal, the following operations are performed for each sorted ZC sequence: Channel estimation is performed by combining the first ZC sequence in the current group of ZC sequences and the detection signal corresponding to the current group of ZC sequences to obtain the channel response value of the frequency point corresponding to the first ZC sequence and the component of the first ZC sequence in the detection signal corresponding to the current group of ZC sequences. In the detection signal corresponding to the first ZC sequence in the current group of ZC sequences, the component corresponding to the first ZC sequence is separated to obtain the separated detection signal; By combining the second ZC sequence in the current ZC sequence group and the separated probe signal, channel estimation is performed to obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current ZC sequence group. In the separated detection signal, the component corresponding to the second ZC sequence is separated to obtain a new separated detection signal; After taking the third ZC sequence in the current group of ZC sequences as the new second ZC sequence, return to the step of combining the second ZC sequence in the current group of ZC sequences and the separated probe signal to perform channel estimation, obtain the channel response value of the frequency point corresponding to the second ZC sequence and the component of the second ZC sequence in the probe signal corresponding to the current group of ZC sequences, until the channel response values of the frequency points corresponding to all ZC sequences in the current group of ZC sequences are obtained.
5. The communication frequency selection method according to claim 4, characterized in that, After determining the channel response value of each frequency point corresponding to each sorted ZC sequence in conjunction with the corresponding detection signal, the method further includes: Based on the channel response value corresponding to each ZC sequence in each sorted ZC sequence group and the component corresponding to each ZC sequence in each sorted ZC sequence group, iterative channel estimation is performed until the number of iterations reaches a preset threshold or the value of the preset cost function during the iteration process is less than a preset value. Based on the channel response value of each frequency point obtained from the last channel estimation, the frequency point used for communication with the slave station is determined from all frequency points of each sub-channel group.
6. The communication frequency selection method according to claim 5, characterized in that, The value of the preset cost function is determined based on the estimation error of the channel response value at the corresponding frequency point of each ZC sequence.
7. A communication frequency selection device, characterized in that, include: The partitioning module is used to divide the full-band spectrum of the VHF system into at least one sub-channel group; Each sub-channel group includes at least one frequency point; The transmitting module is used to transmit a set of ZC sequences to the connected slave stations for each sub-channel group; wherein the number of ZC sequences in each set of ZC sequences is the same as the number of frequency points in the corresponding sub-channel group, and the maximum cross-correlation peak value between any two ZC sequences in any set of ZC sequences is lower than a preset threshold. The receiving module is used to receive the detection signals returned by the slave station based on each group of ZC sequences; The estimation module is used to estimate the signal-to-noise ratio (SNR) of each frequency point for each probe signal based on each ZC sequence in the corresponding group of ZC sequences, and obtain the SNR estimate value of each frequency point. The determination module is used to determine the frequency points for communication with the slave station from all frequency points of each sub-channel group based on each signal-to-noise ratio estimate.
8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the communication frequency selection method as described in any one of claims 1 to 6.
9. A storage medium, said storage medium being a non-transitory computer-readable storage medium, wherein a computer program is stored thereon, characterized in that, When the computer program is executed by the processor, it implements the communication frequency selection method as described in any one of claims 1 to 6.
10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the communication frequency selection method according to any one of claims 1 to 6.