CN1131629C - Method and device for decreasing peak nean power ratio in multi-carrier communication system - Google Patents
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Abstract
The present invention belongs to the field of communication technology, which particularly to comprises the following steps that the power of an input signal of a power amplifier is reassigned through value conversion at the transmitting end; a switching point of the value conversion is determined according to the probability distribution of the input signal power; a rule of the value conversion is determined according to the requirements of the power of a power amplifier input signal; a received signal carries out the inverse conversion according to an inverse conversion rule corresponding to the transmitting end at the receiving end. The present invention can effectively reduce the peak-average power ratio of the power amplifier input signal by the corresponding lower amount of calculation and the real complexity so that non-linear distortion can be avoided when a power amplifier amplifies a signal.
Description
Technical field the invention belongs to communication technical field, and particularly control comprises the effective ways and the implement device thereof of the peak-to-average power ratio that transmits in the multi-carrier communications systems of orthogonal FDM communication system.
Background technology is present, and OFDM (OFDM) technology has been widely applied to digital audio broadcasting (DAB) as a kind of effective wideband transmit technology, digital video broadcasting (DVB), the numerous areas such as transmission of high definition TV (HDTV).But, adopting a subject matter of the system of OFDM technology is the ratio of the peak power and the average power of signal, be that peak-to-average power is more higher than (PAPR), this requires in the system transmitter power amplifier highly linear to cause nonlinear distortion when being avoided amplifying signal, thereby increased difficulty and cost that system realizes greatly, limited further developing of OFDM technology.Particularly for mobile intercommunication system, because transceiver volume and energy consumption are limited, this shortcoming is just more outstanding.And the multi-carrier transmission Scheme Selection of a communication system does not maximally utilise the power that system can use current.
In order to reduce the PAPR of signal in the ofdm communication system, people have done a large amount of research.Existing method roughly can be divided into two classes.
One class is before multiplexer input traffic to be handled, as shown in Figure 1a, to reduce the high possibility that produces of PAPR, as coding, the method for partial transmission sequence and selection mapping.When sub-carrier number was big, this several method all needed bigger amount of calculation or complexity.And at present practical ofdm system, sub-carrier number is generally all bigger, so its amount of calculation or complexity are difficult to accept often.And,, also need to increase extra expense and tell receiving terminal transmission coefficient that transmitting terminal is adopted or assembled scheme for partial transmission sequence and these two kinds of ways of selection mapping.
Another kind of is that the output stream to multiplexer is handled after multiplexer, shown in Fig. 1 b, to reduce the influence that the PAPR height causes, as the method for limit filtration and compand.Signal is carried out amplitude limit can introduce clipped noise, when with the way of filtering when eliminating these noises, can increase the PAPR of signal again again, thereby can not satisfy the requirement of system design.Also having a kind of method is to utilize compand technology in the non-uniform quantizing to reduce the PAPR of signal, leads compand and A leads compand as μ.In traditional communication system, when analog signal is carried out non-uniform quantizing,, can use the compand technology quantized interval of small-signal to be compressed, and the quantized interval of small-signal be expanded at receiving terminal at transmitting terminal in order to reduce quantizing noise.In the multi-carrier digital communications system, if at the transmitting terminal compressed signal, according to the input-output characteristic of compressor reducer, the average power of the signal after the compression can increase and peak power remains unchanged, and the PAPR of signal just can be reduced so.Though this way realizes simple, but because be respectively signal to be compressed and expands at the two ends that transmit and receive of system, and do not consider the probability distribution of signal power or amplitude, so increased the average power of the input signal of transmitting terminal power amplifier, signal after the feasible compression is non-linear responsive more to power amplifier, finally causes system performance degradation.
Summary of the invention the objective of the invention is to for overcoming the weak point of prior art, a kind of method and apparatus that reduces the peak-to-average power ratio of signal in the multi-carrier communications systems is proposed, it can be with relative smaller calculation and implementation complexity, reduce the PAPR of the input signal of power amplifier effectively, cause nonlinear distortion when avoiding the power amplifier amplifying signal.
A kind of method of coming the peak-to-average power ratio of signal in the reduction system by numerical transformation of the present invention.This method is before the D/A switch or in D/A switch, and the range value of input signal each point is mapped as the range value of output signal according to specific functional relation, and this output signal satisfies the requirement of system's intermediate power amplifier to signal PAPR.In other words, this method is the transmitting terminal in communication system, by numerical transformation the power of signal is redistributed, and strengthens small-signal and weakens large-signal simultaneously, not only reduces the PAPR of signal but also the noise robustness of raising small-signal.Be appreciated that receiving terminal,, need before signal decision, carry out corresponding inverse transformation to received signal, promptly weaken small-signal and strengthen large-signal simultaneously in order to make correct signal decision for communication system.Because the power amplifier of receiving terminal is generally the small signal power amplifier, it can have good linear properties, so inverse transformation does not have too much influence to the performance of whole system.
This method specifically may further comprise the steps:
The first step, at transmitting terminal, determine the numerical transformation transfer point: according to the probability distribution of input signal power, obtain the desired value (average statistical) of signal power, it is used for determining the transfer point of numerical transformation, promptly just strengthen conversion, just weaken conversion for signal greater than this point value for signal less than this point value; (usually, for different systems, determine the needed characteristics of signals of numerical transformation, comprise that statistical property and temporal properties may be different, wherein the simplest is exactly that the desired value (average statistical) of utilizing signal power and peak value are determined parameter in the numerical transformation.)
In second step,, determine the rule of numerical transformation at transmitting terminal: establish input signal with x (t) expression, through y (t) expression of the output signal of numerical transformation, the rule of numerical transformation, the i.e. relation of Function Mapping between x (t) and the y (t) f[] expression.Among the present invention, f[] by f
1[] and f
2[] two parts are formed, condition below they satisfy:
Wherein
Expression takes absolute value; M is that the function input-output curve of this transformation rule correspondence comprises the conversion curve of linearity, piecewise linearity, non-linear symmetry and non-linear accurate symmetry by the transfer point parameter of the desired value of the signal power that draws in the first step and peak feature decision;
The 3rd step, at receiving terminal, determine to carry out to received signal the rule of the inverse transformation corresponding: same with transmitting terminal, if input signal is represented with x (t), output signal through the numerical value inverse transformation is represented with y (t), the rule of numerical value inverse transformation, the i.e. relation of Function Mapping between x (t) and the y (t) g[] expression.Among the present invention, g[] by g
1[] and g
2[] two parts are formed, condition below they satisfy:
Wherein
Expression takes absolute value; M ' be with second step in the corresponding transfer point parameter of parameter m that draws, the inverse transformation rule satisfies g[]=f
-1[].
This method can be used for comprising that the needs of multi-carrier communications systems reduce transmits peak-to-average power ratio or be equivalent to the system that reduces the peak-to-average power ratio that transmits.
The present invention is used for a kind of device that reduces the peak-to-average power ratio that transmits at the needs that comprise multi-carrier communications systems of said method.This device comprises that one is divided into input signal x (t) | x (t) | 〉=m and | x (t) | the two-part thresholding judging unit of＜m, a reception | x (t) | the expander of 〉=m part signal, a reception | x (t) | the compressor reducer of＜m part signal and a D/A that the digital signal that is applied behind compressed device and the expander is converted to analog signal, wherein m is the transfer point parameter of the desired value decision of the signal power obtained according to the probability distribution of input signal power, expander is decayed to signal, and the decay rule comprises linearity, piecewise linearity, the decay of non-linear symmetry and non-linear accurate symmetric form; Compressor reducer amplifies signal, amplifies the amplification that rule comprises linearity, piecewise linearity, non-linear symmetry and non-linear accurate symmetric form.
The another kind that the present invention is used for said method reduces the device of the peak-to-average power ratio that transmits.This device comprises that one is divided into input signal x (t) | x (t) | 〉=m and | x (t) | the two-part thresholding judging unit of＜m, a reception | x (t) | 〉=m part signal and expanding D/A and a reception that this signal is changed | x (t) |＜m part signal and the compression-type D/A that this signal is changed, wherein m is the transfer point parameter of the desired value decision of the signal power obtained according to the probability distribution of input signal power, the expanding D/A is decayed and digital-to-analogue conversion to signal, and the decay rule comprises linearity, piecewise linearity, the decay of non-linear symmetry and non-linear accurate symmetric form; The compression-type D/A amplifies and digital-to-analogue conversion signal, amplifies the amplification that rule comprises linearity, piecewise linearity, non-linear symmetry and non-linear accurate symmetric form.
Effect of the present invention is, not only reduced the PAPR of signal, the nonlinear distortion that has caused when having avoided the power amplifier amplifying signal effectively with relative smaller calculation and complexity.And improved the noise robustness of small-signal, under additive white Gaussian noise channel, performance of the present invention obviously is better than the method for existing employing limit filtration.
Description of drawings
Fig. 1 a is that traditional input traffic to multiplexer before multiplexer is handled schematic diagram.
Fig. 1 b is traditional schematic diagram of after multiplexer the output stream of multiplexer being handled.
Fig. 2 is four kinds of compand curves of four method embodiment correspondences of the present invention.
Fig. 3 is in method embodiment one of the present invention, the oscillogram of the signal before and after the conversion.
Fig. 4 a is the structured flowchart of first embodiment of converter proposed by the invention.
Fig. 4 b is the structured flowchart of second embodiment of converter proposed by the invention.
Fig. 5 is the block diagram of the transmitter and receiver of an employing multi-carrier communications systems of the present invention.
Fig. 6 is the performance comparison diagram of four method embodiment of the present invention and prior art.
Embodiment is below in conjunction with accompanying drawing, according to four method embodiment and two device embodiment and use and explain the present invention in more detail.
In the present invention, owing to be to strengthen small-signal and weaken large-signal simultaneously by small-signal compression is expanded large-signal simultaneously, therefore, the input-output curve of converter is called the compand curve, the regular f[that numerical transformation is followed] can show well by the input-output curve of converter, as shown in Figure 2.
In the method for the peak-to-average power ratio of signal, the shape that satisfies the compand curve of transformation rule has a variety of, corresponding different compand curves in the reduction multi-carrier communications systems that the present invention proposes, and the present invention provides four diverse ways embodiment.
Embodiment one, referring to Fig. 2, may further comprise the steps:
The first step at transmitting terminal, is determined the transfer point 44 of compand curve in the numerical transformation.At first, obtain its desired value according to the probability distribution of input signal power.Then the transfer point 44 of this desired value as compand, and make the ratio of compand identical, because its power equates greater than this desired value with less than the probability of this desired value for input signal, the gross power of signal is constant before and after the compand.As for the probability distribution of signal power, according to central limit law, the whose amplitude obeys Gaussian Profile of ofdm signal, its power is obeyed Chi-square and is distributed.Because for zero-mean, variance is δ
2Gaussian random variable X, stochastic variable Y=X
2Obey Chi-square and distribute, and E (Y)=δ
2,
E () expression peek term is hoped δ
y 2Variance for Y.For ofdm signal, δ
2Be exactly its average power, can be easy to try to achieve.Therefore, δ
2Be exactly the transfer point 44 pairing numerical value of compand.
In second step, at transmitting terminal, determine the rule of numerical transformation, i.e. the shape of compand curve in the numerical transformation.Its I/O map rule is as follows:
In the formula, parameter k, b are called as slope and intercept respectively, and they satisfy 0＜k＜1 and b=(1-k) * m respectively, and m is the desired value of input signal power herein;
The compand curve of present embodiment is about former point symmetry, is that compand curve on the occasion of part is shown in solid line among Fig. 2 42 for signal.Accordingly, this conversion is called " linear compression expansion ".
The 3rd step, at receiving terminal, determine the shape of compand curve in the inverse transformation, its I/O map rule is as follows:
In the formula, the k that parameter k ' draws in going on foot with second is consistent, parameter b ' satisfy b '=(1-k ') * m ', and m ' is the desired value of inverse transformer input signal power herein.
Fig. 3 is the design sketch of embodiment one, is illustrated among the described method embodiment one waveform transmitting terminal is done linear compression expansion (parameter k=0.1) to signal before and after.Present embodiment makes small-signal be enhanced, and large-signal is weakened simultaneously, and the peak value of signal is by good restraining.Signal after the process compand has reduced the linear requirement to the transmitter final-stage power amplifier, the nonlinear distortion that has caused when having avoided transmitter final-stage power amplifier amplifying signal.
Method embodiment two of the present invention: except that second transformation rule that adopted of step was compand curve and implementation difference thereof, other steps of this embodiment were identical with embodiment one.In described embodiment, the realization of transformation rule adopts digital operational circuit directly to carry out conversion, and finishes D/A switch simultaneously.The compand curve of embodiment two is about former point symmetry, for signal be on the occasion of the compand curve of part shown in solid line among Fig. 2 43, accordingly, this conversion is called " piecewise linearity compand ", its parameter is k.The I/O map rule of present embodiment is as follows:
Wherein, k be one less than 1 positive constant.
Method embodiment three of the present invention: except that second transformation rule that adopted of step was compand curve and implementation difference thereof, other steps of this embodiment were identical with embodiment one.In described embodiment, the realization of transformation rule adopts memory map assignments that input value is shone upon one by one, and finishes D/A switch simultaneously.The compand curve of present embodiment is about former point symmetry, for signal be on the occasion of the compand curve of part shown in dotted line among Fig. 2 40, accordingly, this conversion is called " non-linear symmetrical compand ", wherein, the companding rule adopts general μ to lead companding, and its parameter is compand rate u.
Method embodiment four of the present invention: except that second transformation rule that adopted of step was compand curve and implementation difference thereof, other steps of this embodiment were identical with embodiment one.In described embodiment, the realization of transformation rule adopts digital operational circuit directly to carry out conversion, and finishes D/A switch simultaneously.The compand curve of present embodiment is about former point symmetry, for signal be on the occasion of the compand curve of part shown in Fig. 2 dotted line 41, accordingly, this conversion is called " the symmetrical compand of non-linear standard ", wherein, the companding rule adopts general μ to lead companding, and its parameter is compand rate u.
Two embodiment of the converter that the present invention proposes are respectively described below as shown in Figure 4 in conjunction with the accompanying drawings:
Convertor device embodiment one of the present invention: for designing compandor and D/A respectively, shown in Fig. 4 a, this converter comprises 52, one compressor reducers 53 of 58, one expanders of a thresholding judging unit and a D/A 56.At first, with the output of IFFT digital signal processor 29 supplied with digital signal x (t) 30, and x (t) is divided into by a thresholding judging unit 58 as converter | x (t) | 〉=m and | x (t) | two parts of＜m.The thresholding judging unit can be realized with software program or thresholding decision circuitry, to cooperate the realization of follow-up equipment.Then | x (t) | the part 50 of 〉=m is sent to expander 52, | x (t) | the part 51 of＜m is sent to compressor reducer 53.(before the present invention, compressor reducer is normally used in mould/number conversion realizing non-uniform quantizing, because it compresses the quantized interval of small-signal, thereby is called as compressor reducer.And in the present invention, compressor reducer is used to strengthen small-signal; On the contrary, expander is used to weaken large-signal.This Application feasibility is to be guaranteed by the input-output characteristic of compressor reducer and expander.Usually, compressor reducer 53 and expander 52 can be made up of memory map assignments or digital operational circuit.) then, the digital signal after the compressed and expansion is applied, and forms the digital signal y (t) 54 that peak-to-average power ratio significantly reduces.At last, this digital signal is through the satisfactory analog signal 32 of D/A output peak-to-average power ratio.
Convertor device embodiment two of the present invention: compandor and D/A are carried out co-design.Shown in Fig. 4 b, converter comprises 58, one expanding D/As 56 of a thresholding judging unit and a compression-type D/A 57.In the present embodiment, adopt digital operational circuit that input value is directly carried out conversion according to predetermined functional relation to input value, and finish D/A switch simultaneously.The thresholding judging unit can be realized with software program or thresholding decision circuitry, to cooperate the realization of follow-up equipment.Then | x (t) | part 50 Hes of 〉=m | x (t) | the part 51 of＜m is sent to expanding D/A 56 and compression-type D/A 57 respectively, and their output stack just can be obtained the satisfactory analog signal 32 of peak-to-average power ratio.
Adopt the embodiment of the transceiver of multicarrier intercommunication system of the present invention to constitute as shown in Figure 5, but being appreciated that four method embodiment of the present invention are not limited in is used in the bi-directional communication device, so the multi-carrier communication transmitter can be thought the equipment with multi-carrier communication receiver physical separation.
In the present embodiment, the data symbol stream 24 of the information of carrying that information source 23 produces is sent to encoder 25, and encoder 25 carries out source encoding and chnnel coding to information successively.The purpose of source encoding is the redundancy of packed data symbols streams 24 entrained information normally, to transmit more information in the same time.Chnnel coding then normally by increase correlation between data come enhanced system when information is recovered anti-interference or carry out error control.The binary serial data stream 26 that encoder 25 produces becomes the binary system parallel data stream through deserializer 27.28 pairs of binary system parallel data streams of modulator carry out first time modulation, and binary data on each parallel channel is mapped as point on the signal constellation which, the i.e. data of plural form.In multi-carrier communications systems,, can adopt different modulation systems to the output stream of each parallel channel in order to adapt to the time dependent channel of frequency response.In described embodiment, to consider that its frequency response change of general channel is not too violent, thereby all adopt identical modulation system for each passage, its mapping relations are as shown in table 1 below, promptly so-called quaternary PSK (QPSK), wherein
Table 1 quaternary PSK
| Input | 00 | ?01 | ?10 | ?11 |
| Output | -1-i | ?-1+i | ?1-i | ?1+i |
Then, the parallel sequence of 29 pairs of these complex values of IFFT digital signal processor is carried out the modulation second time, simultaneously the data flow of each passage is merged into serial data stream.Handle because digital signal is carried out IFFT, be equivalent to original signal be carried out frequency modulation(FM), so this process is also referred to as OFDM with one group of orthogonal sine (cosine) signal.Then, the serial data stream after the modulation 30 is sent to converter 31.According to the requirement of system and the equipment that can provide, converter 31 can shine upon input value according to predetermined functional relation one by one by memory map assignments, to satisfy desired PAPR.Output numerical value with memory map assignments carries out D/A switch then, and the mapping precision is by the capacity decision of memory map assignments.Perhaps converter 31 adopts digital operational circuits that input value is directly carried out conversion according to predetermined functional relation to input value, satisfying desired PAPR, and finishes D/A switch simultaneously.The analog signal 32 of converter output is sent to the late-class circuit (not drawing among the figure) that comprises power amplifier at last.At this moment, the PAPR of the analog signal 32 of converter output is fit to the requirement of final-stage power amplifier, and promptly signal can ingoing power amplifier nonlinearity district, so that can not cause nonlinear distortion.
The signal that inverse transformer 33 is sent receiver 22 front-end circuits (not drawing among the figure) here carry out with transmitter 21 in the opposite conversion of operation done of 31 pairs of signals 30 of converter.The design principle of inverse transformer and the design principle of converter are basic identical, promptly can the mould/number conversion of advanced row, input value is shone upon one by one according to predetermined functional relation by memory map assignments then, also can adopt digital operational circuit that input value is directly carried out conversion according to predetermined functional relation to input value, and finish mould/number conversion simultaneously.For inverse transformer 33, the selection of these two kinds of implementation methods not necessarily will be consistent with converter 31, and the requirement of receiver and the equipment that can provide should be provided.The output stream of inverse transformer 33 is finished demodulation, i.e. orthogonal frequency demultiplexing for the first time through FFT digital signal processor 34 earlier.Then the output of FFT digital signal processor 34 is sent to demodulator 35, finishes demodulation for the second time.Because channel disturbance and The noise, the input signal of demodulator 35 is compared with the output signal of the modulator 28 of transmitter 21, there is certain error, show and just be the skew of signal constellation point and rotation on the signal constellation which, therefore demodulator 35 will carry out signal decision, the signal that output conforms to the primary signal constellation point.Parallel-to-serial converter 36 is converted to serial data stream with the parallel data of demodulator 35 outputs.This serial data stream is admitted to decoder 37 then, and decoder 37 is finished channel-decoding and source coding successively.At last, decoder 37 outputs and raw information 24 essentially identical reception information 38 are to satisfy the requirement of the stay of two nights 39.
With the coding of introducing previously, partial transmission sequence and the method for selecting to shine upon are compared, and amount of calculation of the present invention and implementation complexity are obviously all much smaller.
Fig. 6 is the performance of the system of employing four method embodiment of the present invention and the performance comparison diagram of prior art.In all embodiments, ground is without loss of generality, multi-carrier communications systems is got 128 subcarriers and is adopted the QPSK modulation by rational setup parameter, four embodiment of the present invention can both be under the situation that does not increase average power, reduce the PAPR of signal: linear compression expansion (parameter k=0.5) and the symmetrical compand of non-linear standard (parameters u=1) reduce 4.1dB approximately, non-linear symmetrical compand (parameters u=4) reduces 2.9dB approximately, and piecewise linearity compand (parameter k=0.5) reduces 5.6dB approximately.As seen, the present invention can reduce the peak-to-average power ratio of signal greatly, has avoided signal ingoing power amplifier nonlinearity district, thereby has avoided the nonlinear distortion that causes thus.
Be provided with down in same parameter, for additive white Gaussian noise channel, when requiring bit error rate to equal 10
-5The time, linear compression expansion, piecewise linearity compand, non-linear symmetrical compand and the required signal to noise ratio of the symmetrical compand of non-linear standard are respectively 14dB, 13dB, 13.5dB and 12.2dB, and improve for same PAPR, adopting the required signal to noise ratio of method of existing limit filtration is 18dB.Compare with it, linear compression expansion, piecewise linearity compand, non-linear symmetrical compand and the symmetrical compand of non-linear standard have the improvement of 4dB, 5dB, 4.5dB and 5.8dB respectively.As can be seen, the performance improvement of using system of the present invention is tangible.
Certainly can understand that the description of front just provides by way of example, can make amendment within the scope of the invention.For example, can adopt other transformation rule, i.e. other the compand curve and the parameter plan of establishment, and other the physics realization mode that comprises hardware and software.
In present multi-carrier communications systems, the present invention can replace the method for existing limit filtration and compand fully.Simultaneously, for real-time as wireless multimedia communication have relatively high expectations and receiver should not be too complicated system, the present invention can be used as the peak-to-average power ratio that a candidate scheme reduces multi-carrier signal, and the advantage that keeps multi-carrier communications systems itself to be had.
Be noted that adopting multi-carrier communication technology of the present invention to be applied in the optical fiber telecommunications system goes.
Claims (6)
1, a kind of method that reduces the peak-to-average power ratio of signal in the multi-carrier communications systems, it is characterized in that, by numerical transformation the power of transmitting terminal power amplifier input signal is redistributed, is strengthened small-signal and weaken large-signal simultaneously, specifically may further comprise the steps:
The first step, at transmitting terminal, determine the numerical transformation transfer point: according to the probability distribution of input signal power, obtain the desired value of signal power, it is used for determining the transfer point of numerical transformation, just strengthen conversion for signal, just weaken conversion for signal greater than this point value less than this point value;
In second step,, determine the rule of numerical transformation at transmitting terminal: establish input signal with x (t) expression, through y (t) expression of the output signal of numerical transformation, the rule of numerical transformation, the i.e. relation of Function Mapping between x (t) and the y (t) f[] expression; Wherein, f[] by f
1[] and f
2[] two parts are formed, condition below they satisfy:
In the formula
Expression takes absolute value; M is that the function input-output curve of this transformation rule correspondence comprises the conversion curve of linearity, piecewise linearity, non-linear symmetry and non-linear accurate symmetry by the transfer point parameter of the desired value of the signal power that draws in the first step and peak feature decision;
The 3rd step, at receiving terminal, determine to carry out to received signal the rule of the inverse transformation corresponding: same with transmitting terminal, if input signal is represented with x (t), output signal through the numerical value inverse transformation is represented with y (t), the rule of numerical value inverse transformation, the i.e. relation of Function Mapping between x (t) and the y (t) g[] expression; Wherein, g[] by g
1[] and g
2[] two parts are formed, condition below they satisfy:
In the formula
Expression takes absolute value; M ' be with second step in the corresponding transfer point parameter of parameter m that draws, the inverse transformation rule satisfies g[]=f
-1[].
2, the method for claim 1 is characterized in that, in said second step, said I/O map rule is as follows:
In the formula, parameter k, b are called as slope and intercept respectively, and they satisfy 0＜k＜1 and b=(1-k) * m respectively;
3, the method for claim 1 is characterized in that, the I/O map rule in said second step is as follows:
Wherein, k be one less than 1 positive constant.
4, the method for claim 1 is characterized in that, at receiving terminal, determines the shape of compand curve in the inverse transformation in said the 3rd step, and its I/O map rule is as follows:
In the formula, the k that parameter k ' draws in going on foot with second is consistent, parameter b ' satisfy b '=(1-k ') * m ', and m ' is the desired value of inverse transformer input signal power herein.
5, a kind of device that adopts the method for claim 1, it is characterized in that, comprise that one is divided into input signal x (t) | x (t) | 〉=m and | x (t) | the two-part thresholding judging unit of＜m, a reception | x (t) | the expander of 〉=m part signal, a reception | x (t) | the compressor reducer of＜m part signal and a D/A that the digital signal that is applied behind compressed device and the expander is converted to analog signal, wherein m is the transfer point parameter of the desired value decision of the signal power obtained according to the probability distribution of input signal power, expander is decayed to signal, and the decay rule comprises linearity, piecewise linearity, the decay of non-linear symmetry and non-linear accurate symmetric form; Compressor reducer amplifies signal, amplifies the amplification that rule comprises linearity, piecewise linearity, non-linear symmetry and non-linear accurate symmetric form.
6, a kind of device that adopts the method for claim 1, it is characterized in that, comprise that one is divided into input signal x (t) | x (t) | 〉=m and | x (t) | the two-part thresholding judging unit of＜m, a reception | x (t) | 〉=m part signal and expanding D/A and a reception that this signal is changed | x (t) |＜m part signal and the compression-type D/A that this signal is changed, wherein m is the transfer point parameter of the desired value decision of the signal power obtained according to the probability distribution of input signal power, the expanding D/A is decayed and digital-to-analogue conversion to signal, and the decay rule comprises linearity, piecewise linearity, the decay of non-linear symmetry and non-linear accurate symmetric form; The compression-type D/A amplifies and digital-to-analogue conversion signal, amplifies the amplification that rule comprises linearity, piecewise linearity, non-linear symmetry and non-linear accurate symmetric form.
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|---|---|---|---|
| CN 01102211 CN1131629C (en) | 2001-01-18 | 2001-01-18 | Method and device for decreasing peak nean power ratio in multi-carrier communication system |
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| CN 01102211 CN1131629C (en) | 2001-01-18 | 2001-01-18 | Method and device for decreasing peak nean power ratio in multi-carrier communication system |
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| CN1131629C true CN1131629C (en) | 2003-12-17 |
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| CN 01102211 Expired - Fee Related CN1131629C (en) | 2001-01-18 | 2001-01-18 | Method and device for decreasing peak nean power ratio in multi-carrier communication system |
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Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3990974B2 (en) * | 2002-11-26 | 2007-10-17 | 株式会社日立コミュニケーションテクノロジー | Peak factor reduction device |
| US8422434B2 (en) * | 2003-02-18 | 2013-04-16 | Qualcomm Incorporated | Peak-to-average power ratio management for multi-carrier modulation in wireless communication systems |
| US7542517B2 (en) * | 2004-02-02 | 2009-06-02 | Ibiquity Digital Corporation | Peak-to-average power reduction for FM OFDM transmission |
| GB0519051D0 (en) * | 2005-09-19 | 2005-10-26 | Nokia Corp | Search algorithm |
| CN101056129B (en) * | 2007-05-18 | 2011-04-13 | 华为技术有限公司 | Carrier power allocation method and system for the same power amplification |
| US8358680B2 (en) * | 2008-12-23 | 2013-01-22 | Apple Inc. | Reducing power levels associated with two or more signals using peak reduction distortion that is derived from a combined signal |
| CN102497350B (en) * | 2011-12-23 | 2015-01-21 | 中国人民解放军国防科学技术大学 | OFDM (Orthogonal Frequency Division Multiplexing) peak-to-average power ratio lowering method based on constellation linear expansion |
| EP3089417A1 (en) | 2015-04-30 | 2016-11-02 | Thomson Licensing | Apparatus and method for reducing peak to average power ratio in a signal |
| CN111327558B (en) * | 2020-02-28 | 2022-06-21 | 杭州电子科技大学 | Method and system for GMM non-uniform quantization for filter multi-carrier modulation optical communication |
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