Digital Receiver Baseband Signal Decimation Method, Device, Terminal and Storage Medium

Abstract

The present invention discloses a method, apparatus, terminal and storage medium for downsampling baseband signals of a digital receiver, including: performing a correlation operation on a local PN sequence signal and a received sampled pilot PN sequence signal, and performing downsampling at different positions according to the result; respectively comparing the obtained channel response profiles with a preset threshold value to determine the main path, and calculating the total energy of the main path in each scenario; sorting the total energy of the main path in each scenario to obtain a first scenario and a second scenario ranked in the top two; calculating the SINR corresponding to the minimum main path in the first scenario, and calculating the SINR corresponding to the minimum main path in the second scenario; comparing the two calculated SINRs, selecting the sampling position of the scenario corresponding to the higher SINR for sampling, and outputting the sampled data. The present invention maximizes the total energy of the main path after downsampling and maximizes the SINR of the weakest main path after downsampling, improving the overall performance of the receiver.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and particularly to a method, device, terminal, and storage medium for downsampling baseband signals of a digital receiver. Background Art

[0002] In the field of wireless communication, after a receiver receives a wireless signal, it first converts the radio frequency signal into a baseband signal, and then obtains an original digital signal through analog-to-digital conversion. Usually, the sampling rate of the original digital signal is relatively high, and it is necessary to perform downsampling processing on the original digital signal. After obtaining the target digital signal, subsequent processing such as channel estimation, equalization, and decoding is performed.

[0003] However, due to reasons such as the crystal oscillator frequency offset between the receiver and the transmitter, multipath interference during signal transmission, and the influence of the receiver baseband filter, the received signal will be distorted. The selection of the downsampling position will affect the performance of subsequent modules such as channel estimation, and thus have a significant impact on the overall performance of the receiver.

[0004] In order to reduce the complexity of the receiver, it is necessary to perform downsampling processing on the original digital signal first after baseband filtering. However, in traditional downsampling methods, downsampling is performed according to the position of the maximum value. The downsampling algorithm is not designed from the perspective of comprehensively considering the overall performance of the receiver, but only pursues local optimality, without considering the impact of the downsampling position selection on the receiver performance, resulting in a loss of receiver performance.

[0005] Therefore, the existing technology still needs to be improved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that, aiming at the defects of the existing technology, the present invention provides a method, device, terminal, and storage medium for downsampling baseband signals of a digital receiver to solve the technical problem that the performance of the receiver is reduced due to the deviation of the downsampling position selection in the traditional downsampling method.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0008] In a first aspect, the present invention provides a method for downsampling baseband signals of a digital receiver, including:

[0009] Performing a correlation operation on a local PN sequence signal and a received sampled pilot PN sequence signal, and performing downsampling at different positions according to the correlation result to obtain channel response profiles in multiple scenarios;

[0010] Respectively comparing the obtained channel response profiles with a preset threshold value to determine the main paths corresponding to each scenario, and calculating the total energy of the main paths in each scenario;

[0011] Sort the total energy of the main paths in each scenario to obtain the first scenario and the second scenario ranked in the top two;

[0012] Calculate the SINR corresponding to the smallest main path in the first scenario and calculate the SINR corresponding to the smallest main path in the second scenario;

[0013] Compare the two calculated SINRs, select the sampling position of the scenario corresponding to the higher SINR for sampling, and output the sampling data.

[0014] In one implementation, the correlation operation of the local PN sequence signal and the received sampled pilot PN sequence signal, and downsampling at different positions according to the correlation result to obtain the channel response profiles in multiple scenarios, includes:

[0015] Perform correlation operations on the local PN sequence signal and the received N-fold sampled pilot PN sequence signal in sequence to obtain the correlation result;

[0016] Perform downsampling at N different positions according to the correlation result to obtain the channel response profiles in N scenarios.

[0017] In one implementation, the preset threshold is a preset normalized threshold.

[0018] In one implementation, the comparing the obtained channel response profiles with the preset threshold respectively to determine the corresponding main paths in each scenario and calculating the total energy of the main paths in each scenario, includes:

[0019] Compare the channel response profiles in each scenario with the preset threshold respectively;

[0020] Select the positions exceeding the preset threshold as the main paths in the corresponding scenarios;

[0021] Calculate the total energy of the selected main paths in each scenario respectively.

[0022] In one implementation, it further includes:

[0023] Perform correlation operations on the local PN sequence signal and the received N-fold sampled pilot PN sequence signal in sequence to obtain the correlation result;

[0024] Find the maximum value M in the correlation result;

[0025] Select all values greater than 3 / 4M and record the positions corresponding to the selected values;

[0026] Determine the corresponding channel type according to the recorded positions, and select the corresponding sampling strategy according to the determined channel type, and output the downsampled data.

[0027] In one implementation, the channel types include: long echo channel, Doppler channel.

[0028] In one implementation, determining the corresponding channel type according to the recorded position, selecting the corresponding sampling strategy according to the determined channel type, and outputting downsampled data includes:

[0029] Judging whether the corresponding channel type is the long echo channel according to the recorded position;

[0030] If it is the long echo channel, determine the position of the farthest path among the recorded positions, perform downsampling according to the position of the farthest path, and output the corresponding downsampled data.

[0031] In one implementation, after judging whether the corresponding channel type is the long echo channel according to the recorded position, it further includes:

[0032] If it is not the long echo channel, judge whether the corresponding channel type is the Doppler channel according to the recorded position;

[0033] If it is the Doppler channel, determine the position of the strongest path among the recorded positions, perform downsampling according to the position of the strongest path, and output the corresponding downsampled data.

[0034] In one implementation, after judging whether the corresponding channel type is the Doppler channel according to the recorded position, it further includes:

[0035] If it is not the Doppler channel, sort the total energies of the main paths in each scenario to obtain the SINR corresponding to the smallest main path in the top two scenarios;

[0036] Compare the two calculated SINRs, select the sampling position of the scenario corresponding to the higher SINR for sampling, and output the sampling data.

[0037] In one implementation, determining the corresponding channel type according to the recorded position, selecting the corresponding sampling strategy according to the determined channel type, and outputting downsampled data further includes:

[0038] Determine the corresponding channel type according to the recorded position, and perform downsampling according to the corresponding sampling strategy determined according to the determined channel type;

[0039] Remove interference according to a preset algorithm, and determine the position of the first multipath;

[0040] Output downsampled and synchronization signals.

[0041] In a second aspect, the present invention provides a digital receiver baseband signal decimation device, comprising:

[0042] A first decimation module, configured to perform a correlation operation on a local PN sequence signal and a received sampled pilot PN sequence signal, and perform decimation at different positions according to the correlation result to obtain channel response profiles in multiple scenarios;

[0043] A total energy calculation module, configured to respectively compare the obtained channel response profiles with a preset threshold value to determine the main path corresponding to each scenario, and calculate the total energy of the main path in each scenario;

[0044] A total energy sorting module, configured to sort the total energies of the main paths in each scenario to obtain a first scenario and a second scenario ranked in the top two;

[0045] An SINR calculation module, configured to calculate the SINR corresponding to the minimum main path in the first scenario, and calculate the SINR corresponding to the minimum main path in the second scenario;

[0046] A second decimation module, configured to compare the two calculated SINRs, select the sampling position of the scenario corresponding to the higher SINR for sampling, and output the sampled data.

[0047] In a third aspect, the present invention provides a terminal, comprising: a processor and a memory, where the memory stores a digital receiver baseband signal decimation program, and when the digital receiver baseband signal decimation program is executed by the processor, it is used to implement the operations of the digital receiver baseband signal decimation method as described in the first aspect.

[0048] In a fourth aspect, the present invention further provides a storage medium, where the storage medium is a computer-readable storage medium, and the storage medium stores a digital receiver baseband signal decimation program, and when the digital receiver baseband signal decimation program is executed by a processor, it is used to implement the operations of the digital receiver baseband signal decimation method as described in the first aspect.

[0049] The present invention adopts the above technical solutions and has the following effects:

[0050] The present invention performs a correlation operation on a local PN sequence signal and a received sampled pilot PN sequence signal, and performs downsampling at different positions according to the correlation result, so as to obtain channel response profiles in various scenarios; thereby comparing the obtained channel response profiles with a preset threshold value to determine the main paths corresponding to each scenario, and calculating the total energy of the main paths in each scenario; the total energy of the main paths in each scenario can be sorted to obtain the first scenario and the second scenario ranked in the top two; the present invention calculates the SINR corresponding to the minimum main path in the first scenario and calculates the SINR corresponding to the minimum main path in the second scenario; compares the two calculated SINRs, selects the sampling position of the scenario corresponding to the higher SINR for sampling, and outputs the sampled data; the present invention maximizes the total energy of the main paths after downsampling and maximizes the SINR of the weakest main path after downsampling, improving the overall performance of the receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0052] Figure 1 is a flowchart of a method for downsampling a baseband signal of a digital receiver in an implementation manner of the present invention.

[0053] Figure 2 is a schematic diagram of a normalized channel response profile under 4-fold sampling in an implementation manner of the present invention.

[0054] Figure 3 is a schematic diagram of the downsampling result of the channel response profile at different positions in an implementation manner of the present invention.

[0055] Figure 4 is a schematic diagram of the main path and noise and interference in an implementation manner of the present invention.

[0056] Figure 5 is a flowchart of a downsampling algorithm in an implementation manner of the present invention.

[0057] Figure 6 is a schematic diagram of the synchronization of a DTMB digital television receiver in an implementation manner of the present invention.

[0058] Figure 7 is a functional schematic diagram of a terminal in an implementation manner of the present invention.

[0059] The realization, functional features, and advantages of the present invention will be further described in conjunction with embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer and more definite, the following further describes the present invention in detail with reference to the accompanying drawings and by way of examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0061] Exemplary method

[0062] In order to reduce the complexity of the receiver, after baseband filtering, the original digital signal needs to be decimated first. In traditional decimation methods, decimation is performed according to the position of the maximum value. The decimation algorithm is not designed from the perspective of comprehensively considering the overall performance of the receiver. It only pursues local optimality and does not consider the impact of the decimation position selection on the receiver performance, resulting in the loss of receiver performance.

[0063] To address the above technical problems, in this embodiment, a method for decimating the baseband signal of a digital receiver is provided, which maximizes the total energy of the main path after decimation and maximizes the SINR of the weakest main path after decimation. By analyzing the channel response profiles generated by decimation at different positions, the optimal decimation position is determined, so as to obtain more accurate channel estimation parameters, provide the best channel response for the subsequent channel estimation module of the receiver, and achieve the purpose of improving the receiver performance.

[0064] As Figure 1 shown, an embodiment of the present invention provides a method for decimating the baseband signal of a digital receiver, including the following steps:

[0065] Step S100, perform a correlation operation on the local PN sequence signal and the received sampled pilot PN sequence signal, and perform decimation at different positions according to the correlation result to obtain channel response profiles in multiple scenarios.

[0066] In this embodiment, the method for decimating the baseband signal of the digital receiver is applied to a terminal, and the terminal includes but is not limited to: devices such as a computer, specifically a terminal device with a DTMB digital TV receiver synchronization module.

[0067] In this embodiment, taking the 4-fold sampled data after analog-to-digital conversion at the receiver end as an example (but not limited to the 4-fold sampled data after analog-to-digital conversion), the receiver reduces the oversampled signal to a normal signal at a 1-fold rate, and there are 4 possible decimation positions. Decimation at these 4 positions corresponds to 4 different channel responses.

[0068] The decimation criteria of this embodiment can be summarized as the following two points:

[0069] 1. Maximize the total energy of the main path after downsampling;

[0070] 2. Maximize the SINR (Signal to Interference plus Noise Ratio) of the weakest main path after downsampling.

[0071] Specifically, in one implementation manner of this embodiment, step S100 includes the following steps:

[0072] Step S101a: Perform correlation operations on the local PN sequence signal and the received N-fold sampled pilot PN sequence signal in sequence to obtain the correlation result;

[0073] Step S102a: Perform downsampling at N different positions according to the correlation result to obtain the channel response profiles in N scenarios.

[0074] In this embodiment, after receiving the signal at the receiver end, the receiver end performs analog-to-digital conversion on the received signal to obtain 4-fold sampled data, that is, 4-fold pilot signals; then, perform correlation operations on the received 4-fold pilot signals and the local pilot signals to obtain the channel response profile under 4-fold sampling; among them, the obtained channel response profile is the result after normalization processing, and the normalized result is as Figure 2 shown.

[0075] Specifically, in this embodiment, during the process of performing correlation operations, it is necessary to obtain the local PN (Pseudo-noise Sequence) sequence signal, multiply and accumulate the local PN sequence signal and the received 4-fold sampled pilot PN sequence signal in sequence, then perform normalization processing on the obtained correlation result, and downsample this normalized correlation result to the single-sampling rate to obtain the channel response profiles in 4 scenarios.

[0076] In this embodiment, according to different sampling positions, 4 different downsampling results can be obtained, as Figure 3 shown. When determining the specific corresponding sampling positions, one point can be taken every 4 points, and there are a total of 4 possible positions. Among them, channel estimation can be performed based on the downsampling result obtained at the fourth downsampling position to obtain the best system performance.

[0077] As Figure 3 shown, in this embodiment, for the four downsampling positions in the figure, the specific corresponding sampling positions are that Shift = 0 corresponds to downsampling at the position of the maximum value, and then followed by downsampling with an offset of 1, 2, and 3 points in sequence.

[0078] As Figure 1As shown, in one implementation of the embodiment of the present invention, the digital receiver baseband signal downsampling method further includes the following steps:

[0079] Step S200: Compare the obtained channel response profiles with a preset threshold respectively to determine the main paths corresponding to each scenario, and calculate the total energy of the main paths in each scenario.

[0080] In this embodiment, taking the 4-fold oversampled received signal as an example, after performing a correlation operation on the local PN sequence signal and the received 4-fold sampled pilot PN sequence signal, by downsampling the correlation results at 4 different positions (i.e., determining the sampling positions and data according to the correlation results), the channel response profiles in 4 scenarios are obtained; furthermore, by comparing the channel response profiles in each scenario with a preset threshold, the main paths in different scenarios are determined.

[0081] Specifically, in one implementation of this embodiment, step S200 includes the following steps:

[0082] Step S201: Compare the channel response profiles in each scenario with a preset threshold respectively;

[0083] Step S202: Select the positions exceeding the preset threshold as the main paths corresponding to each scenario;

[0084] Step S203: Calculate the total energy of the selected main paths in each scenario respectively.

[0085] In this embodiment, during the process of determining the main paths in different scenarios, it can be determined sequentially. First, select the channel response profile in one scenario, compare the normalized response values at each position in this channel response profile with a preset threshold T to determine the main path in this scenario; among them, the determined main path is the position exceeding the threshold after downsampling (such as Figure 4 the main path shown).

[0086] In this embodiment, the threshold T can be set to 1 / 2 or 2 / 3 of the strongest path. It can be understood that the preset threshold is a preset normalized value, such as 1 / 2 or 2 / 3.

[0087] Furthermore, after determining all the main paths in a certain scenario, the sum of the energies of all the main paths in this scenario can be calculated to obtain the total energy of the main paths in this scenario; correspondingly, for the remaining scenarios, the same method can be adopted. First, determine the main paths in this scenario, and then obtain the total energy of the main paths in this scenario.

[0088] As Figure 1 shown, in one implementation of the embodiment of the present invention, the digital receiver baseband signal downsampling method further includes the following steps:

[0089] Step S300: Sort the total energy of the main paths in each scenario to obtain the first scenario and the second scenario ranked in the top two.

[0090] Step S400: Calculate the SINR corresponding to the smallest main path in the first scenario and calculate the SINR corresponding to the smallest main path in the second scenario.

[0091] Step S500: Compare the two calculated SINRs, select the sampling position of the scenario corresponding to the higher SINR for sampling, and output the sampled data.

[0092] In this embodiment, after calculating the total energy of the selected main paths in each scenario, sort the total energy of the main paths in each scenario, and select the two downsampling scenarios ranked in the top two in terms of total energy; furthermore, calculate the SINR of the main path with the smallest energy in each of the two selected scenarios. As Figure 4 shown, the main path with the smallest energy in this scenario is the middle main path.

[0093] In this embodiment, compare the worst SINRs of these two scenarios, select the sampling position of the scenario corresponding to the higher SINR for downsampling, and output 1-fold downsampled data.

[0094] In another implementation manner of the embodiment of the present invention, the digital receiver baseband signal downsampling method further includes the following steps:

[0095] Step S10: Perform correlation operations on the local PN sequence signal and the received N-fold sampled pilot PN sequence signal in sequence to obtain the correlation result.

[0096] Step S20: Find the maximum value M in the correlation result.

[0097] Step S30: Select all values greater than 3 / 4M and record the positions corresponding to the selected values.

[0098] Step S40: Determine the corresponding channel type according to the recorded positions, and select the corresponding sampling strategy according to the determined channel type, and output the downsampled data.

[0099] In this embodiment, during the digital receiver baseband signal downsampling process, the channel types that appear include: long echo channel, Doppler channel, and other channels; in these different channels, different sampling strategies can be switched according to the different channel types, so as to maximize the total energy of the main paths after downsampling and maximize the SINR of the weakest main path after downsampling. Through such a downsampling method, the best channel response is provided for the subsequent channel estimation module of the receiver, so as to achieve the purpose of improving the overall performance of the receiver.

[0100] In this embodiment, in a certain scenario, the local PN sequence signal is correlated with the received 4-fold sampled pilot PN sequence signal to find all values greater than 3 / 4×M, and the corresponding channel type is determined to be a long echo channel according to the recorded positions; if the channel type is a long echo channel, the position of the farthest path among the recorded positions is determined, and then downsampling is performed according to the position of the farthest path, and the corresponding downsampled data is output.

[0101] In this embodiment, when determining whether it is a long echo channel, the last main path in this scenario can be found first, and then it is determined whether the distance between the last main path and the previous main path exceeds a certain threshold (for example, the distance threshold is 200 position points); if the threshold is met, the channel type is determined to be a long echo channel; then, the position of the farthest path among the recorded positions is determined, and the downsampled data is output according to the position of the farthest path.

[0102] In this embodiment, if it is not a long echo channel, it is determined whether the corresponding channel type is a Doppler channel according to the recorded positions; if it is a Doppler channel, the position of the strongest path among the recorded positions is determined, and downsampling is performed according to the position of the strongest path, and the corresponding downsampled data is output.

[0103] In this embodiment, if it is neither a long echo channel nor a Doppler channel, the total energies of the main paths in each scenario are sorted to obtain the SINR corresponding to the smallest main path in the top two scenarios; the two calculated SINRs are compared, and the sampling position of the scenario with the higher SINR is selected for sampling, and the sampling data is output, that is, downsampling is performed using the above steps S100 to S500, and the corresponding downsampled data is output.

[0104] Of course, in this embodiment, no matter what downsampling strategy is adopted, after downsampling, interference needs to be removed according to a preset algorithm, and the position of the first multipath (that is, the position of the first value exceeding the preset multipath threshold) is determined; then, the downsampled and synchronization signals are output; where the preset algorithm is the CLEAN algorithm, and interference is removed through the CLEAN algorithm; other methods can also be adopted to remove interference.

[0105] As Figure 6 shown, in the actual application process of this embodiment, the downsampling algorithm provided by this embodiment can not only be applied to DTMB receivers, but also to the receiver structures of other wireless communication systems. Among them, the specific implementation steps of the DTMB receiver synchronization module are:

[0106] Step 101: Perform a correlation operation between the local PN sequence signal and the received 4-fold sampled pilot PN sequence signal;

[0107] Step 102: Find the maximum value M of the relevant results;

[0108] Step 103: Find all values greater than 3 / 4×M;

[0109] Step 104: Record the positions of these values;

[0110] Step 105: Determine whether it is a long echo channel. If so, jump to 106; if not, jump to 107;

[0111] Step 106: Perform downsampling according to the position of the farthest path and jump to 110;

[0112] Step 107: Determine whether it is a Doppler channel. If so, jump to 108; if not, jump to 109;

[0113] Step 108: Perform downsampling according to the position of the strongest path and jump to 110;

[0114] Step 109: Perform downsampling according to the new algorithm proposed in this embodiment;

[0115] Step 110: Use the CLEAN algorithm to remove interference;

[0116] Step 111: Determine the position of the first multipath;

[0117] Step 112: Output the downsampled and synchronization signals.

[0118] As Figure 5 shown, in the actual application process of this embodiment, the specific implementation steps of performing downsampling according to the new algorithm proposed in this embodiment (i.e., the above Step 109) are as follows:

[0119] Correlate the local PN sequence signal (Pseudo-noise Sequence) with the received 4-fold sampled pilot PN sequence signal;

[0120] Step 11: Perform downsampling at 4 different positions to obtain 4 scenarios;

[0121] Step 12: Determine the main path in different scenarios;

[0122] Step 13: Calculate the total energy of the main path in each scenario;

[0123] Step 14: Sort and select the two scenarios with the highest total energy;

[0124] Step 15: Calculate the SINR for the main path with the minimum energy in each scenario;

[0125] Step 16: Compare the worst SINR of the two scenarios;

[0126] Step 17: Select the sampling points corresponding to the high SINR scenario for downsampling;

[0127] In this embodiment, after downsampling according to the proposed new algorithm, 1-fold downsampled data can be output. In this embodiment, the downsampling method of the proposed new algorithm provides the best channel response for the subsequent channel estimation module of the receiver, so as to achieve the purpose of improving the overall performance of the receiver.

[0128] This embodiment achieves the following technical effects through the above technical solutions:

[0129] In this embodiment, by performing a correlation operation on the local PN sequence signal and the received sampled pilot PN sequence signal, and performing downsampling at different positions according to the correlation result, channel response profiles in multiple scenarios can be obtained; then, by comparing the obtained channel response profiles with a preset threshold, the corresponding main paths in each scenario are determined, and the total energy of the main paths in each scenario is calculated; the total energy of the main paths in each scenario can be sorted to obtain the first scenario and the second scenario ranked in the top two; in this embodiment, by calculating the SINR corresponding to the smallest main path in the first scenario and calculating the SINR corresponding to the smallest main path in the second scenario; by comparing the two calculated SINRs, the sampling position of the scenario corresponding to the higher SINR is selected for sampling, and the sampled data is output; this embodiment maximizes the total energy of the main paths after downsampling and maximizes the SINR of the weakest main path after downsampling, improving the overall performance of the receiver.

[0130] Exemplary device

[0131] Based on the above embodiment, the present invention further provides a digital receiver baseband signal downsampling device, including:

[0132] A first downsampling module, configured to perform a correlation operation on the local PN sequence signal and the received sampled pilot PN sequence signal, and perform downsampling at different positions according to the correlation result to obtain channel response profiles in multiple scenarios;

[0133] A total energy calculation module, configured to compare the obtained channel response profiles with a preset threshold respectively to determine the corresponding main paths in each scenario, and calculate the total energy of the main paths in each scenario;

[0134] A total energy sorting module, configured to sort the total energy of the main paths in each scenario to obtain the first scenario and the second scenario ranked in the top two;

[0135] An SINR calculation module, configured to calculate the SINR corresponding to the smallest main path in the first scenario and calculate the SINR corresponding to the smallest main path in the second scenario;

[0136] The second downsampling module is used to compare the two calculated SINRs, select the sampling position of the scenario corresponding to the higher SINR for sampling, and output the sampled data.

[0137] Based on the above embodiments, the present invention further provides a terminal, and its principle block diagram can be as Figure 7 shown.

[0138] The terminal includes: a processor, a memory, an interface, a display screen, and a communication module connected through a system bus; wherein, the processor of the terminal is used to provide computing and control capabilities; the memory of the terminal includes a storage medium and an internal memory; the storage medium stores an operating system and a computer program; the internal memory provides an environment for the operation of the operating system and the computer program in the storage medium; the interface is used to connect external devices, for example, mobile terminals and computers and other devices; the display screen is used to display corresponding information; the communication module is used to communicate with a cloud server or a mobile terminal.

[0139] When the computer program is executed by the processor, it is used to implement the operations of a digital receiver baseband signal downsampling method.

[0140] Those skilled in the art can understand that Figure 7 the principle block diagram shown in

[0141] merely shows the block diagram of some structures related to the solution of the present invention, and does not constitute a limitation on the terminal to which the solution of the present invention is applied. The specific terminal may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0142] In one embodiment, a terminal is provided, which includes: a processor and a memory. The memory stores a digital receiver baseband signal downsampling program. When the digital receiver baseband signal downsampling program is executed by the processor, it is used to implement the operations of the digital receiver baseband signal downsampling method as described above.

[0143] Those of ordinary skill in the art can understand that all or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile storage medium. When the computer program is executed, it may include the processes of the above method embodiments. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided by the present invention may include non-volatile and / or volatile memories.

[0144] In summary, the present invention provides a method, apparatus, terminal, and storage medium for downsampling a baseband signal of a digital receiver. The method includes: performing a correlation operation on a local PN sequence signal and a received sampled pilot PN sequence signal, and performing downsampling at different positions according to the correlation result; respectively comparing the obtained channel response profiles with a preset threshold value to determine the corresponding main paths in each scenario, and calculating the total energy of the main paths in each scenario; sorting the total energies of the main paths in each scenario to obtain a first scenario and a second scenario ranked in the top two; calculating the SINR corresponding to the smallest main path in the first scenario and calculating the SINR corresponding to the smallest main path in the second scenario; comparing the two calculated SINRs, selecting the sampling position of the scenario corresponding to the higher SINR for sampling, and outputting the sampled data. The present invention maximizes the total energy of the main paths after downsampling and maximizes the SINR of the weakest main path after downsampling, improving the overall performance of the receiver.

[0145] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for downsampling the baseband signal of a digital receiver, characterized in that, it includes: Performing a correlation operation on the local PN sequence signal and the received sampled pilot PN sequence signal, and performing downsampling at different positions according to the correlation result to obtain channel response profiles in multiple scenarios; Respectively comparing the obtained channel response profiles with a preset threshold value, determining the corresponding main path in each scenario, and calculating the total energy of the main path in each scenario; Sorting the total energy of the main path in each scenario to obtain the first scenario and the second scenario ranked in the top two; Calculating the SINR corresponding to the smallest main path in the first scenario, and calculating the SINR corresponding to the smallest main path in the second scenario; Comparing the two calculated SINRs, selecting the sampling position of the scenario corresponding to the higher SINR for sampling, and outputting the sampled data.

2. The method for downsampling the baseband signal of a digital receiver according to claim 1, characterized in that, The performing a correlation operation on the local PN sequence signal and the received sampled pilot PN sequence signal, and performing downsampling at different positions according to the correlation result to obtain channel response profiles in multiple scenarios includes: Performing a correlation operation on the local PN sequence signal and the received N-fold sampled pilot PN sequence signal in sequence to obtain the correlation result; Performing downsampling at N different positions according to the correlation result to obtain channel response profiles in N scenarios.

3. The method for downsampling the baseband signal of a digital receiver according to claim 1, characterized in that, The preset threshold value is a preset normalized threshold value.

4. The method for downsampling the baseband signal of a digital receiver according to claim 1, characterized in that, The respectively comparing the obtained channel response profiles with a preset threshold value, determining the corresponding main path in each scenario, and calculating the total energy of the main path in each scenario includes: Respectively comparing the channel response profiles in each scenario with the preset threshold value; Selecting the positions exceeding the preset threshold value as the main path in the corresponding scenario; Respectively calculating the total energy of the selected main path in each scenario.

5. A method for downsampling the baseband signal of a digital receiver, characterized in that, it includes: Performing a correlation operation on the local PN sequence signal and the received N-fold sampled pilot PN sequence signal in sequence to obtain a correlation result; Finding the maximum value M in the correlation result; Selecting all values greater than 3 / 4M and recording the positions corresponding to the selected values; Determining the corresponding channel type according to the recorded positions, and selecting the corresponding sampling strategy according to the determined channel type, and outputting the downsampled data; The channel types include: long echo channel, Doppler channel; The determining the corresponding channel type according to the recorded positions, and selecting the corresponding sampling strategy according to the determined channel type, and outputting the downsampled data includes: Judging whether the corresponding channel type is the long echo channel according to the recorded positions; If it is the long echo channel, determining the position of the farthest path among the recorded positions, performing downsampling according to the position of the farthest path, and outputting the corresponding downsampled data; After determining whether the corresponding channel type is the long echo channel according to the recorded position, the following steps are further included: If it is not the long echo channel, determine whether the corresponding channel type is the Doppler channel according to the recorded position; If it is the Doppler channel, determine the position of the strongest path among the recorded positions, perform downsampling according to the position of the strongest path, and output the corresponding downsampled data; After determining whether the corresponding channel type is the Doppler channel according to the recorded position, the following steps are further included: If it is not the Doppler channel, sort the total energies of the main paths in each scenario to obtain the SINR corresponding to the smallest main path in the top two scenarios; Compare the two calculated SINRs, select the sampling position of the scenario corresponding to the higher SINR for sampling, and output the sampled data.

6. The digital receiver baseband signal downsampling method according to claim 5, wherein, The step of determining the corresponding channel type according to the recorded position, selecting the corresponding sampling strategy according to the determined channel type, and outputting the downsampled data further includes: Determine the corresponding channel type according to the recorded position, and select the corresponding sampling strategy for downsampling according to the determined channel type; Remove interference according to a preset algorithm, and determine the position of the first multipath; Output the downsampled and synchronization signals.

7. A digital receiver baseband signal downsampling device for implementing the digital receiver baseband signal downsampling method according to any one of claims 1-4 or 5-6, wherein, It includes: A first downsampling module for performing a correlation operation on the local PN sequence signal and the received sampled pilot PN sequence signal, and performing downsampling at different positions according to the correlation result to obtain the channel response profiles in multiple scenarios; A total energy calculation module for respectively comparing the obtained channel response profiles with a preset threshold to determine the corresponding main path in each scenario, and calculating the total energy of the main path in each scenario; A total energy sorting module for sorting the total energies of the main paths in each scenario to obtain the first scenario and the second scenario ranked in the top two; A SINR calculation module for calculating the SINR corresponding to the smallest main path in the first scenario, and calculating the SINR corresponding to the smallest main path in the second scenario; A second downsampling module for comparing the two calculated SINRs, selecting the sampling position of the scenario corresponding to the higher SINR for sampling, and outputting the sampled data.

8. A terminal, wherein, It includes: A processor and a memory, the memory stores a digital receiver baseband signal downsampling program, and when the digital receiver baseband signal downsampling program is executed by the processor, it is used to implement the operations of the digital receiver baseband signal downsampling method according to any one of claims 1-4 or 5-6.

9. A storage medium, wherein, The storage medium is a computer-readable storage medium, and the storage medium stores a digital receiver baseband signal downsampling program. When the digital receiver baseband signal downsampling program is executed by a processor, it is used to implement the operations of the digital receiver baseband signal downsampling method described in any one of claims 1-4 or 5-6.

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