CN102340473A - Noise signal estimation device and method - Google Patents

Abstract

The invention provides a noise signal estimation device and a method. The method comprises the steps of: selecting a subcarrier frequency band and constructing an interference matrix A (gamma) according to interference among subcarriers; and then calculating to obtain noise signals according to reference signals received by a receiving end and the interference matrix A (gamma). By adopting the technical scheme, the problem that noise is very difficult to estimate because of inter-carrier interference (ICI) caused by frequency deviation in the existing orthogonal frequency-division multiple access system is solved.

Description

A kind of estimation unit of noise signal and method

Technical field

The present invention relates to OFDMA (OFDM) system, be specifically related to a kind of estimation unit and method of noise signal.

Background technology

Noise Estimation is unusual important techniques in many communication systems, and the quality of Noise Estimation can have influence on the performance of receiver.In the OFDMA system, owing to have the influence of the Doppler frequency shift in crystal oscillator deviation and space, the frequency shift (FS) that can produce subcarrier, and cause inter-carrier interference (ICI) thus, and these disturb the accuracy that has influenced Noise Estimation to a certain extent.Therefore, can there be bigger deviation in the existence owing to these interference when receiving terminal carries out Noise Estimation with reference signal.Present Noise Estimation algorithm is difficult to accurately estimate the noise level of current demand signal when inter-carrier interference is bigger.

Summary of the invention

Technical problem to be solved by this invention provides a kind of estimation unit and method of noise signal, can solve between the subcarrier that the medium frequency skew of existing OFDMA system causes to disturb (ICI) noise estimation value to be had the problem of big difficulty.

The present invention provides a kind of method of estimation of noise signal, comprising:

Choose a subcarrier frequency range, according to the structure of the interference between subcarrier interference matrix A (γ); The reference signal and the said interference matrix A (γ) that receive according to receiving terminal afterwards calculate noise signal.

Further, establish in the said subcarrier frequency range of choosing and comprise the n number of sub-carrier;

Among the interference matrix A (γ) of said structure, capable all the other subcarriers of element representation of k are to the interference of k number of sub-carrier.

Further, the element of establishing said interference matrix is a _Kl, represent of the interference of l number of sub-carrier to the k number of sub-carrier;

When k=l, said $a_{\mathrm{Kl}}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\π\; \γ}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\π\; \γ}}{N}\right)}\right\}\mathrm{Exp}\left(\mathrm{J\π\; \γ}\frac{N-1}{N}\right);$

When k ≠ l, said $a_{k,l}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\π\; \γ}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\π}(l-k+\mathrm{\γ})}{N}\right)}\right\}\mathrm{Exp}(-\mathrm{J\π}\frac{l-k}{N})\mathrm{Exp}\left(\mathrm{J\π\; \γ}\frac{N-1}{N}\right).$

Further, when the said interference matrix A of structure (γ), only consider near the interference of 3 number of sub-carrier of current subcarrier to said current subcarrier, all the other subcarriers are to disturb to be designated as 0 to current subcarrier.

Further, said reference signal that receives according to receiving terminal and said interference matrix calculate noise signal and are meant,

Said A (γ) is disturbed addition, again sequence and the channel estimation sequence h that generates multiplied each other, obtain the reference signal sequence that adds after the interference not with noise, i.e. A (γ) * diag (reference) * h; If the reference signal that receiving terminal receives is receive_reference;

Said noise signal noise=receive_reference-A (γ) * diag (reference) * h;

Noise power spectral density then ${\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="Noise"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">Noise</figure-callout>}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{Noise}}_i\right|}^2.$

The present invention also provides a kind of estimation unit of noise signal, comprises choosing module and computing module;

The said module of choosing is used to choose a subcarrier frequency range;

Said conversion module is used for according to the structure of the interference between subcarrier interference matrix A (γ);

Said computing module is used for calculating noise signal according to reference signal and said interference matrix A (γ) that receiving terminal receives.

Further, establish in the said subcarrier frequency range of choosing and comprise the n number of sub-carrier;

Among the interference matrix A (γ) of said conversion module structure, capable all the other subcarriers of element representation of k are to the interference of k number of sub-carrier.

Further, the element of establishing said interference matrix A (γ) is a _Kl, represent of the interference of l number of sub-carrier to the k number of sub-carrier;

When k=l, said $a_{\mathrm{Kl}}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\&pi;\; \&gamma;}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\&pi;\; \&gamma;}}{N}\right)}\right\}\mathrm{Exp}\left(\mathrm{J\&pi;\; \&gamma;}\frac{N-1}{N}\right);$

When k ≠ l, said $a_{k,l}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\&pi;\; \&gamma;}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\&pi;}(l-k+\mathrm{\&gamma;})}{N}\right)}\right\}\mathrm{Exp}(-\mathrm{J\&pi;}\frac{l-k}{N})\mathrm{Exp}\left(\mathrm{J\&pi;\; \&gamma;}\frac{N-1}{N}\right).$

Further, said conversion module is only considered near the interference of 3 number of sub-carrier of current subcarrier to said current subcarrier when the said interference matrix A of structure (γ), and all the other subcarriers are to disturb to be designated as 0 to current subcarrier.

Further, the reference signal that receives according to receiving terminal of said computing module and said interference matrix calculate noise signal and are meant:

Said computing module disturbs addition to said A (γ), sequence and the channel estimation sequence h that generates is multiplied each other again, and obtains the reference signal sequence that adds after the interference not with noise, i.e. A (γ) * diag (reference) * h; If the reference signal that receiving terminal receives is receive_reference;

Said computing module calculates noise signal by following formula:

noise＝receive_reference-A(γ)*diag(reference)*h；

Corresponding noise power spectral density ${\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="Noise"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">Noise</figure-callout>}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{Noise}}_i\right|}^2.$

In sum, adopt the present invention can solve between the subcarrier that the medium frequency skew of OFDMA system causes and disturb (ICI) problem that influences, can estimate the noise power-value under the various channel circumstances exactly according to the present invention to Noise Estimation.

Description of drawings

Fig. 1 is apparatus of the present invention sketch mapes;

Fig. 2 is the inventive method implementing procedure figure;

Fig. 3 be in the LTE system sign bit and subcarrier concern sketch map;

Fig. 4 is the interference value sketch map on k number of sub-carrier and the adjacent subcarrier in the reference symbol.

Embodiment

Present embodiment provides a kind of estimation unit of noise signal, and is as shown in Figure 1, comprises choosing module, computing module and conversion module;

Choose module, be used to choose a subcarrier frequency range, establish this subcarrier frequency range and comprise the n number of sub-carrier;

Computing module is used for estimating frequency offseting value γ according to the frequency offset estimating algorithm, and γ is normalized frequency offseting value;

γ=freq_offset/ Δ f, Δ f is the frequency interval between subcarrier, freq_offset obtains the Frequency offset estimation value, the same prior art of the evaluation method of freq_offset according to correspondent frequency skew algorithm for estimating.

Computing module; Also be used for local reference signal reference is disturbed addition according to the interference matrix A (γ) that obtains; Be A (γ) * diag (reference), again sequence and the channel estimation sequence h that generates multiplied each other, obtain a reference signal sequence that adds after the interference not with noise; Be A (γ) * diag (reference) * h, and use formula

Noise=receive_reference-A (γ) * diag (reference) * h calculates signal noise noise.

Computing module can also be used to use following formula calculating noise power spectral density:

${\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="noise"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">noise</figure-callout>}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{noise}}_i\right|}^2.$

Conversion module is used for that the expression formula of inter-carrier interference I (k) is carried out conversion and obtains interference matrix A (γ) element a _KlExpression formula;

Wherein, k representes the row of interference matrix A (γ), and l representes the row of interference matrix A (γ), a _KlRepresent of the interference of l number of sub-carrier to the k number of sub-carrier.

Preferably, conversion module is only considered near the interference of 3 number of sub-carrier of current subcarrier to current subcarrier when the said interference matrix A of structure (γ), and all the other subcarriers are to disturb to be designated as 0 to current subcarrier.

Present embodiment provides a kind of method of estimation of noise signal, and is as shown in Figure 2, may further comprise the steps:

Step S1: choose a subcarrier frequency range, establish this subcarrier frequency range and comprise the n number of sub-carrier;

Step S2: estimate frequency offseting value γ according to the frequency offset estimating algorithm, γ is normalized frequency offseting value;

γ=freq_offset/ Δ f, Δ f is the frequency interval between subcarrier, freq_offset obtains the Frequency offset estimation value, the same prior art of the evaluation method of freq_offset according to correspondent frequency skew algorithm for estimating.

Step S3: following ofdm signal formula (1) is done corresponding conversion according to the OFDM characteristic

$Y\left(k\right)=\left(X\left(k\right)H\left(k\right)\right)\left\{\frac{\sin \left(\mathrm{\&pi;\&gamma;}\right)}{N\sin \left(\frac{\mathrm{\&pi;\&gamma;}}{N}\right)}\right\}\exp \left(\mathrm{j\&pi;\&gamma;}\frac{N-1}{N}\right)+I\left(k\right)+W\left(k\right)---\left(1\right)$

Can derive interference matrix and signal noise relationship expression (2):

A(γ)*diag(reference)*h+noise＝receive_reference (2)

K is the k number of sub-carrier, and γ is normalized frequency offseting value, and I (k) disturbs (ICI) between subcarrier, and W (k) is a noise sequence, and N is the signal sampling point.

A (γ) is an interference matrix; Noise is a signal noise; Receive_reference is the reference signal that receiving terminal receives, and reference is local reference signal, and diag (reference) is the diagonal matrix of being write as according to local reference signal; H is a channel estimation sequence, can calculate the channel estimation value h on the current subcarrier frequency range according to the channel estimation method in the OFDMA system.

And according to inter-carrier interference I (k) structure interference matrix A (γ);

Particularly, the expression formula of inter-carrier interference I (k) is:

$I\left(k\right)=\underset{l=0,l\&NotEqual;k}{\overset{N}{\mathrm{\&Sigma;}}}\left(X\left(l\right)H\left(l\right)\right)\left\{\frac{\sin \left(\mathrm{\&pi;\&gamma;}\right)}{N\sin \left(\frac{\mathrm{\&pi;}(l-k+\mathrm{\&gamma;})}{N}\right)}\right\}\exp \left(\mathrm{j\&pi;\&gamma;}\frac{N-1}{N}\right)\exp (-\mathrm{j\&pi;}\frac{l-k}{N})---\left(3\right)$

I (k) representes the interference sum of all the other subcarriers to subcarrier k;

Each element expression that can obtain among the interference matrix A (γ) according to the expression formula of above-mentioned I (k) is:

In the formula (4), k representes the row of interference matrix A (γ), and l representes the row of interference matrix A (γ), a _KlRepresent of the interference of l number of sub-carrier to the k number of sub-carrier.

Can formula (5) and formula (6) expression further be used in formula (4), promptly

$\mathrm{\&beta;}=\sin (\mathrm{\&pi;}*\mathrm{\&gamma;})*\exp (\mathrm{j\&pi;}*\mathrm{\&gamma;}*\left(\frac{N-1}{N}\right))---\left(5\right)$

w _i＝exp(-jπ*(i)/N)/(N*sin(π*(i+γ)/N))*β (6)

Formula (6) expression k+i number of sub-carrier d _K+iTo k number of sub-carrier d _kInterference.

Can obtain interference matrix A (γ) thus:

$A\left(\mathrm{\&gamma;}\right)=\left(\begin{array}{ccccc}{a}_{11}& a_{12}& a_{13}& ......& a_{1n}\\ a_{21}& a_{22}& a_{23}& ......& a_{2n}\\ & & & ..........& \\ a_{k1}& a_{k2}& a_{\mathrm{<figure-callout\; id="3"\; label="k"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">k</figure-callout>}3}& ......& a_{\mathrm{kn}}\\ & & & ..........& \\ a_{n1}& a_{n2}& a_{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">n</figure-callout>}3}& ......& a_{\mathrm{nn}}\end{array}\right)$

In the above-mentioned matrix, each subcarrier of k line display is to the interference of k number of sub-carrier.N is the sampling number that system bandwidth is confirmed, supposes that current subcarrier is k, a _K1Represent of the interference of the 1st number of sub-carrier, a to the k number of sub-carrier _KlRepresent of the interference of l number of sub-carrier to the k number of sub-carrier.

Step S4: to formula (2)

A(γ)*diag(reference)*h+noise＝receive_reference

Carry out conversion and can obtain the computing formula (7) of noise:

noise＝receive_reference-A(γ)*diag(reference)*h (7)

Noise signal obtains through following process:

At first local reference signal reference is disturbed addition according to the interference matrix A (γ) that obtains; Be A (γ) * diag (reference); Again sequence and the channel estimation sequence h that generates multiplied each other; Obtain one add to disturb after not with the reference signal sequence of noise, i.e. A (γ) * diag (reference) * h.

Receiving terminal extracts reference signal receive_reference after through the OFDM demodulation, deduct again add disturb after not with burst A (γ) * diag (reference) the * h of noise, be signal noise noise.

Afterwards, calculating noise power spectral density

${\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="Noise"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">Noise</figure-callout>}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{Noise}}_i\right|}^2,$ Promptly the noise power on each subcarrier is asked average.

Because different with the sub-carrier number that the user distributes according to system bandwidth, the noise power that calculates need be adjusted a constant coefficient, C is a constant of confirming according to the subcarrier number of distributing.

Application example

Be that example is described in detail with the subcarrier in the LTE system below.

In the LTE system, a sub-frame has two time slots, on the Resource Block RB 12 number of sub-carrier is arranged, and subcarrier spacing is Δ f=15000Hz.The system bandwidth of supposing current employing is 20MHz, and corresponding sampling points is counted N=2048.The reference signal that transmitting terminal generates condition according to the rules is mapped in the resource grid, and generation SC-FDMA symbol is launched.Through behind the channel, receiving terminal receives the data of eating dishes without rice or wine, and extracts the reference signal behind the channel, and is as shown in Figure 3.

The estimation procedure of noise is specific as follows:

Step 101: the reference signal receive_reference that obtains according to reception carries out the LS channel estimating with local with reference to reference, takes out the sub-carrier signal on the milder RB of channel.

Step 102: adopt the channel estimation method in the ofdm system to estimate the channel estimation value h on the current RB, the same prior art of its method.

Step 103: estimated the frequency offseting value γ of subcarrier behind the channel, Δ f=15000Hz through the frequency offset estimating algorithm.Suppose the frequency offseting value freq_offset=300Hz that estimates, γ after the normalization=freq_offset/ Δ f=0.02.

Step 104:, calculate the interference matrix A (γ) on the current RB according to the frequency offseting value γ that obtains.Because it is that adjacent nearest several number of sub-carrier influences are bigger that most of ICI disturb, thus current get near the subcarrier about each 3 number of sub-carrier calculate their influence, as shown in Figure 4.

This moment N=2048

$\mathrm{\&beta;}=\sin (\mathrm{\&pi;}*0.02)*\exp (\mathrm{j\&pi;}*0.02*\left(\frac{2048-1}{2048}\right))$

w _-3＝exp(-jπ*(-3)/2048)/(2048*sin(π*(-3+0.02)/2048))*β

w _-2＝exp(-jπ*(-2)/2048)/(2048*sin(π*(-2+0.02)/2048))*β

w _-1＝exp(-jπ*(-1)/2048)/(2048*sin(π*(-1+0.02)/2048))*β

w ₀＝exp(-jπ*(0)/2048)/(2048*sin(π*(0+0.02)/2048))*β

w ₁＝exp(-jπ*(1)/2048)/(2048*sin(π*(1+0.02)/2048))*β

w ₂＝exp(-jπ*(2)/2048)/(2048*sin(π*(2+0.02)/2048))*β

w ₃＝exp(-jπ*(3)/2048)/(2048*sin(π*(3+0.02)/2048))*β

$A\left(\mathrm{\&gamma;}\right)=\left(\begin{array}{cccccccccccc}{w}_0& w_1& w_2& w_3& 0& 0& 0& 0& 0& 0& 0& 0\\ w_{-1}& w_0& w_1& w_2& w_3& 0& 0& 0& 0& 0& 0& 0\\ w_{-2}& w_{-1}& w_0& w_1& w_2& w_3& 0& 0& 0& 0& 0& 0\\ w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2& w_3& 0& 0& 0& 0& 0\\ 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2& w_3& 0& 0& 0& 0\\ 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2& w_3& 0& 0& 0\\ 0& 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2& w_3& 0& 0\\ 0& 0& 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2& w_3& 0\\ 0& 0& 0& 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2& w_3\\ 0& 0& 0& 0& 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1& w_2\\ 0& 0& 0& 0& 0& 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0& w_1\\ 0& 0& 0& 0& 0& 0& 0& 0& w_{-3}& w_{-2}& w_{-1}& w_0\end{array}\right)$

Step 105: according to noise=receive_reference-A (γ) * diag (reference) * h calculating noise signal;

(γ) disturbs addition to the local reference signal on the current RB with matrix A, and the sequence and the channel estimation sequence h that generate then multiply each other, and obtains reference signal sequence A (γ) * diag (reference) * h who adds after the interference not with noise.Receiving terminal extracts the reference signal on the current RB after through the OFDM demodulation, deduct again add disturb after not with the reference signal sequence of noise, just obtain the signal noise on the current RB.

Step 106: calculating noise power spectral density

${\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="Noise"\; filenames="HSA00000208564800022.png"\; state="\{\{state\}\}">Noise</figure-callout>}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{Noise}}_i\right|}^2,$ Be that noise power on each subcarrier asks average.

Because different with the sub-carrier number that the user distributes according to system bandwidth, the noise power that calculates need be adjusted a constant coefficient, C is a constant of confirming according to the subcarrier number of distributing.

One of ordinary skill in the art will appreciate that all or part of step in the said method can instruct related hardware to accomplish through program, said program can be stored in the computer-readable recording medium, like read-only memory, disk or CD etc.Alternatively, all or part of step of the foregoing description also can use one or more integrated circuits to realize.Correspondingly, each the module/unit in the foregoing description can adopt the form of hardware to realize, also can adopt the form of software function module to realize.The present invention is not restricted to the combination of the hardware and software of any particular form.

Claims (10)

1. the method for estimation of a noise signal comprises:

Choose a subcarrier frequency range, according to the structure of the interference between subcarrier interference matrix A (γ); The reference signal and the said interference matrix A (γ) that receive according to receiving terminal afterwards calculate noise signal.

2. the method for claim 1 is characterized in that:

If comprise the n number of sub-carrier in the said subcarrier frequency range of choosing;

Among the interference matrix A (γ) of said structure, capable all the other subcarriers of element representation of k are to the interference of k number of sub-carrier.

3. method as claimed in claim 2 is characterized in that:

If the element of said interference matrix is a _Kl, represent of the interference of l number of sub-carrier to the k number of sub-carrier;

When k=l, said $a_{\mathrm{Kl}}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\&pi;\; \&gamma;}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\&pi;\; \&gamma;}}{N}\right)}\right\}\mathrm{Exp}\left(\mathrm{J\&pi;\; \&gamma;}\frac{N-1}{N}\right);$

When k ≠ l, said $a_{k,l}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\&pi;\; \&gamma;}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\&pi;}(l-k+\mathrm{\&gamma;})}{N}\right)}\right\}\mathrm{Exp}(-\mathrm{J\&pi;}\frac{l-k}{N})\mathrm{Exp}\left(\mathrm{J\&pi;\; \&gamma;}\frac{N-1}{N}\right).$

4. like claim 2 or 3 described methods, it is characterized in that:

When the said interference matrix A of structure (γ), only consider near the interference of 3 number of sub-carrier of current subcarrier to said current subcarrier, all the other subcarriers are to disturb to be designated as 0 to current subcarrier.

5. like claim 1 or 2 or 3 described methods, it is characterized in that:

Said reference signal that receives according to receiving terminal and said interference matrix calculate noise signal and are meant,

Said A (γ) is disturbed addition, again sequence and the channel estimation sequence h that generates multiplied each other, obtain the reference signal sequence that adds after the interference not with noise, i.e. A (γ) * diag (reference) * h; If the reference signal that receiving terminal receives is receive_reference;

Said noise signal noise=receive_reference-A (γ) * diag (reference) * h;

Noise power spectral density then ${\mathrm{\&sigma;}}_{\mathrm{Noise}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{Noise}}_i\right|}^2.$

6. the estimation unit of a noise signal comprises and chooses module and computing module; It is characterized in that:

The said module of choosing is used to choose a subcarrier frequency range;

Said conversion module is used for according to the structure of the interference between subcarrier interference matrix A (γ);

Said computing module is used for calculating noise signal according to reference signal and said interference matrix A (γ) that receiving terminal receives.

7. device as claimed in claim 6 is characterized in that:

If comprise the n number of sub-carrier in the said subcarrier frequency range of choosing;

Among the interference matrix A (γ) of said conversion module structure, capable all the other subcarriers of element representation of k are to the interference of k number of sub-carrier.

8. device as claimed in claim 7 is characterized in that:

If the element of said interference matrix A (γ) is a _Kl, represent of the interference of l number of sub-carrier to the k number of sub-carrier;

When k=l, said $a_{\mathrm{Kl}}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\&pi;\; \&gamma;}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\&pi;\; \&gamma;}}{N}\right)}\right\}\mathrm{Exp}\left(\mathrm{J\&pi;\; \&gamma;}\frac{N-1}{N}\right);$

When k ≠ l, said $a_{k,l}=\left\{\frac{\mathrm{Sin}\left(\mathrm{\&pi;\; \&gamma;}\right)}{N\mathrm{Sin}\left(\frac{\mathrm{\&pi;}(l-k+\mathrm{\&gamma;})}{N}\right)}\right\}\mathrm{Exp}(-\mathrm{J\&pi;}\frac{l-k}{N})\mathrm{Exp}\left(\mathrm{J\&pi;\; \&gamma;}\frac{N-1}{N}\right).$

9. like claim 7 or 8 described devices, it is characterized in that:

Said conversion module is only considered near the interference of 3 number of sub-carrier of current subcarrier to said current subcarrier when the said interference matrix A of structure (γ), all the other subcarriers are to disturb to be designated as 0 to current subcarrier.

10. like claim 6 or 7 or 8 described devices, it is characterized in that:

Reference signal that said computing module receives according to receiving terminal and said interference matrix calculate noise signal and are meant:

Said computing module disturbs addition to said A (γ), sequence and the channel estimation sequence h that generates is multiplied each other again, and obtains the reference signal sequence that adds after the interference not with noise, i.e. A (γ) * diag (reference) * h; If the reference signal that receiving terminal receives is receive_reference;

Said computing module calculates noise signal by following formula:

noise＝receive_reference-A(γ)*diag(reference)*h；

Corresponding noise power spectral density ${\mathrm{\&sigma;}}_{\mathrm{Noise}}^2=C*\frac{1}{M}\underset{i=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\left|{\mathrm{Noise}}_i\right|}^2.$

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