CN101616106B - Blind self-adaption CDMA receiver based on inclined projection and receiving method thereof - Google Patents

Abstract

The invention relates to a blind self-adaption CDMA receiver based on inclined projection and a receiving method thereof. The blind self-adaption CDMA receiver based on inclined projection comprises a signal receiving terminal, a filtering unit, a PN code synchronous unit and a noise variance estimation unit, wherein the signal receiving terminal is used for receiving external signals and connected with the filtering unit; the PN code synchronous unit and the noise variance estimation unit are arranged between the signal receiving terminal and the filtering unit. The receiving method of the blind self-adaption CDMA receiver based on inclined projection comprises the following steps: one. determining spreading code information of target signals; two. determining the variance of the noise, establishing subspace of the target signals according to the data information of the target signals in the step one; third. determining the subspace of the target signals established in the step two and inclined projection operators which the variance of the noise is corresponding to; four. according to the inclined projection operators obtained in the step three, extracting the target signals, and filtering interference signals. The invention has the advantages of little calculated amount, low complexity, simpleness, convenience, etc.

Description

Based on oblique projection blind self-adaption CDMA receiver and method of reseptance thereof

[technical field]

The present invention relates to mobile communication receiver and method of reseptance thereof, particularly relate to utilize in traditional C DMA communication system that shadow casting technique realizes under the situation that need not know interference user information that targeted customer and interference user be separated based on oblique projection blind self-adaption CDMA receiver and method of reseptance thereof.

[background technology]

Because direct sequence CDMA technology (DS-CDMA) is widely used in cellular communication, in the communication systems such as indoor wireless communication and personal communication network.But in traditional cdma system, it is exactly that multiple access disturbs (MAI) that a very big defective is arranged self, and the reason that produces the multiple access interference mainly contains two:

(1), because the communication frequency that each user uses is identical, and frequency expansion sequence can not carry out complete quadrature between different user, promptly cross-correlation coefficient is non-vanishing;

(2) even frequency expansion sequence can quadrature, the asynchronous transmission in the actual channel also can be introduced correlation.

Input is disturbed multiple access and is regarded as Gaussian noise and handles in traditional C DMA system, thereby ignores the existence that multiple access disturbs, the influence that can bring following two aspects like this:

(1) power system capacity is restricted: in system number of users more after a little while, multiple access disturb because of the good cross correlation of pseudo noise code can be too not serious.But along with the increase of while connecting system number of users, what multiple access disturbed influences meeting gradually seriously, causes the rising of error rate of system, makes the capacity of system be affected.Especially the employing of jumbo requirement and multi-antenna emission diversity in the 3G system all will cause the cdma system capacity to receive having a strong impact on of multiple access interference.

(2) had a strong impact on the performance of system: if interference user is more much closer apart from the base station than the targeted customer; Even ignore the influence of decline; The path loss of signal also is directly proportional with the cube of user distance base station distance, and at this moment interference signal can be more much bigger than the received power of targeted customer signal in the received power of base station, and the multiple access interference deal in traditional receiver output can be very heavy; So that targeted customer's signal floods, and near-far interference occurs.

In order to overcome the influence that multiple access disturbs, conventional method has following several kinds:

(1) design of spreading code: it is the incomplete orthogonality between spreading code that multiple access disturbs the root that produces, if the complete at any time quadrature of spreading code energy collecting, multiple access just disturbs and can not exist so.But in actual channel, all have asynchronism in various degree, it almost is impossible designing the sign indicating number collection that can both keep orthogonality in office when the prolonging.

(2) power control: power control can effectively reduce near-far interference; But power control can not fundamentally be eliminated multiple access and disturb, because the restriction of receptivity can receive each user's received power and equate the time, and some shortcomings below existing; Like the control information of busy channel delivering power; Have the algorithm the convergence speed problem, and performance is relevant with user moving speed, system is comparatively complicated.

(3) forward error correction coding: utilize the additional redundancy of coding to correct the error bit judgement that produces because of channel distortions, become an important means that improves communication quality, disturb the mistake that causes effective too for correcting multiple access.But the cost that adopts forward error correction coding is the transmission speed of useful information under the same channel transmission rate can descend to some extent.

(4) space filtering technology: carry out spatial domain processing can reducing multiple access to received signal with smart antenna and disturb influence, adopt fan anteena also can suppress to remove other interference in a certain angle simultaneously with certain orientation property to signal, and the raising systematic function.But the smart antenna complexity is high, and energy consumption is big.

(5) multiuser detection: the basic thought of Multiuser Detection theory and technology is to utilize cross-correlation information between the user that multiple access comprises in disturbing to estimate to disturb and reduce, eliminate the influence of interference; But it need know the parameter and the information of all interference users; And these information major parts are ignorant, if the information of interference user can know, disturb in order to eliminate multiple access; Amount of calculation wherein and computation complexity all are suitable high, are not easy to realize.

In traditional cdma system; There are a plurality of users in the cellular cell; If these users communicate by letter simultaneously, between them with the phase mutual interference, in the information of all interference user spreading codes of portable terminal there is no telling of user; Therefore suppress to disturb and to accomplish at portable terminal, and can only in the base station, accomplish.All users' spreading code information can be known in the base station, need great amount of calculation but utilize all interference user spreading code information to suppress interference, and computation complexity is high, and is very inconvenient, and the power consumption of system is big, and reduce useful life.Also can produce between neighbor cell base station and the base station and be similar to the multiple access that produces between user and the user and disturb, the information of used base station around base station there is no telling, suppressing peripheral base station will be very complicated thing to its interference.

[summary of the invention]

The power consumption that has the interference of cdma receiver inhibition multiple access now is big, reduce useful life and inhibition interference calculation complicated technology problem in order to solve, and the invention provides a kind of based on the oblique projection blind self-adaption CDMA receiver.

The power consumption that has the interference of cdma receiver inhibition multiple access now is big, reduce useful life and inhibition interference calculation complicated technology problem in order to solve, and the present invention also provides a kind of method of reseptance based on the oblique projection blind self-adaption CDMA receiver.

The present invention solves the prior art problem; The technical scheme that is adopted is: provide a kind of based on the oblique projection blind self-adaption CDMA receiver; Comprise signal receiving end, saidly also comprise filter unit, PN sign indicating number lock unit and noise variance estimation unit based on the oblique projection blind self-adaption CDMA receiver; Wherein, Said signal receiving end is used to receive external signal; And be connected with said filter unit; Said PN sign indicating number lock unit and said noise variance estimation unit are arranged between said signal receiving end and the said filter unit, are used to receive the interference signal that said signal receiving end is sent into, and the echo signal after the interference signal is eliminated in output.

According to an optimal technical scheme of the present invention: said filter unit is the multiple access interference filter.

The present invention also provides a kind of method of reseptance based on the oblique projection blind self-adaption CDMA receiver, and said method of reseptance based on the oblique projection blind self-adaption CDMA receiver comprises step: the first step, confirm the spreading code information of echo signal; Second goes on foot, confirms the variance of noise, sets up the echo signal subspace by the data message of echo signal in the said first step; The 3rd goes on foot, confirms the echo signal subspace and the pairing oblique projection operator of noise variance of foundation in said second step; The 4th step, by the oblique projection operator that obtains in said the 3rd step, extract echo signal, filtering interference signals.

According to an optimal technical scheme of the present invention: the said first step comprises substep: at first, receive external signal through signal receiving end; Secondly, in signal, confirm the spreading code information of echo signal through PN sign indicating number lock unit.

According to an optimal technical scheme of the present invention: the parameter value of said echo signal is a PN sign indicating number sequence;

Echo signal is expressed as: S _Target=A ₁c ₁(t) a ₁(t);

Wherein, a ₁(t) the expression echo signal in the traditional base station bit stream before the spread spectrum, c ₁(t) the expression echo signal in the traditional base station spread spectrum code sequence before the spread spectrum;

A ₁The amplitude of expression targeted customer signal;

a ₁(t)=a ₁g _a(t-T _a), c ₁(t)=c ₁g _c(t-T _c), a ₁{ ± 1} is the desired user data to ∈;

c ₁{ ± 1} is targeted customer's spreading code to ∈.

According to an optimal technical scheme of the present invention: said second step is specially: in base station signal, estimate the variance of noise through noise variance estimation unit, set up the echo signal subspace by the data parameters of echo signal in the said first step again.

According to an optimal technical scheme of the present invention: noise variance is the white Gaussian noise variance in said second step, and the autocorrelation matrix of the mixed signal that receives is:

R _rr＝E{r ^H(t)r(t)}＝C ^HR _AAC+σ ²I＝R _xx+σ ²I

The pseudoinverse that target adds the correlation matrix of interference is:

$R_{\mathrm{xx}}^{+}={(R_{\mathrm{yy}}-{\mathrm{\σ}}^{2}I)}^{+}$

Wherein, X representes the mixing of echo signal and interference signal; The pseudoinverse of

representing matrix; The special transposition in Hami of H representing matrix, I is a unit matrix, R representes to receive the autocorrelation matrix of signal.

According to an optimal technical scheme of the present invention: the pairing oblique projection operator in echo signal spreading code subspace is in said the 3rd step:

${\mathrm{<figure-callout\; id="1"\; label="E\; c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">E</figure-callout>}}_{c_{}}={\left({c_1}^H{R}_{\mathrm{xx}}^{+}{c}_1\right)}^{-1}{c_1}^H{R}_{\mathrm{xx}}^{+}$

Wherein, ∑ is represented the information of other interference users.

According to an optimal technical scheme of the present invention: extract echo signal A through following formula in said the 4th step ₁c ₁(t) a ₁(t):

$A_1{c}_1\left(t\right)a_1\left(t\right)={\mathrm{<figure-callout\; id="1"\; label="E\; c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">E</figure-callout>}}_{c_{}}r\left(t\right).$

According to an optimal technical scheme of the present invention: said the 4th step specifically comprises substep: one, the echo signal that extracts is carried out despreading; Two, the echo signal after the despreading is adjudicated; Three, the echo signal of output filtering interference signals.

Beneficial effect of the present invention is:

One, can need not to know under the situation of interference user spreading code information; Only utilize echo signal spreading code information and estimating noise variance to suppress interference user and obtain echo signal; When suppressing multiple access interference (MAI); Can break-evenly obtain echo signal, this receiver need not estimate that the information of the spreading code of interference user also can suppress interference signal, target signal generating is not influenced simultaneously.

Two, need not estimate the spreading code information of interference user, as long as the spreading code information and the noise variance σ of estimating target signal ²

Three, utilize to receive the auto-correlation information of signal and the estimation of noise variance substituted the spreading code information of interference user, can realize the accurate recovery of echo signal, and have that amount of calculation is little, complexity is low, simple and convenient.

Four, the complexity of computing and number of users are irrelevant when Multiuser Detection, and the scope of application is wider.

Five, can user terminal be taken in multiple access interference between the inhibition user and realized, reduce the burden of base station and simplified complexity, and suppressed the meeting of multiple access effects of jamming better.

[description of drawings]

Fig. 1. the present invention is based in oblique projection blind self-adaption CDMA receiver and the method for reseptance thereof based on oblique projection blind self-adaption CDMA receiver modular structure sketch map;

Fig. 2. the present invention is based in oblique projection blind self-adaption CDMA receiver and the method for reseptance thereof method of reseptance flow chart based on the oblique projection blind self-adaption CDMA receiver;

Fig. 3. the present invention is based on the comparison sketch map of oblique projection and traditional C DMA multi-user spreading code BER curve when non-orthogonal;

Fig. 4. the present invention is based on the comparison sketch map of oblique projection and single user BER curve.

[embodiment]

Below in conjunction with accompanying drawing technical scheme of the present invention is further specified:

Seeing also Fig. 1 the present invention is based in oblique projection blind self-adaption CDMA receiver and the method for reseptance thereof based on oblique projection blind self-adaption CDMA receiver modular structure sketch map.As shown in Figure 1; It is a kind of based on the oblique projection blind self-adaption CDMA receiver that technical scheme of the present invention provides; Have the filter unit of the base station signal that obtains from signal element, also be provided with PN sign indicating number lock unit and noise variance estimation unit between said signal element and the filter unit; Said PN sign indicating number lock unit and said noise variance estimation unit are used to receive the interference signal that said base station signal is sent into, and the echo signal after the interference signal is eliminated in output.

At filter unit described in the optimal technical scheme of the present invention is the multiple access interference filter.

See also Fig. 2 and the present invention is based in oblique projection blind self-adaption CDMA receiver and the method for reseptance thereof method of reseptance flow chart based on the oblique projection blind self-adaption CDMA receiver; As shown in Figure 2, the present invention also provides a kind of method of reseptance based on the oblique projection blind self-adaption CDMA receiver, and said method of reseptance based on the oblique projection blind self-adaption CDMA receiver comprises step: the first step, confirm the spreading code information of echo signal; Second goes on foot, confirms the variance of noise, sets up the echo signal subspace by the data message of echo signal in the said first step; The 3rd goes on foot, confirms the echo signal subspace and the pairing oblique projection operator of noise variance of foundation in said second step; The 4th step, by the oblique projection operator that obtains in said the 3rd step, extract echo signal, filtering interference signals.

In the conventional synchronization cdma system, have k user to be transmitted in simultaneously on the white Gaussian noise channel, the signal r (t) that the base station receives can be expressed as: $r\left(t\right)=\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{A}_k{c}_k\left(t\right)a_k\left(t\right)+n\left(t\right),$ Here a _k(t) and c _k(t) represent bit stream and k user's spread spectrum code sequence before the spread spectrum of traditional base station respectively, A _kThe amplitude of representing k subscriber signal, n (t) is a zero-mean, variance is σ ²White Gaussian noise; Wherein $a\left(t\right)=\underset{n=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{a}_n{g}_a(t-n{T}_a),$ $c\left(t\right)=\underset{n=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{c}_n{g}_c(t-n{T}_c),$ a _n{ ± 1} is a user data to ∈, c _n{ ± 1} is a spreading code to ∈, and the code length of spreading code is N.g _aAnd g _cBe rectangular pulse, the cycle is T _aAnd T _c, T wherein _a" T _c1 subscriber's meter is shown echo signal, and then system model can be expressed as the form that echo signal adds the interference signal plus noise, that is: $r\left(t\right)=A_1{c}_1\left(t\right)a_1\left(t\right)+\underset{k=2}{\overset{K}{\mathrm{\&Sigma;}}}{A}_k{c}_k\left(t\right)a_k\left(t\right)+n\left(t\right),$ Corresponding spatial model is following: $r=\left[{\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_1\right|{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&CenterDot;\&CenterDot;\&CenterDot;c_k]\left[\begin{array}{c}{A}_1{a}_1\\ -\\ A_2{a}_2\\ \&CenterDot;\\ \&CenterDot;\\ \&CenterDot;\\ A_k{a}_k\end{array}\right]+n=\left[{\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_1\right|\mathrm{\&Sigma;}]{\left[A_1{a}_1\right|v]}^T+n,$ The transposition of T representing matrix wherein, following formula can be abbreviated as: r=CA+n, wherein C=[c ₁| ∑], A=[A ₁a ₁| v] ^T

Comprise substep in the first step described in the optimal technical scheme of the present invention: at first, from signal element, export base station signal; Secondly, in base station signal, confirm the spreading code information of echo signal through PN sign indicating number lock unit, wherein, the parameter value of said echo signal is a PN sign indicating number sequence;

Echo signal is expressed as: S _Target=A ₁c ₁(t) a ₁(t);

Wherein, a ₁(t) the expression echo signal in the traditional base station bit stream before the spread spectrum, c ₁(t) the expression echo signal in the traditional base station spread spectrum code sequence before the spread spectrum;

A ₁The amplitude of expression targeted customer signal;

a ₁(t)=a ₁g _a(t-T _a), c ₁(t)=c ₁g _c(t-T _c), a ₁{ ± 1} is the desired user data to ∈;

c ₁{ ± 1} is targeted customer's spreading code to ∈.

In optimal technical scheme of the present invention: said second step is specially: the variance that in base station signal, estimates noise through noise variance estimation unit; Set up the echo signal subspace by the data parameters of echo signal in the said first step again; Wherein, Noise variance is the white Gaussian noise variance in said second step, and the autocorrelation matrix of the mixed signal that receives is:

R _rr＝E{r ^H(t)r(t)}＝C ^HR _AAC+σ ²I＝R _xx+σ ²I

The pseudoinverse that target adds the correlation matrix of interference is:

$R_{\mathrm{xx}}^{+}={(R_{\mathrm{yy}}-{\mathrm{\&sigma;}}^{2}I)}^{+}$

Wherein, X representes the mixing of echo signal and interference signal; The pseudoinverse of

representing matrix; The special transposition in Hami of H representing matrix, I is a unit matrix, R representes to receive the autocorrelation matrix of signal.

In optimal technical scheme of the present invention: the pairing oblique projection operator in echo signal spreading code subspace is in said the 3rd step:

${\mathrm{<figure-callout\; id="1"\; label="E\; c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">E</figure-callout>}}_{c_{}}={\left({c_1}^H{R}_{\mathrm{xx}}^{+}{c}_1\right)}^{-1}{c_1}^H{R}_{\mathrm{xx}}^{+}$

Wherein, ∑ is represented the information of other interference users.

Setting in said the 4th step and receiving signal indication is r (t), extracts echo signal A through following formula ₁c ₁(t) a ₁(t):

$A_1{c}_1\left(t\right)a_1\left(t\right)={\mathrm{<figure-callout\; id="1"\; label="E\; c"\; filenames="H2009101088396E00011.png,H2009101088396E00021.png"\; state="\{\{state\}\}">E</figure-callout>}}_{c_{}}r\left(t\right).$

In optimal technical scheme of the present invention: said the 4th step specifically comprises substep: one, the echo signal that extracts is carried out despreading; Two, the echo signal after the despreading is adjudicated; Three, the echo signal of output filtering interference signals.

See also the comparison sketch map that Fig. 3 the present invention is based on oblique projection and traditional C DMA multi-user spreading code BER curve when non-orthogonal.

Can find out that from this figure traditional C DMA receiver is not along with the rising error rate of bit signal to noise ratio obviously descends, traditional C DMA receiver can not guarantee that the orthogonality of address code causes interference not suppress fully thereby this is, so the error rate is very big; And utilize the receiver of the method for oblique projection under the non-orthogonal situation of address code, good restraining to disturb, and showing the method receiver that utilizes oblique projection among the figure, error rate meditation descends when the bit signal to noise ratio increases, shows to disturb by obviously inhibition.

See also the comparison sketch map that Fig. 4 the present invention is based on oblique projection and single user BER curve.

As can be seen from the figure, along with the lifting of number of users, utilize the lifting of the receiver of this method along with number of users, performance does not obviously descend, and shows that this receiver is little with how many relations of number of users, has embodied the advantage of blind adaptive.

After adopting technical scheme of the present invention; Can need not to know under the situation of interference user spreading code information; Only utilize echo signal spreading code information and estimating noise variance to suppress interference user and obtain echo signal, when suppressing multiple access interference (MAI), can break-evenly obtain echo signal; This receiver need not estimate that the information of the spreading code of interference user also can suppress interference signal; Not to the target signal generating influence, need not estimate the spreading code information of interference user simultaneously, as long as the spreading code information and the noise variance σ of estimating target signal ²Utilize to receive the auto-correlation information of signal and the estimation of noise variance substituted the spreading code information of interference user, can realize the accurate recovery of echo signal, and have that amount of calculation is little, complexity is low, simple and convenient; The complexity of computing and number of users are irrelevant when Multiuser Detection, and the scope of application is wider; Can multiple access between the inhibition user be disturbed and take the user terminal realization, reduce the burden of base station and simplified complexity, and suppressed the meeting of multiple access effects of jamming better.

Above content is to combine concrete optimal technical scheme to the further explain that the present invention did, and can not assert that practical implementation of the present invention is confined to these explanations.For the those of ordinary skill of technical field under the present invention, under the prerequisite that does not break away from the present invention's design, can also make some simple deduction or replace, all should be regarded as belonging to protection scope of the present invention.

Claims (10)

1. one kind based on the oblique projection blind self-adaption CDMA receiver, comprises signal receiving end (1), it is characterized in that: saidly also comprise filter unit (2), PN sign indicating number lock unit (3) and noise variance estimation unit (4) based on the oblique projection blind self-adaption CDMA receiver; Wherein, Said signal receiving end (1) is used to receive external signal; And be connected with said filter unit (2); Said PN sign indicating number lock unit (3) and said noise variance estimation unit (4) are arranged between said signal receiving end (1) and the said filter unit (2), are used to receive the interference signal that said signal receiving end (1) is sent into, and the echo signal after the interference signal is eliminated in output.

2. said based on the oblique projection blind self-adaption CDMA receiver according to claim 1, it is characterized in that: said filter unit (2) is the multiple access interference filter.

3. method of reseptance based on the oblique projection blind self-adaption CDMA receiver, it is characterized in that: said method of reseptance based on the oblique projection blind self-adaption CDMA receiver comprises step:

A: the spreading code information of confirming echo signal;

B: confirm noise variance, set up the echo signal subspace by the data message of echo signal in the said steps A;

C: confirm echo signal subspace and the pairing oblique projection operator of noise variance set up among the said step B;

D: the oblique projection operator by said step C obtains, extract echo signal, filtering interference signals.

4. according to the said method of reseptance based on the oblique projection blind self-adaption CDMA receiver of claim 3, it is characterized in that: said steps A comprises substep:

A1: receive external signal through signal receiving end (1);

A2: the spreading code information of in signal, confirming echo signal through PN sign indicating number lock unit (3).

5. according to claim 3 or 4 said method of reseptances based on the oblique projection blind self-adaption CDMA receiver, it is characterized in that: the parameter value of said echo signal is a PN sign indicating number sequence;

Echo signal is expressed as: S _Target=A ₁c ₁(t) a ₁(t);

Wherein, a ₁(t) the expression echo signal in the traditional base station bit stream before the spread spectrum, c ₁(t) the expression echo signal in the traditional base station spread spectrum code sequence before the spread spectrum;

A ₁The amplitude of expression targeted customer signal;

a ₁(t)=a ₁g _a(t-T _a), c ₁(t)=c ₁g _c(t-T _c), a ₁{ ± 1} is the desired user data to ∈; g _aAnd g _cBe rectangular pulse, the cycle is T _aAnd T _c, T wherein _a" T _c

c ₁{ ± 1} is targeted customer's spreading code to ∈.

6. according to the said method of reseptance of claim 3 based on the oblique projection blind self-adaption CDMA receiver; It is characterized in that: said step B is specially: in base station signal, estimate the variance of noise through noise variance estimation unit (4), set up the echo signal subspace by the data parameters of echo signal in the said steps A again.

7. according to claim 3 or 6 said method of reseptances based on the oblique projection blind self-adaption CDMA receiver, it is characterized in that: noise variance is the white Gaussian noise variance among the said step B, and the autocorrelation matrix of the mixed signal that receives is:

R _rr＝E{r ^H(t)r(t)}＝C ^HR _AAC+σ ²I＝R _xx+σ ²I

The pseudoinverse that target adds the correlation matrix of interference is:

$R_{\mathrm{xx}}^{+}={(R_{\mathrm{yy}}-{\mathrm{\&sigma;}}^{2}I)}^{+}$

Wherein, x representes the mixing of echo signal and interference signal,

The pseudoinverse of representing matrix, the special transposition in Hami of H representing matrix, I is a unit matrix, R representes to receive the autocorrelation matrix of signal; C=[c ₁| ∑], A=[A ₁a ₁| v] ^T∑ is represented the information of other interference users; The reception signal of r (t) expression receiver; σ is used for the size of expression signal transmission course noise, wherein σ ²The power of expression noise.

8. according to the said method of reseptance based on the oblique projection blind self-adaption CDMA receiver of claim 3, it is characterized in that: the pairing oblique projection operator in echo signal spreading code subspace is among the said step C:

$E_{c_1\mathrm{\&Sigma;}}={\left({c_1}^H{R}_{\mathrm{xx}}^{+}{c}_1\right)}^{-1}{c_1}^H{R}_{\mathrm{xx}}^{+}$

Wherein, ∑ is represented the information of other interference users; X representes the mixing of echo signal and interference signal; R representes to receive the autocorrelation matrix of signal; c ₁For echo signal in the traditional base station spread spectrum code sequence before the spread spectrum.

9. according to the said method of reseptance of claim 3, it is characterized in that: extract echo signal A through following formula among the said step D based on the oblique projection blind self-adaption CDMA receiver ₁c ₁(t) a ₁(t):

$A_1{c}_1\left(t\right)a_1\left(t\right)=E_{c_1\mathrm{\&Sigma;}}r\left(t\right)$

Wherein, A ₁The amplitude of expression targeted customer signal; a ₁(t) the expression echo signal in the traditional base station bit stream before the spread spectrum; c ₁(t) the expression echo signal in the traditional base station spread spectrum code sequence before the spread spectrum; The reception signal of r (t) expression receiver; ∑ is represented the information of other interference users; c ₁For echo signal in the traditional base station spread spectrum code sequence before the spread spectrum.

10. according to the said method of reseptance based on the oblique projection blind self-adaption CDMA receiver of claim 3, it is characterized in that: said step D specifically comprises substep:

D1: the echo signal to extracting is carried out despreading;

D2: the echo signal to after the despreading is adjudicated;

D3: the echo signal of output filtering interference signals.

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