Signal detection method, signal processing method and signal processing model
The present disclosure relates to the technical field of signal detection, and specifically, provides a signal detection method, a signal processing method, and a signal processing model. The signal detection method includes: preprocessing a signal, namely processing a signal point in a signal segment, to obtain a processed value of the signal point; and detecting whether the processed value exceeds a specified overflow threshold range, to select a different reprocessing method based on a detection result of the processed value. Especially in a detection process before signal reprocessing, the signal can be processed in a targeted manner based on the detection result of the processed value, thereby effectively improving a processing effect of the signal.
1 . A signal detection method, comprising:
preprocessing a signal, namely processing a signal point in a signal segment, to obtain a processed value of the signal point; and
detecting whether the processed value exceeds a specified overflow threshold range, to select a different reprocessing method based on a detection result of the processed value,
wherein selecting the different reprocessing method based on the detection result of the processed value comprises:
when the processed value of the signal point exceeds the specified overflow threshold range, performing mapping encoding on the processed value of the signal point, wherein the mapping encoding comprises:
performing N iterative mapping operations on the processed value of the signal point until the processed value of the signal point is within the specified overflow threshold range, obtaining a mapped marker and a mapped value, and encoding the signal point into N mapped markers+M mapped values, wherein M represents a type of the mapped value, and M≥1.
2 . The signal detection method according to claim 1 , wherein:
the processed value is a filtered value, or a residual value measured by a signal preprocessing model for the signal point; and
the signal preprocessing model comprises any one of an autoregressive (AR) model, a single-point differencing model, a periodic differencing model, or a model combining single-point differencing and periodic differencing, wherein
when the signal is free from periodic interference and has a high sampling rate, the single-point differencing model is used to measure the residual value of the signal point;
when the signal has periodic interference, the periodic differencing model is used to measure the residual value of the signal point; and
when the signal has periodic interference and a high sampling rate, the model combining the single-point differencing and the periodic differencing is used to measure the residual value of the signal point.
3 . The signal detection method according to claim 2 , wherein:
the residual value of the signal point measured according to the single-point differencing model is calculated by: residual value single-point differencing =original value of a current signal point−original value of a previous signal point;
the residual value of the signal point measured according to the periodic differencing model is calculated by: residual value periodic differencing =original value of a current periodic segment−J×estimated value of the current periodic segment, wherein the estimated value of the current periodic segment=original value of a previous periodic segment, and J represents a coefficient; and
the residual value of the signal point measured according to the model combining the single-point differencing and the periodic differencing is obtained by: combining the signal point into a plurality of periodic segments and measuring the residual value based on the periodic differencing, namely residual value combined differencing =residual value periodic differencing (k)−residual value periodic differencing (k−1), wherein k=2, 3, . . . , and K.
4 . The signal detection method according to claim 1 , wherein:
the signal detection method further comprises: performing phase detection on the signal segment before preprocessing the signal; and
the phase detection comprises:
performing processing by sliding a window;
detecting a fluctuation of the signal within the window; and
detecting a phase of the signal based on a fluctuation result of the signal within the window.
5 . The signal detection method according to claim 4 , wherein:
the fluctuation result of the signal within the window is represented as any one of a variance and a mean of the signal within the window, and a normalized line length of the signal within the window;
detecting the phase of the signal based on the variance and the mean of the signal within the window comprises:
measuring the variance and the mean of the signal within the window; and
determining that a signal segment with the variance not less than a second threshold is in a fluctuating phase, and determining that a signal segment with the variance less than the second threshold is in a stationary phase; and
detecting the phase of the signal based on the normalized line length of the signal within the window comprises:
obtaining the normalized line length, namely measuring an average absolute value of a first-order difference of the signal within the window as follows:
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wherein, A represents a quantity of signal points within the window, x(a) represents an a th signal point within the window, and a=1, 2, . . . , and A−1; and
determining that a signal segment with the normalized line length exceeding an overflow threshold is in the fluctuating phase, and determining that a signal segment with the normalized line length not exceeding the overflow threshold is in the stationary phase.
6 . A signal processing method based on the signal detection method according to claim 1 , wherein:
when M=1, the N iterative mapping operations each comprise a subtraction operation; and
when M=2, the N iterative mapping operations each comprise any one of a logarithmic operation or a quotient-remainder operation.
7 . The signal processing method according to claim 6 , wherein:
the subtraction operation is to subtract an overflow threshold from the processed value of the signal point; and when the mapped value is a difference obtained from a last subtraction operation, the signal point is encoded into the N mapped markers+the difference.
8 . The signal processing method according to claim 6 , wherein:
the logarithmic operation is Z=log 2 (D), wherein D represents the processed value, and the mapped value is a floating-point value Z obtained from a last logarithmic operation, with an integer part of the floating-point value Z being int(Z) and a decimal part of the floating-point value Z being Z-int(Z); and the signal point is encoded into the N mapped markers+the int(Z)+the Z-int(Z); and
the quotient-remainder operation is to divide the processed value of the signal point by an overflow threshold, and the mapped value is a quotient value Q obtained from a last quotient-remainder operation and N remainders C obtained from N quotient-remainder operations; and the signal point is encoded into the N mapped markers+the quotient value Q+the N remainders C.
9 . The signal processing method according to claim 7 , wherein:
the specified overflow threshold range is determined by the overflow threshold, wherein the overflow threshold is −2 n−1 or 2 n−1 , n represents an expected code bit width, and the specified overflow threshold range is (−2 n−1 , 2 n−1 );
an n-bit overflow rate of a signal segment is set to be equal to a value of dividing a quantity of signal points with processed values exceeding the specified overflow threshold range in the signal segment by a total quantity of signal points in the signal segment;
when the signal segment is in a stationary phase and the n-bit overflow rate of the signal segment is less than a first threshold, mapping encoding based on the subtraction operation is selected to encode the processed value;
when the signal segment is in a fluctuating phase and an average information entropy of the signal segment is less than a specified entropy threshold, mapping encoding based on the logarithmic operation is selected to encode the processed value; and
when the signal segment is in the fluctuating phase and the average information entropy of the signal segment is not less than the specified entropy threshold, or when the signal segment is in the stationary phase and the n-bit overflow rate of the signal segment is greater than the first threshold, mapping encoding based on the quotient-remainder operation is selected to encode the processed value.
10 . The signal processing method according to claim 1 , wherein:
the selecting the different reprocessing method based on the detection result of the processed value further comprises: performing secondary encoding on a signal point obtained after the mapping encoding or a signal point with a processed value that does not exceed the specified overflow threshold range, wherein
the secondary encoding comprises at least one of Huffman encoding, a variant of the Huffman encoding, arithmetic encoding, a variant of the arithmetic encoding, range encoding, a variant of the range encoding, or asymmetric digital systematic encoding.
11 . A signal processing model, comprising:
a processing module configured to execute the signal processing method according to claim 6 ; and
a storage module configured to store a processed signal.