CN102480457B - Frequency offset compensation method of orthogonal frequency division multiplex access (OFDMA) system and apparatus thereof - Google Patents

Abstract

The invention relates to a frequency offset compensation method of an orthogonal frequency division multiplex access (OFDMA) system and an apparatus thereof. The method comprises receiving a time domain OFDM sequence in which a CP part is cut off; carrying out frequency offset compensation processing to the time domain OFDM sequence according to a frequency offset compensation expectation value of a user. In the invention, the multi-user frequency offset compensation in receiver baseband front processing can be realized. Self-inter-carrier interference (ICI) of the user can be effectively weakened. Link quality can be improved and system measuring accuracy can be increased. In addition, the apparatus is easy to be implemented and the apparatus can be flexibly used. Actual frequency offset estimation can be performed according to the link. Frequency offset compensation adjustment with arbitrary precision frequency offset sizes can be performed dynamically. A calibration result can be fully used so that the frequency offset compensation can be implemented with small cost and then the residual frequency offset can be compensated. The user frequency offset compensation can be performed on a pilot frequency symbol position and can be performed on a data symbol position, which is beneficial to system measurement on the pilot frequency symbol position and is good for processing on the data symbol position.

Description

The frequency bias compensation method of OFDMA system and device

Technical field

The present invention relates to communication technical field, relate in particular to frequency bias compensation method and the device of a kind of OFDMA (Orthogonal FrequencyDivision Multiplex Access, OFDM access) system.

Background technology

Be widely used in various wireless communication technology fields taking OFDMA as basic multiple access access, its user resources flexible configuration is convenient, but ICI (the Inter-carrier Interference between the user that the subcarrier energy leakage causing because of Frequency Synchronization reason causes, between subcarrier, disturb) and user's self self-ICI, user performance that will this receiving terminal of appreciable impact, particularly the interference rank of self-ICI can change with user self power, if certain user is because channel Doppler or upstream plant reason, can there is larger system frequency deviation, when serious, can cause link performance " flat " phenomenon.In addition, larger system frequency deviation, also can introduce stronger ICI distracter to communication system, and then affect the performance of receiver measurement index, as CQI (Channel Quality Indication, channel quality instruction) and CSI (Channel StateIndication, channel status instruction), when serious, even can cause receiver measured value to depart from truth completely, and then have a strong impact on upper strata scheduler judgement and systematic function.

Traditional frequency bias compensation method directly carries out in time domain, this kind of method inevitably needs each user to carry out FFT (Fast Fourier Transform, fast fourier transform)/IFFT (Inverse FastFourier Transform, invert fast fourier transformation) computing, or directly carry out compensate of frequency deviation at frequency domain by means of convolution algorithm, but the complexity of these methods, all with the proportional increase of number of users, implements and all has the problems such as hardware spending, computational complexity and computing relay are large.In addition, for the elimination of the residual frequency deviation after compensate of frequency deviation, traditional frequency bias compensation method needs again to implement secondary compensate of frequency deviation again, and its implementation complexity need to continue multiplication.Therefore, the realizing cost and will become very high because of factors such as its complexity, processing delay and computing expenses of traditional frequency bias compensation method.

Summary of the invention

Main purpose of the present invention is to provide a kind of frequency bias compensation method and device of OFDMA system, is intended to realize cost with less compensate of frequency deviation and improves systematic function.

In order to achieve the above object, the present invention proposes a kind of frequency bias compensation method of OFDMA system, comprising:

Receive the time domain OFDM sequence that has cut out CP part;

According to user's compensate of frequency deviation desired value, described time domain OFDM sequence is carried out to compensate of frequency deviation processing.

Preferably, described step of described time domain OFDM sequence being carried out to compensate of frequency deviation processing according to user's compensate of frequency deviation desired value comprises:

Described time domain OFDM sequence is carried out to P road time domain and proofread and correct processing, obtain the different time domain output sequence in P road, wherein P is natural number;

Described P road time domain output sequence is carried out respectively to FFT processing, obtain P road frequency domain output sequence;

From frequency domain output sequence described in each road, isolate the subcarrier set of each CU; Obtain each user's P way carrier set;

According to described each user's compensate of frequency deviation desired value, described each user's P way carrier set is weighted to merge by subcarrier and processes, obtain the subcarrier in frequency domain set after each user's compensate of frequency deviation.

Preferably, described P is definite according to multi-user's compensate of frequency deviation desired value distribution, and described multi-user's compensate of frequency deviation desired value distribution is expressed as [f ₀-ε ₀, f ₀+ ε ₀], wherein, f ₀for compensate of frequency deviation desired value distribution center, ε ₀for reference radius.

Preferably, work as ε ₀≤ 0.05 o'clock, P=2; Work as ε ₀=0.15 o'clock, P=3.

The present invention also proposes a kind of compensate of frequency deviation device of OFDMA system, comprising:

Receiver module, for receiving the time domain OFDM sequence that cuts out CP part;

Compensate of frequency deviation module, for carrying out compensate of frequency deviation processing according to user's compensate of frequency deviation desired value to described time domain OFDM sequence.

Preferably, described compensate of frequency deviation module comprises:

P time domain correcting unit, proofreaies and correct processing for described time domain OFDM sequence being carried out to P road time domain, obtains the different time domain output sequence in P road, and wherein P is natural number;

P FFT unit, for described P road time domain output sequence is carried out respectively to FFT processing, obtains P road frequency domain output sequence;

P sub-carrier separation unit, for isolating the subcarrier set of each CU from frequency domain output sequence described in each road; Obtain each user's P way carrier set;

Weighting merge cells, for according to described each user's compensate of frequency deviation desired value, is weighted to merge by subcarrier to described each user's P way carrier set and processes, and obtains the subcarrier in frequency domain set after each user's compensate of frequency deviation.

Preferably, described P is definite according to multi-user's compensate of frequency deviation desired value distribution, and described multi-user's compensate of frequency deviation desired value distribution is expressed as [f ₀-ε ₀, f ₀+ ε ₀], wherein, f ₀for compensate of frequency deviation desired value distribution center, ε ₀for reference radius.

Preferably, work as ε ₀≤ 0.05 o'clock, P=2; Work as ε ₀=0.15 o'clock, P=3.

Frequency bias compensation method and the device of a kind of OFDMA system that the present invention proposes, according to user's compensate of frequency deviation desired value, the time domain OFDM sequence that cuts out CP part receiving is carried out to compensate of frequency deviation processing, realize the multi-user's compensate of frequency deviation in the front-end processing of receiver base band, effectively weaken user's self-ICI, improve link-quality, improve systematic survey accuracy.Only need in the front-end processing of receiver base band, increase the correction of several roads, FFT computing (irrelevant with user's number) and simple weighting union operation (proportional with user's number).In the time of the reducing of user's frequency deviation distribution, correction in the inventive method and device and the way of FFT computing can be reduced to 3 tunnels, or even 2 tunnel, greatly reduce implementation complexity and the processing delay of device, reduce expense, in addition, device of the present invention is implemented simple, flexibly, can be according to the actual frequency offset estimation of link, dynamically carry out the compensate of frequency deviation adjustment of arbitrary accuracy frequency deviation size, and can make full use of calibration result, with compensating again of residual frequency deviation after very little cost enforcement compensate of frequency deviation, compensation user frequency deviation both can be carried out on pilot frequency symbol position, also can in data symbol positions, carry out, not only be conducive to the systematic survey at pilot frequency symbol position place, more be of value to the processing in data symbol positions.

Brief description of the drawings

Fig. 1 is the frequency bias compensation method one embodiment schematic flow sheet of OFDMA system of the present invention;

Fig. 2 is the schematic flow sheet that time domain OFDM sequence is carried out to compensate of frequency deviation processing according to user's compensate of frequency deviation desired value in frequency bias compensation method one embodiment of OFDMA system of the present invention;

Fig. 3 is the compensate of frequency deviation device one example structure schematic diagram of OFDMA system of the present invention;

Fig. 4 is the structural representation of the compensate of frequency deviation device one embodiment frequency deviation compensating module of OFDMA system of the present invention.

In order to make technical scheme of the present invention clearer, clear, be described in further detail below in conjunction with accompanying drawing.

Embodiment

Solution for embodiment of the invention is mainly to cut out CP (Cyclic Prefix according to user's compensate of frequency deviation desired value to what receive, Cyclic Prefix) part time domain OFDM sequence carry out compensate of frequency deviation processing, to weaken user's self-ICI, improve link-quality, improve systematic survey accuracy.

As shown in Figure 1, one embodiment of the invention proposes a kind of frequency bias compensation method of OFDMA system, comprising:

Step S101, receives the time domain OFDM sequence that has cut out CP part;

The present embodiment method running environment relates to base station upgoing O FDMA system, first the signal that base station receives from outside is processed through the RF processing unit of the receiver in base station, send into afterwards baseband processing unit and carry out respective handling, the process of the present embodiment method frequency deviation compensation deals is positioned at the front-end processing part of baseband processing unit, is specifically completed by the compensate of frequency deviation device that is arranged on baseband processing unit front end.

First, receive and cut out the time domain OFDM sequence that CP time domain OFDM symbol partly forms by compensate of frequency deviation device.

Step S102, carries out compensate of frequency deviation processing according to user's compensate of frequency deviation desired value to time domain OFDM sequence.

Wherein, user's compensate of frequency deviation desired value is the value that user that user determines according to actual needs considers appropriate.

In the time that the OFDM sequence receiving is carried out to compensate of frequency deviation processing, first time domain OFDM sequence is carried out to P road time domain and proofread and correct processing, obtain the different time domain output sequence in P road, wherein, P determines according to the distribution of multi-user's compensate of frequency deviation desired value; Afterwards, time domain output sequence is carried out to FFT processing, obtain P road frequency domain output sequence, the subcarrier set of isolating each CU from each road frequency domain output sequence; Obtain each user's P way carrier set, last, according to each user's compensate of frequency deviation desired value, each user's P way carrier set is weighted to merge by subcarrier and processes, obtain the subcarrier in frequency domain set after each user's compensate of frequency deviation.

As shown in Figure 2, step S102 comprises:

Step S1021, carries out P road time domain to time domain OFDM sequence and proofreaies and correct processing, obtains the different time domain output sequence in P road, and wherein P is natural number;

In the present embodiment, in the front-end processing of receiver base band, increase the time domain correction of several roads, FFT computing (irrelevant with user's number) and any compensate of frequency deviation compose operation (proportional with user's number), to the time domain OFDM sequence that cuts out CP part of input, utilize the calibration module that P road prestores to carry out different correction processing, and make all users' compensate of frequency deviation desired value distribution drop on interval [f ₀-ε ₀, f ₀+ ε ₀] in.Wherein, f ₀for compensate of frequency deviation desired value distribution center, ε ₀for reference radius, when this interval range less, such as ε ₀≤ 0.05 o'clock, select 2 tunnels proofread and correct, i.e. P=2, when this interval range larger, such as ε ₀, select 3 tunnels to proofread and correct, i.e. P=3 at=0.15 o'clock.

Carrying out P road time domain timing, the correction sequence that first P road prestored is by frequency deviation region center f ₀carry out the frequency deviation configuration of time domain, obtain required P road correction sequence, then P road correction sequence is carried out to pointwise product calculation with the time domain OFDM sequence of input respectively, obtain P road and proofread and correct output sequence.

Step S1022, carries out respectively FFT processing to P road time domain output sequence, obtains P road frequency domain output sequence;

Step S1023, the subcarrier set of isolating each CU from each road frequency domain output sequence; Obtain each user's P way carrier set;

To each road frequency domain output sequence, suppose to comprise M user, by the relations of distribution of each user's subcarrier, therefrom extract the subcarrier set of each CU, according to P road frequency domain output sequence, obtain altogether P*M sub-carrier set like this, each user has P way carrier set.

Step S1024, according to each user's compensate of frequency deviation desired value, is weighted to merge by subcarrier to each user's P way carrier set and processes, and obtains the subcarrier in frequency domain set after each user's compensate of frequency deviation.

The P*M obtaining according to a step S1023 carrier set, and by user's compensate of frequency deviation desired value, the P way carrier set of each CU is weighted to merge by subcarrier and processes, its weights are only relevant with this user's oneself compensate of frequency deviation desired value, repeat M time so like this, can obtain the subcarrier in frequency domain set after M user compensate of frequency deviation separately.

With instantiation, the present embodiment technical scheme is elaborated below.

Suppose to have an OFDM symbol (no matter being pilot tone or data symbol), clipping after CP, obtain N point time domain sequences x (n), n=0,1, Λ, N-1, u (u=1 ..., M) q of CU ^(u)the subscript collection of individual subcarrier is if all users' normalization compensate of frequency deviation desired value all falls within interval [f ₀-ε ₀, f ₀+ ε ₀], wherein f ₀represent interval center, i.e. compensate of frequency deviation desired value distribution center.

Step 1: the correction sequence that prestores β _λ(n) press compensate of frequency deviation scope center f ₀carry out the frequency deviation configuration of time domain, obtain required correction sequence wherein λ=1,2, Λ, P

${\mathrm{\β}}_{\mathrm{\λ}}\left(n\right)=\mathrm{ifft}\{a_{\mathrm{\λ}}\left(k\right)\·e^{j\frac{\mathrm{\π}}{N}k}\},\mathrm{\λ}=\mathrm{1,2},\mathrm{\ΛP}---\left(1\right)$

Wherein, a _λ(k) meet: as ε ∈ [ε ₀, ε ₀] time,

$a_{\mathrm{\λ}}\left(k\right)=\underset{\mathrm{\λ}=\mathrm{1,2,3}}{\underset{a_{\mathrm{\λ}}\left(k\right)}{\arg \min }}\left|\right|g(\mathrm{\ϵ},k)-\underset{\mathrm{\λ}=1}{\overset{P}{\mathrm{\Σ}}}{a}_{\mathrm{\λ}}\left(k\right)\·{\mathrm{\ϵ}}^{(\mathrm{\λ}-1)}\left|\right|---\left(2\right)$

$g(\mathrm{\ϵ},k)=\left\{\begin{array}{cc}N& \mathrm{\ϵ}=k=0\\ \sin (\mathrm{\π}\·\mathrm{\ϵ})/\sin \left(\frac{\mathrm{\π}}{N}(\mathrm{\ϵ}-k)\right)& \mathrm{\ϵ}\≠0\end{array}\right.$

An above-mentioned formula mistake! Do not find Reference source.) in, in the time of ε=0, make ε ₀=1.

represent to change A to make { } reach minimum, || { } || represent the norm (desirable 2 norms) of { }, a _λ(k) can be by calculating after simple numerical operation.

Step 2: with P road correction sequence to input correction module sequence x (n) carry out the different correction in P road, list entries x (n) respectively with P road correction sequence

carry out pointwise product calculation, obtain P road and proofread and correct output sequence y _λ(n)

Step 3: to the P road time domain correction sequence y of step 2 gained _λ(n) carry out respectively FFT processing, obtain sequences y after the correction of P road frequency domain _λ(k), k=0,1, Λ, N-1,

$Y_{\mathrm{\λ}}\left(k\right)=\underset{n=0}{\overset{N-1}{\mathrm{\Σ}}}{y}_{\mathrm{\λ}}\left(n\right)\·e^{-j\frac{2\mathrm{\π}}{N}\mathrm{nk}}---\left(4\right)$

Step 4: sequence Y after the correction of each the road frequency domain to step 3 gained _λ(k), by u (u=1 ..., M) the subcarrier subscript collection K of CU _uextract this user's subcarrier

$Y_{\mathrm{\λ}}^{\left(u\right)}\left(k\right)=Y_{\mathrm{\λ}}\left(k\right),k\∈K_u---\left(5\right)$

Step 5: to u user (u=1 ..., M) P way carrier wave collection λ=1,2, Λ, P, by weights γ _λ(ε _u) be weighted summation, wherein ε _urepresent u user's compensate of frequency deviation desired value, the user's subcarrier Z being so just eliminated after u user self-ICI ^(u)(k),

$Z^{\left(u\right)}\left(k\right)=\underset{\mathrm{\λ}=1}{\overset{P}{\mathrm{\Σ}}}{\mathrm{\γ}}_{\mathrm{\λ}}\left({\mathrm{\ϵ}}_u\right)\·Y_{\mathrm{\λ}}^{\left(u\right)}\left(k\right)---\left(6\right)$

${\mathrm{\γ}}_{\mathrm{\λ}}\left({\mathrm{\ϵ}}_u\right)=e^{j\frac{\mathrm{\π}}{N}(N-1)\·{\mathrm{\ϵ}}_u}\·{{\mathrm{\ϵ}}_u}^{\mathrm{\λ}-1}$

Repeating step five M time, can obtain all users (M user) and remove the subcarrier in frequency domain output Z after self-ICI ^(u)(k), u=1 ..., M.

It should be noted that, device of the present invention is mainly the compensate of frequency deviation problem in order to solve OFDMA system, each user's compensate of frequency deviation desired value is only as input parameter of the present invention, in addition, device of the present invention separates and is not also limited or describe in detail for user's subcarrier of multi-user, and user's compensate of frequency deviation desired value separates with user and can adopt various conventional or ripe algorithms.

Above-mentioned any frequency deviation refers to f ₀centered by, with ε ₀for reference radius with reference in scope, i.e. interval [f ₀-ε ₀, f ₀+ ε ₀] interior any frequency deviation, according to the scope of multi-user's frequency deviation distribution or the required enforcement of compensate of frequency deviation, can dynamically adjust the way P of the OFDMA sequence correction of input.

In the time carrying out the synthetic calculating of any compensate of frequency deviation of multi-user, after each user's of Jiang Mei road frequency domain output sequence subcarrier collection extracts, the multichannel subcarrier collection that belongs to certain user is carried out being weighted to merge by corresponding subcarrier processing, its weights only determine by this user's oneself compensate of frequency deviation desired value, and the compensate of frequency deviation between each user is processed uncorrelated mutually.

The present embodiment, in conjunction with actual OFDMA system, has been realized the multi-user's compensate of frequency deviation in the front-end processing of base station receiver base band with less cost, effectively weakens user's self-ICI, improves link-quality, improves systematic survey accuracy.

In addition, the present embodiment is simple, flexible, can be according to the actual frequency offset estimation of link, dynamically carry out the compensate of frequency deviation adjustment of arbitrary accuracy frequency deviation size, and can make full use of calibration result, after enforcement compensate of frequency deviation, residual frequency deviation compensates again, compensation user frequency deviation both can be carried out on pilot frequency symbol position, also can in data symbol positions, carry out, not only be conducive to the systematic survey at pilot frequency symbol position place, more be of value to the processing in data symbol positions.

As shown in Figure 3, one embodiment of the invention proposes a kind of compensate of frequency deviation device of OFDMA system, comprising: receiver module 301 and compensate of frequency deviation module 302, and the present embodiment device is arranged on the baseband processing unit front end of inner receiver processing section, base station, wherein:

Receiver module 301, for receiving the time domain OFDM sequence that cuts out CP part;

Receive and cut out the time domain OFDM sequence that CP time domain OFDM symbol partly forms by receiver module 301, and the different time domain correcting unit in P road in the time domain OFDM sequence input compensate of frequency deviation module 302 of receiving is proofreaied and correct to processing.

Compensate of frequency deviation module 302, carries out compensate of frequency deviation processing for the compensate of frequency deviation desired value according to user to time domain OFDM sequence.

In the present embodiment, user's compensate of frequency deviation desired value is the value that user that user determines according to actual needs considers appropriate.

In the time that the OFDM sequence receiving is carried out to compensate of frequency deviation processing, first compensate of frequency deviation module 302 is carried out time domain OFDM sequence P road time domain and is proofreaied and correct processing, obtain the different time domain output sequence in P road, wherein, P determines according to the distribution of multi-user's compensate of frequency deviation desired value; Afterwards, time domain output sequence is carried out to FFT processing, obtain P road frequency domain output sequence, the subcarrier set of isolating each CU from each road frequency domain output sequence; Obtain each user's P way carrier set, last, according to each user's compensate of frequency deviation desired value, each user's P way carrier set is weighted to merge by subcarrier and processes, obtain the subcarrier in frequency domain set after each user's compensate of frequency deviation.

As shown in Figure 4, compensate of frequency deviation module 302 comprises: time domain correcting unit 3021, FFT unit 3022, subcarrier separative element 3023, weighting merge cells 3024, wherein:

Time domain correcting unit 3021, proofreaies and correct processing for time domain OFDM sequence being carried out to P road time domain, obtains the different time domain output sequence in P road; Time domain correcting unit 3021 is P, and wherein P is natural number.

The correction sequence that P road time domain correcting unit 3021 is prestored by P road and P road multiplier form.

In the present embodiment, in the front-end processing of receiver base band, increase the time domain correction of several roads, FFT computing (irrelevant with user's number) and any compensate of frequency deviation compose operation (proportional with user's number), to the time domain OFDM sequence that cuts out CP part of input, utilize the calibration module that P road prestores to carry out different correction processing, and make all users' compensate of frequency deviation scope drop on interval [f ₀-ε ₀, f ₀+ ε ₀] in.Wherein, f ₀for compensate of frequency deviation scope center, ε ₀for reference radius, when this interval range less, such as ε ₀≤ 0.05 o'clock, select 2 tunnels proofread and correct, i.e. P=2, when this interval range larger, such as ε ₀, select 3 tunnels to proofread and correct, i.e. P=3 at=0.15 o'clock.

Carrying out P road time domain timing, first each time domain correcting unit 3021 prestores P road correction sequence by frequency deviation region center f ₀carry out the frequency deviation configuration of time domain, obtain required P road correction sequence, then P road correction sequence is carried out to pointwise product calculation with the time domain OFDM sequence that time domain correcting unit 3021 receives respectively, obtain P road and proofread and correct output sequence.

FFT unit 3022, for time domain output sequence is carried out to FFT processing, obtains P road frequency domain output sequence;

The number of FFT unit 3022 is corresponding with the number of time domain correcting unit 3021, is P.

Subcarrier separative element 3023, for the subcarrier set of isolating each CU from each road frequency domain output sequence; Obtain each user's P way carrier set;

The number of subcarrier separative element 3023 is corresponding with the number of time domain correcting unit 3021, for P, to each road frequency domain output sequence, suppose to comprise M user, by the relations of distribution of each user's subcarrier, therefrom extract the subcarrier set of each CU, like this according to P road frequency domain output sequence, obtain altogether P*M sub-carrier set, each user has P way carrier set.

Weighting merge cells 3024, for according to each user's compensate of frequency deviation desired value, is weighted to merge by subcarrier to each user's P way carrier set and processes, and obtains the subcarrier in frequency domain set after each user's compensate of frequency deviation.

Weighting merge cells 3024 gathers the shared subcarrier set of each user that comes from subcarrier separative element 3023, obtain P*M sub-carrier set, and by user's compensate of frequency deviation desired value, the P way carrier set of each CU is weighted to merge by subcarrier and processes, its weights are only relevant with this user's oneself compensate of frequency deviation desired value, repeat M time so like this, can obtain the subcarrier in frequency domain set after M user compensate of frequency deviation separately.

Because each user's synthetic calculating of any compensate of frequency deviation has same way of realization, therefore carry out the synthetic weighting merge cells 3024 calculating of any compensate of frequency deviation of multi-user and can split into the synthetic computing unit of several parallel any compensate of frequency deviation in alone family, its input comes from the P way carrier set of the unique user that P road frequency domain user's subcarrier separative element 3023 exports.

Frequency bias compensation method and the device of the OFDMA system that the embodiment of the present invention provides, can in frequency domain, carry out the compensate of frequency deviation of any frequency deviation size to any user simultaneously, effectively weaken the subcarrier energy leakage that user self frequency deviation causes, improve the performance of link performance " flat " effect and receiver measurement index.

In the time of the reducing of user's frequency deviation distribution, time domain in embodiment of the present invention method and apparatus is proofreaied and correct and the way of FFT computing can be reduced to 3 tunnels, or even 2 tunnel, greatly reduce implementation complexity and the processing delay of device, reduce expense, in addition, device of the present invention is implemented simple, flexibly, can be according to the actual frequency offset estimation of link, dynamically carry out the compensate of frequency deviation adjustment of arbitrary accuracy frequency deviation size, and can make full use of calibration result, with compensating again of residual frequency deviation after very little cost enforcement compensate of frequency deviation, compensation user frequency deviation both can be carried out on pilot frequency symbol position, also can in data symbol positions, carry out, not only be conducive to the systematic survey at pilot frequency symbol position place, more be of value to the processing in data symbol positions, thereby improve significantly the performance of system.

The foregoing is only the preferred embodiments of the present invention; not thereby limit the scope of the claims of the present invention; every equivalent structure or flow process conversion that utilizes specification of the present invention and accompanying drawing content to do; or be directly or indirectly used in other relevant technical field, be all in like manner included in scope of patent protection of the present invention.

Claims (6)

1. a frequency bias compensation method for OFDM access OFDMA system, is characterized in that, comprising:

Receive the time domain orthogonal frequency division multiple access OFDM sequence that has cut out CP part;

According to user's compensate of frequency deviation desired value, described time domain OFDM sequence is carried out to compensate of frequency deviation processing; Specifically comprise:

Described time domain OFDM sequence is carried out to P road time domain and proofread and correct processing, obtain the different time domain output sequence in P road, wherein P is natural number; Described P determines according to multi-user's compensate of frequency deviation desired value distribution;

Described P road time domain output sequence is carried out respectively to fast fourier transform FFT processing, obtain P road frequency domain output sequence;

From frequency domain output sequence described in each road, isolate the subcarrier set of each CU; Obtain each user's P way carrier set;

According to described each user's compensate of frequency deviation desired value, described each user's P way carrier set is weighted to merge by subcarrier and processes, obtain the subcarrier in frequency domain set after each user's compensate of frequency deviation.

2. method according to claim 1, is characterized in that, described multi-user's compensate of frequency deviation desired value distribution is expressed as [f ₀-ε ₀, f ₀+ ε ₀], wherein, f ₀for compensate of frequency deviation desired value distribution center, ε ₀for reference radius.

3. method according to claim 2, is characterized in that, works as ε ₀≤ 0.05 o'clock, P=2; Work as ε ₀=0.15 o'clock, P=3.

4. a compensate of frequency deviation device for OFDMA system, is characterized in that, comprising:

Receiver module, for receiving the time domain OFDM sequence that cuts out CP part;

Compensate of frequency deviation module, for carrying out compensate of frequency deviation processing according to user's compensate of frequency deviation desired value to described time domain OFDM sequence; Described compensate of frequency deviation module comprises:

P time domain correcting unit, proofreaies and correct processing for described time domain OFDM sequence being carried out to P road time domain, obtains the different time domain output sequence in P road, and wherein P is natural number; Described P determines according to multi-user's compensate of frequency deviation desired value distribution;

P FFT unit, for described P road time domain output sequence is carried out respectively to FFT processing, obtains P road frequency domain output sequence;

P sub-carrier separation unit, for isolating the subcarrier set of each CU from frequency domain output sequence described in each road; Obtain each user's P way carrier set;

Weighting merge cells, for according to described each user's compensate of frequency deviation desired value, is weighted to merge by subcarrier to described each user's P way carrier set and processes, and obtains the subcarrier in frequency domain set after each user's compensate of frequency deviation.

5. device according to claim 4, is characterized in that, described multi-user's compensate of frequency deviation desired value distribution is expressed as [f ₀-ε ₀, f ₀+ ε ₀], wherein, f ₀for compensate of frequency deviation desired value distribution center, ε ₀for reference radius.

6. device according to claim 5, is characterized in that, works as ε ₀≤ 0.05 o'clock, P=2; Work as ε ₀=0.15 o'clock, P=3.

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