CN102223338B - Self-adaption peak clipping method and device of multi-carrier system - Google Patents
Self-adaption peak clipping method and device of multi-carrier system Download PDFInfo
- Publication number
- CN102223338B CN102223338B CN 201010150248 CN201010150248A CN102223338B CN 102223338 B CN102223338 B CN 102223338B CN 201010150248 CN201010150248 CN 201010150248 CN 201010150248 A CN201010150248 A CN 201010150248A CN 102223338 B CN102223338 B CN 102223338B
- Authority
- CN
- China
- Prior art keywords
- peak
- clipping
- carrier
- peak value
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The embodiment of the invention provides a self-adaption peak clipping method and device of a multi-carrier system. The method comprises the following steps: receiving a multi-carrier combined signal of the multi carrier system; comparing the multi-carrier combined signal and a peak detection threshold to obtain the peak adjustment quantity of the signal over the peak detection threshold; and determining a multi-carrier peak clipping coefficient, and carrying out self-adaption peak clipping to the multi-carrier combined signal according to the multi-carrier peak clipping coefficient and the peak adjustment quantity. The embodiment of the invention also provides a self-adaption device of a multi-carrier system, which comprises a receiving module, a peak adjustment module and a peak clipping module. According to the method and the device provided by the embodiment of the invention, the problem of worsening of EVM (Error Vector Magnitude) during multi-carrier mixed modulation and unequalpower transmission can be solved, simultaneously, under the conditions that the EVM and ACLR (Adjacent Channel Leakage Ratio) are met, the better peak clipping effect can be obtained under a mode of multi-carrier hybrid modulation, so that the multi-carrier combined signal has lower peak mean ratio, and the power amplifying cost can be effectively reduced.
Description
Technical field
The present invention relates to digital communicating field, particularly, the present invention relates to self-adapting peak-clipping method and the device of multicarrier system.
Background technology
3G (3rd-Generation, 3G (Third Generation) Moblie technology) refers to support the honeycomb mobile communication technology of high speed data transfer.The 3G service can transmit sound and data message simultaneously, and its representative feature provides high-speed data service.
The 3G wireless communication system has all adopted multicarrier to carry out cell capacity-enlarging at present.In multi-carrier district, because needing the multi-carrier signal of emission partly to carry out linear superposition at digital intermediate frequency merges, sharing a cover transmitter launches, therefore the antenna transmission end returns back out existing higher peak-to-average force ratio signal, so just require power amplifier to have the larger range of linearity, thereby the Efficiency Decreasing that causes power amplifier, and then cause the raising of power amplifier cost, for these problems that exist, in mobile communication system, usually adopt the signal peak-to-average ratio of peak clipping Techniques For Reducing ingoing power amplifier.
The implementation that reduces at present peak-to-average force ratio mainly contains peak value window, noise shaping and peak value offset scheme.Wherein peak value offset scheme complexity is minimum, and performance is also better.
In patent CN200710002958.4, considered according to the power estimated value of each carrier wave baseband signal the respective filter adjustment that gains, then the multi-carrier signal behind the involutory road carries out matched filtering peak clipping processing, avoids the distorted signals energy imbalance that uses the identical match filter gain to bring to the different carrier wave of power.But the carrier wave for the high modulation mode, especially 64QAM (Quadrature amplitudemodulation, quadrature amplitude modulation) is to EVM (Error Vector Magnitude, error vector magnitude) relatively more responsive, be not easy to satisfy the EVM requirement.
But, PC-CFR (Peak Cancellation-Crest Factor Reduction, peak value offsets crest factor to be reduced) when the present situation of peak clipping algorithm is present Realization of Product, general power and the requirement of the EVM under the different modulating mode difference of also not considering carrier wave, its peak-to-average force ratio that can suppress is limited.Mainly comprise following 2 problems:
(1) in the actual environment, owing to the impact of power control on the R4 carrier wave, and the difference of each carrier wave code channel occupancy, the power of carrier wave may be not identical, and the power difference maximum of intercarrier can reach 20db.If adopt the PC-CFR algorithm of not considering carrier power, so that lower-powered carrier wave EVM deterioration is more serious.
(2) in the actual networking, can be divided into the R4 business for downlink business, namely take speech business as main, QPSK modulation system, and H (High Speed Downlink Packet Access, high speed downlink packet access) business, i.e. data service.H is professional can to select the different modulating mode according to its channel quality, increase along with number of modulation levels, signal is also more responsive to noise, and the restriction to the EVM of high modulation technology among the 3GPP (3rd Generation Partnership Project, third generation partner program) is also stricter.If the carrier wave of different modulating mode is waited the PC-CFR peak clipping of gain, the deterioration degree EVM of each carrier wave is similar so, is unfavorable for further reducing peak-to-average force ratio.
Summary of the invention
Purpose of the present invention is intended to solve at least one of above-mentioned technological deficiency, consider especially the power of carrier wave and the antijamming capability of different modulating mode, the multi-transceiver combination signal is carried out the digital intermediate frequency peak clipping process, proposed a kind of self-adapting peak-clipping method and device of multicarrier system.
For achieving the above object, an aspect of embodiments of the invention has proposed a kind of self-adapting peak-clipping method and device of multicarrier system, may further comprise the steps:
Receive the multi-transceiver combination signal of multicarrier system;
Described multi-transceiver combination signal and peak value detection threshold are compared, will carry out the peak value adjustment above the signal of peak value detection threshold, obtain the peak value adjustment amount;
Determine the multi-carrier peak-clipping coefficient, the described multi-transceiver combination signal after the peak value adjustment is carried out adaptive peak clipping according to described multi-carrier peak-clipping coefficient, peak value adjustment amount.
The adaptive peak clipping device that has proposed on the other hand a kind of multicarrier system of embodiments of the invention comprises receiver module, peak value adjusting module and peak-clipping module,
Described receiver module is for the multi-transceiver combination signal that receives multicarrier system;
Described peak value adjusting module is used for described multi-transceiver combination signal and peak value detection threshold are compared, and will carry out the peak value adjustment above the signal of peak value detection threshold, obtains the peak value adjustment amount;
Described peak-clipping module is used for determining the multi-carrier peak-clipping coefficient, and the described multi-transceiver combination signal after the peak value adjustment is carried out adaptive peak clipping according to described multi-carrier peak-clipping coefficient, peak value adjustment amount.
According to method and the device of the embodiment of the invention, the difference that considers multi-carrier power is different without the antijamming capability of the carrier wave of modulation system with employing, the EVM deterioration problem when having solved the emission of multicarrier compound modulation and unequal power.Simultaneously satisfying EVM and ACLR (AdjacentChannel Leakage Ratio, the adjacent channel leakage ratio) under the condition that requires, under multicarrier hybrid modulation pattern, can obtain better peak clipping effect, so that the multi-transceiver combination signal has more low peak average ratio, reduce greatly the power amplifier cost.
The such scheme that the present invention proposes, very little to the change of existing system, can not affect the compatibility of system, and realize simple, efficient.
The aspect that the present invention adds and advantage in the following description part provide, and part will become obviously from the following description, or recognize by practice of the present invention.
Description of drawings
Above-mentioned and/or the additional aspect of the present invention and advantage are from obviously and easily understanding becoming the description of embodiment below in conjunction with accompanying drawing, wherein:
Fig. 1 is the FB(flow block) according to the self-adapting peak-clipping method of the multicarrier system of the embodiment of the invention;
Fig. 2 is according to adaptive peak clipping algorithm schematic diagram of the invention process;
Fig. 3 is the structured flowchart according to the adaptive peak clipping device of the multicarrier system of the embodiment of the invention;
Fig. 4 is for considering intercarrier power, not the original signal spectrum schematic diagram during peak clipping;
Fig. 5 is signal peak-to-average ratio CCDF after the primary signal peak clipping among Fig. 4 (ComplementaryComplementary Cumulative Distribution Function, contrary cumulative distribution function) curve comparison figure
Fig. 6 is for considering the carrier modulation mode, not the original signal spectrum schematic diagram during peak clipping
Fig. 7 is signal peak-to-average ratio CCDF curve comparison figure after the primary signal peak clipping among Fig. 6
Fig. 8 is the spectrum diagram according to the peak clipping filter of the embodiment of the invention.
Embodiment
The below describes embodiments of the invention in detail, and the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or the element with identical or similar functions from start to finish.Be exemplary below by the embodiment that is described with reference to the drawings, only be used for explaining the present invention, and can not be interpreted as limitation of the present invention.
At first peak value window method, noise shaping scheme and peak value offset scheme are introduced the present invention in order better to explain.
Specifically, peak value window method (PW-CFR, Peak Window-Crest Factor Reduction) refer to will be higher than the hard peak clipping pulse of thresholding through filter smoothing, come the expansion of inhibition zone external spectrum, its performance depends on the window that adopts and the length of window.Filter order is higher, affects sampled point more, and the EVM index worsens just larger.On the other hand, multicarrier the probability of continuous peak value occurs in a period of time can be larger, because the filter of higher-order number may cause the situation that signal is repeated weighting, peak value window method is carried out the just desirable slicing effect of impossible acquisition of peak clipping to multi-carrier signal like this during the realization of peak value window crest suppression method.
Noise shaping scheme (NS-CFR, Noise Shaping-Crest Factor Reduction) refers to by calculating the peak clipping threshold value of input signal power acquisition dynamic change, then cut down all sampled points that surpass some thresholdings based on this threshold value, and the error signal of calculating and primary signal.Error signal is subsequently by noise shaping, dropped within the signal band by the noise that amplitude limit causes guaranteeing.Through the subsequently cancellation from primary signal of noise shaped error signal, thereby reduce PAPR (Peak to Average Power Ratio, papr).Above-mentioned processing may cause peak value again to rise.
Peak value offset scheme PC-CFR technology refers to adopt the technology that is similar to NS-CFR to dwindle PAPR.Yet different from above-mentioned NS-CFR is that the offseting signal of being regenerated by spectrum shaping in the PC-CFR scheme is based on peak value sampling point, namely surpasses the maximum in the thresholding area sampling point.This signal is used to cut down the parent mass peak value signal above thresholding after the suitable delay disposal of process.As the method for simplifying of only cutting down with the peak value sampling point, its distortion factor is less, and only needs computation burden still less.
Comprehensive three kinds of methods, the PC-CFR complexity is minimum, and performance is also better.But, when the present situation of PC-CFR peak clipping algorithm is present Realization of Product, do not consider not also that generally the power of carrier wave and the EVM under the different modulating mode require difference, its peak-to-average force ratio that can suppress is limited.
Therefore the embodiment of the invention need to provide a kind of, and the difference that considers multi-carrier power is different without the antijamming capability of the carrier wave of modulation system with employing, the self-adapting peak-clipping method with better peak clipping effect.
In order to realize the present invention's purpose, the invention discloses a kind of self-adapting peak-clipping method of multicarrier system, Fig. 1 shows the FB(flow block) of said method.The method comprises the steps:
S101: the multi-transceiver combination signal that receives multicarrier system.
In conjunction with shown in Figure 2, adopt Digital Up Convert to signal modulate, spread spectrum and filtering processes, and obtains each road carrier signal.Above-mentioned each road carrier signal is superposeed, obtain the multi-transceiver combination signal.Receive the multi-transceiver combination signal of above-mentioned multicarrier system.
Above-mentioned multi-transceiver combination signal can be expressed as:
Wherein, x
k(i) be to process k the carrier signal that obtains through ovennodulation, spread spectrum and filtering, K is total carrier number, f
kBe the k carrier frequency point, f
sBe the digital intermediate frequency sampling frequency, T is the data number.
S102: multi-transceiver combination signal and peak value detection threshold are compared, will carry out the peak value adjustment above the signal of peak value detection threshold.
In conjunction with shown in Figure 2, above-mentioned multi-transceiver combination signal is found out peak value window by peak detection block.Specifically, according to multi-transceiver combination signal y (i) and peak value detection threshold A
1, find out peak value window, namely | y (i) |＞A
1, i ∈ [i
1, i
2], wherein,
x
k(i) be to process k the carrier signal that obtains through ovennodulation, spread spectrum and filtering, K is total carrier number, f
kBe the k carrier frequency point, f
sBe the digital intermediate frequency sampling frequency, T is the data number.
Pass through following formula | y (i) |＞A
1, i ∈ [i
1, i
2] as can be known, if all samples all below target gate, transmit y (i), algorithm finishes.Otherwise, in peak value window, find the peak-peak position at i
Max, the peak point data are y (i
Max).
To carry out the peak value adjustment above the signal of peak value detection threshold, calculate maximal peak point y (i
Max) and the peak clipping threshold value A
2Difference,
a(i
max)＝y(i
max)-A
2exp(j*angle(y(i
max)))，
Guarantee difference a (i
Max) amplitude and phase place and peak point remain unchanged.
Wherein, peak value detection threshold A
1Generally to be higher than slightly the peak clipping threshold value A
2, i.e. A
1〉=A
2
S103: determine the multi-carrier peak-clipping coefficient, the multi-transceiver combination signal after the peak value adjustment is carried out adaptive peak clipping according to multi-carrier peak-clipping coefficient and peak value adjustment amount.
Before the multi-transceiver combination signal after the peak value adjustment is carried out adaptive peak clipping, at first to determine the multi-carrier peak-clipping coefficient.In the present embodiment, estimate and/or multicarrier weights calculative determination multi-carrier peak-clipping coefficient by multi-carrier power.Specifically, determine that the multi-carrier peak-clipping coefficient comprises the steps:
(1) multi-carrier power is estimated
The power that calculates each carrier wave by base band multicarrier baseband signal obtains the performance number of intercarrier.According to above-mentioned performance number, the power proportions pass that obtains each carrier wave is p
1: p
2: ...: p
K
(2) the multicarrier weights calculate
Because the Anti-jamming of signal ability of different modulating mode is different.3GPP TS 25.105 given EVM require as shown in table 1:
Table 1
| Modulation system | EVM |
| QPSK(EVM 1) | 17.5％ |
| 16QAM(EVM 2) | 12.5％ |
| 64QAM(EVM 3) | 8％ |
As shown in Table 1, EVM
1: EVM
2: EVM
3=2.1875: 1.5625: 1.Suppose that the modulation system that every road carrier signal adopts is M
k(k=1 ... K), wherein M is order of modulation.
During M=2, modulation system is QPSK; The M=4 modulation system is 16QAM; During M=6, modulation system is 64QAM.Determine the weights of carrier wave according to the modulation system of carrying signal on each carrier wave, comprise following dual mode:
(1) carrying signal only has a kind of modulation system on carrier wave, and then each carrier wave weights computing formula is as follows:
That is, when modulation system is QPSK, q
k=2.1875; When modulation system is 16QAM, q
k=1.5625; When modulation system is 64QAM, q
k=1.
(2) when carrier data includes Different Modulations, q
kChoose weights corresponding to high-order modulating of signal in this carrier wave.Can guarantee thus the EVM performance of high order modulation.
According to the multicarrier weights that obtain in the above-mentioned steps, the weights ratio that obtains each carrier wave is q
1: q
2: ...: q
K
Closing according to the power proportions of each carrier wave in above-mentioned multi-carrier power estimation and the calculating of multicarrier weights is p
1: p
2: ...: p
K, the weights ratio of each carrier wave is q
1: q
2: ...: q
K, the gain g of each carrier wave of calculating multicarrier
k, g
k=p
kq
k, k=1 wherein ... K.
Preferably, the gain g of each carrier wave
kCan also estimate p by multi-carrier power
KOr the weights q of multicarrier
KOne of obtain.
Work as q
k=1 o'clock, g
kEstimate p by multi-carrier power
KWhen calculating, i.e. g
k=p
k
Work as p
K=1 o'clock, g
kEstimate q by multi-carrier power
KWhen calculating, i.e. g
k=q
K
Obtain by the way the gain g of each carrier wave
k, also belong to protection scope of the present invention.
For the multicarrier configuration, design a prototype filter b (n), this prototype filter and single spectrum of carrier coupling.According to the carrier frequency configuration, the frequency domain of prototype filter is moved on the center frequency point of each carrier wave each the carrier gains value g that then obtains according to the multicarrier gain regulation module
k, adjust every carrier gains, addition obtains multi-carrier peak-clipping filter h (n), namely
Wherein, N is the length of peak clipping filter h (n).
Above-mentioned h (n) according to maximum normalization, is obtained multi-carrier peak-clipping coefficient h ' (n),
h′(n)＝h(n)/max(abs(h))，
Wherein, abs is for asking absolute value, and max () asks vector maximization, h=h (1) ..., h (N).
With a (i that obtains in multi-carrier peak-clipping coefficient h ' (n) and the step 102
Max) multiplying each other obtains pulse vector for offsetting.The above-mentioned vectorial y (i) that subtracts each other after obtaining upgrading with multi-transceiver combination data y (i) of pulse that obtains is the signal after the peak clipping,
y(i)＝y(i)-a(i
max)·h′(j)，
i∈[i
max-floor(N/2)，i
max+floor(N/2)]，j＝imod[i
max-floor(N/2)]。
In conjunction with Fig. 2 as can be known, the multi-transceiver combination data y (i) before the renewal is the signal after the multi-transceiver combination signal process time-delay that generates in the step 101.By above-mentioned time-delay process, the multi-transceiver combination data y (i) before guaranteeing the pulse vector and upgrading is synchronous.
Y (i) according to after upgrading makes i=i
2+ 1, then repeating step 102 and step 103 stop after i is greater than data amount check.
In the present embodiment, all be removed for guaranteeing all peak values, usually adopt the mode of multi-stage iteration to carry out adaptive peak clipping.All peak points of the signal of namely exporting after iteration self-adapting peak clipping repeatedly are less than peak value detection threshold A
1The time stop the iteration self-adapting peak clipping.
Preferably, the signal of exporting after the peak clipping is carried out digital pre-distortion, can improve the linear characteristic of power amplification efficiency and power amplifier, reduce the caloric value of base station.
The method of the adaptive peak clipping that the embodiment of the invention provides, the difference that considers multi-carrier power is different without the antijamming capability of the carrier wave of modulation system with employing, the EVM deterioration problem when having solved the emission of multicarrier compound modulation and unequal power.Under the condition that satisfies EVM and ACLR requirement, under the high order modulation pattern, can obtain better peak clipping effect simultaneously, so that the multi-transceiver combination signal after the peak clipping has more low peak average ratio, reduce greatly the power amplifier cost.
The embodiment of the invention also provides a kind of adaptive peak clipping device of multicarrier system, and in conjunction with shown in Figure 3, this device 300 comprises receiver module 310, peak value adjusting module 320 and peak-clipping module 330.
Wherein, receiver module 310 is for the multi-transceiver combination signal that receives multicarrier system.
Specifically, in conjunction with shown in Figure 2, receiver module 310 adopt Digital Up Converts to signal modulate, spread spectrum and filtering processes, and obtains each road carrier signal.Above-mentioned each road carrier signal is superposeed, obtain the multi-transceiver combination signal.Receiver module 310 receives the multi-transceiver combination signal of above-mentioned multicarrier system.
Above-mentioned multi-transceiver combination signal can be expressed as:
Wherein, x
k(i) be to process k the carrier signal that obtains through ovennodulation, spread spectrum and filtering, K is total carrier number, f
kBe the k carrier frequency point, f
sBe the digital intermediate frequency sampling frequency, T is the data number.
In conjunction with shown in Figure 2, peak value adjusting module 320 is found out peak value window with above-mentioned multi-transceiver combination signal by peak detection block.Peak value adjusting module 320 is used for multi-transceiver combination signal and peak value detection threshold are compared, and will carry out the peak value adjustment above the signal of peak value detection threshold.
Specifically, peak value adjusting module 320 is according to multi-transceiver combination signal y (i) and peak value detection threshold A
1, find out peak value window, namely | y (i) |＞A
1, i ∈ [i
1, i
2], wherein,
x
k(i) be to process k the carrier signal that obtains through ovennodulation, spread spectrum and filtering, K is total carrier number, f
kBe the k carrier frequency point, f
sBe the digital intermediate frequency sampling frequency, T is the data number.
Pass through following formula | y (i) |＞A
1, i ∈ [i
1, i
2] as can be known, if all samples all below target gate, transmit y (i), algorithm finishes.Otherwise, in peak value window, find the peak-peak position at i
Max, the peak point data are y (i
Max).
Peak value adjusting module 320 will carry out the peak value adjustment above the signal of peak value detection threshold, calculate maximal peak point y (i
Max) and the peak clipping threshold value A
2Difference,
a(i
max)＝y(i
max)-A
2 exp(j*angle(y(i
max)))，
Guarantee difference a (i
Max) amplitude and phase place and peak point remain unchanged.
Wherein, peak value detection threshold A
1Generally to be higher than slightly the peak clipping threshold value A
2, i.e. A
1〉=A
2
Adaptive peak clipping device 300 also comprises peak-clipping module 330, is used for determining the multi-carrier peak-clipping coefficient, and the multi-transceiver combination signal after the peak value adjustment is carried out adaptive peak clipping according to the multi-carrier peak-clipping coefficient.
Before the multi-transceiver combination signal after the peak value adjustment was carried out adaptive peak clipping, peak-clipping module 330 at first will be determined the multi-carrier peak-clipping coefficient.In the present embodiment, peak-clipping module 330 is estimated and/or multicarrier weights calculative determination multi-carrier peak-clipping coefficient by multi-carrier power.Specifically, determine that the multi-carrier peak-clipping coefficient comprises the steps:
(1) multi-carrier power is estimated
The power that calculates each carrier wave by base band multicarrier baseband signal obtains the performance number of intercarrier.According to above-mentioned performance number, the power proportions pass that obtains each carrier wave is p
1: p
2: ...: p
K
(2) the multicarrier weights calculate
Because the Anti-jamming of signal ability of different modulating mode is different.3GPP TS 25.105 given EVM require as shown in table 1.
As shown in Table 1, EVM
1: EVM
2: EVM
3=2.1875: 1.5625: 1.Suppose that the modulation system that every road carrier signal adopts is M
k(k=1 ... K), wherein M is order of modulation.
During M=2, modulation system is QPSK; The M=4 modulation system is 16QAM; During M=6, modulation system is 64QAM.Determine the weights of carrier wave according to the modulation system of carrying signal on each carrier wave, comprise following dual mode:
(1) carrying signal only has a kind of modulation system on carrier wave, and then each carrier wave weights computing formula is as follows:
That is, when modulation system is QPSK, q
k=2.1875; When modulation system is 16QAM, q
k=1.5625; When modulation system is 64QAM, q
k=1.
(2) when carrier data includes Different Modulations, q
kChoose weights corresponding to high-order modulating of signal in this carrier wave.Can guarantee thus the EVM performance of high order modulation.
Peak-clipping module 330 is according to the multicarrier weights that obtain in the above-mentioned steps, and the weights ratio that obtains each carrier wave is q
1: q
2: ...: q
K
Closing according to the power proportions of each carrier wave in above-mentioned multi-carrier power estimation and the calculating of multicarrier weights is p
1: p
2: ...: p
K, the weights ratio of each carrier wave is q
1: q
2: ...: q
K, peak-clipping module 330 calculates the gain g of each carrier wave of multicarrier
k, g
k=p
kq
k, k=1 wherein ... K.
Preferably, the gain g of each carrier wave
kCan also estimate p by multi-carrier power
KOr the weights q of multicarrier
KOne of obtain.
Work as q
K=1 o'clock, g
kEstimate p by multi-carrier power
KWhen calculating, i.e. g
k=p
k
Work as p
K=1 o'clock, g
kEstimate q by multi-carrier power
KWhen calculating, i.e. g
k=q
K
Obtain by the way the gain g of each carrier wave
k, also belong to protection scope of the present invention.
For the multicarrier configuration, peak-clipping module 330 design prototype filter b (n), this prototype filter and single spectrum of carrier coupling.According to the carrier frequency configuration, the frequency domain of prototype filter is moved on the center frequency point of each carrier wave each the carrier gains value g that then obtains according to the multicarrier gain regulation module
k, adjust every carrier gains, addition obtains multi-carrier peak-clipping filter h (n), namely
Wherein, N is the length of peak clipping filter h (n).
Above-mentioned h (n) according to maximum normalization, is obtained multi-carrier peak-clipping coefficient h ' (n),
h′(n)＝h(n)/max(abs(h))，
Wherein, abs is for asking absolute value, and max () asks vector maximization, h=h (1) ..., h (N).
Peak-clipping module 330 with the multi-carrier peak-clipping coefficient h ' with peak value adjusting module 320 in a (i that obtains
Max) multiplying each other obtains pulse vector for offsetting.The above-mentioned vectorial y (i) that subtracts each other after obtaining upgrading with multi-transceiver combination data y (i) of pulse that obtains is the signal after the peak clipping,
y(i)＝y(i)-a(i
max)·h′(j)，
i∈[i
max-floor(N/2)，i
max+floor(N/2)]，j＝imod[i
max-floor(N/2)]。
In conjunction with Fig. 2 as can be known, the multi-transceiver combination data y (i) before the renewal is the signal after the multi-transceiver combination signal process time-delay that receives in the receiver module 310.By above-mentioned time-delay process, the multi-transceiver combination data y (i) before guaranteeing the pulse vector and upgrading is synchronous.
Peak-clipping module 330 makes i=i according to the y (i) after upgrading
2+ 1, then above-mentioned module repeats above-mentioned peak clipping operation, stops after i is greater than data amount check.
In the present embodiment, peak-clipping module 330 adopts the mode of multi-stage iteration to carry out adaptive peak clipping for guaranteeing that all peak values all are removed usually.All peak points of the signal of namely exporting after iteration self-adapting peak clipping repeatedly are less than peak value detection threshold A
1The time stop the iteration self-adapting peak clipping.
Preferably, the signal of exporting after the peak clipping is carried out digital pre-distortion, can improve the linear characteristic of power amplification efficiency and power amplifier, reduce the caloric value of base station.
The adaptive peak clipping device that the embodiment of the invention provides, the difference that considers multi-carrier power is different without the antijamming capability of the carrier wave of modulation system with employing, the EVM deterioration problem when having solved the emission of multicarrier compound modulation and unequal power.Under the condition that satisfies EVM and ACLR requirement, under the high order modulation pattern, can obtain better peak clipping effect simultaneously, so that the multi-transceiver combination signal after the peak clipping has more low peak average ratio, reduce greatly the power amplifier cost.
With TD-SCDMA system example, self-adapting peak-clipping method and device that the embodiment of the invention provides are described among Fig. 4～Fig. 8, the performance when considering the EVM of intercarrier power and different modulating mode.
The below just considers respectively intercarrier power and considers that the carrier modulation mode describes.
(1) considers intercarrier power.
For 12 carrier waves, 8 user data source, modulation system is QPSK, and the peak clipping thresholding is 6.8dB.Its 1st carrier power is than the low 12db of other carrier waves.The frequency spectrum of the signal when Fig. 4 shows not peak clipping, abscissa are the frequency of primary signal, and unit is MHz; Ordinate is the power of primary signal, and unit is dB.
Fig. 5 shows peak clipping front and back signal peak-to-average ratio CCDF (Complementary CumulativeDistribution Function, complementary cumulative distribution function) comparison diagram.In Fig. 5, abscissa is PAR (peak-to-average ratio, peak-to-average force ratio), and unit is dB; Ordinate is that contrary accumulated probability distributes (CCDF), and unit is %.In Fig. 5, the power before black circle ". " the expression peak clipping, wherein the maximum input of signal PAR is 9.8049; Be 10 at probability
-4Under peak-to-average force ratio be 9.3521.Soft dot "." power of expression after the peak clipping, wherein the maximum input of peak clipping PAR is 6.9268; Be 10 at probability
-4Under peak-to-average force ratio be 6.9254.Table 2 is two kinds of EVM performance comparison under the different peak clipping modes.
Table 2
| Carrier number | Deng gain PC-CFR EVM[%] | Consider power, PC-CFR EVM[%] |
| 1 | 13.971 | 5.103 |
| 2 | 4.518 | 4.663 |
| 3 | 4.615 | 4.791 |
| 4 | 4.521 | 4.684 |
| 5 | 4.476 | 4.635 |
| 6 | 4.33 | 4.492 |
| 7 | 4.418 | 4.583 |
| 8 | 4.298 | 4.462 |
| 9 | 4.406 | 4.573 |
| 10 | 4.404 | 4.585 |
| 11 | 4.337 | 4.502 |
| 12 | 4.351 | 4.514 |
As can be seen from Table 2, when waiting gain PC-CFR peak clipping, No. 1 carrier wave is because power is less, and mis-behave is larger after the peak clipping, reaches 13.9%.And when considering carrier power, No. 1 carrier wave EVM is 5.1%.By relatively can finding, when considering carrier power after the peak clipping performance improvement a lot, other carrier waves EVM only has small deterioration.
(2) consider the carrier modulation mode.
For 12 carrier waves, the carrier wave constant power.Table 3 is two kinds of EVM performance comparison under the different peak clipping modes.As shown in table 3, carrier number is that 1～4 carrier modulation mode is 64QAM, and carrier number is that 5～8 carrier modulation mode is 16QAM, and carrier number is that 9～12 carrier modulation mode is QPSK, and SF=1, peak clipping thresholding are 6.0dB.The frequency spectrum of the signal when Fig. 6 is not peak clipping, abscissa are the frequency of primary signal, and unit is MHz; Ordinate is the power of primary signal, and unit is dB.
Fig. 7 is signal peak-to-average ratio CCDF comparison diagram before and after the peak clipping.In Fig. 7, abscissa is PAR, and unit is dB; Ordinate is that contrary accumulated probability distributes (CCDF), and unit is %.In Fig. 7, the power before black circle ". " the expression peak clipping, wherein the maximum input of signal PAR is 10.0604; Be 10 at probability
-4Under peak-to-average force ratio be 9.4192.Soft dot "." power of expression after the peak clipping, wherein the maximum input of peak clipping PAR is 6.1851; Be 10 at probability
-4Under peak-to-average force ratio be 6.001.
Fig. 8 is the spectrogram of peak clipping filter, and abscissa is the frequency of primary signal, and unit is MHz; Ordinate is the power of primary signal, and unit is dB.
Table 3 is two kinds of EVM performance comparison under the different peak clipping modes.
Table 3
As can be seen from Table 3, when peak-to-average force ratio is cut to 6dB, adopt and wait each carrier wave EVM performance of gain PC-CFR scheme to approach.And consider modulation system PC-CFR scheme because the carrier wave of high-order modulating is had less peak clipping weights, so the peak clipping degree is lighter, EVM compares and waits the PC-CFR scheme better performances that gains.For the carrier wave of low-order-modulated mode, it is less better that EVM such as compares at the gain PC-CFR scheme.For waiting gain PC-CFR, the 1st, No. 4 just discontented football association view requirements of carrier wave, and each the carrier wave EVM of method that considers modulation system PC-CFR satisfies protocol requirement, considers that therefore the antijamming capability difference of modulation system can further reduce peak-to-average force ratio under the prerequisite that guarantees the EVM protocol requirement.
Because carrier power and modulation system can change along with the factors such as continuous variation of channel circumstance, the self-adapting peak-clipping method that the embodiment of the invention provides and device can come self adaptation to adjust peak clipping filter gain value according to current carrier power and modulation system, reach than low peak average ratio, guarantee simultaneously the EVM performance of carrier wave under the various modulation systems.
The self-adapting peak-clipping method and the device that provide by the embodiment of the invention, the difference that considers multi-carrier power is different without the antijamming capability of the carrier wave of modulation system with employing, the EVM deterioration problem when having solved the emission of multicarrier compound modulation and unequal power.Under the condition that satisfies EVM and ACLR requirement, under the high order modulation pattern, can obtain better peak clipping effect simultaneously, so that the multi-transceiver combination signal after the peak clipping has more low peak average ratio, reduce greatly the power amplifier cost.
One of ordinary skill in the art will appreciate that and realize that all or part of step that above-described embodiment method is carried is to come the relevant hardware of instruction to finish by program, described program can be stored in a kind of computer-readable recording medium, this program comprises step of embodiment of the method one or a combination set of when carrying out.
In addition, each functional unit in each embodiment of the present invention can be integrated in the processing module, also can be that the independent physics of unit exists, and also can be integrated in the module two or more unit.Above-mentioned integrated module both can adopt the form of hardware to realize, also can adopt the form of software function module to realize.If described integrated module realizes with the form of software function module and during as independently production marketing or use, also can be stored in the computer read/write memory medium.
The above-mentioned storage medium of mentioning can be read-only memory, disk or CD etc.
The above only is preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (6)
1. the self-adapting peak-clipping method of a multicarrier system is characterized in that, may further comprise the steps:
Receive the multi-transceiver combination signal of multicarrier system;
Described multi-transceiver combination signal and peak value detection threshold are compared, will carry out the peak value adjustment above the signal of peak value detection threshold, obtain the peak value adjustment amount;
Determine the multi-carrier peak-clipping coefficient, described multi-transceiver combination signal is carried out adaptive peak clipping according to described multi-carrier peak-clipping coefficient and peak value adjustment amount;
Wherein, will carry out the peak value adjustment above the signal of peak value detection threshold comprises:
According to multi-transceiver combination signal y (i) and peak value detection threshold A
1, find out peak value window, namely | y (i) |〉A
1, i ∈ [i
1, i
2], wherein,
I=1,2 ..., T, x
k(i) be to process k the carrier signal that obtains through ovennodulation, spread spectrum and filtering, K is total carrier number, f
kBe the k carrier frequency point, f
sBe the digital intermediate frequency sampling frequency, T is the data number;
Carry out the peak value adjustment, calculate maximal peak point and peak clipping threshold value A
2Difference so that the amplitude of difference and phase place and peak point remain unchanged a (i
Max)=y (i
Max)-A
2Exp (j*angle (y (i
Max))), A wherein
1〉=A
2
Wherein, determine that the multi-carrier peak-clipping coefficient comprises: estimate and/or multicarrier weights calculative determination multi-carrier peak-clipping coefficient according to multi-carrier power;
Wherein, determine that the multi-carrier peak-clipping coefficient comprises:
Calculate the gain g of each carrier wave of multicarrier
k=p
kq
k, wherein, it is p that the power proportions of each carrier wave is closed
1: p
2: ...: p
K, the weights ratio of each carrier wave is q
1: q
2: ...: q
K
Design a prototype filter b (n), described prototype filter and single spectrum of carrier coupling according to the carrier frequency configuration, are moved the frequency domain of prototype filter on the center frequency point of each carrier wave, according to multicarrier gain g
k=p
kq
kAdjust every carrier gains, addition obtains multi-carrier peak-clipping filter h (n),
2. the self-adapting peak-clipping method of multicarrier system as claimed in claim 1 is characterized in that, the described multi-transceiver combination signal after the peak value adjustment is carried out adaptive peak clipping according to described multi-carrier peak-clipping coefficient, peak value adjustment amount comprise:
With a (i
Max) obtain for the pulse vector of offsetting with the h multiplication of vectors, the y (i) that then subtracts each other after obtaining upgrading with multi-transceiver combination data y (i) is the signal after the peak clipping,
y(i)=y(i)-a(i
max)·h'(j)，i∈[i
max-floor(N/2),i
max+floor(N/2)],
j=imod[i
max-floor(N/2)],h'(n)=h(n)max(abs(h))，
Wherein, floor is that abs is for asking absolute value to rounding under the data, and max () asks vector maximization.
3. the self-adapting peak-clipping method of multicarrier system as claimed in claim 2, it is characterized in that, described multi-transceiver combination signal y (i) is carried out the multi-stage iteration adaptive peak clipping, and all peak points of the signal of exporting after iteration self-adapting peak clipping repeatedly are less than peak value detection threshold A
1The time stop the iteration self-adapting peak clipping.
4. the adaptive peak clipping device of a multicarrier system is characterized in that, comprises receiver module, peak value adjusting module and peak-clipping module,
Described receiver module is for the multi-transceiver combination signal that receives multicarrier system;
Described peak value adjusting module is used for described multi-transceiver combination signal and peak value detection threshold are compared, and will carry out the peak value adjustment above the signal of peak value detection threshold, obtains the peak value adjustment amount;
Described peak-clipping module is used for determining the multi-carrier peak-clipping coefficient, and described multi-transceiver combination signal is carried out adaptive peak clipping according to described multi-carrier peak-clipping coefficient, peak value adjustment amount;
Wherein, described peak value adjusting module will carry out the peak value adjustment and comprise above the signal of peak value detection threshold:
Described peak value adjusting module is according to multi-transceiver combination signal y (i) and peak value detection threshold A
1, find out peak value window, namely | y (i) |〉A
1, i ∈ [i
1, i
2], wherein,
I=1,2 ..., T, x
k(i) be to process k the carrier signal that obtains through ovennodulation, spread spectrum and filtering, K is total carrier number, f
kBe the k carrier frequency point, f
sBe the digital intermediate frequency sampling frequency, T is the data number;
Described peak value adjusting module carries out the peak value adjustment, calculates maximal peak point and peak clipping threshold value A
2Difference so that the amplitude of difference and phase place and peak point remain unchanged a (i
Max)=y (i
Max)-A
2Exp (j*angle (y (i
Max))), A wherein
1〉=A
2
Wherein, described peak-clipping module determines that the multi-carrier peak-clipping coefficient comprises: described peak-clipping module is estimated and/or multicarrier weights calculative determination multi-carrier peak-clipping coefficient according to multi-carrier power;
Wherein, described peak-clipping module determines that the multi-carrier peak-clipping coefficient comprises:
Calculate the gain g of each carrier wave of multicarrier
k=p
kq
k, wherein, it is p that the power proportions of each carrier wave is closed
1: p
2: ...: p
K, the weights ratio of each carrier wave is q
1: q
2: ...: q
K
Design a prototype filter b (n), described prototype filter and single spectrum of carrier coupling according to the carrier frequency configuration, are moved the frequency domain of prototype filter on the center frequency point of each carrier wave, according to multicarrier gain g
k=p
kq
kAdjust every carrier gains, addition obtains multi-carrier peak-clipping filter h (n),
5. the adaptive peak clipping device of multicarrier system as claimed in claim 4 is characterized in that, the described multi-transceiver combination signal of described peak-clipping module after to the peak value adjustment carries out adaptive peak clipping according to described multi-carrier peak-clipping coefficient, peak value adjustment amount and comprise:
Described peak-clipping module is with a (i
Max) obtain for the pulse vector of offsetting with the h multiplication of vectors, the y (i) that then subtracts each other after obtaining upgrading with multi-transceiver combination data y (i) is the signal after the peak clipping,
y(i)=y(i)-a(i
max)·h'(j)，i∈[i
max-floor(N/2),i
max+floor(N/2)],
j=imod[i
max-floor(N/2)],h'(n)=h(n)max(abs(h))，
Wherein, floor is that abs is for asking absolute value to rounding under the data, and max () asks vector maximization.
6. the adaptive peak clipping device of multicarrier system as claimed in claim 5, it is characterized in that, described peak-clipping module carries out the multi-stage iteration adaptive peak clipping to described multi-transceiver combination signal y (i), and all peak points of the signal of exporting after iteration self-adapting peak clipping repeatedly are less than peak value detection threshold A
1The time stop the iteration self-adapting peak clipping.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010150248 CN102223338B (en) | 2010-04-15 | 2010-04-15 | Self-adaption peak clipping method and device of multi-carrier system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010150248 CN102223338B (en) | 2010-04-15 | 2010-04-15 | Self-adaption peak clipping method and device of multi-carrier system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102223338A CN102223338A (en) | 2011-10-19 |
| CN102223338B true CN102223338B (en) | 2013-10-16 |
Family
ID=44779770
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010150248 Active CN102223338B (en) | 2010-04-15 | 2010-04-15 | Self-adaption peak clipping method and device of multi-carrier system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102223338B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107783077A (en) * | 2016-08-25 | 2018-03-09 | 大连楼兰科技股份有限公司 | The method for crossing the processing of thresholding peak point |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102437994B (en) * | 2012-01-19 | 2014-05-21 | 电信科学技术研究院 | Crest clipping method and equipment for multiband broadband signal |
| CN103812811B (en) * | 2012-11-07 | 2017-08-25 | 京信通信系统（中国）有限公司 | Data signal peak power automaton and method |
| US9521024B2 (en) | 2013-03-18 | 2016-12-13 | Telefonaktiebolaget Lm Ericsson (Publ) | Device of crest factor reduction |
| US8792572B1 (en) * | 2013-05-30 | 2014-07-29 | Telefonaktiebolaget L M Ericsson (Publ) | Universal peak power reduction in communication radios |
| CN106034099B (en) * | 2015-03-12 | 2019-06-21 | 富士通株式会社 | Estimation device, compensation device and the receiver of the clipping distortion of multi-carrier signal |
| WO2016172860A1 (en) * | 2015-04-28 | 2016-11-03 | 华为技术有限公司 | Signal processing method and device |
| CN107743105B (en) * | 2017-09-15 | 2020-11-20 | 北京航天控制仪器研究所 | Crest factor reduction control method for multi-frequency digital communication system |
| WO2019095265A1 (en) * | 2017-11-17 | 2019-05-23 | Telefonaktiebolaget Lm Ericsson (Publ) | Device and method for signal processing in licensed assisted access radio system |
| CN110071892A (en) * | 2019-04-30 | 2019-07-30 | 中国联合网络通信集团有限公司 | A kind of method and device emitting signal |
| CN112968854B (en) * | 2021-02-03 | 2022-03-29 | 青岛鼎信通讯股份有限公司 | Segmentation threshold peak clipping method suitable for medium-voltage carrier system |
| CN114070699B (en) * | 2021-10-29 | 2023-08-08 | 白盒子(上海)微电子科技有限公司 | Peak factor reduction system |
| US11770284B1 (en) | 2022-05-23 | 2023-09-26 | Meta Platforms, Inc. | Per carrier scaling of a cancellation pulse of a multi-carrier signal |
| CN114978847B (en) * | 2022-06-29 | 2023-07-11 | 深圳市兆驰数码科技股份有限公司 | Peak-average ratio processing method, peak-average ratio processing device, electronic equipment and medium |
| CN115551003B (en) * | 2022-12-05 | 2023-04-07 | 南京典格通信科技有限公司 | Resource optimization peak reduction CFR implementation system and implementation method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1870616A (en) * | 2005-05-27 | 2006-11-29 | 华为技术有限公司 | Multi-carrier signal clipping device and method |
| CN101453440A (en) * | 2007-12-07 | 2009-06-10 | 大唐移动通信设备有限公司 | Method and apparatus for lowering multi-carrier signal PAR |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7418043B2 (en) * | 2000-07-19 | 2008-08-26 | Lot 41 Acquisition Foundation, Llc | Software adaptable high performance multicarrier transmission protocol |
-
2010
- 2010-04-15 CN CN 201010150248 patent/CN102223338B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1870616A (en) * | 2005-05-27 | 2006-11-29 | 华为技术有限公司 | Multi-carrier signal clipping device and method |
| CN101453440A (en) * | 2007-12-07 | 2009-06-10 | 大唐移动通信设备有限公司 | Method and apparatus for lowering multi-carrier signal PAR |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107783077A (en) * | 2016-08-25 | 2018-03-09 | 大连楼兰科技股份有限公司 | The method for crossing the processing of thresholding peak point |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102223338A (en) | 2011-10-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102223338B (en) | Self-adaption peak clipping method and device of multi-carrier system | |
| US7583583B2 (en) | System and method for reducing peak-to-average power ratio in orthogonal frequency division multiplexing signals using reserved spectrum | |
| US8259846B2 (en) | Apparatus and method for generating a multicarrier communication signal having a reduced crest factor | |
| CN101222468B (en) | Peak-to-average ratio restraining method and device in multi-carrier orthogonal frequency division multiplexing system | |
| CN101136890B (en) | Optimized multi-carrier signal slicing device and method therefor | |
| US8842757B2 (en) | Method and system for adaptive peak to average power ratio reduction in orthogonal frequency division multiplexing communication networks | |
| CN100454793C (en) | Method and device for reducing peak-to-average power ratio in mobile communication system using orthogonal frequency division multiplexing | |
| CN101227446A (en) | Method for reducing signal PAR based on self-adapting EVM | |
| Ghassemi et al. | Joint sidelobe and peak power reduction in OFDM-based cognitive radio | |
| CN101257481A (en) | System and method for cutting peak of preprocess discontinuousness allocating multiple carrier waves | |
| US20080112496A1 (en) | Peak-to-average-power reduction of OFDM signals | |
| Devlin et al. | Peak to average power ratio reduction technique for OFDM using pilot tones and unused carriers | |
| CN101848182A (en) | Method and device for realizing adaptive peak clipping | |
| Ortega et al. | Performance evaluation of GFDM over nonlinear channel | |
| CN100553244C (en) | A kind of method for lowering peak-flat ratio of low complexity orthogonal frequency division duplex communication system | |
| CN101483627B (en) | Method for reducing PAR of carrier signal | |
| US20130028160A1 (en) | Communication method and device for enhancing energy efficiency | |
| JP2002044054A (en) | Combination carrier transmission circuit with limiter circuit | |
| CN101369998B (en) | Digital despicking method and device | |
| US8654891B2 (en) | Peak suppressing apparatus, peak suppressing method and wireless communications apparatus | |
| Shaheen et al. | Modified square rooting companding technique to reduced PAPR for FBMC/OQAM | |
| Ghassemi et al. | PAPR reduction in OFDM based cognitive radio with blockwise-subcarrier activation | |
| CN101447966B (en) | A method of controlling self-adapting adjusting peak-to-average ratio of threshold | |
| Montalvo et al. | Comparison and analysis of PAPR reduction techniques in OFDMA and SC-FDMA systems | |
| Wei et al. | Performance analysize of joint processing of sidelobe suppression and PAPR reduction in NC-OFDM systems |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 100191 No. 40, Haidian District, Beijing, Xueyuan Road Patentee after: CHINA ACADEMY OF TELECOMMUNICATIONS TECHNOLOGY Address before: 100191 No. 40, Haidian District, Beijing, Xueyuan Road Patentee before: CHINA ACADEMY OF TELECOMMUNICATIONS TECHNOLOGY |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210615 Address after: 100085 1st floor, building 1, yard 5, Shangdi East Road, Haidian District, Beijing Patentee after: DATANG MOBILE COMMUNICATIONS EQUIPMENT Co.,Ltd. Address before: 100191 No. 40, Haidian District, Beijing, Xueyuan Road Patentee before: CHINA ACADEMY OF TELECOMMUNICATIONS TECHNOLOGY |