SOQPSK signal soft value determination method, device and communication equipment

Abstract

The present disclosure provides a method, apparatus, and communication device for determining the soft value of a SOQPSK signal. The method comprises: performing matched filtering on a received SOQPSK signal through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 for the i-th symbol; subtracting Y0 from the local matched filtering results of the first matched filter under eight states, taking the absolute value of the result, and then dividing the result by a coefficient V. 0,i Get the first value, take the absolute value of the result of subtracting Y1 from the local matched filtering result of the second matched filter in 8 states and divide it by the coefficient V 1,i Obtain a second value, and add the real part of the first value and the second value under the same state to obtain branch metric values ​​under 8 states; determine the first soft value component and the second soft value component according to the maximum value of the branch metric values ​​under the 8 states; align the first soft value component and the second soft value component and add them to obtain the soft value of the i-th symbol of the SOQPSK signal.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a method and apparatus for determining a soft value of a SOQPSK signal, and a communication device. Background Art

[0002] Shaped Offset Quadrature Phase Shift Keying (SOQPSK) is a continuous phase modulation method developed from OQPSK.

[0003] The demodulation process of SOQPSK signals usually includes two major steps. The first step is to determine the soft value of the SOQPSK signal. The second step is to demodulate the SOQPSK signal based on the determined soft value of the SOQPSK signal using algorithms such as Viterbi decoding, soft output Viterbi decoding (SOVA), and improved SOVA.

[0004] In related technologies, the soft value of a SOQPSK signal is usually determined based on a maximum path algorithm. However, this method is computationally intensive and consumes a large amount of resources, making it unsuitable for engineering practice. Summary of the Invention

[0005] The present disclosure provides a method, apparatus, and communication device for determining the soft value of a SOQPSK signal. The technical solution is as follows:

[0006] At least one embodiment of the present disclosure provides a method for determining a soft value of a SOQPSK signal, the method comprising:

[0007] The received SOQPSK signal is matched filtered through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 of the i-th symbol, where i is a positive integer greater than 2, and the filter coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively;

[0008] Get the coefficient V under the 8 states corresponding to P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states where the i-2, i-1 and i symbols are 0 and 1 respectively;

[0009] The absolute value of the result of subtracting Y0 from the local matched filtering results of the first matched filter in the eight states is divided by V 0,i Obtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,iObtaining a second value, and adding the first value and the second value in the same state to obtain a real part, to obtain branch metric values ​​under the eight states, where the local matched filtering results under the eight states are matched filtering results under the eight states corresponding to the SOQPSK signal transmitted under an ideal state;

[0010] Determining a first soft value component and a second soft value component according to a maximum value of the branch metrics under the eight states;

[0011] The first soft value component and the second soft value component are aligned and then added to obtain a soft value of the i-th symbol of the SOQPSK signal.

[0012] Optionally, the coefficients under the eight states corresponding to P0(t) are obtained according to the following formula:

[0013] V 0,i =0.5[(b i-1 +b i )+j(-1) i (b i-1 -b i )],

[0014] Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, and the coefficients when the i-2th symbol is 0 and 1 are the same;

[0015] The coefficients of the eight states corresponding to P1(t) are obtained according to the following formula:

[0016] V 1,i =sqrt(2) / 8*[3b i-1 -b i-2 b i-1 b i +b i-2 +b i +j*(-1) i (3b i-1 -b i -2b i-1 b i -b i-2 -b i )],

[0017] Among them, b i-2 is the value of the i-2th symbol.

[0018] Optionally, the local matched filtering results of the first matched filter in the eight states are obtained according to the following formula:

[0019] R 00 V 0,i+R 10 V 1,i ;

[0020] Among them, R 00 represents the result of matching filter P0(t) by using the first matched filter, R 10 represents the result of matched filtering P1(t) using the first matched filter;

[0021] The local matched filtering results of the second matched filter in the eight states are obtained according to the following formula:

[0022] R 01 V 0,i +R 11 V 1,i ;

[0023] Among them, R 01 represents the result of matching filter P0(t) by using the second matched filter, R 11 It represents the result of matching filtering P1(t) by using the second matched filter.

[0024] Optionally, determining the first soft value component according to the maximum value of the branch metrics in the eight states includes:

[0025] Sort the branch metrics in the eight states in the order of (000, 010, 100, 110, 001, 011, 101, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i-th symbols, respectively;

[0026] Determine the maximum value of the branch metric under the eight states;

[0027] If the maximum value is in the first group of branch metric values, determining that the sign of the first soft value component is negative; if the maximum value is in the second group of branch metric values, determining that the sign of the first soft value component is positive, the first group of branch metric values ​​corresponding to sequence numbers (000, 010, 100, 110), and the second group of branch metric values ​​corresponding to sequence numbers (001, 011, 101, 111);

[0028] Subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value; subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value;

[0029] The two absolute values ​​are added, and a determined sign is assigned to the addition result to obtain the first soft value component.

[0030] Optionally, determining the second soft value component according to the maximum value of the branch metrics in the eight states includes:

[0031] Sort the branch metrics in the eight states in the order of (000, 001, 100, 101, 010, 011, 110, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i-th symbols, respectively;

[0032] Determine the maximum value of the branch metric under the eight states;

[0033] If the maximum value is in the third group of branch metric values, determining that the sign of the second soft value component is negative; if the maximum value is in the fourth group of branch metric values, determining that the sign of the second soft value component is positive, the third group of branch metric values ​​corresponding to sequence numbers (000, 001, 100, 101), and the fourth group of branch metric values ​​corresponding to sequence numbers (010, 011, 110, 111);

[0034] Subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value; subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value;

[0035] The two absolute values ​​are added, and a determined sign is assigned to the addition result to obtain the second soft value component.

[0036] At least one embodiment of the present disclosure provides a device for determining a soft value of a SOQPSK signal, the device comprising:

[0037] a matched filtering module, configured to perform matched filtering on the received SOQPSK signal through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 of the i-th symbol, where i is a positive integer greater than 2, and the filter coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively;

[0038] Acquisition module, used to obtain the coefficient V under the 8 states corresponding to the P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states where the i-2, i-1 and i symbols are 0 and 1 respectively;

[0039] A branch metric module is used to take the absolute value of the result of subtracting the local matched filtering results of the first matched filter in the eight states from the Y0 and then divide it by the V 0,iObtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,i Obtaining a second value, and adding the first value and the second value in the same state to obtain a real part, to obtain branch metric values ​​under the eight states, where the local matched filtering results under the eight states are matched filtering results under the eight states corresponding to the SOQPSK signal transmitted under an ideal state;

[0040] A soft value determination module is used to determine a first soft value component and a second soft value component according to the maximum value of the branch metric values ​​under the eight states; align the first soft value component and the second soft value component and add them to obtain a soft value of the i-th symbol of the SOQPSK signal.

[0041] Optionally, the acquisition module is configured to determine the coefficients under the eight states corresponding to P0(t) according to the following formula:

[0042] V 0,i =0.5[(b i-1 +b i )+j(-1) i (b i-1 -b i )],

[0043] Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, and the coefficients when the i-2th symbol is 0 and 1 are the same;

[0044] The coefficients of the eight states corresponding to P1(t) are determined according to the following formula:

[0045] V 1,i =sqrt(2) / 8*[3b i-1 -b i-2 b i-1 b i +b i-2 +b i +j*(-1) i (3b i-1 -b i -2b i-1 b i -b i-2 -b i )],

[0046] Among them, b i-2 is the value of the i-2th symbol.

[0047] Optionally, the soft value determination module is configured to:

[0048] Sort the branch metric values ​​in the eight states in the order of (000, 010, 100, 110, 001, 011, 101, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i symbols, respectively; determine the maximum value of the branch metric values ​​in the eight states; if the maximum value is in the first set of branch metric values, determine that the sign of the first soft value component is negative; if the maximum value is in the second set of branch metric values, determine that the sign of the first soft value component is negative. is positive, the first group of branch metric values ​​corresponds to sequence numbers (000, 010, 100, 110), and the second group of branch metric values ​​corresponds to sequence numbers (001, 011, 101, 111); subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value, subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; add the two absolute values, assign the determined sign to the result of the addition, and obtain the first soft value component;

[0049] Sort the branch metric values ​​in the eight states in the order of (000, 001, 100, 101, 010, 011, 110, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i symbols, respectively; determine the maximum value of the branch metric values ​​in the eight states; if the maximum value is in the third group of branch metric values, determine that the sign of the second soft value component is negative; if the maximum value is in the fourth group of branch metric values, determine the sign of the second soft value component is positive, the third group of branch metric values ​​corresponds to serial numbers (000, 001, 100, 101), and the fourth group of branch metric values ​​corresponds to serial numbers (010, 011, 110, 111); subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value, subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; add the two absolute values, assign a determined sign to the result of the addition, and obtain the second soft value component.

[0050] At least one embodiment of the present disclosure provides a communication device, comprising a processor and a memory, wherein the memory stores at least one program code, and the program code is loaded and executed by the processor to implement the soft value determination method of the SOQPSK signal as described above.

[0051] At least one embodiment of the present disclosure provides a computer-readable storage medium, wherein the computer-readable storage medium stores at least one program code, and the program code is loaded and executed by a processor to implement the soft value determination method of the SOQPSK signal as described in any of the above items.

[0052] The technical solutions provided by the embodiments of the present disclosure have the following beneficial effects:

[0053] In the disclosed embodiment, a SOQPSK signal is matched filtered. The results are then subtracted from the matched filtering results for eight states corresponding to the ideally transmitted SOQPSK signal, taking the absolute value and dividing by a coefficient to obtain a first value and a second value. The first and second values ​​for the same states are then added together to obtain the real part, yielding branch metrics for each of the eight states. Based on the eight branch metrics, two soft value components are determined, and these two soft value components are then superimposed to obtain a soft value. This solution requires minimal computation and resource consumption, making it suitable for engineering practice. Furthermore, superimposing the two soft value components increases the accuracy of the soft value, thereby improving demodulation capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0055] Figure 1 This is a flow chart of a method for determining a soft value of a SOQPSK signal provided by an embodiment of the present disclosure;

[0056] Figure 2 This is a flow chart of a method for determining a soft value of a SOQPSK signal provided by an embodiment of the present disclosure;

[0057] Figure 3 is a block diagram of a soft value determination device for a SOQPSK signal provided by an embodiment of the present disclosure;

[0058] Figure 4 This is a structural block diagram of a communication device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0060] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words “first”, “second”, “third” and similar terms used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as “one” or “a” do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as “include” or “comprising” and similar terms mean that the elements or objects appearing before “include” or “comprising” cover the elements or objects listed after “include” or “comprising” and their equivalents, and do not exclude other elements or objects.

[0061] Figure 1 This is a flowchart of a method for determining a soft value of a SOQPSK signal provided by an embodiment of the present disclosure.

[0062] See also Figure 1 , the method comprising:

[0063] 101: Perform matched filtering on the received SOQPSK signal through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 of the i-th symbol, where i is a positive integer greater than 2, and the filtering coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively.

[0064] The method for determining the soft value of a SOQPSK signal provided by the embodiment of the present disclosure is executed by a receiving device in a communication system.

[0065] In the embodiment of the present disclosure, when performing matched filtering on a SOQPSK signal, the input signal length is greater than 1 symbol, and two matched filtering results Y0 and Y1 of the i-th symbol are obtained, where both Y0 and Y1 are complex numbers.

[0066] 102: Obtain the coefficient V under the eight states corresponding to P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states in which the i-2, i-1 and i-th symbols are 0 and 1 respectively.

[0067] The SOQPSK signal Y can be decomposed according to the following formula: Y = P0(t)V 0,i +P1(t)V 1,i It can be seen that V 0,i is the coefficient corresponding to the filter coefficient P0(t), V 1,i is the coefficient corresponding to the filter coefficient P1(t).

[0068] These eight states are 000, 001, 010, 011, 100, 101, 110, and 111. In the disclosed embodiment, the three bits representing the state correspond to the values ​​of the i-2nd, i-1st, and i-th symbols, respectively. For example, the first bit is the i-2nd symbol, the second bit is the i-1st symbol, and the third bit is the i-th symbol. In other embodiments, other ordering methods may be used, such as the first bit is the i-th symbol, the second bit is the i-1st symbol, and the third bit is the i-2nd symbol.

[0069] The coefficients in the eight states are generated according to the coefficient generation formula for the values ​​of the i-2th to i-th symbols in the eight states.

[0070] 103: Subtract the local matched filtering results of the first matched filter in the eight states from the Y0, taking the absolute value and dividing it by the V 0,i Obtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,i Obtain a second value, and add the first value and the second value under the same state to obtain the real part to obtain the branch metric values ​​under the 8 states. The local matched filtering results under the 8 states are the matched filtering results under the 8 states corresponding to the SOQPSK signal transmitted under the ideal state.

[0071] The local matched filtering results of the first matched filter in the eight states are the matched filtering results of the symbols in the eight states corresponding to the SOQPSK signal transmitted in the ideal state passing through the first matched filter.

[0072] The local matched filtering results of the second matched filter in the eight states are the matched filtering results of the symbols in the eight states corresponding to the SOQPSK signal transmitted in the ideal state passing through the second matched filter.

[0073] In this step, Y0 is subtracted from the local matched filtering results of the eight first matched filters to obtain eight results. The absolute values ​​of these eight results are taken and then divided by the V 0,i , and get 8 first values.

[0074] Subtract Y1 from the local matched filtering results of the eight second matched filters to obtain eight results. Take the absolute value of these eight results and divide them by the V in the corresponding state. 1,i , and get 8 second values.

[0075] Then, the first value and the second value in the same state are added together, and the real part of the result is taken as the branch metric value in the eight states. For example, the first value in the 000 state and the second value in the 000 state are added together, and the real part of the result is taken as the branch metric value in the eight states.

[0076] 104: Determine a first soft value component and a second soft value component according to a maximum value of the branch metrics in the eight states.

[0077] The first soft value component may also be considered as the soft value component of the (i-1)th symbol, and the second soft value component may also be considered as the soft value component of the (i)th symbol.

[0078] 105: Align the first soft value component and the second soft value component and add them together to obtain a soft value of the i-th symbol of the SOQPSK signal.

[0079] The soft value of the i-th symbol is used for subsequent demodulation of the i-th symbol through an algorithm.

[0080] Among them, the first soft value component is the soft value component corresponding to the 1st to i-th symbols, and the second soft value component is the soft value component corresponding to the 0th to i-th symbols. The part corresponding to the 0th symbol in the sequence of the second soft value component is truncated, and then aligned with the sequence of the first soft value component and added to obtain the soft value of the i-th symbol that can represent the SOQPSK signal.

[0081] In the disclosed embodiment, a SOQPSK signal is matched filtered. The results are then subtracted from the matched filtering results for eight states corresponding to the ideally transmitted SOQPSK signal, taking the absolute value and dividing by a coefficient to obtain a first value and a second value. The first and second values ​​for the same states are then added together to obtain the real part, yielding branch metrics for each of the eight states. Based on the eight branch metrics, two soft value components are determined, and these two soft value components are then superimposed to obtain a soft value. This solution requires minimal computation and resource consumption, making it suitable for engineering practice. Furthermore, superimposing the two soft value components increases the accuracy of the soft value, thereby improving demodulation capabilities.

[0082] Figure 2 This is a flowchart of a method for determining a soft value of a SOQPSK signal provided by an embodiment of the present disclosure.

[0083] See also Figure 2 , the method comprising:

[0084] 201: Perform matched filtering on the received SOQPSK signal through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 of the i-th symbol, where i is a positive integer greater than 2, and the filtering coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively.

[0085] The method for determining the soft value of a SOQPSK signal provided by the embodiment of the present disclosure is executed by a receiving device in a communication system.

[0086] In the embodiment of the present disclosure, when performing matched filtering on a SOQPSK signal, the input signal length is greater than 1 symbol, and two matched filtering results Y0 and Y1 of the i-th symbol are obtained.

[0087] In matched filtering, the two matched filters are standard SOQPSK-TG modulation shaping filters, and the two matched filter coefficients P0(t) and P1(t) are generated according to the Lauren decomposition formula of the generated phase function q(t). The formula is as follows:

[0088] P0(t)=∏(uter(t+vT)2(0≤v≤L-1),

[0089] P1(t)=2(∏(uter(t+vT))(∏(uter(t+vT+t))(0≤v≤L-1);

[0090] Where t is time, T is the symbol period, v is a variable between 0 and L-1, L=8, and L is the number of associated symbols. The uter calculation formula is as follows:

[0091] uter=sin(0.5q(t) / sin(0.5h*pi), (0≤t≤LT),

[0092] uter=sin(0.5h*pi-0.5q(t-LT) / sin(0.5h*pi), (LT≤t≤2LT),

[0093] uter=0 otherwise,

[0094] Here, h is 1 / 2 and pi is π.

[0095] 202: Obtain the coefficient V under the eight states corresponding to the P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states in which the i-2, i-1 and i-th symbols are 0 and 1 respectively.

[0096] These eight states are 000, 001, 010, 011, 100, 101, 110, and 111. In the disclosed embodiment, the three bits representing the state correspond to the values ​​of the i-2nd, i-1st, and i-th symbols, respectively. For example, the first bit is the i-2nd symbol, the second bit is the i-1st symbol, and the third bit is the i-th symbol. In other embodiments, other ordering methods may be used, such as the first bit is the i-th symbol, the second bit is the i-1st symbol, and the third bit is the i-2nd symbol.

[0097] The coefficients in the eight states are generated according to the coefficient generation formula for the values ​​of the i-2th to i-th symbols in the eight states.

[0098] For example, the coefficients of the eight states corresponding to P0(t) are obtained according to the following formula:

[0099] V 0,i =0.5[(b i-1 +b i )+j(-1) i (b i-1 -b i )],

[0100] Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, and the coefficients when the i-2th symbol is 0 and 1 are the same.

[0101] For example, the coefficients of the eight states corresponding to P1(t) are obtained according to the following formula:

[0102] V 1,i =sqrt(2) / 8*[3b i-1 -b i-2 b i-1 b i +b i-2 +b i +j*(-1) i (3b i-1 -b i -2b i-1 b i -b i-2 -b i )],

[0103] Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, b i-2 is the value of the i-2th symbol, and j is the imaginary part symbol of the complex number.

[0104] Substituting the values ​​(0 or 1) of the three symbols in the eight states into the above formula, the coefficients in the eight states corresponding to P0(t) and the coefficients in the eight states corresponding to P1(t) can be obtained.

[0105] 203: Subtract the local matched filtering results of the first matched filter in the eight states from the Y0, taking the absolute value and dividing it by the V 0,i Obtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,i Obtain a second value, and add the first value and the second value under the same state to obtain the real part to obtain the branch metric values ​​under the 8 states. The local matched filtering results under the 8 states are the matched filtering results under the 8 states corresponding to the SOQPSK signal transmitted under the ideal state.

[0106] The local matched filtering results of the first matched filter in the eight states are obtained according to the following formula:

[0107] R 00 V 0,i +R 10 V 1,i ;

[0108] Among them, R 00 represents the result of matching filter P0(t) by using the first matched filter, R 10 represents the result of matched filtering P1(t) using the first matched filter;

[0109] The local matched filtering results of the second matched filter in the eight states are obtained according to the following formula:

[0110] R 01 V 0,i +R 11 V 1,i ;

[0111] Among them, R 01 represents the result of matching filter P0(t) by using the second matched filter, R 11 It represents the result of matching filtering P1(t) by using the second matched filter.

[0112] Among them, the multiplication in the above two formulas is conjugate multiplication.

[0113] Substituting the coefficients in the eight states into the above two formulas, the local matched filtering results of the first matched filter in the eight states and the local matched filtering results of the second matched filter in the eight states can be obtained.

[0114] 204: Sort the branch metric values ​​in the eight states in the order of (000, 010, 100, 110, 001, 011, 101, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i-th symbols, respectively.

[0115] 205: Determine the maximum value of the branch metrics in the eight states.

[0116] 206: If the maximum value is located in the first group of branch metric values, the sign of the first soft value component is determined to be negative; if the maximum value is located in the second group of branch metric values, the sign of the first soft value component is determined to be positive. The first group of branch metric values ​​corresponds to serial numbers (000, 010, 100, 110), and the second group of branch metric values ​​corresponds to serial numbers (001, 011, 101, 111).

[0117] The first group and the second group are divided into two groups according to the value of the i-th symbol.

[0118] 207: Subtract the first branch metric value and the third branch metric value of the group where the maximum value is located, and take the absolute value; subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located, and take the absolute value.

[0119] For example, if the maximum value is in the first set of branch metric values, subtract 100 from the branch metric value corresponding to state 000, and take the absolute value of the corresponding branch metric values; subtract 110 from the branch metric value corresponding to state 010, and take the absolute value.

[0120] For another example, if the maximum value is in the second set of branch metrics, the branch metric value corresponding to state 001 is subtracted from the branch metric value corresponding to 101 and the absolute value is taken, and the branch metric value corresponding to state 011 is subtracted from the branch metric value corresponding to 111 and the absolute value is taken.

[0121] 208: Add the two absolute values, assign a determined sign to the addition result, and obtain the first soft value component.

[0122] For example, if the maximum value is in the first set of branch metric values, the two absolute values ​​are added and a negative sign is obtained; if the maximum value is in the second set of branch metric values, the two absolute values ​​are added and a positive sign is obtained.

[0123] 209: Sort the branch metrics in the eight states in the order of (000, 001, 100, 101, 010, 011, 110, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i-th symbols, respectively.

[0124] 210: Determine the maximum value of the branch metrics in the eight states.

[0125] 211: If the maximum value is in the third group of branch metric values, the sign of the second soft value component is determined to be negative; if the maximum value is in the fourth group of branch metric values, the sign of the second soft value component is determined to be positive. The third group of branch metric values ​​corresponds to the serial number (000, 001, 100, 101), and the fourth group of branch metric values ​​corresponds to the serial number (010, 011, 110, 111).

[0126] The third group and the fourth group are divided into two groups according to the value of the i-1th symbol.

[0127] 212: Subtract the first branch metric value and the third branch metric value of the group where the maximum value is located, and take the absolute value; subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located, and take the absolute value.

[0128] For example, if the maximum value is in the third group of branch metric values, the branch metric value corresponding to state 000 is subtracted from the branch metric value corresponding to 100 and the absolute value is taken, and the branch metric value corresponding to state 001 is subtracted from the branch metric value corresponding to 101 and the absolute value is taken.

[0129] For another example, if the maximum value is in the fourth group of branch metrics, the branch metric corresponding to state 010 is subtracted from the branch metric corresponding to 110 and the absolute value is taken, and the branch metric corresponding to state 011 is subtracted from the branch metric corresponding to 111 and the absolute value is taken.

[0130] 213: Add the two absolute values, assign the determined sign to the addition result, and obtain the second soft value component.

[0131] For example, if the maximum value is in the third group of branch metric values, the two absolute values ​​are added together and a negative sign is obtained; if the maximum value is in the fourth group of branch metric values, the two absolute values ​​are added together and a positive sign is obtained.

[0132] 214: Align the first soft value component and the second soft value component and add them together to obtain a soft value of the i-th symbol of the SOQPSK signal.

[0133] Among them, the first soft value component is the soft value component corresponding to the 1st to i-th symbols, and the second soft value component is the soft value component corresponding to the 0th to i-th symbols. The part corresponding to the 0th symbol in the sequence of the second soft value component is truncated, and then aligned with the sequence of the first soft value component and added to obtain the soft value of the i-th symbol that can represent the SOQPSK signal.

[0134] The soft value determination scheme for SOQPSK signals provided by the present disclosure is simple in operation, consisting of only addition, subtraction, XNOR, negation, and a small amount of multiplication. It is suitable for communication systems based on Field Programmable Gate Array (FPGA) hardware platforms, occupies few hardware resources, and is low in cost. The scheme also superimposes two soft value components, increasing the accuracy of the soft value and correspondingly improving the demodulation capability. The soft value can be calculated in real time, introducing a delay of only four symbols, which is almost negligible.

[0135] Figure 3 Schematic diagram of a soft value determination device for a SOQPSK signal provided by an embodiment of the present disclosure. Figure 3 The soft value determination device of the SOQPSK signal includes: a matched filtering module 301, an acquisition module 302, a branch metric module 303 and a soft value determination module 304.

[0136] The matched filtering module 301 is configured to perform matched filtering on the received SOQPSK signal through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 for the i-th symbol, where i is a positive integer greater than 2, and the filter coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively.

[0137] Acquisition module 302, used to obtain the coefficient V under the eight states corresponding to P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states where the i-2, i-1 and i symbols are 0 and 1 respectively;

[0138] The branch metric module 303 is configured to take the absolute value of the result of subtracting the local matched filtering results of the first matched filter in the eight states from the Y0 and then divide it by the V 0,i Obtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,i Obtaining a second value, and adding the first value and the second value in the same state to obtain a real part, to obtain branch metric values ​​under the eight states, where the local matched filtering results under the eight states are matched filtering results under the eight states corresponding to the SOQPSK signal transmitted under an ideal state;

[0139] The soft value determination module 304 is used to determine a first soft value component and a second soft value component according to the maximum value of the branch metric values ​​under the eight states; align the first soft value component and the second soft value component and add them together to obtain the soft value of the i-th symbol of the SOQPSK signal.

[0140] Optionally, the acquisition module 302 is configured to determine the coefficients of the eight states corresponding to P0(t) according to the following formula:

[0141] V 0,i =0.5[(b i-1 +b i )+j(-1) i (b i-1 -b i )],

[0142] Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, and the coefficients when the i-2th symbol is 0 and 1 are the same;

[0143] The coefficients of the eight states corresponding to P1(t) are determined according to the following formula:

[0144] V 1,i =sqrt(2) / 8*[3b i-1 -b i-2 b i-1 b i +b i-2 +b i +j*(-1) i (3b i-1 -b i -2b i-1 b i -b i-2 -b i )],

[0145] Among them, b i-2 is the value of the i-2th symbol.

[0146] Optionally, the acquisition module 302 is further configured to acquire local matched filtering results of the first matched filter in the eight states according to the following formula:

[0147] R 00 V 0,i +R 10 V 1,i ;

[0148] Among them, R 00 represents the result of matching filter P0(t) by using the first matched filter, R 10 represents the result of matched filtering P1(t) using the first matched filter;

[0149] The local matched filtering results of the second matched filter in the eight states are obtained according to the following formula:

[0150] R 01 V 0,i +R 11 V 1,i ;

[0151] Among them, R 01 represents the result of matching filter P0(t) by using the second matched filter, R 11 It represents the result of matching filtering P1(t) by using the second matched filter.

[0152] Optionally, the soft value determination module 305 is configured to:

[0153] Sort the branch metric values ​​in the eight states in the order of (000, 010, 100, 110, 001, 011, 101, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i symbols, respectively; determine the maximum value of the branch metric values ​​in the eight states; if the maximum value is in the first set of branch metric values, determine that the sign of the first soft value component is negative; if the maximum value is in the second set of branch metric values, determine that the sign of the first soft value component is negative. is positive, the first group of branch metric values ​​corresponds to sequence numbers (000, 010, 100, 110), and the second group of branch metric values ​​corresponds to sequence numbers (001, 011, 101, 111); subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value, subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; add the two absolute values, assign the determined sign to the result of the addition, and obtain the first soft value component;

[0154] Sort the branch metric values ​​in the eight states in the order of (000, 001, 100, 101, 010, 011, 110, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i symbols, respectively; determine the maximum value of the branch metric values ​​in the eight states; if the maximum value is in the third group of branch metric values, determine that the sign of the second soft value component is negative; if the maximum value is in the fourth group of branch metric values, determine the sign of the second soft value component is positive, the third group of branch metric values ​​corresponds to serial numbers (000, 001, 100, 101), and the fourth group of branch metric values ​​corresponds to serial numbers (010, 011, 110, 111); subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value, subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; add the two absolute values, assign a determined sign to the result of the addition, and obtain the second soft value component.

[0155] It should be noted that the SOQPSK signal soft value determination device provided in the above embodiment only uses the division of the above-mentioned functional modules as an example to illustrate the determination of the SOQPSK signal soft value. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the SOQPSK signal soft value determination device provided in the above embodiment and the SOQPSK signal soft value determination method embodiment are based on the same concept. The specific implementation process is detailed in the method embodiment and is not further described here.

[0156] Figure 4 6 is a block diagram of a communication device provided by an embodiment of the present disclosure. Generally, the communication device includes: a processor 601 and a memory 602.

[0157] Processor 601 may include one or more processing cores, such as a quad-core processor or an octa-core processor. Processor 601 may be implemented using at least one of the following hardware forms: a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), or a PLA (Programmable Logic Array). Processor 601 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state.

[0158] Memory 602 may include one or more computer-readable storage media, which may be non-transitory. Memory 602 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in memory 602 is used to store at least one instruction, which is executed by processor 601 to implement the method for determining the soft value of a SOQPSK signal performed by a communication device provided in the method embodiment of the present application.

[0159] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or by a program to instruct the relevant hardware, and the program may be stored in a computer-readable storage medium, which may be a read-only memory, a disk, or an optical disk, etc.

[0160] The above description is merely an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A method for determining a soft value of a SOQPSK signal, characterized in that: The method comprises: The received SOQPSK signal is matched filtered through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 of the i-th symbol, where i is a positive integer greater than 2, and the filter coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively; Get the coefficient V under the 8 states corresponding to P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states where the i-2, i-1 and i symbols are 0 and 1 respectively; The absolute value of the result of subtracting Y0 from the local matched filtering results of the first matched filter in the eight states is divided by V 0,i Obtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,i Obtaining a second value, and adding the first value and the second value in the same state to obtain a real part, to obtain branch metric values ​​under the eight states, where the local matched filtering results under the eight states are matched filtering results under the eight states corresponding to the SOQPSK signal transmitted under an ideal state; Determining a first soft value component and a second soft value component according to a maximum value of the branch metrics under the eight states; The first soft value component and the second soft value component are aligned and then added to obtain a soft value of the i-th symbol of the SOQPSK signal.

2. The method according to claim 1, characterized in that The coefficients under the eight states corresponding to P0(t) are obtained according to the following formula: V 0,i =0.5[(b i-1 +b i )+j(-1) i (b i-1 -b i )], Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, and the coefficients of the i-2th symbol when it is 0 and 1 are the same; j is the symbol of the imaginary part of the complex number; The coefficients of the eight states corresponding to P1(t) are obtained according to the following formula: V 1,i =sqrt(2) / 8*[3b i-1 -b i-2 b i-1 b i +b i-2 +b i +j*(-1) i (3b i-1 -b i -2b i-1 b i -b i-2 -b i )], Among them, b i-2 is the value of the i-2th symbol.

3. The method according to claim 1, characterized in that The local matched filtering results of the first matched filter in the eight states are obtained according to the following formula: R 00 V 0,i +R 10 V 1,i ; Among them, R 00 represents the result of matching filter P0(t) by using the first matched filter, R 10 represents the result of matched filtering P1(t) using the first matched filter; The local matched filtering results of the second matched filter in the eight states are obtained according to the following formula: R 01 V 0,i +R 11 V 1,i ; Among them, R 01 represents the result of matching filter P0(t) by using the second matched filter, R 11 It represents the result of matching filtering P1(t) by using the second matched filter.

4. The method according to any one of claims 1 to 3, characterized in that The determining the first soft value component according to the maximum value of the branch metric values ​​in the eight states includes: Sort the branch metrics in the eight states in the order of (000, 010, 100, 110, 001, 011, 101, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i-th symbols, respectively; Determine the maximum value of the branch metric under the eight states; If the maximum value is in the first group of branch metric values, determining that the sign of the first soft value component is negative; if the maximum value is in the second group of branch metric values, determining that the sign of the first soft value component is positive, the first group of branch metric values ​​corresponding to sequence numbers (000, 010, 100, 110), and the second group of branch metric values ​​corresponding to sequence numbers (001, 011, 101, 111); Subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value; subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; The two absolute values ​​are added, and a determined sign is assigned to the addition result to obtain the first soft value component.

5. The method according to any one of claims 1 to 3, characterized in that The determining the second soft value component according to the maximum value of the branch metric values ​​in the eight states includes: Sort the branch metrics in the eight states in the order of (000, 001, 100, 101, 010, 011, 110, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i-th symbols, respectively; Determine the maximum value of the branch metric under the eight states; If the maximum value is in the third group of branch metric values, determining that the sign of the second soft value component is negative; if the maximum value is in the fourth group of branch metric values, determining that the sign of the second soft value component is positive, the third group of branch metric values ​​corresponding to sequence numbers (000, 001, 100, 101), and the fourth group of branch metric values ​​corresponding to sequence numbers (010, 011, 110, 111); Subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value; subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; The two absolute values ​​are added, and a determined sign is assigned to the addition result to obtain the second soft value component.

6. A soft value determination device for a SOQPSK signal, characterized in that: The device comprises: a matched filtering module, configured to perform matched filtering on the received SOQPSK signal through a first matched filter and a second matched filter, respectively, to obtain two matched filtering results Y0 and Y1 of the i-th symbol, where i is a positive integer greater than 2, and the filter coefficients of the first matched filter and the second matched filter are P0(t) and P1(t), respectively; Acquisition module, used to obtain the coefficient V under the 8 states corresponding to the P0(t) 0,i The coefficients V under the eight states corresponding to P1(t) 1,i , the 8 states refer to the 8 states where the i-2, i-1 and i symbols are 0 and 1 respectively; A branch metric module is used to take the absolute value of the result of subtracting the local matched filtering results of the first matched filter in the eight states from the Y0 and then divide it by the V 0,i Obtain the first value, take the absolute value of the result of subtracting the local matched filtering results of the second matched filter in the eight states from the Y1, and divide it by the V 1,i Obtaining a second value, and adding the first value and the second value in the same state to obtain a real part, to obtain branch metric values ​​under the eight states, where the local matched filtering results under the eight states are matched filtering results under the eight states corresponding to the SOQPSK signal transmitted under an ideal state; A soft value determination module is used to determine a first soft value component and a second soft value component according to the maximum value of the branch metric values ​​under the eight states; align the first soft value component and the second soft value component and add them to obtain a soft value of the i-th symbol of the SOQPSK signal.

7. The device according to claim 6, characterized in that The acquisition module is used to determine the coefficients of the eight states corresponding to P0(t) according to the following formula: V 0,i =0.5[(b i-1 +b i )+j(-1) i (b i-1 -b i )], Among them, b i is the value of the i-th symbol, b i-1 is the value of the i-1th symbol, and the coefficients of the i-2th symbol when it is 0 and 1 are the same; j is the symbol of the imaginary part of the complex number; The coefficients of the eight states corresponding to P1(t) are determined according to the following formula: V 1,i =sqrt(2) / 8*[3b i-1 -b i-2 b i-1 b i +b i-2 +b i +j*(-1) i (3b i-1 -b i -2b i-1 b i -b i-2 -b i )], Among them, b i-2 is the value of the i-2th symbol.

8. The device according to claim 6 or 7, characterized in that The soft value determination module is configured to: Sort the branch metric values ​​in the eight states in the order of (000, 010, 100, 110, 001, 011, 101, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i symbols, respectively; determine the maximum value of the branch metric values ​​in the eight states; if the maximum value is in the first set of branch metric values, determine that the sign of the first soft value component is negative; if the maximum value is in the second set of branch metric values, determine that the sign of the first soft value component is negative. is positive, the first group of branch metric values ​​corresponds to sequence numbers (000, 010, 100, 110), and the second group of branch metric values ​​corresponds to sequence numbers (001, 011, 101, 111); subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value, subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; add the two absolute values, assign the determined sign to the result of the addition, and obtain the first soft value component; Sort the branch metric values ​​in the eight states in the order of (000, 001, 100, 101, 010, 011, 110, 111), where the three bits of each sequence number represent the values ​​of the i-2, i-1, and i symbols, respectively; determine the maximum value of the branch metric values ​​in the eight states; if the maximum value is in the third group of branch metric values, determine that the sign of the second soft value component is negative; if the maximum value is in the fourth group of branch metric values, determine the sign of the second soft value component is positive, the third group of branch metric values ​​corresponds to serial numbers (000, 001, 100, 101), and the fourth group of branch metric values ​​corresponds to serial numbers (010, 011, 110, 111); subtract the first branch metric value and the third branch metric value of the group where the maximum value is located and take the absolute value, subtract the second branch metric value and the fourth branch metric value of the group where the maximum value is located and take the absolute value; add the two absolute values, assign a determined sign to the result of the addition, and obtain the second soft value component.

9. A communication device, characterized in that: The communication device includes a processor and a memory, wherein the memory stores at least one program code, and the program code is loaded and executed by the processor to implement the method for determining the soft value of the SOQPSK signal according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores at least one program code, and the program code is loaded and executed by a processor to implement the method for determining the soft value of a SOQPSK signal according to any one of claims 1 to 5.

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