Signal demodulation method and device

Abstract

The present application discloses a signal demodulation method and device, which can be applied to the field of communications. The method first constructs a received signal at a second target moment and a received signal at a third target moment based on a received signal at a first target moment, wherein the second target moment is later than the first target moment, and the third target moment is later than the second target moment. According to multiple values ​​of the received signal at the second target moment and the received signal at the third target moment, multiple ideal received signals at the second target moment are obtained. From the multiple ideal received signals at the second target moment, the first ideal reference signal and the second ideal reference signal corresponding to the second target moment are determined. Finally, the actual received signal at the second target moment after demodulation is obtained according to the first ideal reference signal and the second ideal reference signal. The present application also discloses a signal demodulation device, which can realize the judgment of the value of the received signal after demodulation while reducing the complexity of the reconstructed signal.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a signal demodulation method and device. Background Art

[0002] In a communication system, information is usually first converted into an original electrical signal, and then the electrical signal is converted into a high-frequency signal suitable for channel transmission. This process is called modulation. Modulation is the process of converting various baseband signals into modulated signals suitable for channel transmission. At the receiving end, the received modulated signal is demodulated to restore the original signal. There are two general demodulation methods: coherent demodulation and incoherent demodulation. Coherent demodulation must restore the coherent carrier (the coherent carrier is of the same frequency and phase as the carrier signal of the original transmitter modulating the digital baseband signal). The original digital baseband signal is obtained by using this coherent carrier and the modulated signal. Incoherent demodulation does not need to recover the coherent carrier and is simpler than coherent demodulation. Phase differential demodulation is a relatively easy-to-implement and low-complexity demodulation algorithm in incoherent demodulation. Its principle is to take the phase of the received baseband signal, then differentiate it front and back, and finally make a direct decision based on the optimal sampling. Generally, GFSK modulated signals will choose phase differential demodulation in the engineering field. When making the optimal sampling decision, a complete Gaussian filter will be used to construct an ideal reference signal as the basis for the decision, which will take up more computing resources. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a signal demodulation method and device, aiming to realize the determination of the value of the actual received signal after demodulation on a signal with less reconstruction.

[0004] In a first aspect, an embodiment of the present application provides a signal demodulation method, the method comprising:

[0005] Constructing a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time, wherein the second target time is later than the first target time, and the third target time is later than the second target time;

[0006] Obtaining multiple ideal received signals at the second target moment according to multiple values ​​of the received signal at the second target moment and the received signal at the third target moment;

[0007] Determine a first ideal reference signal and a second ideal reference signal corresponding to the second target time from a plurality of ideal received signals at the second target time;

[0008] A decision is made according to the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target moment.

[0009] Optionally, constructing a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time includes:

[0010] Based on the received signal at the first target time, construct and obtain the received signal at the second target time, where the value of the received signal at the second target time is 0 or 1;

[0011] Based on the constructed received signal at the second target moment, the received signal at the third target moment is constructed and obtained, and the value of the received signal at the third target moment is 0 or 1.

[0012] Optionally, obtaining a plurality of ideal received signals at the second target moment according to a plurality of values ​​of the received signal at the second target moment and the received signal at the third target moment includes:

[0013] Combining different values ​​of the constructed received signal at the second target moment and the constructed received signal at the third target moment, wherein a value of the received signal at the second target moment in the combination corresponds to a value of the received signal at the third target moment;

[0014] The combined value of the received signal at the second target moment and the value of the received signal at the third target moment are weighted and then summed to obtain a plurality of ideal received signals at the second target moment.

[0015] Optionally, determining the first ideal reference signal and the second ideal reference signal corresponding to the second target time from a plurality of ideal received signals at the second target time includes:

[0016] Determine, among the multiple ideal received signals at the second target time, an ideal received signal calculated when the value of the received signal at the second target time is 0 and the value of the received signal at the third target time is 1 as a first ideal reference signal;

[0017] Among the multiple ideal received signals at the second target moment, the ideal received signal calculated corresponding to the value of the received signal at the second target moment being 1 and the value of the received signal at the third target moment being 0 is determined as the second ideal reference signal.

[0018] Optionally, the making a decision according to the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target time includes:

[0019] Calculating a first absolute value of a difference between the first ideal reference signal and the actual received signal;

[0020] Calculating a second absolute value of a difference between the second ideal reference signal and the actual received signal;

[0021] calculating a difference between the first absolute value and the second absolute value;

[0022] Determine the relationship between the difference between the first absolute value and the second absolute value and a preset threshold value;

[0023] If the difference between the first absolute value and the second absolute value is greater than the preset threshold value, the actual received signal at the second target time after demodulation is 1;

[0024] If the difference between the first absolute value and the second absolute value is not less than the preset threshold value, the actual received signal at the second target time after demodulation is 0.

[0025] Optionally, the method further includes:

[0026] Before demodulating the actual received signal, the frequency offset value of the actual received signal is eliminated.

[0027] In a second aspect, an embodiment of the present application provides a signal demodulation device, the device comprising:

[0028] A signal construction module, configured to construct a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time, wherein the second target time is later than the first target time, and the third target time is later than the second target time;

[0029] A first signal acquisition module, configured to obtain a plurality of ideal received signals at the second target moment according to a plurality of values ​​of the received signal at the second target moment and the received signal at the third target moment;

[0030] A second signal acquisition module, configured to determine a first ideal reference signal and a second ideal reference signal corresponding to the second target moment from a plurality of ideal received signals at the second target moment;

[0031] The demodulated signal acquisition module is used to make a decision based on the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target moment.

[0032] Optionally, the signal construction module is specifically used to:

[0033] Based on the received signal at the first target time, construct and obtain the received signal at the second target time, where the value of the received signal at the second target time is 0 or 1;

[0034] Based on the constructed received signal at the second target moment, the received signal at the third target moment is constructed and obtained, and the value of the received signal at the third target moment is 0 or 1.

[0035] Optionally, the second signal acquisition module is specifically used to:

[0036] When the value of the received signal at the second target time in the ideal received signal is 0, the value of the received signal at the third target time is 1 as the first ideal reference signal;

[0037] When the value of the received signal at the second target moment in the ideal received signal is 1, the signal whose value at the third target moment is 0 is used as the second ideal reference signal.

[0038] Optionally, the demodulated signal acquisition module is specifically used to:

[0039] Calculating a first absolute value of a difference between the first ideal reference signal and the actual received signal;

[0040] Calculating a second absolute value of a difference between the second ideal reference signal and the actual received signal;

[0041] calculating a difference between the first absolute value and the second absolute value;

[0042] Determine the relationship between the difference and a preset threshold value;

[0043] If the difference is greater than the preset threshold value, the actual received signal at the second target time after demodulation is 1;

[0044] If the difference is not less than the preset threshold value, the actual received signal at the second target time after demodulation is 0.

[0045] The present application provides a method and device for signal demodulation. When executing the method, firstly, based on the received signal at the first target moment, the received signal at the second target moment and the received signal at the third target moment are constructed, wherein the second target moment is later than the first target moment, and the third target moment is later than the second target moment. Then, according to the multiple values ​​of the received signal at the second target moment and the received signal at the third target moment, multiple ideal received signals at the second target moment are obtained. Then, from the multiple ideal received signals at the second target moment, the first ideal reference signal and the second ideal reference signal corresponding to the second target moment are determined. Finally, the actual received signal at the second target moment after demodulation is obtained according to the first ideal reference signal and the second ideal reference signal. In this way, it is realized that the reconstruction of many signals in the signal demodulation process is converted into only three-point signals to be reconstructed, and then the ideal received signal at the corresponding moment of the actual received signal is calculated according to the reconstructed signal, and two signals in the ideal received signal are taken as ideal reference signals, and the two ideal reference signals are used as the decision basis for demodulating the actual received signal, so as to determine the value of the demodulated actual received signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A flowchart of a signal demodulation method provided in an embodiment of the present application;

[0048] Figure 2 A flowchart for constructing a received signal provided in an embodiment of the present application;

[0049] Figure 3 A flowchart for constructing an ideal received signal provided in an embodiment of the present application;

[0050] Figure 4 A schematic diagram of the structure of a signal demodulation device provided in an embodiment of the present application;

[0051] Figure 5 A signal demodulation flow chart for an application scenario provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] In the study of the prior art, it is found that with the development of wireless communication technology and communication networks, in the fifth generation of mobile communication technology (5th Generation, 5G), massive machine type communication (Massive Machine Type Communication, mMTC) is listed as one of the three major application scenarios. Among the many physical layer technologies of the Internet of Things for the mMTC scenario, continuous phase shift keying (CPFSK) is widely used for its excellent characteristics of constant envelope, continuous phase and high spectrum efficiency. Gaussian filter frequency shift keying (GFSK) adds a low-pass Gaussian filter as a symbol phase shaping function on the basis of continuous phase modulation of CPFSK. Compared with CPFSK signal, its spectrum out-of-band attenuation is faster and the spectrum efficiency is higher, but the introduction of Gaussian filter shaping will bring additional symbol crosstalk (Inter-symbol interference), and the implementation is more complicated. In the embodiments of the present application, GFSK is mainly used as the main body for discussion. It can be understood that the signal demodulation method proposed in the present application can be applied to various modulation schemes using differential demodulation, not just limited to GFSK.

[0053] There are generally two ways to demodulate a signal: coherent demodulation and incoherent demodulation. GFSK signal demodulation is usually implemented based on incoherent demodulation, because incoherent demodulation does not need to recover the coherent carrier, which is simpler than coherent demodulation, and has low synchronization accuracy requirements and strong channel fading resistance, making it more suitable for low-cost implementation. The currently commonly used incoherent demodulation scheme uses the polarity of the phase change between a single symbol to determine the information carried by the transmitted symbol, that is, the differential demodulation algorithm. Although it is simple to implement, its bit error rate (BER) performance is poor at low received signal-to-noise ratio (SNR), which makes it difficult to meet the requirements of wide coverage. Another incoherent envelope detection algorithm has better performance when the FSK signal modulation factor is large. However, in order to reduce the actual bandwidth occupied by the signal, the GFSK modulation factor is usually less than 1, which does not meet the requirements of orthogonality between symbols, so the BER performance is also poor at low SNR. Since GFSK is a phase-continuous memory signal, the demodulation schemes with better BER performance are mostly multi-symbol detection algorithms based on the maximum likelihood sequence detection (MLSD) idea, such as the best incoherent demodulation algorithm, etc. However, the computational complexity and storage complexity of this algorithm are very high, making it difficult to adapt to practical engineering applications. In this application, the differential demodulation method in incoherent demodulation is mainly optimized.

[0054] Based on this, the present application proposes an optimized incoherent demodulation method, which can achieve better incoherent demodulation performance with lower complexity.

[0055] Figure 1 is a flow chart of a signal demodulation method, such as Figure 1 As shown, a signal demodulation method proposed in the present application can be used in GFSK modulation, in which the signal is 0 or 1, and the method is specifically as follows:

[0056] S11: constructing a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time, wherein the second target time is later than the first target time, and the third target time is later than the second target time.

[0057] Before demodulating the signal, the frequency offset value of the signal estimated in synchronization will be eliminated. Specifically, the synchronization starting point is generally obtained by a related method using a known pilot signal, and the frequency offset value can be obtained using the known pilot signal and the actual received signal according to the synchronization point information. The obtained frequency offset value is then processed to eliminate the frequency offset value of the signal in the synchronization estimation.

[0058] During demodulation, all possibilities of the current signal are reconstructed by Gaussian filtering. Specifically, in the prior art, the signal is judged by using the complete Gaussian function waveform in the Gaussian filter. In the present application, Gaussian filtering is simplified to three-point reconstruction. The most important parameter generated by the Gaussian filter is the standard deviation of the Gaussian distribution. When this standard deviation is known, the center point and two points near the center point can be used to perform a simple approximate reconstruction of the Gaussian filter, that is, the best sampling point of the current symbol is the peak of the Gaussian filter, and the position of the best sampling point before and after the peak is the feedforward and feedback coefficients (Gaussian modulation spans three symbols, and here it is approximately considered that the peak, feedforward, and feedback are the positions corresponding to the three symbols spanned), so the best sampling point of the Gaussian filter is the position where the number of Gaussian filter coefficients is divided by 3, the highest point is the middle point, and the position of the best sampling point before and after the middle point is the feedforward and feedback coefficients, so in the present application, the signal demodulation is completed by a three-point reconstruction method, and the peak point and two points near the peak point are used to reconstruct the ideal received signal, and then the demodulated value of the actual received signal is obtained through judgment. When the method is applied to other signal modulation methods, the number of reconstructed signals can also be appropriately increased to meet the signal demodulation performance.

[0059] S11 mentions: "Based on the received signal at the first target moment, the received signal at the second target moment and the received signal at the third target moment are constructed." The specific way to construct the received signal can be: first construct the received signal at the second target moment based on the received signal at the first target moment, and then construct the received signal at the third target moment based on the constructed received signal at the second target moment. The specific construction method can also be: based on the received signal at the first target moment, the received signal at the second target moment and the received signal at the third target moment are simultaneously constructed. In other words, the received signal at any other known moment is constructed according to the received signal at any known moment. The specific construction method can be selected by technicians in this field according to actual conditions and application scenarios, and is not limited here. In the embodiment of the present application, the first way to construct the received signal is taken as an example, that is, first construct the received signal at the second target moment based on the received signal at the first target moment, and then construct the received signal at the third target moment based on the received signal at the constructed second target moment. The second way to construct the received signal mentioned above is different from the first way to construct the received signal only in the order of constructing the signal, and the specific construction method is similar, so it will not be repeated.

[0060] Figure 2 To construct a flow chart for receiving signals, Figure 2 As shown, the method for constructing an ideal received signal specifically includes:

[0061] S111: Based on the received signal at the first target moment, construct and obtain the received signal at the second target moment, where the value of the received signal at the second target moment is 0 or 1.

[0062] Mark the current received signal as the signal at time N. At this time, the signals before time N, such as the signal at time N-1 and the signal at time N-2 are known. In GFSK modulation, there are only two possibilities for receiving a signal, the signal is 0 or the signal is 1. Since the signal at time N-1 is known, the received signal at time N can be constructed. For example, the received signal at time N-1 is used as the received signal at the first target time, and the received signal at time N is used as the received signal at the second target time. When the received signal at time N-1 (the first target time) is known, the value of the received signal at time N (the second target time) can be 0 or 1. When the value of the constructed received signal at time N (the second target time) is 0, the symbol Indicates; when the value of the received signal at the constructed N-point moment (the second target moment) is 1, the symbol express.

[0063] S112: Based on the constructed received signal at the second target moment, construct and obtain the received signal at the third target moment, where the value of the received signal at the third target moment is 0 or 1.

[0064] In the above S111, two possibilities of the received signal at the N-1 time (the first target time) are determined based on the known received signal at the N-1 time (the first target time), and the value of the received signal at the N-1 time may be 0 or 1. Based on the possibility of the received signal at the N-1 time (the second target time), the received signal at the N+1 time (the third target time) can be constructed. When the value of the received signal at the N-1 time (the second target time) is 0, the value of the received signal at the N+1 time (the third target time) can be 0 or 1; when the received signal at the N-1 time is 1, the value of the received signal at the N+1 time can be 0 or 1. In an embodiment of the present application, the received signal at the first target time corresponds to the received signal at the N-1 time, the received signal at the second target time corresponds to the received signal at the N-1 time, and the received signal at the third target time corresponds to the received signal at the N+1 time, which will not be repeated in the following discussion.

[0065] S12: Obtain multiple ideal received signals at the second target moment according to multiple values ​​of the received signal at the second target moment and the received signal at the third target moment.

[0066] Figure 3 To construct a flow chart of an ideal received signal, Figure 3 As shown, the method for constructing an ideal received signal is specifically as follows:

[0067] S121: Combining different values ​​of the constructed received signal at the second target moment and the constructed received signal at the third target moment, wherein one value of the received signal at the second target moment in the combination corresponds to one value of the received signal at the third target moment.

[0068] Specifically, there are four possibilities for the ideal received signal corresponding to [N-1, N, N+1] constructed by the three-point reconstruction method. When they are combined, they are: when the value of the received signal at point N is 0, the value of the received signal at point N+1 is 0. At this time, the corresponding constructed received signal can be expressed as When the value of the received signal at point N is 0, the value of the received signal at point N+1 is 1. The corresponding constructed received signal can be expressed as When the value of the received signal at point N is 1, the value of the received signal at point N+1 is 0. The corresponding constructed received signal can be expressed as When the received signal value at point N is 1, the received signal value at point N+1 is 1. The corresponding constructed received signal can be expressed as

[0069] S122: weighting the combined values ​​of the received signal at the second target moment and the received signal at the third target moment, respectively, and performing summation calculation to obtain a plurality of ideal received signals at the second target moment.

[0070] The ideal received signal is calculated by permuting and combining the received signal value at the second target moment and the received signal value at the third target moment, and then assigning different weights to the received signal value at the second target moment and the received signal value at the third target moment according to the permutation and combination. The purpose of constructing the ideal received signal is to determine the value of the actual received signal based on the difference between the actual received signal and the received signal.

[0071] The ideal received signal needs to be calculated by calculating the received signal constructed at the N point and the received signal constructed at the N+1 point. Specifically, different weights need to be assigned to the received signal constructed at the N point and the received signal constructed at the N+1 point, and the sum of the weights is calculated to obtain the value of the ideal received signal. The specific calculation formula is as follows:

[0072]

[0073]

[0074]

[0075]

[0076] Wherein a and b are constants between 0 and 1, which can also be understood as weight values. The specific weight values ​​can be freely set by technicians in this field according to actual conditions and application scenarios, and are not limited here.

[0077] S13: Determine a first ideal reference signal and a second ideal reference signal corresponding to the second target time from a plurality of ideal received signals at the second target time.

[0078] Through the above calculation process, we can know that there are four kinds of ideal received signals. Assuming the received signal and The difference between but When the received signal at point N When the value of is 0, When the received signal at point N When the value of is 1, Therefore, only need to keep and It can be called the first signal reconstructed by the Gaussian filter and the second signal reconstructed by the Gaussian filter. Specifically, is the first signal reconstructed by the Gaussian filter, called is the second signal reconstructed as a Gaussian filter. The first signal is used as the first ideal reference signal, and the second signal is used as the second ideal reference signal. The first ideal reference signal and the second ideal reference signal mentioned in S13 are and The two Gaussian filters reconstruct the signal.

[0079] When N points receive signals When it is 0, When point N receives the signal When is 1, The judgment process of this conclusion can be specifically explained as follows:

[0080] The difference between the actual received signal and the ideal received signal can be expressed as follows: in The calculation results in S122 are the same as is closer to 0, so when the actual received signal at point N is When the value of is 0, we can conclude The conclusion. The calculation results in S122 are the same as is closer to 1, so when the actual received signal at point N is When the value of is 1, we can conclude Therefore, we only need to keep and The signals reconstructed by these two Gaussian filters can be used as ideal reference signals. Can be used as the first ideal reference signal, The ideal reference signal can be used as the second ideal reference signal. The ideal reference signal is used as the reference signal of the actual received signal. After the judgment mentioned in S14 is made according to the ideal reference signal, the value of the demodulated actual received signal can be known.

[0081] S14: Making a decision according to the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target time.

[0082] In order to complete the decision process for the actual received signal, it is first necessary to calculate the first absolute value of the difference between the actual received signal and the first ideal reference signal in the ideal reference signal, and also to calculate the second absolute value of the difference between the actual received signal and the second ideal reference signal in the ideal reference signal. Then calculate the difference between the first absolute value and the second absolute value. Finally, determine whether the difference is greater than the preset threshold value; if greater, determine that the demodulated value of the actual received signal is 1, otherwise, determine that the demodulated value of the actual received signal is 0. The "first" and "second" mentioned in the first ideal reference signal and the second ideal reference signal mentioned above do not indicate that there is a sequence relationship between the two, or that the importance is different, but are only a way to distinguish between the two ideal reference signals.

[0083] That is, finally, according to the difference between the received signal and the ideal signal and To determine whether the demodulated value of the actual received signal is 0 or 1, The received signal is compared with the threshold value. If it is greater than the threshold value, the actual received signal is judged as 1; if it is not less than the threshold value, the actual received signal is judged as 0.

[0084] In this embodiment, an ideal received signal is constructed, and then the first ideal reference signal and the second ideal reference signal in the ideal received signal are used as ideal reference signals. Finally, according to the difference between the actual received signal and the ideal reference signal, the value of the actual received signal is judged to be 0 or 1. In this way, the reconstruction of the signal is completed by using the three points in the Gaussian filter, an ideal received signal is constructed, and then two of the signals are taken as reference signals. By calculating the difference between the actual received signal and the ideal reference signal, it is finally judged that the value of the actual received signal is 0 or 1. Compared with the prior art, the number of reconstructed signals is simplified, and the judgment process is simplified, which can save computing resources.

[0085] In an embodiment of the present application, a signal demodulation device is also provided. Figure 4 Schematic diagram of a signal demodulation device. Figure 4 As shown, the signal demodulation device specifically includes:

[0086] A signal construction module 100, configured to construct a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time, wherein the second target time is later than the first target time, and the third target time is later than the second target time;

[0087] A first signal acquisition module 200, configured to obtain a plurality of ideal received signals at the second target moment according to a plurality of values ​​of the received signal at the second target moment and the received signal at the third target moment;

[0088] A second signal acquisition module 300, configured to determine a first ideal reference signal and a second ideal reference signal corresponding to the second target moment from a plurality of ideal received signals at the second target moment;

[0089] The demodulated signal acquisition module 400 is used to obtain the demodulated actual received signal at the second target time according to the first ideal reference signal and the second ideal reference signal.

[0090] In an achievable manner, the signal construction module 100 is specifically used for:

[0091] Based on the received signal at the first target time, construct and obtain the received signal at the second target time, where the value of the received signal at the second target time is 0 or 1;

[0092] Based on the constructed received signal at the second target moment, the received signal at the third target moment is constructed and obtained, and the value of the received signal at the third target moment is 0 or 1.

[0093] In an achievable manner, the first signal acquisition module 200 is specifically used to:

[0094] Combining different values ​​of the constructed received signal at the second target moment and the constructed received signal at the third target moment, wherein a value of the received signal at the second target moment in the combination corresponds to a value of the received signal at the third target moment;

[0095] The combined value of the received signal at the second target moment and the value of the received signal at the third target moment are weighted and then summed to obtain a plurality of ideal received signals at the second target moment.

[0096] In an achievable manner, the second signal acquisition module 300 is specifically used to:

[0097] Determine, among the multiple ideal received signals at the second target time, an ideal received signal calculated when the value of the received signal at the second target time is 0 and the value of the received signal at the third target time is 1 as a first ideal reference signal;

[0098] Among the multiple ideal received signals at the second target moment, the ideal received signal calculated corresponding to the value of the received signal at the second target moment being 1 and the value of the received signal at the third target moment being 0 is determined as the second ideal reference signal.

[0099] In an achievable manner, the demodulated signal acquisition module 400 is specifically used for:

[0100] Calculating a first absolute value of a difference between the first ideal reference signal and the actual received signal;

[0101] Calculating a second absolute value of a difference between the second ideal reference signal and the actual received signal;

[0102] calculating a difference between the first absolute value and the second absolute value;

[0103] Determine the relationship between the difference between the first absolute value and the second absolute value and a preset threshold value;

[0104] If the difference between the first absolute value and the second absolute value is greater than the preset threshold value, the actual received signal at the second target time after demodulation is 1;

[0105] If the difference between the first absolute value and the second absolute value is not less than the preset threshold value, the actual received signal at the second target time after demodulation is 0.

[0106] In an achievable manner, the device further includes a frequency offset elimination module 500, which is specifically configured to eliminate the frequency offset value of the actual received signal before demodulating the actual received signal.

[0107] In this embodiment, a signal demodulation device is provided, by which the complexity of signal reconstruction can be reduced while determining the value of the demodulated actual received signal.

[0108] This application also proposes a signal demodulation process in a practical application scenario. Figure 5 It is a signal demodulation flow chart in the application scenario, such as Figure 5 As shown, the signal demodulation process in the application scenario is specifically as follows:

[0109] First, the frequency offset value of the actual received signal is eliminated before demodulating the actual received signal, and then the actual received signal is reconstructed to construct the ideal received signal. and The specific construction process can be as follows: Since the signal of the previous moment of the actual received signal is known, the possible value of the actual received signal at the corresponding moment can be constructed as 0 or 1 according to the known signal. According to the constructed value of the actual received signal at the corresponding moment, the value of the received signal at the next moment of the actual received signal can be constructed. According to the value of the actual received signal at the moment and the value of the actual received signal at the next moment, the ideal received signal can be obtained through weighted calculation of the above values. Then, the difference between the actual received signal and the above two ideal received signals is calculated respectively. and For the difference and After taking the absolute value, determine the difference in the absolute value of the difference Is it greater than the threshold value? If so, the corresponding value of the actual received signal after demodulation is determined to be 1; otherwise, the corresponding value of the actual received signal after demodulation is determined to be 0.

[0110] The embodiments of the present application also provide corresponding devices and computer-readable storage media for implementing the solutions provided by the embodiments of the present application.

[0111] The device includes a memory and a processor, the memory is used to store instructions or codes, and the processor is used to execute the instructions or codes so that the device executes a signal demodulation method described in any embodiment of the present application.

[0112] In practical applications, the computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0113] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0114] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0115] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0116] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0117] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A signal demodulation method, characterized in that: include: Constructing a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time, wherein the second target time is later than the first target time, and the third target time is later than the second target time; Obtaining multiple ideal received signals at the second target moment according to multiple values ​​of the received signal at the second target moment and the received signal at the third target moment; Determine a first ideal reference signal and a second ideal reference signal corresponding to the second target time from a plurality of ideal received signals at the second target time; Making a decision according to the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target time; The determining according to the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target time comprises: Calculating a first absolute value of a difference between the first ideal reference signal and the actual received signal; Calculating a second absolute value of a difference between the second ideal reference signal and the actual received signal; calculating a difference between the first absolute value and the second absolute value; Determine the relationship between the difference between the first absolute value and the second absolute value and a preset threshold value; If the difference between the first absolute value and the second absolute value is greater than the preset threshold value, the actual received signal at the second target time after demodulation is 1; If the difference between the first absolute value and the second absolute value is not less than the preset threshold value, the actual received signal at the second target time after demodulation is 0.

2. The method according to claim 1, characterized in that The step of constructing a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time includes: Based on the received signal at the first target time, construct and obtain the received signal at the second target time, where the value of the received signal at the second target time is 0 or 1; Based on the constructed received signal at the second target moment, the received signal at the third target moment is constructed and obtained, and the value of the received signal at the third target moment is 0 or 1.

3. The method according to claim 1, characterized in that The obtaining of multiple ideal received signals at the second target moment according to multiple values ​​of the received signal at the second target moment and the received signal at the third target moment comprises: Combining different values ​​of the constructed received signal at the second target moment and the constructed received signal at the third target moment, wherein a value of the received signal at the second target moment in the combination corresponds to a value of the received signal at the third target moment; The combined value of the received signal at the second target moment and the value of the received signal at the third target moment are weighted and then summed to obtain a plurality of ideal received signals at the second target moment.

4. The method according to claim 3, characterized in that The determining, from a plurality of ideal received signals at the second target time, a first ideal reference signal and a second ideal reference signal corresponding to the second target time, comprises: Determine, among the multiple ideal received signals at the second target time, an ideal received signal calculated when the value of the received signal at the second target time is 0 and the value of the received signal at the third target time is 1 as a first ideal reference signal; Among the multiple ideal received signals at the second target moment, the ideal received signal calculated corresponding to the value of the received signal at the second target moment being 1 and the value of the received signal at the third target moment being 0 is determined as the second ideal reference signal.

5. The method according to claim 1, characterized in that The method further comprises: Before demodulating the actual received signal, the frequency offset value of the actual received signal is eliminated.

6. A signal demodulation device, characterized in that: The device comprises: A signal construction module, configured to construct a received signal at a second target time and a received signal at a third target time based on a received signal at a first target time, wherein the second target time is later than the first target time, and the third target time is later than the second target time; A first signal acquisition module, configured to obtain a plurality of ideal received signals at the second target moment according to a plurality of values ​​of the received signal at the second target moment and the received signal at the third target moment; A second signal acquisition module, configured to determine a first ideal reference signal and a second ideal reference signal corresponding to the second target moment from a plurality of ideal received signals at the second target moment; A demodulated signal acquisition module, used to make a decision based on the first ideal reference signal and the second ideal reference signal to obtain a demodulated actual received signal at the second target moment; The demodulated signal acquisition module is specifically used for: Calculating a first absolute value of a difference between the first ideal reference signal and the actual received signal; Calculating a second absolute value of a difference between the second ideal reference signal and the actual received signal; calculating a difference between the first absolute value and the second absolute value; Determine the relationship between the difference and a preset threshold value; If the difference is greater than the preset threshold value, the actual received signal at the second target time after demodulation is 1; If the difference is not less than the preset threshold value, the actual received signal at the second target time after demodulation is 0.

7. The device according to claim 6, characterized in that The signal construction module is specifically used for: Based on the received signal at the first target time, construct and obtain the received signal at the second target time, where the value of the received signal at the second target time is 0 or 1; Based on the constructed received signal at the second target moment, the received signal at the third target moment is constructed and obtained, and the value of the received signal at the third target moment is 0 or 1.

8. The device according to claim 6, characterized in that The second signal acquisition module is specifically used to: When the value of the received signal at the second target time in the ideal received signal is 0, the value of the received signal at the third target time is 1 as the first ideal reference signal; When the value of the received signal at the second target moment in the ideal received signal is 1, the signal whose value at the third target moment is 0 is used as the second ideal reference signal.

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