WO2021232566A1

WO2021232566A1 - Spread spectrum signal sending method and apparatus, spread spectrum signal receiving method and apparatus, and device and medium

Info

Publication number: WO2021232566A1
Application number: PCT/CN2020/101783
Authority: WO
Inventors: 郑波浪; 李晓明; 熊艳伟; 李建龙; 刘伟
Original assignee: 北京升哲科技有限公司
Priority date: 2020-05-20
Filing date: 2020-07-14
Publication date: 2021-11-25
Also published as: CN111614373A; TWI722942B; TW202145732A; CN111614373B

Abstract

Disclosed are a spread spectrum signal sending method and apparatus, a spread spectrum signal receiving method and apparatus, and a device and a medium. The spread spectrum signal sending method comprises: in a signal transmission process, obtaining a preset residual frequency offset tolerance threshold, and determining a spread spectrum modulation optimization parameter; obtaining at least one information unit, the number of the information units matching the spread spectrum modulation optimization parameter; and spreading the information units by adopting a Hadamard matrix to form spread spectrum signals, modulating the spread spectrum signals and sending the modulated spread spectrum signals to a signal receiving device.

Description

Spread spectrum signal transmission method, spread spectrum signal reception method, device, equipment and medium

This disclosure claims the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 202010431747.8 on May 20, 2020, and the entire content of the above application is incorporated into this disclosure by reference.

Technical field

This application relates to the field of Internet of Things communications, for example, to a spread-spectrum signal transmission method, a spread-spectrum signal reception method, device, equipment, and medium.

Background technique

Spread spectrum communication has been widely used because of its strong anti-interference ability and good security performance.

In the M-ary orthogonal spread spectrum system, the spread sequence set is composed of M orthogonal codewords of length n. In the modulation process at the sending end, every n bits (bit) constitute a modulation symbol (n=log ₂ (M)), and the orthogonal codeword of the corresponding sequence number is selected for transmission according to the value of the modulation symbol. At the receiving end, M correlators are usually required to complete the orthogonal despreading operation and determine the sequence number of the transmitted spreading sequence to obtain modulation information. In general, the frequency of the signal will shift during the transmission process. The frequency offset can be estimated and compensated during demodulation to reduce the frequency offset, but the frequency offset cannot be completely eliminated. The compensated frequency offset The amount is the residual frequency offset. The M-ary orthogonal spread spectrum modulation technology usually requires that the residual frequency offset of the spread spectrum sequence is small.

The frequency offset can be estimated by increasing the length of the preamble and using a high-precision synchronization algorithm to improve the accuracy of frequency offset compensation; it can also reduce the introduction of frequency offset by improving the stability of the crystal oscillator. However, the aforementioned methods all require the support of higher-cost hardware equipment, which greatly increases the cost of the spread spectrum system.

Summary of the invention

The embodiments of the application provide a spread spectrum signal transmission method, spread spectrum signal reception method, device, equipment and medium, which can increase the tolerable frequency offset of the system, reduce the complexity of system frequency offset estimation and frequency offset tracking, and reduce the system Cost and complexity of implementation.

In the first aspect, an embodiment of the present application provides a method for transmitting a spread spectrum signal, including:

In the process of signal transmission, the preset residual frequency deviation tolerance threshold is obtained, and the optimization parameters of spread spectrum modulation are determined;

Acquiring at least one information unit, the number of the information unit matches the spread spectrum modulation optimization parameter;

The Hadamard matrix is used to spread the spectrum of each of the information units to form a spread spectrum signal and send the spread spectrum signal to the signal receiving device after being modulated, wherein the spread spectrum modulation optimization parameters are used to provide all the information in advance. The signal receiving device instructs the signal receiving device to correct the signal despreading result.

In the second aspect, an embodiment of the present application also provides a method for receiving a spread spectrum signal, including:

In the process of signal transmission, obtaining a despreading result of the spread spectrum signal, where the despreading result is determined by despreading the spread spectrum signal by using a Hadamard matrix spread spectrum technique;

Acquiring a spread spectrum modulation optimization parameter, where the spread spectrum modulation optimization parameter is determined according to a preset residual frequency offset tolerance threshold;

The despreading result is modified according to the spread spectrum modulation optimization parameter, and at least one information unit is determined, and the number of the information unit matches the spread spectrum modulation optimization parameter.

In a third aspect, an embodiment of the present application also provides a spread spectrum signal sending device, including:

The spread spectrum modulation optimization parameter determination module is configured to obtain a preset residual frequency deviation tolerance threshold during signal transmission, and determine the spread spectrum modulation optimization parameter;

An information unit acquisition module configured to acquire at least one information unit, the number of the information unit matches the spread spectrum modulation optimization parameter;

The signal spreading module is configured to use a Hadamard matrix to spread the spectrum of each of the information units to form a spread spectrum signal and send the spread spectrum signal to the signal receiving device after being modulated, wherein the spread spectrum modulation The optimized parameter is used to provide the signal receiving device in advance to instruct the signal receiving device to correct the signal despreading result.

In a fourth aspect, an embodiment of the present application also provides a spread spectrum signal receiving device, including:

The spread-spectrum signal despreading module is configured to obtain the despreading result of the spread-spectrum signal during signal transmission, and the despreading result is determined by despreading the spread-spectrum signal by using the Hadamard matrix spread spectrum technology ；

A spread spectrum modulation optimization parameter acquisition module configured to acquire a spread spectrum modulation optimization parameter, the spread spectrum modulation optimization parameter being determined according to a preset residual frequency deviation tolerance threshold;

The despreading result correction module is configured to correct the despreading result according to the spread spectrum modulation optimization parameter, and determine at least one information unit, and the number of the information units matches the spread spectrum modulation optimization parameter.

In a fifth aspect, an embodiment of the present application also provides a signal sending device, including a memory, a processor, and a computer program stored in the memory and running on the processor. The processor executes the computer program. The program implements the spread spectrum signal transmission method as described in any of the embodiments of this application.

In a sixth aspect, an embodiment of the present application also provides a signal receiving device, including a memory, a processor, and a computer program stored in the memory and running on the processor. The processor executes the computer The program implements the spread spectrum signal receiving method as described in any of the embodiments of this application.

In a seventh aspect, the embodiments of the present application also provide a computer-readable storage medium, and the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it can achieve the same as any of the embodiments of the present application. The method for transmitting a spread spectrum signal may implement the method for receiving a spread spectrum signal as described in any one of the embodiments of the present application.

Description of the drawings

Figure 1 is a schematic diagram of an autocorrelation peak output by a correlator in the related art;

2 is a flowchart of a method for transmitting a spread spectrum signal in Embodiment 1 of the present application;

FIG. 3 is a schematic diagram of an autocorrelation peak output by a correlator under a residual frequency offset in an embodiment of the present application;

4 is a schematic diagram of an autocorrelation peak output by a correlator under another residual frequency offset in an embodiment of the present application;

FIG. 5 is a flowchart of a method for receiving a spread spectrum signal in Embodiment 2 of the present application;

FIG. 6 is a schematic diagram of an application scenario to which an embodiment of the present application is applicable;

FIG. 7 is a schematic diagram of a signal sending device in Embodiment 3 of the present application;

FIG. 8 is a schematic diagram of a signal receiving device in Embodiment 3 of the present application;

FIG. 9 is a schematic structural diagram of a spread spectrum signal sending device in Embodiment 4 of the present application;

FIG. 10 is a schematic structural diagram of a spread spectrum signal receiving device in Embodiment 5 of the present application;

FIG. 11 is a schematic structural diagram of a computer device in Embodiment 6 of the present application.

Detailed ways

The application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the application, but not to limit the application. In addition, it should be noted that, for ease of description, the drawings only show a part of the structure related to the present application instead of all of the structure.

In order to facilitate the understanding of the embodiments of this application, the Hadamard matrix spread spectrum technology is described:

The Hadamard matrix is an n-th order square matrix composed of +1 and -1 elements and satisfies H _n *H _n '=nI (where H _n 'is _{the transposed matrix of H n} and I is the unit square matrix). In the Hadamard matrix, the row vectors of any two rows are orthogonal to each other, and the column vectors of any two columns are orthogonal to each other. The signal sending device uses M=2 ⁿ row vectors as an M-ary orthogonal spreading sequence set, and selects matching row vectors as the orthogonal spreading sequence _{according to n=log 2 (M) bits for transmission.} Since the row vectors of any two rows are orthogonal to each other, the value of the product between the same row vectors is the largest, that is, each row vector has autocorrelation. The signal receiving device uses M correlators matching the M row vectors of the Hadamard matrix to perform despreading operations, and selects the correlator identification information (such as the correlator serial number) corresponding to the largest correlation value from the M correlators output as the solution Spread output, determine the spreading row vector according to the identification information of the correlator, and the modulation symbol represented by the row vector is the effective data transmitted.

In an example, n=12 and M=4096. In the Hadamard matrix, the row vectors are numbered in the order from top to bottom, where the row vector with the sequence number 500 is used as the spreading sequence, and at the same time, the row vector is numbered , Corresponding to the number of the configured correlator, the i-th correlator multiplies the demodulated signal with the i-th row vector to calculate the peak value. The peak value is actually the amplitude, where i is greater than or equal to 0 and less than n. As shown in Figure 1, the peak output of M correlators is displayed.

Due to the orthogonality of each row vector in the Hadamard matrix, only the output peak value of the serial number 500 is the output peak value of the other correlators. According to the peak value comparison of the correlators, the effective data carried by the spreading sequence can be obtained.

Example one

FIG. 2 is a schematic diagram of a flow chart of a method for transmitting a spread spectrum signal in the first embodiment of the application. This embodiment is applicable to the case of transmitting signals based on the Hadamard matrix spread spectrum technology. The method may be provided by the embodiment of the application. The spread spectrum signal transmission device can be implemented by means of software and/or hardware, and can generally be integrated into computer equipment. As shown in Figure 2, the method of this embodiment may include:

S110: In the process of signal transmission, obtain a preset residual frequency offset tolerance threshold, and determine an optimization parameter of spread spectrum modulation.

The process of signal transmission may refer to the process of signal transmission using the multi-ary orthogonal spread spectrum technology. The signal transmission process can be in the application scenario of long-distance, low-power, narrow-band communications, and the Internet of Things. In this application scenario, the signal transmission data rate is low and the sensitivity is high. Under the premise of interference characteristics, the data transmission efficiency is improved by increasing the number of information bits carried by a single spread spectrum sequence. Among them, the use of multi-ary orthogonal spread spectrum technology to transmit signals can be: acquiring multiple bits, that is, effectively transmitting data, as a modulation symbol, in the same unit time (the unit time can refer to the allocated time slice), The modulation symbol performs multi-ary orthogonal spread spectrum to generate a spread spectrum signal and modulate it to form a radio frequency signal and send it to the signal receiving device. Thus, in this unit time, a set number of bits can be transmitted simultaneously.

The residual frequency deviation tolerance threshold may refer to the maximum value of the residual frequency deviation. The residual frequency deviation tolerance threshold can be a value input in advance by the user or a value preset by the system. The spread spectrum modulation optimization parameter is used to determine the maximum number of bits transmitted in parallel in the same unit time, that is, the spread spectrum modulation optimization parameter is used to specify the number of information units transmitted in the same unit time. The residual frequency offset tolerance threshold is used to determine the optimization parameters of spread spectrum modulation, thereby indirectly determining the maximum number of bits transmitted in parallel in the same unit time. The maximum number of bits can be selected for transmission in the same unit time, which ensures the accuracy of the despreading result while taking into account the transmission efficiency. In some embodiments, the spread spectrum modulation optimization parameter may be calculated according to the correspondence between the preset residual frequency offset tolerance threshold and the spread spectrum modulation optimization parameter, where the correspondence relationship is obtained based on experiments.

In fact, there is a frequency offset phenomenon in the signal transmission process, and after frequency compensation, there is still a residual frequency offset. The residual frequency offset causes an error in the despreading result of the signal receiving device. When the signal to be despread has a residual frequency offset, for example, when the normalized residual frequency offset is 0.2, the peak output of the M correlators in the previous example is shown in FIG. 3. In fact, the residual frequency offset destroys the orthogonality of the row vectors in the Hadamard matrix. Due to the existence of the residual frequency offset, not only the serial number 500 correlator has peaks, but also multiple originally orthogonal correlators will also have peaks. However, based on the maximum peak decision criterion, the system can still correctly obtain the effective data carried by the spreading sequence. Shows that the system has a certain ability to resist frequency offset. However, when the normalized residual frequency offset is greater than 0.5, the peak value of other correlators (such as the correlator with serial number 2620) caused by the residual frequency offset is already greater than the peak value of the correct correlator, as shown in Figure 4, causing the signal receiving device to obtain an error. Effective data carried by the spreading sequence.

In view of this, when there is a residual frequency offset, due to the inherent relationship between the peak sequence number of the correct correlator and the peak sequence number of the wrong correlator, the partial spreading sequence set with the first sequence number can be selected for spreading operation, that is, the reduction in the same unit The number of bits transmitted in time. It can be understood that there is a corresponding relationship between the residual frequency offset and the number of bits transmitted in the same unit time.

The Hadamard matrix has the following iterative structure:

It can be seen from the iterative characteristics:

The row vector of the Hadamard matrix is an even row, which can be divided into two matrices up and down. The order n of the Hadamard matrix is greater than 2, and n is a non-negative integer. The spreading sequences represented by each row vector of the Hadamard matrix are respectively A periodically changing signal. The unit frequency signal is the unit frequency

Where B is the bandwidth and n is the order of the Hadamard matrix. Therefore, the lower half of the Hadamard matrix is equivalent to the product of the upper half of the matrix and the unit frequency signal.

The 2/4 matrix of the Hadamard matrix is equivalent to the product of the 1/4 matrix and twice the unit frequency signal; the 3/4 matrix of the Hadamard matrix is equivalent to the product of the 1/4 matrix and the unit frequency signal; the 4/4 of the Hadamard matrix The matrix is equivalent to the product of the 1/4 matrix and the unit frequency signal, but the 4/4 matrix of the Hadamard matrix and the 3/4 matrix of the Hadamard matrix have different initial phases.

Based on the above characteristics, if the residual frequency offset is less than the unit frequency, the row vector of the upper matrix may be misjudged as the row vector of the lower matrix at the corresponding position. For example, the vector at position p may be misjudged as the position of p+2 ^n-1 . vector. Similarly, if there is a frequency deviation less than twice the unit frequency, the vector corresponding to the 1/4 matrix may be misjudged as the 2/4 matrix, the vector at the corresponding position of the 3/4 matrix or the 4/4 matrix, for example, the vector at the position p may be wrong. It is judged as a vector ^{of p+2 n-2} , p+2*2 ^n-2 or p+3*2 ^n-2.

It should be noted that the normalized residual frequency offset refers to that the residual frequency offset is normalized with a unit frequency as a unit.

Optionally, the obtaining the preset residual frequency deviation tolerance threshold and determining the optimization parameters of spread spectrum modulation includes:

Based on the following formula, calculate the spread spectrum modulation optimization parameter d:

Wherein, A is the residual frequency offset tolerance threshold, B is the bandwidth, n is the order of the Hadamard matrix, and d is a non-negative integer.

In some embodiments, since the formula is an inequality, the calculated d may have multiple values, which may be determined as required, for example, the minimum value may be selected. In fact, d can be infinitely large, but the larger d, the smaller the number of information bits carried by the spreading sequence transmitted at the same time, and the corresponding transmission efficiency is reduced. It can be seen that, in accordance with the above formula, d is smaller , The higher the transmission efficiency.

For example, B=125KHz, n=12, normalized unit frequency

It is 30.5Hz, and A is 32Hz. The formula is 1.05<2 ^d-1 , and d is greater than 1.07. You can choose d as 2.

According to the iterative characteristics of the Hadamard matrix, the correspondence relationship between the residual frequency deviation tolerance threshold and the spread spectrum modulation optimization parameter is determined in advance, so as to calculate the spread spectrum modulation optimization parameter according to the residual frequency deviation tolerance threshold value to ensure the objectiveness of the spread spectrum modulation optimization parameter. , Improve the accuracy of de-spreading results.

As in the previous example, when the residual frequency offset is less than 1 unit frequency and the row vector of the 500th line is used as the spreading sequence, ^{the correlators with serial numbers 500 and 500+2 n-1} will all have auto-correlation peaks. Similarly, when the residual frequency offset is less than twice the unit frequency offset, and the row vector of the 500th line is used as the spreading sequence, the sequence numbers are ^{500, 500+2 n-2} , 500+2*2 ^n-2 and 500+ 3*2 ^n-2 correlators will have auto-correlation peaks. By analogy, when the residual frequency deviation is less than 2 ^d-1 unit frequency deviation, the correlator with the serial number 500+(2 ^j -1)2 ^nd will have an autocorrelation peak, and j is greater than or equal to 0 and less than or equal to d. Exemplarily, when n is 3 and the row vector of the first row is used as a spreading sequence, when there is a residual frequency offset, the correlators with serial numbers 1 and 5 will both have auto-correlation peaks, and the correlator with serial number 1 determines The valid data of is 001, and the valid data determined by the correlator with serial number 5 is 101. For example, when n is 4 and the row vector of the first row is used as a spreading sequence, the correlations with serial numbers 1, 5 and 9 The autocorrelation peak appears in the correlator, the valid data determined by the correlator with serial number 1 is 0001, the valid data determined by the correlator with serial number 5 is 0101, and the valid data determined by the correlator with serial number 9 is 1001. As a result, the correlator sequence number deviation caused by the residual frequency offset will only cause errors in the high bits of the valid data, and will not affect the low bits of the valid data. In this way, the high position in the valid data can be directly zeroed.

S120: Acquire at least one information unit, where the number of the information unit matches the spread spectrum modulation optimization parameter.

The information unit is used to transmit effective information to the signal receiving device, and an information unit may refer to a bit. In fact, multiple information units can be transmitted at the same time in the same unit time, and the number of information units can refer to the number of information units transmitted at the same time. Among them, the number of information units transmitted at the same time is determined according to the optimization parameters of spread spectrum modulation.

Optionally, the obtaining at least one information unit, the number of the information unit matches the spread spectrum modulation optimization parameter, includes: determining the maximum number of information bits carried by the spread spectrum sequence according to the spread spectrum modulation optimization parameter; Acquire multiple information units, and the number of information units is the maximum number of information bits.

The maximum number of information bits carried by the spreading sequence may refer to the maximum number of bits transmitted in the same unit time. It should be noted that, for the n-th order Hadamard matrix spread spectrum technology, the maximum number of bits transmitted in the same unit time is n. Correspondingly, the spread spectrum signal transmission method of the embodiment of the present application is adopted. In some embodiments, the maximum number of information bits carried by the current spread spectrum sequence is the difference between n and the minimum value of the spread spectrum modulation optimization parameter, that is, the maximum number of information bits. k _max =n-the minimum value d _{min of the} optimization parameter of spread spectrum modulation.

In fact, in an application scenario based on the Hadamard matrix spread spectrum technology, the number of bits that can be transmitted in the same unit time is determined according to the order of the Hadamard matrix. Generally, selecting the maximum number of bits that can be transmitted to form a modulation symbol can increase the number of bits transmitted in the same unit time and improve transmission efficiency. However, in this way, a high-complexity synchronization algorithm or a high-stability crystal oscillator is required to reduce the frequency offset and increase the cost of frequency offset compensation. In view of this, the embodiment of the present application determines the acceptable maximum number of bits that can be transmitted in the same unit time according to the residual frequency deviation tolerance threshold, and selects the bits for signal transmission, so as to ensure the accuracy of the despreading result while taking into account the transmission efficiency. .

In some embodiments, it is also possible to select as the number of information units less than the maximum number of information bits (positive integer) carried by the spreading sequence formed based on the multi-ary spreading modulation technology as required.

S130. Use a Hadamard matrix to spread spectrum on each of the information units to form a spread spectrum signal and modulate and send it to a signal receiving device, where the spread spectrum modulation optimization parameter is used to provide the signal receiving device in advance to indicate the The signal receiving device corrects the signal despreading result.

The Hadamard matrix spread spectrum method can be to obtain multiple consecutive information units, determine valid data according to each information unit, and select a row vector matching the valid data from the Hadamard matrix to generate a spread spectrum sequence as a spread spectrum signal . Exemplarily, multiple consecutive information units are respectively: 0, 1, and 0, that is, binary 010, which is equivalent to decimal 2. You can select the row vector of the second row in the Hadamard matrix (the first row is the 0th row) to generate the extension Frequency sequence, as a spread spectrum signal. Correspondingly, in the signal receiving device, the correlator with serial number 2 outputs the peak value. Therefore, the signal receiving device determines that the spreading sequence is the row vector of the second row, which represents binary 010, that is, the effective data transmitted is 0, 1, and 0.

The signal receiving equipment can optimize the parameters according to the spread spectrum modulation, and select the despreading result corresponding to the correlator with the first sequence number as the despreading result, thus, the despreading result corresponding to the wrong correlator can be eliminated, thereby ensuring the accuracy of the despreading result sex.

In the embodiment of the application, during the signal transmission process, the spread spectrum modulation optimization parameter is determined according to the residual frequency deviation tolerance threshold, and the number of information units is designated according to the spread spectrum modulation optimization parameter, and the number of information units is regarded as the same unit time The transmitted valid data is spread spectrum and modulated, sent to the signal receiving device, and instructs the signal receiving device to modify the signal despreading result through the spread spectrum modulation optimization parameters, so that the signal receiving device can obtain the accurate despreading result and realize the pass Optimize the number of information units to be transmitted to improve the accuracy of signal despreading, and solve the problem of high cost and complexity of reducing residual frequency offset in related technologies. The original design of the hardware can be changed without changing the original design of the hardware, and the implementation cost and Complexity, while improving the stability of the spread spectrum system and the accuracy of the despreading results, while taking into account the transmission efficiency.

Example two

FIG. 5 is a flowchart of a method for receiving a spread spectrum signal in the second embodiment of this application. This embodiment is applicable to the case of transmitting signals based on the Hadamard matrix spread spectrum technology. It is executed by a signal receiving device, which can be implemented in software and/or hardware, and can generally be integrated into computer equipment. The method of this embodiment may include:

S210: In the process of signal transmission, a despreading result of the signal is obtained, and the despreading result is determined by despreading the spread spectrum signal by using a Hadamard matrix spread spectrum technique.

For the content in this embodiment, reference may be made to the description in any of the above embodiments.

The spread spectrum signal is actually a signal obtained by demodulating the signal sent by the signal sending device. In the signal generating equipment, the signal is spread by using the Hadamard matrix spread spectrum technology. Correspondingly, the signal is despread by using the Hadamard matrix spread spectrum technology in the signal receiving equipment. In some embodiments, the signal receiving device configures a correlator corresponding to each row vector of the Hadamard matrix. The correlator is used to multiply the spread spectrum signal with the matched row vector. If the spread spectrum signal uses the matched row vector As a spreading sequence, there is autocorrelation between the spreading signal and the matched row vector, and the correlator outputs an autocorrelation peak. By querying the correlator that outputs the autocorrelation peak, the row vector matching the correlator can be determined, and the valid data represented by the row vector can be determined as the despreading result.

The result of despreading is a valid data, and the valid data includes multiple consecutive bits. For example, the valid data 010 in the previous example includes three bits of 0, 1, and 0.

S220: Obtain a spread spectrum modulation optimization parameter, where the spread spectrum modulation optimization parameter is determined according to a preset residual frequency offset tolerance threshold.

The obtaining method may include: receiving user input information and extracting optimization parameters of spread spectrum modulation from the input information; or obtaining optimization parameters of spread spectrum modulation sent by the signal sending device before signal transmission. It should be noted that a signal refers to a signal that carries an information unit.

S230: Correct the despreading result according to the spread spectrum modulation optimization parameter, and determine at least one information unit, where the number of the information unit matches the spread spectrum modulation optimization parameter.

In fact, as in the previous example, the correlators with serial numbers ^{500, 500+2 n-2} , 500+2*2 ^n-2 and 500+3*2 ^n-2 will all have auto-correlation peaks, that is, auto-correlation peaks. The difference between the serial numbers of the correlators is k*2 ^nd (1≤k≤2 ^d -1), and the exact serial number of the correlator can be determined by calculating ^{the difference between the serial number of the correlator and k*2 nd.} In fact, because the number of bits transmitted in the same unit time is reduced, the row vector with the subsequent sequence number is not used to generate the spreading sequence, that is, the sequence number of the correlator that obtains the accurate despreading result is less than 2 ^nd . In some embodiments, the correction method may be to calculate ^{the difference between the serial number of the correlator and k*2 nd} until the serial number of the correlator is less than 2 ^nd , and use the despreading result corresponding to the corrected correlator as the correction data.

It can be seen from the foregoing that the correlator sequence number deviation caused by the residual frequency offset will only cause errors in the high bits of the valid data, and will not affect the low bits of the valid data. The high bits in the despreading result can be corrected to obtain correct and effective data, so as to determine the information unit actually transmitted.

Optionally, the correcting the despreading result according to the spread spectrum modulation optimization parameter, and determining at least one information unit, the number of the information unit matches the spread spectrum modulation optimization parameter, includes: In the spreading result, the bit position that matches the spread spectrum modulation optimization parameter is zero, and the modified data is obtained; according to the modified data, at least one information unit is determined, and the number of the information units matches the spread spectrum modulation optimization parameter.

The despreading result is the effective data carried in the spread spectrum signal, and the despreading result is the data composed of multiple consecutive information units. The valid data may be wrong. The corrected data is correct and valid. The bits matching the optimization parameters of the spread spectrum modulation may refer to the number of bits before the target number in the order from high to low, and the target number is equal to the optimization parameter of the spread spectrum modulation. Exemplarily, d=2, the despreading result is 1101, the first 2 bits are set to zero, and the modified data is 0001.

It can be seen from the foregoing that when n is 4 and the row vector of the first row is used as the spreading sequence, the valid data determined by the correct correlator with serial number 1 is 0001, and the valid data determined by the wrong correlator with serial number 5 is 0101, the valid data determined by the wrong correlator with serial number 9 is 1001. It can be seen that when d=2, the number of valid data error bits is the first highest bit and the second highest bit, that is, the number of incorrect high bits is two at most. When d=1, the number of high bits of error is at most one. Therefore, the first d high-order bits in the valid data can be directly set to zero to determine the despreading result.

Modifying the despreading result can be: zeroing the bits of each valid data that match the spread spectrum modulation optimization parameter to obtain correct valid data, and splitting the valid data into multiple consecutive information units.

Through the relationship between the despreading result, the spread spectrum modulation optimization parameter and the corrected data, the correction method of the corrected data is determined, and accurate despreading results can be obtained quickly, the accuracy of despreading, and the efficiency of error correction can be improved.

Optionally, after obtaining the spread spectrum modulation optimization parameter, the method further includes: if the value of the bit matching the spread spectrum modulation optimization parameter in the despreading result is zero, determining at least one information unit according to the despreading result , The number of the information unit matches the optimization parameter of the spread spectrum modulation.

In the despreading result, the value of the bit matching the spread spectrum modulation optimization parameter is zero, indicating that the despreading result is a correct despreading result, and the information unit is determined directly according to the despreading result.

By judging the result of despreading, and when the result of despreading is correct, no correction is made to improve the efficiency of despreading.

The embodiment of the application modifies the despreading result according to the optimized parameters of spread spectrum modulation during the signal transmission process to obtain accurate despreading results without changing the original design of the hardware, reducing the implementation cost and complexity, and improving the solution. Expand the accuracy of the result while taking into account the transmission efficiency.

Example three

FIG. 6 is a schematic diagram of an application scenario in Embodiment 3 of this application. The spread spectrum signal transmission method described in any one of the embodiments of the present application may be applied to the signal transmitting device 610, and the spread spectrum signal receiving method described in any one of the embodiments of the present application is applied to the signal receiving device 620.

The schematic diagram of the structure of the signal sending device may be as shown in FIG.

The serial-to-parallel converter 710 is configured to perform parallel conversion of the information stream to be sent, which can be a 1:nd conversion relationship, and converts one information stream into nd bits for parallel transmission in the same unit time. The nd bits can be It is transmitted as a modulation symbol.

The Hadamard matrix 760 is configured to generate a spread spectrum signal matching each row vector.

The multiplexer (MUX) 720 is configured to select one output from the spread spectrum signal generated by the Hadamard matrix 760 according to the n-d bits transmitted in parallel.

The shaping filter 730 is configured to shape and filter the spread-spectrum signal output by the multiplexer 720, which can make the signal have a limited bandwidth and process the signal at a variable rate, so as to be suitable for channel transmission.

The up-converter 740 is configured to perform radio frequency modulation on the spread-spectrum signal after shaping and filtering. It may be that the spread-spectrum signal after shaping and filtering is modulated onto a high-frequency carrier to form a radio frequency signal.

The antenna 750 is configured to transmit radio frequency signals to the outside.

In some embodiments, the processor of the signal sending device is configured to control the input of the serial-to-parallel converter 710 to instruct the serial-to-parallel converter 710 to convert n-d bits in the same unit time.

The processor of the signal sending device is also configured to control which channel of the spread spectrum signal is selected by the multiplexer 720 to output. In some embodiments, the processor of the signal transmission device uses the spread spectrum signal transmission method provided in the embodiments of the present application to determine the spread spectrum modulation optimization parameter d, and according to the correspondence between nd bits and the row vector in the Hadamard matrix, ^{Select the target row vector matching the nd bits from the first 2 nd} (from top to bottom) row vectors of the Hadamard matrix to generate a spread spectrum signal, and control the multiplexer 720 to switch to the one that outputs the spread spectrum signal The circuit is turned on to achieve spread spectrum.

In fact, for the M×M Hadamard matrix, the signal sending device can transmit at most n=log ₂ (M) bits in the same unit time. The row vector that can be used as the spreading sequence in the Hadamard matrix is the first M= 2 ⁿ row vectors. In the spread spectrum signal transmission method provided by the embodiment of the present application, the signal transmission device can transmit at most nd bits in the same unit time, and the row vector that can be used as the spread spectrum sequence in the Hadamard matrix is the first 2 ^nd row vectors. It is understandable that the embodiment of the present application does not change the hardware structure of the signal sending device, but only adjusts the serial-to-parallel conversion rate of the serial-to-parallel converter 710 to ensure the number of bits transmitted in the same unit time and the optimization parameters of spread spectrum modulation. Match, and correspondingly correct the despreading result at the signal receiving device to improve the accuracy of the despreading result.

The structure diagram of the signal receiving device is shown in Fig. 8. The signal receiving device may include an antenna 810, a down converter 820, a down sampler 830, a serial-to-parallel converter 840, a correlator 850, a peak comparator 860, and a despreading result correction process. 870 and parallel-serial converter 880.

The antenna 810 is configured to receive radio frequency signals transmitted by the signal transmitting device.

The down converter 820 is configured to demodulate the radio frequency signal received by the antenna 810.

The down-sampler 830 is configured to down-sample the demodulated signal according to the symbol rate to obtain a discrete signal as the spread-spectrum signal to be despread.

The serial-to-parallel converter 840 is configured to convert the spread-spectrum signal into M channels according to a 1:M conversion relationship and transmit the spread-spectrum signal to different correlators 850 in parallel.

The row vectors of the Hadamard matrix matched by different correlators 850 are different. The correlator 850 is configured to multiply the spread spectrum signal with the row vector of the matched Hadamard matrix. If the spread spectrum signal is a signal generated by using a matched row vector as a spreading sequence, the spread spectrum signal and the matched row vector have autocorrelation, and the correlator 850 outputs the peak value of the autocorrelation peak.

The peak comparator 860 is configured to compare the outputs of the M correlators 850, and determine the serial number of the correlator 850 with the largest peak, and use the valid data represented by the row vector of the Hadamard matrix corresponding to the serial number as the despreading result, and provide The processor 870 is corrected for the despreading result. Usually the despreading result includes n bits.

The despreading result correction processor 870 obtains the spread spectrum modulation optimization parameter, and corrects the despreading result provided by the peak comparator 860. In some embodiments, the low n-d bits are truncated in the despreading result, that is, the high d position is zero to eliminate the judgment error of the sequence number of the correlator 850 caused by the residual frequency offset.

The despreading result correction processor 870 sends the corrected despreading result to the parallel-to-serial converter 880.

The parallel-to-serial converter 880 is configured to convert the despreading result into an information stream according to the n-d:1 conversion relationship, and complete the transmission of the information stream from the signal sending device to the signal receiving device.

In fact, in the embodiment of the present application, after the despreading result is determined, a correction step for the despreading result is added to eliminate the judgment error of the sequence number of the correlator 850 caused by the residual frequency offset. This correction step can be performed by the peak comparator 860, or can also be completed by the processor of the signal receiving device, so that the hardware structure of the signal sending device is not changed, and the despreading result is only corrected by adding a correction algorithm for the despreading result. , Improve the accuracy of despreading results.

It should be noted that FIGS. 7 and 8 only show part of the structure, and the signal sending device and the signal receiving device may also include other modules and circuits, which can be set as required.

In the embodiment of the application, the signal sending device determines the spread spectrum modulation optimization parameter according to the residual frequency deviation tolerance threshold, and specifies the number of information units according to the spread spectrum modulation optimization parameter, and the number of information units is regarded as valid data transmitted in the same unit time. , Carry out spread spectrum and modulation, send to the signal receiving equipment, and modify the despreading result in the signal receiving equipment according to the optimization parameters of spread spectrum modulation. The original hardware design of the signal sending equipment and signal receiving equipment hardware can be changed without changing the original hardware design of the signal sending equipment and signal receiving equipment, reducing At the same time, the signal receiving equipment realizes the correction of the despreading result through the zero operation of the bit position, reduces the complexity of the implementation, improves the stability of the spread spectrum system, improves the accuracy of the despreading result, and takes into account the transmission efficiency.

Example four

FIG. 9 is a schematic diagram of a spread spectrum signal sending device in the fourth embodiment of this application. The fourth embodiment is a corresponding device that implements the spread spectrum signal transmission method provided in the foregoing embodiment of the present application. The device can be implemented in software and/or hardware, and can generally be integrated into a computer device, such as a processor of a signal transmission device. .

Correspondingly, the device of this embodiment may include:

The spread spectrum modulation optimization parameter determination module 910 is configured to obtain a preset residual frequency deviation tolerance threshold during signal transmission, and determine the spread spectrum modulation optimization parameter;

The information unit obtaining module 920 is configured to obtain at least one information unit, and the number of the information unit matches the spread spectrum modulation optimization parameter;

The signal spreading module 930 is configured to use a Hadamard matrix to spread the spectrum of each of the information units to form a spread spectrum signal and modulate it to be sent to the signal receiving device, wherein the spread spectrum modulation optimization parameters are used to provide The signal receiving device instructs the signal receiving device to correct the signal despreading result.

In some embodiments, the spread spectrum modulation optimization parameter determination module 910, the information unit acquisition module 920, and the signal spread spectrum module 930 may refer to modules in the processor of the signal sending device.

In some embodiments, the spread spectrum modulation optimization parameter determination module 910 includes: a spread spectrum modulation optimization parameter calculation unit configured to calculate the spread spectrum modulation optimization parameter d based on the following formula:

In some embodiments, the information unit acquisition module 920 includes: a maximum transmission quantity determination unit configured to determine the maximum number of information bits carried by a spreading sequence according to the spreading modulation optimization parameter; and acquiring multiple pieces of information Unit, the number of information units is the maximum number of information bits.

The above-mentioned device can execute the spread spectrum signal transmission method provided by the embodiment of the present application, and has functional modules and beneficial effects corresponding to the execution method.

Example five

FIG. 10 is a schematic diagram of a spread spectrum signal receiving device in Embodiment 5 of this application. The fifth embodiment is a corresponding device that implements the spread spectrum signal receiving method provided in the above embodiments of this application. The device can be implemented in software and/or hardware, and can generally be integrated into a computer device, such as a processor of a signal receiving device. .

Correspondingly, the device of this embodiment may include:

The spread-spectrum signal despreading module 101 is configured to obtain a despreading result of the signal in the process of signal transmission, and the despreading result is determined by despreading the spread-spectrum signal by using the Hadamard matrix spread spectrum technology;

The spread spectrum modulation optimization parameter acquisition module 102 is configured to acquire a spread spectrum modulation optimization parameter, and the spread spectrum modulation optimization parameter is determined according to a preset residual frequency deviation tolerance threshold;

The despreading result modification module 103 is configured to modify the despreading result according to the spread spectrum modulation optimization parameter, and determine at least one information unit, the number of which matches the spread spectrum modulation optimization parameter.

In some embodiments, the spread-spectrum signal despreading module 101, the spread-spectrum modulation optimization parameter acquisition module 102, and the despreading result correction module 103 may refer to modules in the despreading result correction processor of the signal receiving device.

In some embodiments, the despreading result correction module 103 includes: a high position zero unit configured to zero the bit positions in the despreading result that match the spread spectrum modulation optimization parameter to obtain modified data; According to the modified data, at least one information unit is determined, and the number of the information unit matches the spread spectrum modulation optimization parameter.

In some embodiments, the spread spectrum signal receiving device further includes: a despreading result determination module configured to, after obtaining the spread spectrum modulation optimization parameter, if the bits in the despreading result match the spread spectrum modulation optimization parameter If the value of is zero, at least one information unit is determined according to the despreading result, and the number of the information unit matches the spread spectrum modulation optimization parameter.

Example Six

FIG. 11 is a schematic structural diagram of a computer device provided in Embodiment 6 of this application. FIG. 11 shows a block diagram of an exemplary computer device 12 suitable for implementing the embodiments of the present application. The computer device 12 shown in FIG. 11 is only an example. The computer device 12 may include a signal transmitting device or a signal receiving device.

As shown in FIG. 11, the computer device 12 is represented in the form of a general-purpose computing device. The components of the computer device 12 may include: one or more processors or processing units 16, a system memory 28, and a bus 18 connecting different system components (including the system memory 28 and the processing unit 16). The computer device 12 may be a device connected to a bus.

The bus 18 represents one or more of several types of bus structures, including a memory bus or a memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any bus structure among multiple bus structures. For example, these architectures may include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, enhanced ISA bus, Video Electronics Standards Association, VESA) local bus and PerIPheral Component Interconnect (PCI) bus.

The computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 12, including volatile and nonvolatile media, removable and non-removable media.

The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32. The computer device 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. For example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media (commonly referred to as "hard drives"). It can provide disk drives for reading and writing to removable non-volatile disks (such as "floppy disks"), as well as for removable non-volatile optical disks (such as Compact Disc Read-Only Memory, CD- ROM), digital video disc (Digital Video Disc-Read Only Memory, DVD-ROM) or other optical media) read and write optical disc drives. In these cases, each drive can be connected to the bus 18 through one or more data media interfaces. The system memory 28 may include at least one program product. The program product has a set of (for example, at least one) program modules that are configured to perform the functions of the embodiments of the present application.

A program/utility tool 40 having a set of (at least one) program module 42 may be stored in, for example, the system memory 28. Such program module 42 may include an operating system, one or more application programs, other program modules, and program data, Each of these examples or some combination may include the implementation of a network environment. The program module 42 usually executes the functions and/or methods in the embodiments described in this application.

The computer device 12 may also communicate with one or more external devices 14 (such as keyboards, pointing devices, displays 24, etc.), and may also communicate with one or more devices that enable users to interact with the computer device 12, and/or communicate with Any device (such as a network card, modem, etc.) that enables the computer device 12 to communicate with one or more other computing devices. This communication can be performed through an input/output (Input/Output, I/O) interface 22. In addition, the computer device 12 may also communicate with one or more networks (for example, Local Area Network (LAN), Wide Area Network, WAN) through the network adapter 20. As shown in the figure, the network adapter 20 communicates with one or more networks through the bus 18. Communication with other modules of the computer equipment 12. It should be understood that other hardware and/or software modules that can be used in conjunction with the computer equipment 12 may include: microcode, device drivers, redundant processing units, and external disk drive arrays (Redundant Arrays of Expensive Disks) , RAID) system, tape drive and data backup storage system.

The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28. For example, a signal sending device implements the spread spectrum signal sending method provided by any embodiment of the present application, or a signal receiving device implements the present application. The spread spectrum signal receiving method provided by any embodiment.

Example Seven

The seventh embodiment of the present application provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the method as provided in all the application embodiments of the present application is implemented:

That is, when the program is executed by the processor, it is realized: in the process of signal transmission, the preset residual frequency deviation tolerance threshold is obtained, and the optimization parameter of spread spectrum modulation is determined; at least one information unit is obtained. The spread spectrum modulation optimization parameter matching; the Hadamard matrix is used to spread spectrum to each of the information units to form a spread spectrum signal and modulate and send it to the signal receiving device, wherein the spread spectrum modulation optimization parameter is used to provide the signal receiver in advance Device to instruct the signal receiving device to correct the signal despreading result.

Or, when the program is executed by the processor, it is realized: in the process of signal transmission, the despreading result of the signal is obtained, and the despreading result is determined by despreading the spread spectrum signal by using the Hadamard matrix spread spectrum technology; and obtaining the spread spectrum Modulation optimization parameters, the spread spectrum modulation optimization parameters are determined according to a preset residual frequency offset tolerance threshold; the despreading result is corrected according to the spread spectrum modulation optimization parameters, and at least one information unit is determined, the information unit The number of is matched with the optimization parameters of the spread spectrum modulation.

The computer storage medium of the embodiment of the present application may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the above. Examples of computer-readable storage media (non-exhaustive list) may include: electrical connections with one or more wires, portable computer disks, hard disks, RAM, Read Only Memory (ROM), erasable memory Erasable Programmable Read Only Memory (EPROM), flash memory, optical fiber, portable CD-ROM, optical storage device, magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device.

The computer-readable signal medium may include a data signal propagated in baseband or as a part of a carrier wave, and computer-readable program code is carried therein. This propagated data signal can take many forms, and can include electromagnetic signals, optical signals, or any suitable combination of the foregoing. The computer-readable signal medium may also be any computer-readable medium other than the computer-readable storage medium. The computer-readable medium may send, propagate, or transmit the program for use by or in combination with the instruction execution system, apparatus, or device .

The program code contained on the computer-readable medium can be transmitted by any suitable medium, which can include wireless, wire, optical cable, radio frequency (Radio Frequency, RF), etc., or any suitable combination of the above.

The computer program code used to perform the operations of this application can be written in one or more programming languages or a combination thereof. The programming languages include object-oriented programming languages—such as Java, Smalltalk, C++, and also conventional Procedural programming language-such as "C" language or similar programming language. The program code can be executed entirely on the user's computer, partly on the user's computer, executed as an independent software package, partly on the user's computer and partly executed on a remote computer, or entirely executed on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network including LAN or WAN, or may be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

The embodiment of the application determines the optimization parameter of spread spectrum modulation according to the residual frequency deviation tolerance threshold during signal transmission, and specifies the number of information units according to the optimization parameter of spread spectrum modulation. The number of information units is a single spread spectrum sequence. The number of information bits carried, the number of information units is used as the effective data transmitted in the same unit time, which is spread and modulated, and sent to the signal receiving device, and instructs the signal receiving device to optimize the parameters of the signal despreading result through the spread spectrum modulation Make corrections to enable the signal receiving device to obtain accurate despreading results, to improve the accuracy of signal despreading by optimizing the number of transmitted information units, and to solve the high cost and complexity of reducing residual frequency offset in related technologies. For high problems, the original design of the hardware can be reduced without changing the implementation cost and complexity, while at the same time improving the stability of the spread spectrum system, improving the accuracy of the despreading result, and taking into account the transmission efficiency.

Claims

A method for transmitting spread spectrum signals includes:

In the process of signal transmission, the preset residual frequency deviation tolerance threshold is obtained, and the optimization parameters of spread spectrum modulation are determined;

Acquiring at least one information unit, the number of the information unit matches the spread spectrum modulation optimization parameter;

The Hadamard matrix is used to spread the spectrum of each of the information units to form a spread spectrum signal and send the spread spectrum signal to the signal receiving device after being modulated, wherein the spread spectrum modulation optimization parameters are used to provide all the information in advance. The signal receiving device instructs the signal receiving device to correct the signal despreading result.
The method according to claim 1, wherein said obtaining a preset residual frequency offset tolerance threshold and determining a spread spectrum modulation optimization parameter comprises:

Based on the following formula, calculate the spread spectrum modulation optimization parameter d:

Wherein, A is the residual frequency offset tolerance threshold, B is the bandwidth, n is the order of the Hadamard matrix, and d is a non-negative integer.
The method according to claim 1, wherein said acquiring at least one information unit, the number of said information unit matching the spread spectrum modulation optimization parameter, comprises:

Determining the maximum number of information bits carried by the spreading sequence according to the spread spectrum modulation optimization parameter;

Acquire multiple information units, and the number of the information units is the maximum number of information bits.
A method for receiving spread spectrum signals includes:

In the process of signal transmission, obtaining a despreading result of the spread spectrum signal, where the despreading result is determined by despreading the spread spectrum signal by using a Hadamard matrix spread spectrum technique;

Acquiring a spread spectrum modulation optimization parameter, where the spread spectrum modulation optimization parameter is determined according to a preset residual frequency offset tolerance threshold;

The despreading result is modified according to the spread spectrum modulation optimization parameter, and at least one information unit is determined, and the number of the information unit matches the spread spectrum modulation optimization parameter.
The method according to claim 4, wherein the despreading result is modified according to the spread spectrum modulation optimization parameter, and at least one information unit is determined, and the number of the information unit is optimized with the spread spectrum modulation Parameter matching, including:

Zeroing a bit position in the despreading result that matches the spread spectrum modulation optimization parameter to obtain modified data;

According to the correction data, at least one information unit is determined, and the number of the information unit matches the spread spectrum modulation optimization parameter.
The method according to claim 5, after obtaining the optimization parameters of spread spectrum modulation, the method further comprises:

Based on the judgment result that the value of the bit matching the spread spectrum modulation optimization parameter in the despreading result is zero, at least one information unit is determined according to the despreading result, and the number of the information unit is equal to that of the spread spectrum. Modulation optimization parameter matching.
A spread spectrum signal sending device includes:

The spread spectrum modulation optimization parameter determination module is configured to obtain a preset residual frequency deviation tolerance threshold during signal transmission, and determine the spread spectrum modulation optimization parameter;

An information unit acquisition module configured to acquire at least one information unit, the number of the information unit matches the spread spectrum modulation optimization parameter;

The signal spreading module is configured to use a Hadamard matrix to spread the spectrum of each of the information units to form a spread spectrum signal and send the spread spectrum signal to the signal receiving device after being modulated, wherein the spread spectrum modulation The optimized parameter is used to provide the signal receiving device in advance to instruct the signal receiving device to correct the signal despreading result.
A spread spectrum signal receiving device, including:

The spread-spectrum signal despreading module is configured to obtain the despreading result of the spread-spectrum signal during signal transmission, and the despreading result is determined by despreading the spread-spectrum signal by using the Hadamard matrix spread spectrum technology ；

A spread spectrum modulation optimization parameter acquisition module configured to acquire a spread spectrum modulation optimization parameter, the spread spectrum modulation optimization parameter being determined according to a preset residual frequency deviation tolerance threshold;

The despreading result correction module is configured to correct the despreading result according to the spread spectrum modulation optimization parameter, and determine at least one information unit, and the number of the information units matches the spread spectrum modulation optimization parameter.
A signal sending device, comprising a memory, a processor, and a computer program stored on the memory and running on the processor. The processor executes the computer program as described in claims 1-3 Any one of the spread spectrum signal transmission methods.
A signal receiving device, comprising a memory, a processor, and a computer program stored on the memory and running on the processor, and the processor executes the computer program as in claims 4-6 Any one of the spread spectrum signal receiving methods.
A computer-readable storage medium having a computer program stored on the computer-readable storage medium, and when the computer program is executed by a processor, the method for transmitting a spread spectrum signal according to any one of claims 1 to 3 is realized, Or implement the spread spectrum signal receiving method according to any one of claims 4-6.