Method and apparatus for decoding a short burst signal in a high dynamic range

Abstract

The application discloses a decoding method and device of a short burst signal under a high dynamic range, and relates to the field of satellite communication. The method solves the problem that the signal amplitude is not considered in the decoding process in the prior art, or the signal amplitude is considered but other problems occur, resulting in the decoding performance of the short burst signal being reduced. The short burst signal received by a receiver is soft-demodulated to obtain likelihood information, and a data sequence of the short burst signal is obtained according to the likelihood information. The data sequence is subjected to mean value calculation to obtain a data mean value of the data sequence, and a scaling factor of the data mean value is obtained according to the data mean value. The data sequence is scaled according to the scaling factor to obtain scaled data. The scaled data is subjected to decoding processing to obtain a decoding result. The decoding performance is improved while the decoding supportable signal dynamic range is increased, and the short burst signal can be processed without analog or digital AGC.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite communication, more particularly, it relates to a decoding method and device of short burst signal in high dynamic range. BACKGROUND

[0002] With the rapid development of aerospace technology, satellite communication has become one of the mainstream communication methods. Satellite communication has the characteristics of wide communication range, strong disaster resistance and support for various services, and has become one of the indispensable communication means in modern times.

[0003] Channel coding technology has a relatively independent position in the whole communication system, and is one of the key technologies, which determines the performance of the communication system. In recent years, Shannon limit coding, such as Turbo, LDPC, etc., has attracted widespread attention due to its low signal-to-noise ratio operating threshold and high gain. By comparing the performance of Turbo, LDPC, and Polar codes, it can be seen that in the case of short burst, the theoretical performance of Turbo code is better than the other two.

[0004] The traditional Turbo decoding is of two types: one is to first perform soft demodulation at the receiving end, and then directly perform Turbo decoding on the obtained likelihood information, without considering the influence of signal amplitude. When the signal amplitude is too large or too small, it will lead to poor decoding performance, that is, the signal dynamic range that can be supported is small; the other is to first perform analog or digital AGC on the received signal at the receiving end, and then perform soft demodulation, and then perform Turbo decoding on the obtained likelihood information. Although this method takes into account the signal amplitude, it also introduces other problems. For example, using analog AGC increases hardware cost, and if digital AGC is used, the loop converges too slowly and is not suitable for short burst services in satellite communication. SUMMARY

[0005] The purpose of the present application is to provide a decoding method and device of short burst signal in high dynamic range, to solve the problem that the influence of signal amplitude is not considered when Turbo decoding is performed in the prior art, or other problems such as increased hardware cost or slow loop convergence are considered when the signal amplitude is considered, which leads to reduced decoding performance of short burst signal. The present application takes into account the influence of signal amplitude on decoding performance, increases the signal dynamic range that can be supported by decoding, improves the reliability of signal transmission of the communication system, and can process short burst signal without analog or digital AGC, which improves the decoding performance without additional cost in hardware implementation.

[0006] The above technical purpose of the present application is achieved by the following technical scheme:

[0007] A decoding method of short burst signal in high dynamic range, the method comprising:

[0008] Step one, soft demodulation is performed on the short burst signal received by the receiver to obtain likelihood information, and a data sequence of the short burst signal is acquired according to the likelihood information;

[0009] Step two, mean value calculation is performed on the data sequence to obtain a data mean value of the data sequence, and a scaling factor of the data mean value is acquired according to the data mean value;

[0010] Step three, scaling is performed on the data sequence according to the scaling factor to obtain scaled data.

[0011] Step four, decoding processing is performed on the scaled data to obtain a decoding result.

[0012] The present application performs soft demodulation on the received short burst signal by the receiver to obtain likelihood information, and then scales the data in the likelihood information by a scaling factor, so that the amplitude of the scaled data is greatly improved compared with the amplitude of the data before scaling. Then, decoding processing is performed on the scaled data, so that the influence of the signal amplitude on the decoding performance is eliminated, the decoding supportable signal dynamic range is increased, the reliability of the signal transmission of the communication system is improved, and the scaled data does not need to be processed by analog or digital AGC after decoding, so that the decoding performance is improved, and no additional cost is brought in the hardware implementation.

[0013] Further, the data sequence acquired from the likelihood information is S before ={s1, s2, s3, …, s N ,};wherein, S before represents the data sequence after soft demodulation of the short burst signal.

[0014] Further, the data mean value obtained by mean value calculation on the data sequence is b=abs(S before ), and the scaling factor is acquired by calculating the data mean value, and the calculation formula of the scaling factor is α=mean(b); wherein, α represents the scaling factor, b represents the data mean value, and S before represents the data sequence after soft demodulation of the short burst signal.

[0015] Further, the scaling factor is acquired according to the scaling factor, and the calculation formula of the scaling factor is wherein, β represents the scaling factor, and α represents the scaling factor.

[0016] Further, the calculation formula of the scaled data obtained by scaling the data sequence according to the scaling factor is S after =β*S before ; wherein, S after represents the scaled data, and S beforewherein β represents the scaling factor.

[0017] A signal processing device for performing the method, the device comprising:

[0018] A first obtaining module, configured to perform soft demodulation on a short burst signal received by a receiver to obtain likelihood information, and obtain a data sequence of the short burst signal according to the likelihood information;

[0019] A second obtaining module, configured to obtain a data mean of the data sequence, and obtain a scaling factor of the data mean according to the data mean;

[0020] A first performing module, configured to scale the data sequence according to the scaling factor to obtain scaled data.

[0021] A second performing module, configured to perform decoding processing on the scaled data to obtain a decoding result.

[0022] Further, the second obtaining module is further configured to calculate the data mean to obtain a scaling coefficient of the data mean.

[0023] A computer readable storage medium, having a computer program stored thereon, the computer program being executed by a processor to implement the steps of the method.

[0024] An electronic device, comprising: a memory having a computer program stored thereon; and a processor configured to execute the computer program in the memory to implement the steps of the method.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The present application performs soft demodulation on a short burst signal received by a receiver to obtain likelihood information, scales the likelihood information by a scaling factor, decodes the scaled data to obtain a processed signal, reduces the influence of noise on the short burst signal, improves the reliability of information obtained by the receiver, and considers the influence of signal amplitude on decoding performance to improve the signal dynamic range that can be supported by the short burst signal. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0028] Figure 1 is a flowchart of a decoding method for a short burst signal in a high dynamic range according to the present application.

[0029] Figure 2 A comparison chart of decoding performance of the decoding method of the present application and the decoding method in the prior art;

[0030] Figure 3 A symbol constellation chart of the generated short burst signal;

[0031] Figure 4 A symbol constellation chart of the short burst signal added with noise and attenuation;

[0032] Figure 5 A symbol constellation chart outputted by the receiver after soft demodulation;

[0033] Figure 6 An amplitude chart of the output signal of the receiver;

[0034] Figure 7 A comparison chart of amplitudes before and after scaling of the signal of the present application;

[0035] Figure 8 A comparison chart of bit error rate of the decoding method of the present application and the decoding method in the prior art;

[0036] Figure 9 A block diagram of a signal processing device of the present application. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and the accompanying drawings, and the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and are not intended to limit the present application.

[0038] It should be noted that when a component is referred to as being "fixed" or "set" on another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected" to another component, it can be directly or indirectly connected to the other component.

[0039] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0041] Embodiment

[0042] The present embodiment I proposes a decoding method of a short burst signal in a high dynamic range, as shown in the formula (1) : Figure 1 The method comprises the following steps:

[0043] S1, performing soft demodulation on the short burst signal received by the receiver to obtain likelihood information, and acquiring a data sequence of the short burst signal according to the likelihood information;

[0044] S2, performing mean value calculation on the data sequence to obtain a data mean value of the data sequence, and acquiring a scaling factor of the data mean value according to the data mean value;

[0045] S3, performing scaling on the data sequence according to the scaling factor to obtain scaled data.

[0046] S4, performing decoding processing on the scaled data to obtain a decoding result.

[0047] Specifically, the soft demodulation in step S1 is one of the common technical means in the data transmission process of satellite communication, and the present application does not elaborate on this.

[0048] Specifically, the decoding processing method in step S4 adopts Turbo decoding, wherein the decoding process comprises hierarchical combining, deinterleaving and Turbo decoding of data; wherein hierarchical combining, channel deinterleaving, Turbo decoder decoding and descrambling are the conventional means of the decoding process in satellite communication technology, and the present application does not elaborate on this. The method proposed in the present embodiment is applied to a receiver in a communication system or other signal receiver.

[0049] The Turbo decoder adopts a feedback iterative structure, and each decoding module mainly includes two cascaded component decoders in addition to an interleaver and a deinterleaver; the soft decision information output by one component decoder is processed to become extrinsic information input to another component decoder, forming iterative decoding, and after a certain number of iterations, hard decision is output.

[0050] The decoding method provided by the application carries out soft demodulation on the received short burst signal, obtains likelihood information, carries out scaling on the likelihood information through a scaling factor, decodes the scaled data, and obtains a processed signal, thereby reducing the influence of noise on the short burst signal, improving the reliability of the information obtained by the receiver, and improving the signal dynamic range that can be supported by the short burst signal while improving the decoding performance without bringing additional cost in hardware implementation.

[0051] Preferably, in step S1, the data sequence obtained from the likelihood information is S before ={s1, s2, s3, …, s N ,};wherein S before represents the data sequence obtained by soft demodulation of the short burst signal.

[0052] First, parameters are set, the short burst signal type is DTB voice, the SNR is set to 7dB-20dB with a step of 1dB, the signal attenuation values are 0dB, 30dB and 60dB respectively, and the modulation mode is CQPSK debugging.

[0053] The short burst modulation signal is generated according to the above set parameters, and the short burst modulation signal is generated, including CRC, Turbo encoding, CQPSK modulation, shaping filtering and the like, which are all common technical means in the signal data transmission process, and will not be described in detail. Figure 3 As shown in the figure.

[0054] In the process of adding noise and attenuation to the generated signal, noise and attenuation are added to the signal according to the set parameters, and the symbol constellation point obtained is as shown in the figure (taking SNR=15dB and attenuation 0dB as an example). Figure 4 Among them, the noise refers to narrowband random Gaussian white noise, and the attenuation refers to reducing the signal power.

[0055] In the receiving process of the receiver, the techniques such as matched filtering and symbol synchronization are all common technical means for receiving signals of the receiver, and thus will not be described here, and the symbol constellation diagram output by the receiver is as shown in the figure (taking SNR=15dB and attenuation 0dB as an example). Figure 5

[0056] In the soft demodulation of the receiver, the carrier signal received by the receiver is soft demodulated to obtain likelihood information. Soft demodulation is one of the common technical means in the data transmission process in satellite communication, and will not be described in detail, and the amplitude of the output soft demodulation information is as shown in the figure (taking SNR=15dB and attenuation 0dB as an example). Figure 6 ​​

[0057] Preferably, in step S2, the data mean value obtained according to the data sequence is b = abs(S before ), the data mean value is calculated, and a scaling coefficient is obtained, and the calculation formula of the scaling coefficient is a = mean(b); wherein a represents the scaling coefficient, b represents the data mean value, and S before represents the data sequence after soft adjustment of the short burst signal.

[0058] In the calculation of the scaling factor, the scaling coefficient a used for scaling the data is determined, and the scaling coefficient a = mean(abs(S before )) is obtained according to the formula of step S2, and the scaling coefficient a = 0.1251 is calculated.

[0059] Preferably, according to the scaling coefficient, a scaling factor is obtained, and the calculation formula of the scaling factor is wherein b represents the scaling factor, and a represents the scaling coefficient.

[0060] The scaling factor b is the reciprocal of the scaling coefficient a, and thus according to the scaling coefficient a = 0.1251, the scaling factor b = 7.9936 is calculated.

[0061] Preferably, in step S3, the data sequence is scaled according to the scaling factor, and the calculation formula of the scaled data is S after = b * S before ; wherein S after represents the scaled data, S before represents the data, and b represents the scaling factor.

[0062] According to the scaling factor b = 7.9936, the data sequence of the likelihood information is scaled to calculate S after = b * S before , and the scaled data is obtained, and the amplitude before and after scaling is obtained as shown in Figure 7 ,

[0063] The Turbo decoding processing is performed on the scaled data, and the processed signal is obtained, the influence of noise on the short burst signal is reduced, and the reliability of the information obtained by the receiver is improved.

[0064] In the calculation of the bit error rate, the statistical method is that 1000 groups of random short burst signals are repeatedly sent under the same parameter setting, the decoding method proposed in the application is applied, the proportion of all error bits in the total number of sent bits is counted, and Figure 2 and Figure 8 are obtained; as Figure 8As shown in the SNR is 7dB~15dB, each step 1dB, attenuation is 0, 30dB and 60dB conditions, when the attenuation is 0, can be known in SNR=11dB, the prior art still exist bit number, so that its bit error rate is not 0, and the application of the decoding method in the present application, when SNR=11dB, the bit error rate is already 0, the remaining 30dB and 60dB are the same example, that is not described.

[0065] As Figure 2 shown, the bit error rate curve of the application and the bit error rate curve of the prior art are compared, and it can be concluded that the decoding performance of the application is better. Figure 8 The data comparison graph and the curve comparison graph of Figure 2 both can represent that the decoding method of the application can obtain better decoding performance.

[0066] In summary, the decoding method described in the application can obtain better decoding performance.

[0067] Figure 9 A block diagram of a signal processing device provided in the embodiment is shown in Figure 9 The signal processing device 100 includes a first acquisition module 101, a second acquisition module 102, a first execution module 103 and a second execution module 104.

[0068] The first acquisition module 101 is configured to perform soft demodulation on a short burst signal received by a receiver to obtain likelihood information, and acquire a data sequence of the short burst signal according to the likelihood information.

[0069] The second acquisition module 102 is configured to acquire a data mean of the data sequence, and acquire a scaling factor of the data mean according to the data mean.

[0070] The first execution module 103 is configured to scale the data sequence according to the scaling factor to obtain scaled data.

[0071] The second execution module 104 is configured to perform decoding processing on the scaled data to obtain a decoding result.

[0072] The calculation formula of the scaling factor is The calculation formula of the scaling of the data is S after =β*S before .

[0073] Preferably, the second acquisition module 102 is further configured to calculate the data mean to obtain a scaling coefficient of the data mean.

[0074] The calculation formula of the scaling coefficient is α=mean(abs(S before )).

[0075] The present application also provides a computer readable storage medium, having stored thereon computer program instructions, which, when executed by a processor, implement the steps of the decoding method provided by the present application.

[0076] Specifically, the computer readable storage medium can be a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a programmable read only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, etc.

[0077] As to the computer readable storage medium in the above embodiments, the steps of the decoding method when the computer program stored thereon is executed have been described in detail in the embodiments related to the method, and thus will not be described in detail here.

[0078] The present application also provides an electronic device, comprising: a memory having stored thereon a computer program; and a processor configured to execute the computer program in the memory to implement the steps of the decoding method described above.

[0079] The above detailed description of the specific embodiments of the present application has further explained the objects, technical solutions and advantages of the present application. It should be understood that the above detailed description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A decoding method for short burst signals in a high dynamic range, characterized in that, The method includes: Step 1: Soft demodulate the short burst signal received by the receiver to obtain likelihood information, and obtain the data sequence of the short burst signal based on the likelihood information; Step two: Calculate the modulus of the data sequence to obtain the data modulus value; and obtain the scaling factor of the data modulus value based on the data modulus value; wherein, the data modulus value obtained by calculating the modulus of the data sequence is... The mean of the data modulus is calculated to obtain the scaling factor, and the scaling factor is calculated using the following formula: ;in; This represents the scaling factor, and b represents the data modulus. This represents the data sequence after soft demodulation of a short burst signal; based on the scaling factor, the scaling factor is obtained, and the formula for calculating the scaling factor is: ;in, Indicates the scaling factor. Indicates the scaling factor; Step 3: Scale the data sequence according to the scaling factor to obtain the scaled data; Step four: Decode the scaled data to obtain the decoding result.

2. The decoding method for short burst signals in a high dynamic range according to claim 1, characterized in that, The data sequence obtained from the likelihood information is ;in, This represents the data sequence after soft demodulation of a short burst signal.

3. The decoding method for short burst signals in a high dynamic range according to claim 1, characterized in that, The data sequence is scaled according to the scaling factor, and the formula for obtaining the scaled data is as follows: ;in, This represents the scaled data. This represents the data sequence after soft demodulation of a short burst signal. This represents the scaling factor.

4. A signal processing apparatus, characterized in that, The apparatus for performing a decoding method for a short burst signal in a high dynamic range as described in any one of claims 1-3, the apparatus comprising: The first acquisition module is used to perform soft demodulation on the short burst signal received by the receiver to obtain likelihood information, and to acquire the data sequence of the short burst signal based on the likelihood information. The second acquisition module is used to perform modulus calculation on the data sequence to obtain the data modulus value of the data sequence, and to obtain a scaling factor for the data modulus value based on the data modulus value; wherein the data modulus value obtained by performing modulus calculation on the data sequence is The mean of the data modulus is calculated to obtain the scaling factor, and the scaling factor is calculated using the following formula: ;in; This represents the scaling factor, and b represents the data modulus. This represents the data sequence after soft demodulation of a short burst signal; based on the scaling factor, the scaling factor is obtained, and the formula for calculating the scaling factor is: ;in, Indicates the scaling factor. Indicates the scaling factor; The first execution module is used to scale the data sequence according to the scaling factor to obtain the scaled data; The second execution module decodes the scaled data and obtains the decoding result.

5. The signal processing apparatus according to claim 4, characterized in that, The second acquisition module is also used to calculate the mean of the data modulus and obtain the scaling factor of the data modulus.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of a decoding method for short burst signals in a high dynamic range as described in any one of claims 1-3.

7. An electronic device, characterized in that, include: A memory on which computer programs are stored; A processor is configured to execute the computer program in the memory to implement the steps of a decoding method for short burst signals in a high dynamic range as described in any one of claims 1-3.

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