A signal clipping method, device and CFR

Abstract

The present invention discloses a signal clipping method, comprising: generating a first detection signal from a signal to be clipped; judging whether the first detection signal is greater than a preset threshold; generating a first control enable signal when the first detection signal is not greater than the preset threshold, and controlling an N-times-speed upsampling module of a current CFR not to perform filtering operation according to the first control enable signal; generating a second control enable signal when the first detection signal is greater than the preset threshold, and controlling an N-times-speed upsampling module of the current CFR to output a specific N-times-speed upsampling signal of the signal to be clipped according to the second control enable signal; sending the signal to be detected after being upsampled by the N-times-speed upsampling module to a peak detection module in the current CFR for peak detection; and sending the detected peak information of the signal to be clipped to a CPG control module in the current CFR, so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped.

Description

Technical Field

[0001] The present invention relates to the field of signals, and further to a signal clipping method, device and CFR. Background Art

[0002] In the prior art, the N-times upsampling module in each stage of CFR is always working, resulting in very high power consumption of the N-times upsampling module. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a signal clipping method, device and CFR, which significantly reduce the power consumption of the N-times speed upsampling module and improve the working efficiency.

[0004] Specifically, the technical solution of the present invention is as follows:

[0005] A signal clipping method comprises the steps of:

[0006] The signal to be clipped generates a first detection signal;

[0007] Determining whether the first detection signal is greater than a preset threshold;

[0008] When the first detection signal is not greater than a preset threshold, a first control enable signal is generated, and the N-times speed upsampling module of the current CFR is controlled not to perform filtering operation according to the first control enable signal;

[0009] When the first detection signal is greater than a preset threshold, a second control enable signal is generated, and according to the second control enable signal, an N-fold speed upsampling module of the current CFR is controlled to perform filtering operation on some sample points of the signal to be clipped, and a specific N-fold speed upsampling signal is output;

[0010] Sending the signal to be detected after being upsampled by the N-times speed upsampling module to the peak detection module in the current CFR for peak detection;

[0011] The detected peak value information of the signal to be clipped is sent to the CPG control module in the current CFR, so that the CPG control module allocates idle clipping pulses to clip the peak value of the signal to be clipped.

[0012] In some implementations, after determining whether the first detection signal is greater than a preset threshold, the following steps are specifically included:

[0013] When the first detection signal is not greater than a preset threshold, controlling the current low-pass filter not to perform filtering operation according to the first control enable signal;

[0014] When the first detection signal is greater than a preset threshold, controlling the current low-pass filter to perform filtering operation on some samples of the signal to be clipped according to the second control enable signal;

[0015] The signal upsampled by the current low-pass filter is sent to the next low-pass filter.

[0016] In some implementations, after sending the signal upsampled by the current low-pass filter to the next-stage low-pass filter, the method further includes the following steps:

[0017] According to the first control enable signal or the second control enable signal, the current low-pass filter is controlled to output a corresponding signal.

[0018] In some implementations, after sending the signal upsampled by the current low-pass filter to the next-stage low-pass filter, the method further includes the following steps:

[0019] Generate a second detection signal through the signal sampled by the previous low-pass filter;

[0020] It is determined whether the second detection signal is greater than a preset threshold, and a third control enable signal is generated to control the current low-pass filter to output a corresponding signal.

[0021] In some embodiments, it is characterized in that after the detected peak information of the signal to be clipped is sent to the CPG control module in the current CFR so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped, the step further includes:

[0022] If the peak value of the signal to be clipped is allocated with the idle clipping pulse, generating a first control signal;

[0023] If the peak value of the signal to be clipped is not allocated with the idle clipping pulse, generating a second control signal;

[0024] The first control signal and / or the second control signal are sent to a next-stage CFR, so that the next-stage CFR clips the clipped signal to be clipped according to the first control signal and / or the second control signal.

[0025] In some implementations, after the signal to be clipped generates a first detection signal and before determining whether the first detection signal is greater than a preset threshold, the process further includes the following steps:

[0026] The sample points in the first detection signal whose amplitude is smaller than the coarse detection threshold are screened out by the coarse detection module.

[0027] In some implementations, the preset thresholds corresponding to each level of low-pass filters are independent of each other.

[0028] The present invention also provides a signal clipping device, comprising:

[0029] A generating unit, configured to generate a first detection signal from a signal to be clipped;

[0030] A judging unit, configured to judge whether the first detection signal is greater than a preset threshold;

[0031] The generating unit is further configured to generate a first control enable signal when the first detection signal is not greater than a preset threshold;

[0032] A control unit, configured to control the N-times-speed upsampling module of the current CFR not to perform filtering operation according to the first control enable signal;

[0033] The generating unit is further configured to generate a second control enable signal when the first detection signal is greater than a preset threshold;

[0034] The control unit is further used to control the N-times-speed up-sampling module of the current CFR to perform filtering operation on some samples of the signal to be clipped according to the second control enable signal;

[0035] A sending unit, used for sending the signal to be detected after being upsampled by the N-times speed upsampling module to the peak detection module in the current CFR for peak detection;

[0036] The sending unit is further used to send the detected peak information of the signal to be clipped to the CPG control module in the current CFR, so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped.

[0037] In some embodiments,

[0038] The control unit is further configured to control the current low-pass filter not to perform filtering operation according to the first control enable signal when the first detection signal is not greater than a preset threshold;

[0039] The control unit is further configured to control the current low-pass filter to perform filtering operation on some samples of the signal to be clipped according to the second control enable signal when the first detection signal is greater than a preset threshold;

[0040] The sending unit is also used to send the signal upsampled by the current low-pass filter to the next-stage low-pass filter.

[0041] The present invention also provides a CFR for clipping a signal to be clipped, wherein the signal to be clipped generates a cancellation signal of the peak value of the signal to be clipped through the signal clipping method described in the aforementioned embodiment, and the cancellation signal of the peak value of the signal to be clipped is added to the signal to be clipped to obtain the clipped signal to be clipped.

[0042] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0043] 1. By generating a control enable signal, the low-pass filter performs filtering operations on specific samples only when the control enable signal is valid. The N-times upsampling module outputs samples that may exceed the clipping threshold, which significantly reduces the power consumption of filtering operations in the N-times upsampling module.

[0044] 2. By generating a control signal through the previous CFR, the N-times upsampling module in the next CFR only needs to calculate and generate a control enable signal in the area corresponding to the control signal to control the filtering operation of the low-pass filter, further reducing the power consumption of the N-times upsampling module.

[0045] 3. When multiple low-pass filters are cascaded, all low-pass filters can control the low-pass filters to output the corresponding signal of the signal to be sampled according to the control signal generated by the first-stage low-pass filter; or each stage of the low-pass filter can be set with its own control signal to control the output of the corresponding signal of the signal to be sampled. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0047] Figure 1 is a flow chart of an embodiment of a signal clipping method of the present invention;

[0048] Figure 2 is a flow chart of an embodiment of a signal clipping method of the present invention;

[0049] Figure 3 is a schematic diagram of an embodiment of a signal clipping method of the present invention;

[0050] Figure 4 is a schematic diagram of an embodiment of a signal clipping method of the present invention;

[0051] Figure 5 is a schematic diagram of an embodiment of a signal clipping method of the present invention;

[0052] Figure 6 is a schematic diagram of an embodiment of a signal clipping method of the present invention;

[0053] Figure 7 is a simplified structural diagram of an embodiment of a signal clipping method of the present invention;

[0054] Figure 8 is a simplified structural diagram of an embodiment of a signal clipping method of the present invention;

[0055] Fig. 9 is a simplified structural diagram of an embodiment of a signal clipping method of the present invention;

[0056] Fig.10 is a simplified structural diagram of an embodiment of a signal clipping method of the present invention;

[0057] Fig.11 is a simplified structural diagram of an embodiment of a signal clipping method of the present invention;

[0058] Fig.12 is a simplified structural diagram of an embodiment of a signal clipping method of the present invention;

[0059] Fig.13 It is a simplified structural diagram of another embodiment of a signal clipping method of the present invention. DETAILED DESCRIPTION

[0060] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0061] In order to simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0062] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0063] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0065] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

[0066] In one embodiment, Figure 1 As shown, the present invention provides a signal clipping method, characterized in that it includes the steps of:

[0067] S100: The signal to be clipped generates a first detection signal.

[0068] S110, determining whether the first detection signal is greater than (or greater than or equal to) a preset threshold, and generating a control enable signal.

[0069] S120, when the control enable signal is invalid (for example, 0), the N-times-speed upsampling module of the current CFR is controlled to operate in an extremely low power consumption mode (no filtering operation is performed).

[0070] S130, when the control enable signal is valid (eg, 1), the N-times speed upsampling module of the current CFR is controlled to operate in a low power consumption mode (a small number of samples are filtered to generate a specific N-times speed upsampling signal).

[0071] Specifically, when the N-times upsampling module is implemented by HBF (Half Band Lowpass Filter): the signal to be clipped generates a first detection signal. If the first detection signal is greater than (or greater than or equal to) a preset threshold, the control enable signal is valid, that is, the control enable signal is specified as the second control enable signal. Otherwise, the control enable signal is invalid, that is, the control enable signal is specified as the first control enable signal.

[0072] When the control enable signal is invalid, the N-speed upsampling module in the current CFR does not perform filtering operations. In fact, the odd paths of the HBF in the N-speed upsampling module do not perform filtering operations (odd paths output 0). The even paths of the HBF output normally, and the even paths do not need filtering operations.

[0073] When the control enable signal is valid, the N-times upsampling module in the current CFR performs filtering operations on some samples of the clipping signal. In fact, the odd paths of the HBF in the N-times upsampling module perform filtering operations at specific times, and do not perform filtering operations at other times (odd paths output 0). The even paths of the HBF output normally, and the even paths do not need filtering operations. Thus, a specific N-times upsampling signal is generated.

[0074] S140, sending the signal to be detected after being upsampled by the N-times speed upsampling module to the peak detection module in the current CFR for peak detection.

[0075] S150, sending the detected peak information of the signal to be clipped to the CPG control module in the current CFR, so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped.

[0076] Specifically, the sample points less than the clipping threshold in the up-sampled signal to be detected are screened out by the coarse detection module, and the signal to be detected after the coarse detection is sent to the peak detection module in the current CFR for peak detection.

[0077] Further, the detected peak information of the signal to be clipped (for example, peak position, amplitude, phase, etc.) is sent to the CPG control module, wherein the CPG control module contains a clipping pulse (actually a prototype clipping pulse, which is used to generate a 1x speed cancellation signal according to the position, amplitude and phase of the peak information, and the cancellation signal is added to the signal to be clipped to obtain the clipped signal to be clipped, which means the clipping is completed). If the CPG control module contains an idle clipping pulse, the idle clipping pulse is allocated to clip the peak value. If it does not contain an idle clipping pulse, the signal to be clipped enters the next level CFR for clipping.

[0078] In one embodiment, the present invention provides a signal clipping method, wherein the N-times-speed upsampling module includes at least one low-pass filter. Based on the above embodiment, after determining whether the first detection signal is greater than (or greater than or equal to) a preset threshold and generating a control enable signal, the method specifically includes the following steps:

[0079] When the control enable signal is invalid (ie, the control enable signal is specified as the first control enable signal), the current low-pass filter does not perform filtering operation.

[0080] When the control enable signal is valid (ie, the control enable signal is specified as the second control enable signal), the current low-pass filter performs a filtering operation on the specific sample point.

[0081] The signal upsampled by the current low-pass filter is sent to the next low-pass filter.

[0082] Specifically, the N-times speed upsampling module is composed of a number of low-pass filters connected in series, and these low-pass filters can be 2x speed, 3x speed or other speeds, etc. Therefore, assuming that HBF is used to implement 2x speed upsampling, before the signal to be clipped enters the first-stage HBF for upsampling, the signal to be clipped generates a first detection signal, and then generates a control enable signal based on the first detection signal and a preset threshold.

[0083] When the control enable signal is invalid, the odd paths of HBF do not perform filtering operations (odd paths output 0). The even paths of HBF output normally, and the even paths do not need filtering operations.

[0084] When the control enable signal is valid, the odd path of HBF performs filtering operation at a specific time, and does not perform filtering operation at other times (odd path outputs 0). The even path of HBF outputs normally, and the even path does not need filtering operation. Thus, a specific N-times speed upsampling signal is generated.

[0085] Furthermore, according to the control enable signal, the signal to be clipped is sent to the next HBF after being upsampled by the nth HBF to continue upsampling, that is, the n+1th level generates a second detection signal for the signal after the nth HBF is upsampled, and determines whether the second detection signal is greater than (greater than or equal to) a preset threshold, and generates a corresponding third control enable signal. When the third control enable signal is valid, the odd path of the n+1th HBF performs filtering operations at specific times, and does not perform filtering operations at other times (the odd path outputs 0).

[0086] When the third control enable signal is invalid, the odd paths of the n+1th HBF do not perform filtering operations (odd paths output 0). The even paths of the HBF output normally, and the even paths do not need filtering operations.

[0087] Furthermore, before determining the first detection signal or the second detection signal, the coarse detection module filters out the samples in the first detection signal whose amplitude is smaller than the coarse detection threshold, and calculates the modulus of the first or second detection signal after the coarse detection.

[0088] The signal output by the N-times speed upsampling module enters the subsequent coarse detection module, peak detection module, etc. for clipping.

[0089] In one embodiment, Figure 2As shown, the present invention provides a signal clipping method, which is applied to multi-level CFR. On the basis of the above embodiment, after the detected peak information of the signal to be clipped is sent to the CPG control module in the current CFR so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped, the method further includes the steps of:

[0090] S200 , if the peak value of the signal to be clipped is allocated with an idle clipping pulse, a first control signal is generated.

[0091] S210: If the peak of the signal to be clipped is not allocated with an idle clipping pulse, generate a second control signal.

[0092] S220, sending the first control signal and / or the second control signal to the next stage CFR, so that the next stage CFR clips the clipped signal to be clipped according to the first control signal and / or the second control signal.

[0093] Specifically, if the peak value of the signal to be clipped is allocated with an idle clipping pulse, a corresponding first control signal for allocating an idle clipping pulse peak value is generated.

[0094] Furthermore, if the peak of the signal to be clipped is not allocated with an idle clipping pulse, a corresponding second control signal of the unallocated idle clipping pulse peak is generated. The areas of the first control signal and the second control signal may be the same or different. In actual situations, in order to save clipping power consumption, the area of ​​the second search window is smaller than the area of ​​the first search window.

[0095] Furthermore, the current CFR sends the first control signal and / or the second control signal to the next-level CFR. The low-power N-fold upsampling module of the next-level CFR only needs to generate the first detection signal and the control enable signal in the area corresponding to the first control signal and / or the second control signal. The control enable signal in other areas is invalid, thereby further reducing the power consumption of the low-power N-fold upsampling module.

[0096] When the previous stage CFR does not generate the first control signal and / or the second control signal, the low power consumption N-fold up-sampling module, the first detection signal and the control enable signal of the next stage CFR need to work all the time.

[0097] In one embodiment, the present invention provides a signal clipping method, which, based on the above embodiment, further includes the steps of:

[0098] Figure 3 It is a traditional implementation of a 1-stage HBF (Half Band Lowpass Filter). Figure 4 The coefficients of the 11-tap HBF.

[0099] When using 1-level HBF to achieve 2x upsampling, one method A is:

[0100] HBF inputs complex signal X(n), calculates A(2n+1)=X(n)+X(n+1), calculates

[0101] B(2n+1)=|A(2n+1)| k , where |A| represents the amplitude of the complex signal A, |A| k It represents the calculation of |A| to the power of k, where k is usually 1 or 2. Only when B(2n+1) exceeds the threshold, the odd path Y(2n+1) may exceed the clipping threshold.

[0102] When B(2n+1) is greater than (or greater than or equal to) the set threshold value Threshold, the control enable signal C(2n+1)=1, otherwise the control enable signal C(2n+1)=0.

[0103] When C(2n+1)=1, the odd path Y(2n+1) of HBF is filtered (multiplication / addition is performed normally) and the correct odd path Y(2n+1) is output.

[0104] When C(2n+1)=0, the odd path Y(2n+1) of HBF does not perform filtering operation (no multiplication / addition operation), and the output Y(2n+1)=0.

[0105] The even path Y(2n) of HBF is always output. The even path does not require filtering operation, and the power consumption of the even path is much smaller than that of the odd path.

[0106] Traditional HBF does not calculate A / B / C signals, but the odd paths always perform filtering operations, which consumes a lot of power. The cost of calculating A / B / C signals is much less than the filtering operation of the odd paths Y(2n+1). By controlling the enable signal C, only a few odd paths Y(2n+1) perform filtering operations, and most odd paths Y(2n+1) do not perform filtering operations. This significantly reduces the power consumption of HBF.

[0107] Furthermore, when using 1-level HBF to achieve 2x upsampling, another method B is:

[0108] HBF inputs complex signal X(n) and calculates A(2n+1)=(X(n)+X(n+1))*3–

[0109] (X(n-1)+X(n+2)), calculate B(2n+1)=|A(2n+1)| k , where |A| represents the amplitude of the complex signal A, |A| k It represents the calculation of |A| to the power of k, where k is usually 1 or 2. Only when B(2n+1) exceeds the threshold, the odd path Y(2n+1) may exceed the clipping threshold.

[0110] When B(2n+1) is greater than (or greater than or equal to) the set threshold value Threshold, the control enable signal C(2n+1)=1, otherwise the control enable signal C(2n+1)=0.

[0111] When C(2n+1)=1, the odd path Y(2n+1) of HBF is filtered (multiplication / addition is performed normally) to generate the correct odd path Y(2n+1).

[0112] When C(2n+1)=0, the odd path Y(2n+1) of HBF does not perform filtering operation (no multiplication / addition operation), and the output Y(2n+1)=0.

[0113] The even path Y(2n) of HBF is always output. The even path does not require filtering operation, and the power consumption of the even path is much smaller than that of the odd path.

[0114] Traditional HBF does not calculate A / B / C signals, but the odd paths always perform filtering operations, which consumes a lot of power. The cost of calculating A / B / C signals is much less than the filtering operation of the odd paths Y(2n+1). By controlling the enable signal C, only a few odd paths Y(2n+1) perform filtering operations, and most odd paths Y(2n+1) do not perform filtering operations. This significantly reduces the power consumption of HBF.

[0115] Further, such as Figure 6 As shown, when a 1-stage low-pass filter (even number of taps) is used to filter an N-fold upsampled signal, one method C is:

[0116] Input complex signal X(n), calculate A(N)=X(n)+X(n+1), calculate B(N)=|A(N)| k , where |A| represents the amplitude of the complex signal A, |A| k It represents the calculation of |A| to the kth power, where k is usually 1 or 2. Only when B(N) exceeds the threshold can the output Y(N) of the low-pass filter exceed the clipping threshold.

[0117] When B(N) is greater than (or greater than or equal to) a set threshold value Threshold, the control enable signal C(N)=1, otherwise the control enable signal C(N)=0.

[0118] When C(N)=1, the output Y(N) of the low-pass filter is filtered to generate the correct output Y(N).

[0119] When C(N)=0, the output Y(N) of the low-pass filter does not undergo filtering operation (no multiplication / addition operation is performed), and the output Y(N)=0.

[0120] Further, such as Figure 5As shown, when a 1-stage low-pass filter (odd number of taps) is used to filter the N-fold upsampled signal, another method D is:

[0121] Input complex signal X(n), calculate A(N)=X(n)*4+(X(n-1)+X(n+1))*3, calculate B(N)=|A(N)| k , where |A| represents the amplitude of the complex signal A, |A| k It represents the calculation of |A| to the kth power, where k is usually 1 or 2. Only when B(N) exceeds the threshold can the output Y(N) of the low-pass filter exceed the clipping threshold.

[0122] When B(N) is greater than (or greater than or equal to) a set threshold value Threshold, the control enable signal C(N)=1, otherwise the control enable signal C(N)=0.

[0123] When C(N)=1, the output Y(N) of the low-pass filter is filtered to generate the correct output Y(N).

[0124] When C(N)=0, the output Y(N) of the low-pass filter does not undergo filtering operation (no multiplication / addition operation is performed), and the output Y(N)=0.

[0125] In one embodiment, the present invention provides a low-power N-fold upsampling method, which, based on the above embodiment, further includes the following steps:

[0126] like Figure 7 As shown, the control signal C required by the above-mentioned methods A / B / C / D can be generated.

[0127] Specifically, generate A module and generate A.

[0128] For example, when using 1-stage HBF to achieve 2x upsampling, A(2n+1)=X(n)+X(n+1) or A(2n+1)=(X(n)+X(n+1))*3–(X(n-1)+X(n+2)) or

[0129] A(2n+1)=(X(n)+X(n+1))*6–(X(n-1)+X(n+2))*2+(X(n-2)+X(n+3)) or other methods to calculate A.

[0130] Further, a B module is generated, generating B = |A| k

[0131] For example, when k=1, B=|A|, and the amplitude of the complex signal A can be calculated using cordic or other methods.

[0132] When k=2, B=|A| 2, to calculate the power of the complex signal A, it can be done with B = (the real part of A) 2 +(the imaginary part of B) 2 and it can also be implemented in other ways.

[0133] Furthermore, generate module C to generate C.

[0134] For example, when implementing 2x upsampling with 1-stage HBF, when B(2n + 1) is greater than (or greater than or equal to) the set threshold Threshold, control the enable signal C(2n + 1) = 1, otherwise C(2n + 1) = 0.

[0135] Furthermore, a coarse detection module (an optional module) is used to further reduce the power consumption of subsequent modules.

[0136] For example, when implementing 2x upsampling with 1-stage HBF and k = 1,

[0137] when [|real(A)| < Threshold / sqrt(2)] and [|imag(A)| < Threshold / sqrt(2)], the amplitude |A| must be < the threshold Threshold. The generation of module B does not need to work, and the generation of module C directly outputs the control enable signal C(2n + 1) = 0.

[0138] [|real(A)| >= Threshold / sqrt(2)] or [|imag(A)| >= Threshold / sqrt(2)]

[0139] At this time, the subsequent modules work normally, generate B, and generate the control enable signal C(2n + 1).

[0140] In one embodiment, the present invention provides a low-power Nx upsampling method. On the basis of the above embodiment, it further includes the steps:

[0141] When implementing Nx upsampling with a multi-stage cascaded filter, one way E is: using the same control enable signal C to control the output of specific signals by different stages of filters.

[0142] Such as Figure 8 shown, that is, implementing 4x upsampling with a 2-stage cascaded HBF (similarly, 8x upsampling can be implemented with a 3-stage cascaded HBF, etc.)

[0143] 1x speed signal [...X(n - 2)X(n - 1)X(n)X(n + 1)X(n + 2)...]

[0144] Traditional 4x upsampling will generate continuous 4x signals […X(4n-8)X(4n-7)X(4n-6)X(4n-5)X(4n-4)X(4n-3)X(4n-2)X(4n-1)X(4n)X(4n+1)X(4n+2)X(4n+3)X(4n+4)X(4n+5)X(4n+6)X(4n+7)X(4n+8)X(4n+9)X(4n+10)X(4n+11)…]. When (4n+m) is a non-integer multiple of 4, a large number of filtering operations are required to generate X(4n+m).

[0145] B = |X(n)+X(n+1)| and control signal C are calculated on the 1x speed signal. By comparing B with the threshold value, it can be determined in advance that only the signal interpolated between X(n) and X(n+1) can be the peak value exceeding the clipping threshold, and the amplitude of the signal interpolated between other points cannot exceed the clipping threshold. That is, the 4x upsampling module needs to correctly interpolate [X(4n+1)X(4n+2)X(4n+3)], and the interpolated points at other positions no longer need to be calculated (they can be directly output as 0 to reduce power consumption), which does not affect the final output signal of CFR.

[0146] Assume that the second-stage HBF has a total of 11 taps, that is, when interpolating X(4n+1), the correct [X(4n-4)X(4n-2)X(4n)X(4n+2)X(4n+4)X(4n+6)] is required. When interpolating X(4n+3), the correct [X(4n-2)X(4n)X(4n+2)X(4n+4)X(4n+6)X(4n+8)] is required.

[0147] Therefore, the first-stage HBF needs to interpolate the correct odd-path output [X(4n-2)X(4n+2)X(4n+6)].

[0148] The C generation module generates a control signal C. The first-stage HBF controls the odd-path output of the first-stage HBF to [X(4n-2)X(4n+2)X(4n+6)] according to the control signal C, and the outputs of other odd-paths are 0 (no filtering operation is performed), and the even-path is controlled to always output […X(4n-8)X(4n-4)X(4n)X(4n+4)X(4n+8)…]. The second-stage HBF controls the odd-path output of the second-stage HBF to [X(4n+1)X(4n+3)] according to the control signal C, and the outputs of other odd-paths are 0 (no filtering operation is performed), and the even-path is controlled to always output. Finally, a 4x-speed signal with the following characteristics is generated […X(4n-8)000X(4n-4)0X(4n-2)0X(4n)X(4n+1)X(4n+2)X(4n+3)X(4n+4)0X(4n+6)0X(4n+8)000…]. That is, only a small number of points need to be filtered, which significantly reduces power consumption.

[0149] When multiple stages of filters are connected in series to achieve N-fold upsampling, another method F is: different control enable signals C control filters of different stages to output specific signals.

[0150] like Fig. 9 As shown, 2-stage HBF in series achieves 4-fold upsampling (3-stage HBF in series can also achieve 8-fold upsampling, etc.).

[0151] 1x speed signal […X(n-2)X(n-1)X(n)X(n+1)X(n+2)…]

[0152] Traditional 4x upsampling will generate continuous 4x signals […X(4n-8)X(4n-7)X(4n-6)X(4n-5)X(4n-4)X(4n-3)X(4n-2)X(4n-1)X(4n)X(4n+1)X(4n+2)X(4n+3)X(4n+4)X(4n+5)X(4n+6)X(4n+7)X(4n+8)X(4n+9)X(4n+10)X(4n+11)…]. When (4n+m) is a non-integer multiple of 4, a large number of filtering operations are required to generate X(4n+m).

[0153] B1 = |X(n)+X(n+1)| and control signal C1 are calculated on the 1x speed signal. By comparing B1 with the threshold value, it can be determined in advance that only the signal interpolated between X(n) and X(n+1) can be the peak value exceeding the clipping threshold, and the amplitude of the signal interpolated between other points cannot exceed the clipping threshold. That is, the 4x upsampling module needs to correctly interpolate [X(4n+1)X(4n+2)X(4n+3)], and the points interpolated at other positions do not affect the final output signal of CFR.

[0154] Assume that the second-stage HBF has a total of 11 taps, that is, when interpolating X(4n+1), the correct [X(4n-4)X(4n-2)X(4n)X(4n+2)X(4n+4)X(4n+6)] is required. When interpolating X(4n+3), the correct [X(4n-2)X(4n)X(4n+2)X(4n+4)X(4n+6)X(4n+8)] is required.

[0155] Therefore, the first-stage HBF needs to interpolate the correct odd-path output [X(4n-2)X(4n+2)X(4n+6)].

[0156] The C1 module generates the control signal C1. The first stage HBF, according to the control signal C1, controls the odd path output of the first stage HBF to [X(4n-2)X(4n+2)X(4n+6)], the other odd paths output to 0, and controls the even paths to always output […X(4n-8)X(4n-4)X(4n)X(4n+4)X(4n+8)…].

[0157] B2 and control signal C2 are calculated on the 2x speed signal. By comparing B2 and the threshold value, it can be determined in advance that the specific signal interpolated between X(n) and X(n+1) is not a peak value exceeding the clipping threshold. For example, X(4n+3) is not a peak value.

[0158] According to the control signal C2, the odd-path output of the second-stage HBF is controlled to be [X(4n+1)], the outputs of other odd-paths are 0, and the even-path is controlled to be always output. Finally, the following characteristic 4x speed signal […X(4n-8)000X(4n-4)0X(4n-2)0X(4n)X(4n+1)X(4n+2)0X(4n+4)0X(4n+6)0X(4n+8)000…] is generated. That is, only a small number of points need to be filtered, which significantly reduces power consumption.

[0159] Method F can control the final output signal more finely than method E, but at the cost of generating an additional control signal.

[0160] Further, such as Fig.10 As shown, in the 1st level CFR, method E or method F is used to achieve low power consumption N-fold upsampling.

[0161] Further, such as Fig.11 As shown, in the multi-stage CFR module connected in series, mode E or mode F is adopted in each stage of CFR to control the N-fold upsampling module to generate a specific N-fold upsampling signal, thereby reducing the power consumption of the N-fold upsampling module. The control enable signal C for N-fold upsampling in this stage of CFR needs to be generated all the time.

[0162] In one embodiment, Fig.12 ,13 As shown, the present invention provides a signal clipping method, which, based on the above embodiment, further includes the steps of:

[0163] For a multi-stage CFR module connected in series, the first stage CFR adopts mode E or mode F and generates a control signal for the second stage CFR at the same time. Other stages CFR, mode E or mode F are additionally controlled by the control signal of the previous stage CFR.

[0164] like Fig.13 As shown, each level of CFR uses the control signal of the previous level so that the control enable signal C of N-fold upsampling in the current level of CFR is only generated within a specific time, and C=0 at other times, further reducing the power consumption of the N-fold upsampling module.

[0165] In one embodiment, the present invention provides a CFR for clipping a signal to be clipped, wherein the signal to be clipped generates a cancellation signal of the peak value of the signal to be clipped through the signal clipping method described in the aforementioned embodiment, and the peak clipping pulse of the signal to be clipped is accumulated with the cancellation signal to obtain the clipped signal to be clipped.

[0166] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A signal clipping method, characterized in that: Includes steps: The signal to be clipped generates a first detection signal; Determining whether the first detection signal is greater than a preset threshold; When the first detection signal is not greater than a preset threshold, a first control enable signal is generated, and the N-times speed upsampling module of the current CFR is controlled not to perform filtering operation according to the first control enable signal; When the modulus of the first detection signal is greater than a preset threshold, a second control enable signal is generated, and according to the second control enable signal, an N-fold speed upsampling module of the current CFR is controlled to perform filtering operation on some sample points of the signal to be clipped, and a specific N-fold speed upsampling signal is output; The signal to be detected after being upsampled by the N-times speed upsampling module is sent to the peak detection module in the current CFR for peak detection; The detected peak value information of the signal to be clipped is sent to the CPG control module in the current CFR, so that the CPG control module allocates idle clipping pulses to clip the peak value of the signal to be clipped.

2. The signal clipping method according to claim 1, wherein the N-times-speed upsampling module comprises at least one low-pass filter, characterized in that: After determining whether the first detection signal is greater than a preset threshold, the method specifically includes the following steps: When the first detection signal is not greater than a preset threshold, controlling the current low-pass filter not to perform filtering operation according to the first control enable signal; When the first detection signal is greater than a preset threshold, controlling the current low-pass filter to perform filtering operation on some samples of the signal to be clipped according to the second control enable signal; The signal upsampled by the current low-pass filter is sent to the next low-pass filter.

3. The signal clipping method according to claim 2, characterized in that: After sending the signal upsampled by the current low-pass filter to the next-stage low-pass filter, the method further includes the following steps: According to the first control enable signal or the second control enable signal, the current low-pass filter is controlled to output a corresponding signal.

4. The signal clipping method according to claim 2, characterized in that: After sending the signal upsampled by the current low-pass filter to the next-stage low-pass filter, the method further includes the following steps: Generate a second detection signal through the signal sampled by the previous low-pass filter; It is determined whether the second detection signal is greater than a preset threshold, and a third control enable signal is generated to control the current low-pass filter to output a corresponding signal.

5. The signal clipping method according to claim 1, applied to multi-level CFR, characterized in that: After sending the detected peak information of the signal to be clipped to the CPG control module in the current CFR so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped, the method further includes the following steps: If the peak value of the signal to be clipped is allocated with the idle clipping pulse, generating a first control signal; If the peak value of the signal to be clipped is not allocated with the idle clipping pulse, generating a second control signal; The first control signal and / or the second control signal are sent to a next-stage CFR, so that the next-stage CFR clips the clipped signal to be clipped according to the first control signal and / or the second control signal.

6. The signal clipping method according to claim 1, characterized in that: After the signal to be clipped generates a first detection signal, before determining whether the first detection signal is greater than a preset threshold, the method further includes the following steps: The sample points in the first detection signal whose amplitude is smaller than the coarse detection threshold are screened out by the coarse detection module.

7. The signal clipping method according to claim 4, characterized in that: The preset thresholds corresponding to each level of low-pass filters are independent of each other.

8. A signal clipping device, characterized in that: include: A generating unit, configured to generate a first detection signal from a signal to be clipped; A judging unit, configured to judge whether the first detection signal is greater than a preset threshold; The generating unit is further configured to generate a first control enable signal when the first detection signal is not greater than a preset threshold; A control unit, configured to control the N-times-speed upsampling module of the current CFR not to perform filtering operation according to the first control enable signal; The generating unit is further configured to generate a second control enable signal when the first detection signal is greater than a preset threshold; The control unit is further used to control the N-times-speed up-sampling module of the current CFR to perform filtering operation on some samples of the signal to be clipped according to the second control enable signal; A sending unit, used for sending the signal to be detected after being upsampled by the N-times speed upsampling module to the peak detection module in the current CFR for peak detection; The sending unit is further used to send the detected peak information of the signal to be clipped to the CPG control module in the current CFR, so that the CPG control module allocates idle clipping pulses to clip the peak of the signal to be clipped.

9. The signal clipping device according to claim 8, characterized in that: The control unit is further configured to control the current low-pass filter not to perform filtering operation according to the first control enable signal when the first detection signal is not greater than a preset threshold; The control unit is further configured to control the current low-pass filter to perform filtering operation on some samples of the signal to be clipped according to the second control enable signal when the first detection signal is greater than a preset threshold; The sending unit is also used to send the signal upsampled by the current low-pass filter to the next-stage low-pass filter.

10. A CFR for treating a clipped signal as a clipped signal, wherein: The signal to be clipped generates a cancellation signal of the peak value of the signal to be clipped through the signal clipping method described in any one of claims 1 to 7, and the cancellation signal of the peak value of the signal to be clipped is added to the signal to be clipped to obtain the clipped signal to be clipped.

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