CN1889383A - AR model method and apparatus for lowering OFDM system peak-to-average power ratio - Google Patents

AR model method and apparatus for lowering OFDM system peak-to-average power ratio Download PDF

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CN1889383A
CN1889383A CNA2006101044229A CN200610104422A CN1889383A CN 1889383 A CN1889383 A CN 1889383A CN A2006101044229 A CNA2006101044229 A CN A2006101044229A CN 200610104422 A CN200610104422 A CN 200610104422A CN 1889383 A CN1889383 A CN 1889383A
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model
unit
ofdm
transfer function
side information
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CN100499394C (en
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杨刚
王科研
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Xidian University
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Abstract

This invention discloses an AR model method and a device for reducing mean power ratio of the OFDM system, which converts the parallel input sequences of the OFDM modulation signals to signals similar to white noises to reduce its self-correlation so as to reduce the PAPR of the OFDM system and complexity of computation, in which, an AR model mapping device is added at the sending end and an inverse AR model mapping device is added at the receiving end and the AR model mapping device includes an AR model unit, a mean power regulating parameter unit, a function transferring unit, a difference equation unit, a sideband information combination unit and a combining unit, the inverse AR model mapping device includes a separating unit, a sideband information splitting unit, a function transferring unit and a difference equation unit, which only needs one time of IFFT conversion and linear transformation to reduce the mean power ratio of a system peak so as to reduce the complexity of the system.

Description

Reduce the AR model method and the device of ofdm system peak-to-average power ratio
Technical field
The invention belongs to communication technical field, relate to peak-to-average power ratio PAPR (the Peak-to-Average Power Ratio) problem in orthogonal frequency division multiplex OFDM (the Orthogonal Frequency DivisionMultiplexing) communication system, specifically a kind of ofdm system peak-to-average power ratio and system complexity method of reducing undistortedly.
Background technology
The orthogonal frequency division multiplex OFDM technology is with its availability of frequency spectrum, good anti-multipath decline performance and be considered to one of core technology of the 4th third-generation mobile communication 4G efficiently, and the OFDM technology is obtaining extensive use in ADSL (Asymmetric Digital Subscriber Line) (ADSL), digital audio broadcasting (DAB) and fields such as digital television broadcasting (DVB), mobile communication and power line broadband data communication at present.
The basic principle of OFDM is exactly that data flow is at a high speed passed through string and conversion, is assigned in the relatively low experimental process channel of transmission rate and transmits.Because the symbol period in each subchannel can increase relatively, therefore can alleviate the influence of the multidiameter expansion of wireless channel.And can between the OFDM symbol, insert protection at interval, the order protection greater than the maximum delay expansion of wireless channel, so just can be eliminated because the intersymbol interference (ISI) that multipath brings at interval to greatest extent.And, generally all adopt Cyclic Prefix at interval, thereby can avoid the interchannel interference (ICI) that brings by multipath as protection.
Time domain sample sequence { the x of the OFDM of power normalization nAs follows: wherein N is a sub-carrier number, X kRepresent k the modulation symbol on the subcarrier.
x n = 1 N Σ k = 0 N - 1 X k exp ( j 2 πkn N ) n = 0,1 , . . . . . . , N - 1
Compare with single-carrier system, because the OFDM symbol is independently to be formed through the sub-carrier signal addition of ovennodulation by a plurality of, such composite signal just might produce bigger peak power (peak power), can bring bigger peak-to-average power ratio PAPR thus.Peak-to-average force ratio can be defined as:
PAPR ( dB ) = 10 log 10 max { | x n | 2 } n E { | x n | 2 }
This just requires some parts of system, for example power amplifier, A/D, and D/A converters etc. have very big linear dynamic range.And conversely, the non-linear of these parts also can produce nonlinear distortion to the bigger signal of dynamic range, and the harmonic wave that is produced can cause the phase mutual interference between subchannel, thereby influences the performance of ofdm system.
The method of existing reduction PAPR can be divided into following several: new component injection method comprises selectivity mapping (SLM), partial transmission sequence (PTS), carrier wave is studied in France (TR) in advance and carrier wave insertion (TI) etc.; The component revised law comprises amplitude limit (clipping), compression transform expansion (companding transform) and coding etc.; Operation rule change method comprises wavelet transformation etc.
Wherein the PTS method is the method that a kind of undistorted ground effectively reduces ofdm system PAPR, its basic principle is that the data symbol of input is divided into some groupings, by the auxiliary weight coefficient of suitable selection, just can make peak signal reach optimization, and then merge these groupings, thereby reduce PAPR.
Auxiliary theoretically weight coefficient b vCan [0,2 π) between get any number, but general b vCan be in a discrete phase sets value, when the scale of this set is bigger, for the PTS method that is divided into V subsequence, { b v, v=1,2 ..., the value of V} has P VKind.PTS of every enforcement just needs to calculate V N point IDFT conversion, then needs to calculate VP altogether VIndividual IDFT conversion, the operand of needed complex multiplication of the IDFT that each N is ordered and complex addition is respectively:
n mul = N 2 log 2 N
n add=Nlog 2N
This is a very white elephant for ofdm system.Though can be by restriction b vValue, adopt suitable dividing method and suboptimization algorithm to reduce computation complexity, but the complexity of ofdm system has still increased widely.
The content of invention
The object of the invention is to avoid the deficiency of above-mentioned prior art, by analyzing the basic reason that ofdm system PAPR problem produces, start with from the autocorrelation that reduces the parallel list entries of ofdm modulation signal, propose the autoregression AR model method that a kind of undistorted ground effectively reduces ofdm system PAPR, reduced the implementation complexity of ofdm system very effectively.
The foundation that realizes AR model method of the present invention is the autocorrelation of ofdm modulation signal and the relation between the ofdm system PAPR.The instantaneous power P of ofdm signal c(t)=x (t) x *(t) be:
P c ( t ) = 1 + 2 N Re { Σ k = 1 N - 1 e - j 2 πt Σ n = 0 N - 1 - k c n c * n + k }
Wherein x (t) is the OFDM time-domain signal, and N is the OFDM sub-carrier number, c nBe the OFDM modulated symbol.For any plural z, have inequality: Re (z)≤| z| and | ∑ z n|≤∑ | z n|.Therefore
P c ( t ) ≤ 1 + 2 N Σ k = 1 N - 1 | ρ ( k ) |
Wherein
ρ ( k ) = Σ n = 0 N - 1 - k c n c * n + k , ( k = 0,1 , · · · , N - 1 ) ,
ρ (k) expression auto-correlation coefficient aperiodic, | ρ (k) | the mould value of expression auto-correlation coefficient aperiodic.As seen, if the input data symbol aperiodic auto-correlation coefficient mould value smaller, then also can be less through the maximum power value of resulting signal after the multicarrier combination, the while amplitude of OFDM time-domain signal also can be less, so PAPR will diminish.AR model method of the present invention is exactly the signal that the parallel list entries of ofdm modulation signal is transformed into similar white noise, because the autocorrelation of white noise signal is very low, its, mould value of auto-correlation coefficient was also very little aperiodic, so this method can reduce the PAPR of ofdm system effectively.
The random signal of any reasonable power spectral density can be regarded as by a certain physical network of a white-noise excitation and be formed, according to this principle, we can use its anti-process, utilization is transformed into ofdm modulation signal the signal of similar white noise, make the autocorrelation of the parallel sequence of ofdm modulation signal fall very lowly, thereby effectively reduce the PAPR of ofdm system.In AR model method of the present invention, along with the increase of AR model order p, the PAPR performance is become better and better.The present invention adopts following process to carry out the reduction of PAPR and system complexity in ofdm system.
Transmitting terminal
(1) according to the ofdm system parameter, coordinate PAPR and reduce degree and system complexity, select AR model order p, p is greater than zero integer less than sub-carrier number N, is used for determining AR model parameter { α 1, α 2..., α pIn the number of α;
(2) according to AR model order p that has selected and the parallel list entries of OFDM, determine AR model parameter { α by the Yule-Walker equation 1, α 2..., α pAnd determine AR Model Transfer function;
(3) according to the AR Model Transfer function of determining, determine that parameter M makes that the average power of ofdm signal is constant, and with AR model parameter { α 1, α 2..., α pAnd average power adjust parameter M and be combined into side information and transmit;
(4), determine ssystem transfer function H (z) according to AR Model Transfer function and parameter M;
(5) determine difference equation according to ssystem transfer function H (z);
(6) utilize difference equation that the OFDM symbol is carried out conversion, again with OFDM symbol and side information { α 1, α 2..., α pAnd M combination after, conversion sends through IFFT.
Receiving terminal
(1) signal that receives is carried out the FFT conversion after, original OFDM symbol is separated with side information;
(2) side information is split as { α 1, α 2..., α pAnd M, and according to { α 1, α 2..., α pAnd M determine ssystem transfer function H (z);
(3) utilize transfer function H (z) to determine difference equation;
(4) according to the definite difference equation of H (z) the original OFDM symbol that separation obtains is carried out conversion, convert primary signal to.
The device of realizing said method of the present invention comprises transmitting terminal and receiving terminal, and the characteristics of transmitting terminal are to have increased AR model mapper; The characteristics of receiving terminal are to have increased contrary AR model mapper;
The AR model mapper of transmitting terminal comprises: AR model unit, average power are adjusted parameter unit, transfer function unit, difference equation unit, side information assembled unit, assembled unit; Wherein:
The AR model unit is used for determining AR model order p, and determines AR model parameter { α according to the parallel list entries of the OFDM after string and the conversion 1, α 2..., α p, thereby determine AR Model Transfer function, { α simultaneously 1, α 2..., α pConstitute the first of the side information of transmission;
Average power is adjusted the parameter unit, is used to handle the AR model, determines the parameter M that makes that the ofdm signal average power remains unchanged, and M constitutes the second portion of the side information that needs transmission;
The transfer function unit is used to handle the AR model unit and average power is adjusted the data that the parameter unit sends, and determines ssystem transfer function H (z);
The difference equation unit is used for determining difference equation according to ssystem transfer function H (z), and the parallel list entries of the OFDM after string and the conversion is carried out conversion, makes its signal that becomes similar white noise, reduces its autocorrelation, thereby has reduced the PAPR of ofdm system;
The side information assembled unit is used for { α 1, α 2..., α pAnd M be combined into side information and transmit;
Assembled unit is used for parallel list entries of a frame OFDM and side information are combined into a complete OFDM symbol, sends to IFFT then.
The contrary AR model mapper of receiving terminal comprises separative element, side information split cells, transfer function unit, difference equation unit; Wherein:
Separative element, the Signal Separation that is used for receiving is a two paths of signals, one tunnel transmission side information, the original OFDM symbol of one tunnel transmission;
The side information split cells is used for side information is split into { α 1, α 2..., α pAnd M;
The transfer function unit is used to handle the side information { α that the side information split cells sends 1, α 2..., α pAnd M, and definite ssystem transfer function H (z);
The difference equation unit is used for determining difference equation according to ssystem transfer function H (z), and the original OFDM symbol that separative element separated is carried out conversion.
The present invention compares with the PTS method, has the following advantages:
1, a PTS conversion of the every enforcement of PTS method will be carried out VP VIndividual IFFT conversion, even use sub-optimal algorithm also to want VP IFFT conversion, and AR model method of the present invention only needs an IFFT conversion, has reduced system complexity widely;
2, the PTS method need be carried out searching of optimum side information by iterative algorithm, has increased the running time of system greatly, and the bright AR model method of we only carries out the once linear conversion, and is fast simple;
3, for the ofdm system of sub-carrier number N bigger (for example N=1024), the PAPR performance and the complexity performance of AR model method of the present invention are better than the PTS method.
4, by simulation result as can be seen, along with the increase of p value, the PAPR performance is become better and better.Work as p=N/3, with respect to original ofdm signal, the AR model method can have the improvement of about 2.2dB.When reaching identical PAPR performance, adopt adjacent dividing method, cutting apart several V is 32, alternative weighted number W is that 2 PTS method needs 64 IFFT at least, and AR model method (p=N/20) only needs an IFFT, obviously, adopt the complexity of the ofdm system of AR model method to reduce widely with respect to the PTS method.
Description of drawings
Fig. 1 is the AR model method flow chart that the present invention proposes
Fig. 2 is the AR model method ofdm system block diagram that the present invention proposes
Fig. 3 is an AR model mapper block diagram of the present invention
Fig. 4 is the contrary AR model mapper block diagram of the present invention
Fig. 5 is the complementary cumulative distribution function C of an AR model method of the present invention CDF comparison diagram
Embodiment
Followingly the present invention is described in further detail with reference to accompanying drawing.
With reference to Fig. 1, be used for AR model method of the present invention at ofdm system, carry out according to the following procedure:
The first step according to the ofdm system parameter, is coordinated PAPR and is reduced degree and system complexity, selects AR model order p;
The ofdm system parameter mainly contains: bandwidth, bit rate and time delay expansion.
The time delay expansion is decision protection length at interval directly, and generally protecting interlude length is 2 to 4 times that time delay is expanded mean-square value.In case determined protection at interval, the then symbol Cycle Length just can have been fixed, generally selecting the symbol Cycle Length is 5 times of protection gap length, like this owing to insert the signal to noise ratio loss of protecting the interval to be caused and have only about 1dB.To have determined after symbol period and the protection at interval, the quantity of subcarrier can directly utilize-and three dB bandwidth obtains divided by subcarrier spacing (promptly removing the inverse of the symbol period after the protection at interval).Perhaps, can utilize desired bit rate to determine the quantity of subcarrier divided by the bit rate in each subchannel.The bit rate of transmitting in each subchannel can be determined by modulation type, code rate and character rate.
After number of subcarriers was determined, (for example, N=1024), then system's implementation complexity can be very big, for effective reduction system implementation complexity, sacrificial section PAPR performance, can select AR model order p=N/20 if number of subcarriers is big; (for example, N=64), then system's implementation complexity is relatively low, therefore will reduce PAPR as far as possible, can select AR model order p=N/10 or p=N/3 if number of subcarriers is less.
Second step is according to AR model order p and the parallel list entries { x of ofdm system 1, x 2..., x N, determine AR model parameter { α by the Yule-Walker equation 1, α 2..., α p, thereby determine AR Model Transfer function D (z),
D ( z ) = 1 1 + Σ k = 1 p a k z - k
A wherein kBe AR model parameter { α 1, α 2..., α pInterior element;
The 3rd step is according to AR model parameter { α 1, α 2..., α pDetermine average power adjustment parameter M, and with AR model parameter { α 1, α 2..., α pAnd average power adjust parameter M and be combined into side information and transmit;
M ≈ | 1 + Σ k = 1 p a k e - jωk |
In the 4th step, determine ssystem transfer function H (z) according to AR Model Transfer function D (z) and average power adjustment parameter M;
H ( z ) = M 1 + Σ k = 1 p a k z - k
The 5th step, determine AR model mapper difference equation according to ssystem transfer function H (z),
Mw ( n ) = x ( n ) + &Sigma; k = 1 p a k x ( n - k ) , k < n
Wherein w (n) is the similar white noise signal after the conversion, and x (n) is the ofdm signal of input;
In the 6th step, according to AR model mapper difference equation the parallel list entries of OFDM is carried out conversion, again with OFDM symbol and side information { α 1, α 2..., α pAnd M combination after, conversion sends through IFFT;
The 7th step, the signal that receives carried out the FFT conversion after, original OFDM symbol is separated with side information;
In the 8th step, side information is split as { α 1, α 2..., α pAnd M, and according to { α 1, α 2..., α pAnd M determine ssystem transfer function H (z);
In the 9th step, determine contrary AR model mapper difference equation according to ssystem transfer function H (z);
x ( n ) = Mw ( n ) + &Sigma; k = 1 p a k x ( n - k ) , k < n
The tenth step, according to contrary AR model mapper difference equation to the FFT conversion after the separative element parallel sequence of original OFDM of separating carry out conversion, then through and the string conversion send.
With reference to Fig. 2, realize that the system and device of the inventive method comprises transmitting terminal and receiving terminal.Be characterized in having increased AR model mapper 4 at transmitting terminal; Increased contrary AR model mapper 16 at receiving terminal.
As shown in Figure 3, AR model mapper 4 is made up of AR model unit 19, average power adjustment parameter unit 20, side information assembled unit 21, transfer function unit 22, difference equation unit 23 and assembled unit 24.
As shown in Figure 4, contrary AR model mapper 16 is made up of separative element 25, side information split cells 26, transfer function unit 27 and difference equation unit 28.
According to Fig. 2, Fig. 3 and shown in Figure 4, the course of work that device enforcement AR model method of the present invention reduces ofdm communication system PAPR is as follows:
One, the transmitting terminal of ofdm communication system
The random data symbols streams that random signal generator 1 produces is as ofdm signal; through baseband modulator 2 modulation; can adopt QAM or QPSK modulation; ofdm signal is mapped as the signal of plural form; through deserializer 3 ofdm modulation signal is converted into parallel input signal then; promptly be assigned in the relatively low N of the transmission rate channel and transmit; again N parallel input signal carried out the mapping of AR model mapper 4; parallel input signal is transformed to the signal of similar white noise; reduce its autocorrelation to greatest extent; thereby effectively reduce the PAPR of ofdm system; through IFFT 5 conversion; change frequency-region signal into time-domain signal; by parallel-to-serial converter 6 parallel data stream is converted to serial data stream again; in order to eliminate intersymbol interference (ISI) to greatest extent; also between each OFDM symbol, insert protection at interval by protection interval inserter 7; the data flow of protection spacer 7 outputs is through digital to analog converter 8; digital signal is converted to analog signal; pass through low pass filter 9 filtering again; the signal of output sends to channel 10; this channel can be that wire message way also can be a wireless channel; if wireless channel; then need the data of low pass filter 9 outputs are carried out upconversion process, for example adopt additive white Gaussian noise (AWGN) channel.
In AR model mapper 4, the parallel input signal of OFDM is at first determined AR Model Transfer function through AR model unit 19, adjust parameter unit 20 by average power again and determine parameter M, adjust parameter M by transfer function unit 22 definite AR model mapper transfer function H (z) according to AR Model Transfer function and average power, determine difference equation according to AR model mapper transfer function H (z) by difference equation unit 23 then, come the parallel input signal of OFDM is carried out conversion by difference equation, be transformed into the signal of similar white noise, the autocorrelation of the parallel input signal of OFDM just has been lowered widely like this, thereby reduced the PAPR of ofdm system indirectly, and this conversion process all is linear, thereby it is too many can not to increase system complexity.Pass through side information assembled unit 21 in addition with AR model parameter { α 1, α 2..., α pAnd average power adjust parameter M and combine as side information and send to assembled unit 24, by assembled unit 24 the OFDM parallel signal of difference equation unit 23 conversion and side information are combined as a complete ofdm signal and send to IFFT5.
Two, the receiving terminal of ofdm communication system
At the ofdm communication system receiving terminal; at first will carry out filtering by low pass filter 16 through the signal that receives after the Channel Transmission; be digital signal through analog to digital converter 12 with analog signal conversion again; again after overprotection interval removal 13 is removed protection at interval; data are sent into deserializer 14; after the FFT15 conversion; time-domain signal is converted to frequency-region signal; recover by contrary 16 pairs of parallel signals that receive of AR model mapper again; by parallel-to-serial converter 17 parallel data stream is converted to serial data stream then, through base band demodulator 18 serial data stream is demodulated into the ofdm signal that will receive at last and sends.
In contrary AR model mapper 16, at first the signal after the FFT15 conversion is sent to separative element 25, original OFDM symbol is separated with side information, then side information is split by side information split cells 26, determine AR model mapper transfer function by transfer function unit 27 again, pass through the required contrary AR model mapper difference equation of difference equation unit 28 specified data conversion at last, the original OFDM symbol that separative element is separated carries out conversion, and sends to parallel-to-serial converter 17.
Effect of the present invention can further specify by Fig. 5.
Emulation 1
In order to illustrate that the present invention reduces the advantage of ofdm system complexity widely with respect to the PTS method, Fig. 5 has provided the CCDF CCDF curve of AR model method ofdm system with respect to the PTS method.CCDF promptly calculates the probability that peak-to-average power ratio surpasses a certain threshold value, and its mathematic(al) representation is:
Pr{PAPR>PAPR0}=1-(1-e -PAPR0) N
PAPR0>0
Simulated conditions is as follows: ofdm signal is produced by random signal source, the 4QAM modulation, and sub-carrier number is 1024, adopts 4096 IFFT, i.e. 4 times of over-samplings.
As seen from Figure 5, along with the increase of p value, when reaching identical PAPR value, the CDDF value of AR model method ofdm system is more and more littler, and promptly the PAPR performance is become better and better.Work as p=N/3, CCDF=10 -3The time, with respect to original ofdm signal, the AR model method can have the improvement of about 2.2dB.In addition among the figure also emulation adopt adjacent dividing method, cutting apart several V is 32, alternative weighted number W is 2 PTS method CCDF curve, comparative analysis AR model method CCDF curve and PTS method CCDF curve are as can be known, when reaching identical PAPR performance, the ofdm system complexity of AR model method is significantly less than the ofdm system complexity of PTS method, for example, works as CCDF=10 -3When the CCDF value is approximately 10.1dB, adopt adjacent dividing method, cutting apart several V is 32, alternative weighted number W is that 2 PTS method needs 64 IFFT at least, and AR model method (p=N/20) only needs an IFFT, and the complexity of ofdm system has reduced widely like this, and the PAPR performance does not become.In addition, the AR model is a linear model, therefore can not increase system complexity too much.
As long as the reception side information { α that receiving terminal can be correct 1, α 2..., α pAnd M, the bit error rate performance of AR model method ofdm system does not just have too big reduction.

Claims (2)

1. AR model method that reduces the ofdm system peak-to-average power ratio, it is characterized in that: the signal that the parallel list entries of ofdm modulation signal is transformed into similar white noise, its autocorrelation is reduced, thereby reduce the peak-to-average power ratio PAPR and the computation complexity of ofdm system effectively, the AR model method that is used to reduce PAPR carries out according to the following procedure:
Transmitting terminal
(1) according to the ofdm system parameter, coordinate PAPR and reduce degree and system complexity, select AR model order p;
(2) according to AR model order p and the parallel list entries { x of OFDM 1, x 2..., x N, determine AR model parameter { a by the Yule-Walker equation 1, a 2..., a p, and definite AR Model Transfer function D (z);
(3) according to the AR Model Transfer function D (z) that determines, determine the average power parameter M of ofdm signal, and with AR model parameter { a 1, a 2..., a pAnd average power adjust parameter M and be combined into side information and transmit,
M &ap; | 1 + &Sigma; k = 1 p a k e - j&omega;k |
A wherein kBe AR model parameter { a 1, a 2..., a pInterior element;
(4) according to AR Model Transfer function D (z) and average power parameter M, determine ssystem transfer function H (z);
H ( z ) = M 1 + &Sigma; k = 1 p a k z - k
(5) determine difference equation according to ssystem transfer function H (z),
Mw ( n ) = x ( n ) + &Sigma; k = 1 p a k x ( n - k ) , k < n
Wherein w (n) is the similar white noise signal after the conversion, and x (n) is the ofdm signal for input;
(6) utilize difference equation that the OFDM sign reversing is become similar white noise signal, again with OFDM symbol and side information { a 1, a 2..., a pAnd M combination after, conversion sends through IFFT;
Receiving terminal
(1) signal that receives is carried out the FFT conversion after, original OFDM symbol is separated with side information;
(2) side information is split as { a 1, a 2..., a pAnd M, and according to { a 1, a 2..., a pAnd M determine ssystem transfer function H (z);
(3) utilize ssystem transfer function H (z) to determine difference equation;
(4) with difference equation the original OFDM symbol that separation obtains is carried out conversion, be reduced into primary signal.
2. a device of realizing the described method of claim 1 comprises transmitting terminal and receiving terminal, it is characterized in that: increased AR model mapper at transmitting terminal; Increased contrary AR model mapper at receiving terminal;
Described AR model mapper comprises: AR model unit, average power are adjusted parameter unit, transfer function unit, difference equation unit, side information assembled unit, assembled unit; Wherein:
The AR model unit is used for determining AR model order p, and determines AR model parameter { a according to the parallel list entries of the OFDM after string and the conversion 1, a 2..., a p, thereby determine AR Model Transfer function, { a simultaneously 1, a 2..., a pConstitute the first of the side information of transmission;
Average power is adjusted the parameter unit, is used to handle AR Model Transfer function, determines the parameter M that makes that the ofdm signal average power remains unchanged, and M constitutes the second portion of the side information of transmission;
The transfer function unit is used to handle the AR model unit and average power is adjusted the data that the parameter unit sends, and determines ssystem transfer function H (z);
Difference equation is determined according to ssystem transfer function H (z) in the difference equation unit, and the parallel list entries of the OFDM after string and the conversion is transformed into similar white noise signal, reduces its autocorrelation, thereby reduces the PAPR of ofdm signal;
The side information assembled unit is used for { a 1, a 2..., a pAnd M be combined into side information and transmit;
Assembled unit is combined into a complete OFDM symbol with parallel list entries of the OFDM behind the frame transform and side information, sends to IFFT then;
Described contrary AR model mapper comprises separative element, side information split cells, transfer function unit, difference equation unit; Wherein:
Separative element, the Signal Separation that is used for receiving is a two paths of signals, one tunnel transmission side information, the original OFDM symbol of another road transmission;
The side information split cells is used for side information is split into { a 1, a 2..., a pAnd M;
The transfer function unit is used to handle the side information { a that the side information split cells sends 1, a 2..., a pAnd M, and definite ssystem transfer function H (z);
Difference equation is determined according to ssystem transfer function H (z) in the difference equation unit, and the original OFDM symbol that separative element separated is carried out conversion.
CNB2006101044229A 2006-07-28 2006-07-28 AR model method and apparatus for lowering OFDM system peak-to-average power ratio Expired - Fee Related CN100499394C (en)

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CN101035105B (en) * 2007-04-06 2010-11-03 西安电子科技大学 Method and device for reserving the sub-carrier to reduce the peak average power ratio of the OFDM system based on IFFT/FFT
CN102208931A (en) * 2010-03-29 2011-10-05 中兴通讯股份有限公司 Modeling method of multi-antenna channel antenna branch power ratio and modeling apparatus thereof
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CN101005478B (en) * 2007-01-18 2010-08-25 西安电子科技大学 Matrix block interveaving method and device for reducing OFDM system peak-to-average power ratio
CN101035105B (en) * 2007-04-06 2010-11-03 西安电子科技大学 Method and device for reserving the sub-carrier to reduce the peak average power ratio of the OFDM system based on IFFT/FFT
TWI449363B (en) * 2007-06-04 2014-08-11 Ibiquity Digital Corp Method and apparatus for implementing a digital signal quality metric
CN102208931A (en) * 2010-03-29 2011-10-05 中兴通讯股份有限公司 Modeling method of multi-antenna channel antenna branch power ratio and modeling apparatus thereof
CN102208931B (en) * 2010-03-29 2014-12-10 中兴通讯股份有限公司 Modeling method of multi-antenna channel antenna branch power ratio and modeling apparatus thereof

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