CN103179059A - Method and device for eliminating inter-carrier interference (ICI) - Google Patents
Method and device for eliminating inter-carrier interference (ICI) Download PDFInfo
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Abstract
The invention discloses a method and a device for eliminating ICI. The method comprises the steps of obtaining channel time-domain information according to a receiving signal and a transmitting signal corresponding to the receiving signal; obtaining an inter-carrier interference factor corresponding to a channel according to the obtained channel time-domain information; and eliminating the ICI according to the inter-carrier interference factor. The method and the device solve the problems that the performance of an orthogonal frequency division multiplexing (OFDM) system is affected by the ICI caused by the fact that channel time-varying characteristics in the prior art damage the inter-carrier orthogonality in the system, so that the inter-carrier interference factor can be obtained according to the channel time-domain information, the corresponding ICI can be eliminated, the accuracy of balanced demodulation can be improved, and the performance of the system is optimized.
Description
Technical field
The present invention relates to the communications field, in particular to a kind of subcarrier interference ICI removing method and device.
Background technology
OFDM (Orthogonal Frequency Division Muhiplexing, referred to as OFDM) be a kind of digital multi-carrier modulation technique, its principle is after the data serial to parallel conversion, to be modulated on the closely-spaced orthogonal sub-carriers such as a group, this process can be by discrete Fourier transform (IFFT) realization, and OFDM is particularly useful for frequency-selective channel and high speed data transfers channel.In ofdm system, data symbol persistence length on each subcarrier increases relatively, thereby the intersymbol interference that the temporal dispersion that can effectively reduce wireless channel brings, be intersymbol interference (Inter-Symbol interference, referred to as ISI), therefore, reduced, in receiver, subcarrier is carried out to balanced complexity, sometimes even can not adopt equalizer, the method for only by employing, inserting Cyclic Prefix just can be eliminated the adverse effect of ISI.
Frequency spectrum between the subcarrier of ofdm system is overlapped, require between subcarrier mutually orthogonal, yet, the time variation of wireless channel, frequency error between frequency shift (FS) in signals transmission and system transmitter and receiver local oscillator all can destroy the orthogonality between the ofdm system subcarrier, and, the impact that OFDM is subject to frequency departure becomes in the time of can causing channel quick, for example, it is quick time-varying channel that Doppler under high-speed mobile condition (Doppler) frequency deviation causes channel, when bullet train moves with constant speed v, suppose when distinguishable multipath signal arrives receiver and the angle of the receiver direction of motion while being α, the centre frequency transmitted is f
cthe time, the Doppler frequency deviation f of direct wave
dfor:
Wherein, λ is the wavelength of carrier signal, f
max=v/ λ is maximum Doppler frequency deviation, and the Doppler frequency deviation is larger, and the channel temporal evolution is also just faster.
Therefore, wireless channel of the prior art can destroy the orthogonality between the ofdm system sub-carriers, causes the interference between subcarrier, affects the performance of system.
Summary of the invention
The invention provides a kind of subcarrier interference ICI removing method and device, at least to solve wireless channel of the prior art, can destroy the orthogonality between the ofdm system sub-carriers, cause the interference between subcarrier, affect the problem of the performance of system.
According to an aspect of the present invention, provide a kind of subcarrier interference ICI removing method, having comprised: according to receive signal and with corresponding the transmitting of described reception signal, obtain channel time domain information; According to the described channel time domain information of obtaining, obtain the mutual interference coefficient of subcarrier that described channel is corresponding; The mutual interference coefficient according to described subcarrier, eliminate the interference between described subcarrier.
Preferably, according to the described channel time domain information of obtaining, obtain the mutual interference coefficient of subcarrier that described channel is corresponding and comprise: according to the described channel time domain information got, set up channel time domain matrix hc; By formula H=Fh
cf
hcalculate equivalent channel frequency domain characteristic matrix, wherein, H is described equivalent channel frequency domain characteristic matrix, and F is Fourier transform matrix, F
hfor the discrete Fourier transform matrix, the mutual interference coefficient of subcarrier that the described channel of element representation in described equivalent channel frequency domain characteristic matrix is corresponding.
Preferably, also comprise: before the interference of eliminating between described subcarrier, described subcarrier is carried out to equilibrium.
Preferably, the interference of eliminating between described subcarrier comprises: calculate the signal interference ratio of the corresponding channel of each subcarrier, wherein, described signal interference ratio is that signal on described channel and described channel are to the ratio between the interference sum of other channel; According to signal interference ratio, order is from big to small eliminated the interference between described subcarrier successively.
Preferably, eliminate one of in the following manner the interference between described subcarrier: select a subcarrier, eliminate the interference of chosen other subcarrier of subcarrier pair; Perhaps, select a subcarrier, eliminate the interference of the selected subcarrier of other subcarrier pair.
Preferably, one of in the following manner described subcarrier is carried out to equilibrium: minimum variance LS equalization, least mean-square error MMSE equalization.
According to a further aspect in the invention, provide a kind of subcarrier interference ICI cancellation element, having comprised: the first acquisition module, for according to receive signal and with corresponding the transmitting of described reception signal, obtain channel time domain information; The second acquisition module, for the described channel time domain information according to obtaining, obtain the mutual interference coefficient of subcarrier that described channel is corresponding; Cancellation module, for the interference coefficient mutual according to described subcarrier, eliminate the interference between described subcarrier.
Preferably, described the second acquisition module comprises: the 3rd acquisition module, set up channel time domain matrix h for the described channel time domain information according to getting
c; Computing module, for passing through formula H=Fh
cf
hcalculate equivalent channel frequency domain characteristic matrix, wherein, H is described equivalent channel frequency domain characteristic matrix, and F is Fourier transform matrix, F
hfor the discrete Fourier transform matrix, the mutual interference coefficient of subcarrier that the described channel of element representation in described equivalent channel frequency domain characteristic matrix is corresponding.
Preferably, also comprise balance module, before the interference eliminating between described subcarrier, described subcarrier is carried out to equilibrium.
Preferably, described cancellation module comprises: the second computing module, and for calculating the signal interference ratio of the corresponding channel of each subcarrier, wherein, described signal interference ratio is that signal on described channel and described channel are to the ratio between the interference sum of other channel; The second cancellation module, for the foundation signal interference ratio, order is from big to small eliminated the interference between described subcarrier successively.
By the present invention, according to receiving signal and the channel time domain information that transmits get corresponding with receiving signal; Obtain the mutual interference coefficient of subcarrier that channel is corresponding; According to the interference coefficient got, eliminate the interference between subcarrier, solve channel time variation of the prior art and destroyed the orthogonality between the ofdm system sub-carriers, cause the interference between subcarrier, affect the problem of the performance of system, and then reached according to the interference coefficient between the channel time domain acquisition of information subcarrier of channel, thereby between corresponding subcarrier, disturbing and eliminated, improved the accuracy of equalizing demodulation, the effect of optimization system performance.
The accompanying drawing explanation
Accompanying drawing described herein is used to provide a further understanding of the present invention, forms the application's a part, and schematic description and description of the present invention the present invention does not form inappropriate limitation of the present invention for explaining.In the accompanying drawings:
Fig. 1 is the flow chart according to the subcarrier interference ICI removing method of the embodiment of the present invention;
Fig. 2 is the structured flowchart according to the subcarrier interference ICI cancellation element of the embodiment of the present invention;
Fig. 3 is the structured flowchart according to the second acquisition module of the subcarrier interference ICI cancellation element of the embodiment of the present invention;
Fig. 4 is the structured flowchart of subcarrier interference ICI cancellation element according to the preferred embodiment of the invention;
Fig. 5 is the structured flowchart according to the cancellation module 26 of the subcarrier interference ICI cancellation element of the embodiment of the present invention;
Fig. 6 is the structural representation of expression H under time varying channel according to the embodiment of the present invention;
Fig. 7 is the flow chart according to the LS serial iteration ICI removing method of the embodiment of the present invention;
Fig. 8 is the flow chart according to the MMSE serial iteration ICI removing method of the embodiment of the present invention;
Fig. 9 is the simulated effect figure according to employing first channel model of the embodiment of the present invention;
Figure 10 is the simulated effect figure according to the employing second channel model of the embodiment of the present invention.
Embodiment
Hereinafter with reference to accompanying drawing, also describe the present invention in detail in conjunction with the embodiments.It should be noted that, in the situation that do not conflict, embodiment and the feature in embodiment in the application can combine mutually.
In following each embodiment, communication can realize by wireless connections or wired connection or its both combination, and the present invention does not do restriction to this.
A kind of subcarrier interference ICI removing method is provided in the present embodiment, and Fig. 1 is that as shown in Figure 1, the method comprises the steps: according to the flow chart of the subcarrier interference ICI removing method of the embodiment of the present invention
Step S102, according to receive signal and with corresponding the transmitting of this reception signal, obtain channel time domain information;
Step S104, according to this channel time domain information of obtaining, obtain the mutual interference coefficient of subcarrier that this channel is corresponding;
Step S106, the mutual interference coefficient according to this subcarrier, eliminate the interference between this subcarrier.
Pass through above-mentioned steps, consider time varying channel characteristic over time, the mutual interference coefficient of subcarrier corresponding to channel time domain acquisition of information channel by the time varying channel that gets, interference for this interference coefficient antithetical phrase intercarrier is eliminated, solved the time change due to channel in the prior art and caused the phase mutual interference between subcarrier, affected the problem of systematic function, the interference of antithetical phrase intercarrier is eliminated, improve the accuracy of subcarrier demodulation, promoted systematic function.
According to this channel time domain information of obtaining, obtaining the mutual interference coefficient of subcarrier that this channel is corresponding can realize in several ways, for example, can rely on the channel estimating of technical staff to each channel, the channel tap information of obtaining according to channel estimating, obtain the correlation (correlation of this interchannel means by interference coefficient) of each interchannel by existing computational methods, by this correlation, obtain the interference between subcarrier corresponding on each channel.Again for example, the mode that can also calculate by math matrix is obtained the interference coefficient of each interchannel according to the tap information of each channel, for example, according to pilot reception signal and the pilot transmission signal corresponding with described reception signal, obtain the time-domain matrix information of channel (, the tap information of channel), set up channel time domain matrix hc according to the tap coefficient in this tap information got; By formula H=Fh
cf
hcalculate equivalent channel frequency domain characteristic matrix, wherein, H is this equivalence channel frequency domain characteristic matrix, and F is Fourier transform matrix, F
hfor the discrete Fourier transform matrix, the mutual interference coefficient of subcarrier corresponding to this channel of element representation in this equivalence channel frequency domain characteristic matrix.By such processing mode, tap information due to whole channels of enumerating in matrix, and the matrix operation through science, therefore, the interference coefficient of each interchannel obtained is comparatively objective, and just can clearly know the interference of channel corresponding to row or column to other channel by the row or column to corresponding in matrix.
When implementing, for the interference between the subcarrier that makes to obtain more accurate, before the interference of eliminating between this subcarrier, this subcarrier is carried out to equilibrium, or the interference that will eliminate subcarrier combines simultaneously and carries out with balanced process, adopt such processing mode, the intersymbol interference that can not only can avoid multipath to bring, can also eliminate the reduced complexity disturbed between subcarrier.Balanced purpose is to eliminate the interference between data symbol between subcarrier, it is the interference of intersymbol, subcarrier is carried out to balanced mode can be multiple, for example, can adopt the minimum variance equalization also can adopt the Minimum Mean Square Error equalization, the thinking difference that above-mentioned two kinds of equalization methods adopt while implementing, the physical parameter of required employing is also different, for example, the frequency-region signal of applying corresponding subcarrier when adopting the minimum variance equalization calculates, and the balanced rule of Minimum Mean Square Error is to obtain according to the equivalent channel frequency domain characteristic matrix of interference coefficient formation and the matrix operation between noise variance between subcarrier.
After having got the interference between subcarrier, can be eliminated according to the interference of the regular antithetical phrase intercarrier pre-established, for example, the rule set in advance can be signal interference ratio order from big to small, specific as follows: the signal interference ratio that calculates the corresponding channel of each subcarrier, wherein, this signal interference ratio is that signal on this channel and this channel are to the ratio between the interference sum of other channel; According to signal interference ratio, order is from big to small eliminated the interference between this subcarrier successively.Can certainly be eliminated by the rule of other formulation, for example, for example, for some specific subcarriers (interference of this other subcarrier of subcarrier pair is all maximum usually with respect to other subcarrier), need to pay close attention to constantly the interference of this other subcarrier of subcarrier pair, therefore, when obtaining the interference of this other subcarrier of subcarrier pair, with regard to the first interference caused to this other subcarrier of subcarrier pair, eliminated.After having obtained the interference coefficient between subcarrier, the interference of eliminating between subcarrier also can adopt multiple mode, for example, can select a subcarrier, eliminates the interference of chosen other subcarrier of subcarrier pair; Perhaps, also can select a subcarrier, eliminate the interference of the selected subcarrier of other subcarrier pair.
A kind of subcarrier interference ICI cancellation element is provided in the present embodiment, a kind of frequency offset processing device also is provided in the present embodiment, this device, for realizing above-described embodiment and preferred implementation, had carried out repeating no more of explanation.As used below, the combination of software and/or the hardware of predetermined function can be realized in term " module ".Although the described device of following examples is preferably realized with software, hardware, or the realization of the combination of software and hardware also may and be conceived.
Fig. 2 is the structured flowchart according to the subcarrier interference ICI cancellation element of the embodiment of the present invention, and as shown in Figure 2, this device comprises the first acquisition module 22, the second acquisition module 24 and cancellation module 26.Below this device is described.
The first acquisition module 22, for according to receive signal and with corresponding the transmitting of this reception signal, obtain channel time domain information; The second acquisition module 24, be connected to the first acquisition module 22, for this channel time domain information according to obtaining, obtains the mutual interference coefficient of subcarrier that this channel is corresponding; Cancellation module 26, be connected to the second acquisition module 24, for the interference coefficient mutual according to this subcarrier, eliminates the interference between this subcarrier.
Fig. 3 is the structured flowchart according to the second acquisition module of the subcarrier interference ICI cancellation element of the embodiment of the present invention, and as shown in Figure 3, this second acquisition module 24 comprises the 3rd acquisition module 242 and computing module 244.Below this second acquisition module is described.The 3rd acquisition module 242, set up channel time domain matrix h for this channel time domain information according to getting
c; Computing module 244, for passing through formula H=Fh
cf
hcalculate equivalent channel frequency domain characteristic matrix, wherein, H is this equivalence channel frequency domain characteristic matrix, and F is Fourier transform matrix, F
hfor the discrete Fourier transform matrix, the mutual interference coefficient of subcarrier corresponding to this channel of element representation in this equivalence channel frequency domain characteristic matrix.
Fig. 4 is the structured flowchart of subcarrier interference ICI cancellation element according to the preferred embodiment of the invention, as shown in Figure 4, this device is except comprising all modules shown in Fig. 2, also comprise balance module 42, this balance module 42, be connected to the second acquisition module 24 and cancellation module 26, before the interference eliminating between this subcarrier, this subcarrier carried out to equilibrium.
Fig. 5 is the structured flowchart according to the cancellation module 26 of the subcarrier interference ICI cancellation element of the embodiment of the present invention, as shown in Figure 5, this cancellation module 26 comprises: the second computing module 262, for calculating the signal interference ratio of the corresponding channel of each subcarrier, wherein, this signal interference ratio is that signal on this channel and this channel are to the ratio between the interference sum of other channel; The second cancellation module 264, for the foundation signal interference ratio, order is from big to small eliminated the interference between this subcarrier successively.
In the present embodiment, under the condition of the Obtaining Accurate characteristic of channel, adopt the method for iteration elimination, eliminate between subcarrier and disturb, effectively improve systematic function.The ICI removing method of a kind of LTE under the time varying channel condition is provided in the present embodiment, and the method comprises the steps:
S1, under the condition of Obtaining Accurate channel tap information, set up channel " circulation " the convolution matrix h of OFDM symbol in time domain
c;
S2, according to the time domain channel matrix, calculate the frequency domain equivalent channel matrix, H=Fh
cf
h, wherein, F and F
hbeing respectively FFT and IFFT transformation matrix, is all unitary matrice;
S3, according to the frequency domain equivalent channel matrix, calculate the signal interference ratio SIR on each subcarrier, and arranged the signal interference ratio on each subcarrier is descending;
S4, the subcarrier corresponding to maximum signal interference ratio carries out equalizing demodulation, then remaps;
S5, eliminate the impact of other subcarriers of subcarrier pair that rule out from the signal received, and the row corresponding with this subcarrier in this frequency domain equivalent channel matrix H be set to zero;
S6, repeating step S4, the order descending by SIR carried out equalizing demodulation successively.
By above-mentioned ICI removing method, accurately obtaining under the condition of channel tap information, the subcarrier larger to signal interference ratio carries out equalizing demodulation, simultaneously, eliminate the impact of these other subcarriers of subcarrier pair, just be equivalent to eliminate the interference ICI of this subcarrier on other subcarriers, method by iteration, eliminate successively the ICI on subcarrier, improved the accuracy of equalizing demodulation, optimized systematic function.
The ICI removing method of the embodiment of the present invention can be applied to the communication system under multiple time varying channel condition, the ICI removing method adopted also can be multiple, for example, minimum variance (Least Square, referred to as LS) serial iteration ICI removing method and least mean-square error (Minimum Mean Square Error, referred to as MMSE) serial iteration ICI removing method, below take respectively LS serial iteration ICI removing method and MMSE serial iteration ICI removing method to describe as example in long evolving system.
Before the above-mentioned two kinds of serial iteration ICI removing methods of explanation, the model of an ofdm system of given first.
Suppose in this ofdm system model to contain N subcarrier, the symbol of information source binary message after interweaving, encode, shining upon is x=[X[0], X[1], X[m] ... X[N-1]], obtain time-domain matrix x=[x (0) through N point IFFT modulating transformation afterwards, x (1) ... x (n), x (N-1)], wherein the pass between x (n) and X is:
x＝F
HX (1)
Wherein, F
hfor the IFFT matrix, ()
hmean transpose conjugate.For avoiding multipath to bring intersymbol interference (ISI), add Cyclic Prefix (CP) before each OFDM symbol, and CP length is greater than channel impulse response length L, the OFDM symbol is carried out through digital-to-analogue conversion (D/A), sending after parallel serial conversion.The rear reception signal y (n) obtained of x (n) the channel h (n, l) that now transmits can be expressed as:
y＝h
cx+w (2)
Wherein, h
cmean the channel time domain impulse response matrix, expression formula is suc as formula (3), and h (n, l) means the n tap coefficient of path l constantly.W is for adding part white Gaussian noise (AWGN).
At receiving terminal, supposing the system obtains accurate synchronization, after removing each OFDM symbol cyclic prefix (CP), carries out N point FFT demodulation, and the frequency domain obtained receives signal and is:
Y＝Fh
cF
HX+W＝HX+W (4)
Wherein, F is the FFT transformation matrix, the FFT conversion that W is white Gaussian noise w.Under time invariant channel, h
cbe Top's profit thatch (Toeplitz) matrix of ring shift right, H is the pair of horns battle array.And under time varying channel, h
cno longer the Toeplitz matrix of ring shift right, the vectorial h of row
neach tap be linear change.Channel convolution matrix h
cafter the diagonalization of formula (4), obtain:
H is the ICI matrix, and H is the off-diagonal matrix, is zonal distribution.Wherein a (i, j) means the ICI coefficient of i subcarrier of i-j subcarrier pair.As shown in Figure 6, Fig. 6 is the structural representation of expression H under time varying channel according to the embodiment of the present invention.
Utilize above-mentioned principle, at receiving terminal, suppose that accurate synchronization receives and can obtain the information of channel estimating, the method for the serial iteration elimination ICI that adopts the present invention to propose, can partly eliminate the interference between subcarrier, improves the performance of system.Below to describing for LS serial iteration ICI removing method in long evolving system and MMSE serial iteration ICI removing method respectively
Fig. 7 is that as shown in Figure 7, the method comprises the steps: at receiving terminal according to the flow chart of the LS serial iteration ICI removing method of the embodiment of the present invention
Step S702, channel estimating;
Step S704, obtain channel time domain information, or claim the time domain tap characteristic of channel, sets up time-domain pulse response matrix h
c;
Step S706, carry out diagonalization to the time-domain pulse response matrix obtained, and sets up equivalent channel frequency domain characteristic matrix H=Fh
cf
h;
Step S708, calculate the signal interference ratio of the corresponding channel of each subcarrier,
wherein, H
diag(k) mean to get the diagonal entry of H, H (k :)-H
diag(k) mean the off diagonal element in capable of k in H, the i.e. interference coefficient of k subcarrier;
Step S710, the SIR that step S808 is calculated is sorted, and takes out the subcarrier i of signal interference ratio maximum;
Step S712, carry out equilibrium to subcarrier i and obtain
by z
ijudgement obtains
Step S714, eliminate and receive i the ICI that other subcarriers of subcarrier pair produce in signal,
h wherein
ithe i row of representing matrix H;
Step S716, after the i row ZF to matrix H, repeating step S710, until all subcarrier demodulation are complete.
Fig. 8 is that as shown in Figure 8, the method comprises the steps: at receiving terminal according to the flow chart of the MMSE serial iteration ICI removing method of the embodiment of the present invention
Step S802, channel estimating;
Step S804, obtain channel time domain information, or claim time domain tap characteristic, sets up time-domain pulse response matrix h
c;
Step S806, carry out diagonalization to the time-domain pulse response matrix obtained, and sets up equivalent channel frequency domain characteristic matrix H=Fh
cf
h;
Step S808, calculate the signal interference ratio of the corresponding channel of each subcarrier,
wherein, H
diag(k) mean to get the diagonal entry of H, H (k :)-H
diag(k) mean the off diagonal element in capable of k in H, the i.e. interference coefficient of k subcarrier;
Step S810, the SIR that step S808 is calculated is sorted, and takes out the subcarrier i of signal interference ratio maximum;
Step S812, set up the balanced matrix of MMSE, G
h=(H
hh+ σ
2i
n)
-1h
h, wherein, I
nfor N * N unit matrix, σ
2for noise variance, g wherein
irow for G;
Step S814, carry out equilibrium to the subcarrier i of signal interference ratio maximum
wherein
for balanced matrix G
hin a line, then the judgement obtain
Step S816, eliminate and receive i the ICI that other subcarriers of subcarrier pair produce in signal,
h wherein
ithe i row of representing matrix H;
Step S818, after the i row ZF to matrix H, repeating step S810, until all subcarrier demodulation are complete.
The beneficial effect of above-described embodiment and preferred embodiment can be analyzed by the emulation of computer.Table 1 is the parameter adopted while according to the mode of the embodiment of the present invention, carrying out Computer Simulation, as shown in table 1:
Table 1
Fig. 9 is the simulated effect figure according to employing first channel model of the embodiment of the present invention, Figure 10 is the simulated effect figure according to the employing second channel model of the embodiment of the present invention, as shown in Fig. 9,10, it should be noted that, normalization Doppler frequency deviation in Fig. 9 is 0.1707, channel model is model 1, and namely the first footpath is that single-frequency is inclined to one side, the two-path model that the second footpath is Jakes.Normalization Doppler frequency deviation in Figure 10 is 0.1707, and channel model is model 2, and namely two footpaths are all the two-path model of Jakes.In Fig. 9,10, the performance that the method for using direct extraction channel tap coefficient is carried out to the serial iteration elimination by the method for LS and MMSE compares.Wherein real ". " line TV (time various) LS means that time varying channel is directly balanced by the LS method, and empty ". " line TV LS SIC (Successive Interference Cancellation) expression time varying channel is eliminated with LS method serial iteration; " △ " line TV MMSE means that time varying channel is directly balanced by the MMSE method in fact, and empty " △ " line TVMMSE SIC means MMSE method serial iteration elimination for time varying channel.From this figure, can obtain, there is certain advantage in the MMSE method than LS method aspect the improving of performance.Carry out the serial iteration elimination and really can be promoted performance, and, along with the increase of signal to noise ratio, the effect of lifting is more obvious.
Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with general calculation element, they can concentrate on single calculation element, perhaps be distributed on the network that a plurality of calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in storage device and be carried out by calculation element, and in some cases, can carry out step shown or that describe with the order be different from herein, perhaps they are made into respectively to each integrated circuit modules, perhaps a plurality of modules in them or step being made into to the single integrated circuit module realizes.Like this, the present invention is not restricted to any specific hardware and software combination.
The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.
Claims (10)
1. a subcarrier interference ICI removing method, is characterized in that, comprising:
According to receive signal and with corresponding the transmitting of described reception signal, obtain channel time domain information;
According to the described channel time domain information of obtaining, obtain the mutual interference coefficient of subcarrier that described channel is corresponding;
The mutual interference coefficient according to described subcarrier, eliminate the interference between described subcarrier.
2. method according to claim 1, is characterized in that, according to the described channel time domain information of obtaining, obtains the mutual interference coefficient of subcarrier that described channel is corresponding and comprise:
Set up channel time domain matrix h according to the described channel time domain information got
c;
By formula H=Fh
cf
hcalculate equivalent channel frequency domain characteristic matrix, wherein, H is described equivalent channel frequency domain characteristic matrix, and F is Fourier transform matrix, F
hfor the discrete Fourier transform matrix, the mutual interference coefficient of subcarrier that the described channel of element representation in described equivalent channel frequency domain characteristic matrix is corresponding.
3. method according to claim 1, is characterized in that, also comprises: before the interference of eliminating between described subcarrier, described subcarrier is carried out to equilibrium.
4. method according to claim 1, is characterized in that, the interference of eliminating between described subcarrier comprises:
Calculate the signal interference ratio of the corresponding channel of each subcarrier, wherein, described signal interference ratio is that signal on described channel and described channel are to the ratio between the interference sum of other channel;
According to signal interference ratio, order is from big to small eliminated the interference between described subcarrier successively.
5. method according to claim 1, is characterized in that, eliminates one of in the following manner the interference between described subcarrier:
Select a subcarrier, eliminate the interference of chosen other subcarrier of subcarrier pair; Perhaps, select a subcarrier, eliminate the interference of the selected subcarrier of other subcarrier pair.
6. method according to claim 3, is characterized in that, one of in the following manner described subcarrier carried out to equilibrium:
Minimum variance LS equalization, least mean-square error MMSE equalization.
7. a subcarrier interference ICI cancellation element, is characterized in that, comprising:
The first acquisition module, for according to receive signal and with corresponding the transmitting of described reception signal, obtain channel time domain information;
The second acquisition module, for the described channel time domain information according to obtaining, obtain the mutual interference coefficient of subcarrier that described channel is corresponding;
Cancellation module, for the interference coefficient mutual according to described subcarrier, eliminate the interference between described subcarrier.
8. device according to claim 7, is characterized in that, described the second acquisition module comprises:
The 3rd acquisition module, set up channel time domain matrix h for the described channel time domain information according to getting
c;
Computing module, for passing through formula H=Fh
cf
hcalculate equivalent channel frequency domain characteristic matrix, wherein, H is described equivalent channel frequency domain characteristic matrix, and F is Fourier transform matrix, F
hfor the discrete Fourier transform matrix, the mutual interference coefficient of subcarrier that the described channel of element representation in described equivalent channel frequency domain characteristic matrix is corresponding.
9. device according to claim 7, is characterized in that, also comprises balance module, before the interference eliminating between described subcarrier, described subcarrier carried out to equilibrium.
10. device according to claim 7, is characterized in that, described cancellation module comprises:
The second computing module, for calculating the signal interference ratio of the corresponding channel of each subcarrier, wherein, described signal interference ratio is that signal on described channel and described channel are to the ratio between the interference sum of other channel;
The second cancellation module, for the foundation signal interference ratio, order is from big to small eliminated the interference between described subcarrier successively.
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| WO2016019659A1 (en) * | 2014-08-07 | 2016-02-11 | 中兴通讯股份有限公司 | Inter-carrier interference cancellation method, apparatus and computer storage media |
| CN108234366A (en) * | 2016-12-14 | 2018-06-29 | 三星电子株式会社 | For the device and method of interference compensation between frequency domain carriers |
| CN110036678A (en) * | 2016-11-28 | 2019-07-19 | 三星电子株式会社 | Base station and its operating method in wireless communication system |
| CN111698185A (en) * | 2020-06-16 | 2020-09-22 | Oppo广东移动通信有限公司 | Carrier interference elimination method and device, electronic equipment and storage medium |
| CN112565141A (en) * | 2020-10-22 | 2021-03-26 | 浙江工商大学 | OFDM system multipath time-varying channel mixed interference resisting method adopting time domain filtering |
| CN113247050A (en) * | 2021-07-07 | 2021-08-13 | 天津七一二移动通信有限公司 | Method for realizing train approaching early warning and collision avoidance based on CSTMDMA |
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