CN101106412B - MC-DS-CDMA uplink receiving method and device for array antenna - Google Patents

Abstract

The invention relates to an uplink receiving method of array antenna MC-DS-CDMA system. The method is carried out with the steps that: first, the signals received by each array unit of the array antenna are respectively transmitted to carrier signal separation modules and are multiplied with a corresponded sub-carrier, which realizes the sub-carrier signal separation and obtains an output signal; second, de-spread and matched filter process to each separated array unit sub-carrier signal are carried out to realize user signal de-spreading and get the user sub-carrier signal matched filter output; third, the matched filter output signals on different array units are combined in the air domain to get user sub-carrier signal final judge variable and get the air domain diversity gain; fourth, user sub-carrier signal final judge variable after air domain combination is judged to get the user sub-carrier signal judge result. The method obviously enhances MC-DS-CDMA system performance.

Description

Array antenna MC-DS-CDMA method for receiving uplink and device

Technical field

The present invention relates to a kind of array antenna MC-DS-CDMA method for receiving uplink and device, belong to MC-DS-CDMA cell mobile communication systems array antenna technical field.

Background technology

In the third generation (3G) mobile communication system, CDMA is a kind of topmost technology, and multi-carrier modulation will be the key technology of following wideband wireless transmission system.Merge CDMA technology with multi-transceiver technology, constituting multi-carrier CDMA system is one of important directions of future mobile communications development.The scheme that multi-transceiver technology combines with CDMA technology mainly contains CDMA multiple carrier (MC-CDMA), multi-carrier direct sequence spectrum CDMA (MC-DS-CDMA) and three kinds of typical forms of multitone modulation CDMA (MT-CDMA) [Hara S and Prasad R.An Overview of Multi-carrier CDMA.IEEEComm.Mag.1997; 35 (12), pp.126-33.; Hara S and Prasad R. CDMA multiple carrier summary .IEEE communication magazine, 1997; 35 (12), pp.126-33].Wherein, the MC-DS-CDMA scheme has the advantage that can directly merge the DS-CDMA technology of 3G with multi-transceiver technology, is mobile communication system from the important technology of 3G to super three generations (B3G) development, will obtain important use in the future mobile communications architecture.

The same with cdma system, use array antenna can improve capacity, spectrum efficiency, communication quality and the coverage of system significantly at the MC-DS-CDMA system base-station.

At present, the basic structure of the existing array antenna MC-DS-CDMA system that is proposed under MC-DS-CDMA basic conception and method for receiving uplink and method proposed by the invention have very big difference, and the signal processing complexity.Have signal processing directly, simply than the array antenna MC-DS-CDMA system method of the present invention that has proposed, and utilized the spatial domain redundant information of array antenna fully, improved the performance of MC-DS-CDMA system significantly.

Summary of the invention

The present invention has proposed a kind of array antenna MC-DS-CDMA method for receiving uplink and device for solving the problems of the technologies described above, this method and device merge by the spatial domain has realized the spatial domain diversity reception of array antenna MC-DS-CDMA system, has good receptivity.

The technical solution adopted in the present invention is:

A kind of array antenna MC-DS-CDMA method for receiving uplink may further comprise the steps:

The signal that each array element of array antenna is received carries out the sub-carrier signal separation steps;

With the sub-carrier signal of isolated each array element carry out despreading and matched filter processing, realize the despreading of subscriber signal, obtain the step of the matched filtering output of user's sub-carrier signal;

Matched filter output signal on the different array elements is carried out the spatial domain merge, obtain the conclusive judgement variable of user's sub-carrier signal, obtain the step of spatial domain diversity gain;

Conclusive judgement variable to resultant user's sub-carrier signal after the spatial domain merges is adjudicated, and obtains the step of the court verdict of user's sub-carrier signal.

A kind of array antenna MC-DS-CDMA up link receiving system comprises:

What connect after each array element of array antenna finishes the corresponding subcarrier of input signal and transmitting terminal modulation system multiplication mutually, realizes the carrier signal separation module that sub-carrier signal separates;

With the sub-carrier signal of isolated each array element send into connect behind each carrier signal separation module carry out despreading and matched filter processing, obtain the despreading and the matched filtering module of the pairing user's subcarrier of each array element bit signal matched filtering output;

Obtain vector, and merge weight vector by the spatial domain, finish each array element matched filter output signal spatial domain and merge, the spatial domain that obtains user's sub-carrier signal conclusive judgement variable merges module;

The conclusive judgement variable of user's sub-carrier signal is carried out polarity decision, obtain the signal decision module of arbitrary user's sub-carrier signal court verdict.

Concrete signal processing is as follows: at first, each array element received signal of array antenna is sent into the carrier signal separation module that connects after each array element of array antenna, finish the corresponding subcarrier of input signal and transmitting terminal modulation system multiplication mutually, realize the separation of sub-carrier signal; Secondly, the sub-carrier signal of isolated each array element of institute is sent into despreading and the matched filtering module that connects behind each carrier signal separation module, carry out despreading and matched filter processing, the matched filtering that obtains the pairing user's subcarrier of each array element bit signal is exported; Then, the parallel spatial domain of sending into of the pairing user's subcarrier of each array element bit signal matched filtering output is merged module, obtain vector, and merge weight vector by the spatial domain, finish each array element matched filter output signal spatial domain and merge, obtain user's sub-carrier signal conclusive judgement variable; The conclusive judgement variable of user's sub-carrier signal is sent into the signal decision module carry out polarity decision, obtain the court verdict of arbitrary user's sub-carrier signal.

The carrier signal separation module that connects after each array element of array antenna, despreading and matched filtering module are connected in series successively, pairing despreading of each array element afterwards and matched filtering module are parallel again joins with spatial domain merging module, and the spatial domain merges module and connects the signal decision module at last again.

Beneficial effect of the present invention:

Because isolated sub-carrier signal is carried out despreading and matched filter processing earlier, suppressed the multiple access interference to a great extent, to make the signal processing of receiver based on disturbing repressed signal to carry out, stability and performance that this can improve receiver greatly make the method for reseptance that is proposed have practical outstanding advantage.

The spatial domain of signal merges has adopted suboptimum to merge weight vector, does not need to calculate optimum spatial domain and merges the contrary of the necessary interference plus noise correlation matrix of weight vector, greatly reduce the complexity that weight vector calculates, and systematic function descends very little.

The spatial domain that is proposed merges method of reseptance and has obtained the spatial domain diversity gain by the spatial domain merging, makes system have good receptivity.

Description of drawings

Fig. 1 is that the spatial domain of arbitrary subcarrier l of the arbitrary user k of array antenna MC-DS-CDMA system up-link merges the reception structured flowchart;

Fig. 2 be the inventive method adopt optimum respectively and suboptimum merging weight vector and array antenna array number not simultaneously error rate of system to the simulation result of number of users.

Embodiment

Below in conjunction with accompanying drawing method of the present invention is described in detail.

Embodiment 1: following method of the present invention is discussed:

1, the separation of sub-carrier signal

Investigate array antenna MC-DS-CDMA system up-link, array antenna is adopted in the base station, and travelling carriage adopts single antenna.Travelling carriage uplink scheme adopts typical single antenna MC-DS-CDMA transmission plan [Hara S and Prasad R.An Overview of Multi-carrier CDMA.IEEE Comm.Mag.1997; 35 (12), pp.126-33.; Hara S and Prasad R. CDMA multiple carrier summary .IEEE communication magazine, 1997; 35 (12), pp.126-33] and biphase phase shift keying (Binary Phase ShiftKeying, BPSK) modulation system.

K mobile subscriber arranged in certain cellular cell in the supposing the system.Each subcarrier of MC-DS-CDMA transmission plan is carried independent user information, such k (signal launched of l the subcarrier of individual user of 1≤k≤K) can be expressed as:

$s_{k,l}\left(t\right)=\sqrt{P_{k,l}}{b}_{k,l}\left(t\right)c_k\left(t\right)\cos \left({\mathrm{\ω}}_{l}t\right)$ [formula 1]

Wherein, P _{K, l}It is the signal power of l subcarrier of k user. $b_{k,l}\left(t\right)=\underset{i=-\∞}{\overset{\∞}{\mathrm{\Σ}}}{b}_{k,l,i}\mathrm{rect}(t-i{T}_b)$ Be the information bit of l subcarrier, b _{K, l, i}Be the digital signal of corresponding getting ± 1, rect (t) is to be T the duration _bSquare-wave pulse, promptly bit period is Tb. $c_k\left(t\right)=\underset{g=1}{\overset{G}{\mathrm{\Σ}}}{c}_{k,g}(t-g{T}_c)$ Be that chip period is T _cFrequency expansion sequence, g (t) is a yard pulse-shaping signal, thereby spread processing gain is G=T _b/ T _cω _lBe the carrier frequency of l subcarrier, l=1,2, L, L.Typical MC-DS-CDMA transmission plan number of sub carrier wave is equated that with the spread processing gain G L=G is promptly arranged.

To each subcarrier experience of MC-DS-CDMA transmission plan is that the frequency non-selective fading is to keep the orthogonality between each subcarrier, can suppose that all subcarriers have all experienced the independent frequency non-selective fading, the channel impulse response of l subcarrier of k user is expressed as follows

$h_{k,l}\left(t\right)={\mathrm{\ρ}}_{k,l}{e}^{-j{\mathrm{\φ}}_{k,l}}\mathrm{\δ}(t-{\mathrm{\τ}}_{k,l})$ [formula 2]

Wherein, Be the multiple Gaussian random variable of zero-mean, variance is σ _{K, l} ²τ _{K, l}=(l-1) T _c+ Δ _{K, l}Be the time delay of l subcarrier of user k, Δ _{K, l}Be the independent same distribution stochastic variable, [0, T _c) between evenly distribute.

Suppose that the base station adopts equidistantly linear battle array, like this base station array antenna n (=1, L, N) signal that receives on the individual array element is:

$+e_n\left(t\right)$ [formula 3]

Wherein, $a_{k,l,n}=\exp [-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;d}}{{\mathrm{\&lambda;}}_{k,l}}(n-1)\sin \left({\mathrm{\&theta;}}_{k,l}\right)]$ Be the array response of n array element of array antenna, λ _{K, l}Be l subcarrier carrier wavelength of user k, d is the distance between the adjacent array element, θ _{K, l}Be the angle of arrival of l sub-carrier signal of user k, It is the phase shift of l sub-carrier signal of user k.e _n(t) be additive white Gaussian noise, power spectral density is N ₀/ 2.

Like this array antenna received to resultant signal can be expressed as:

$r\left(t\right)={[r_1\left(t\right),L,r_N\left(t\right)]}^T$

[formula 4]

Wherein, () ^TBe the transposition computing, e (t)=[e ₁, L, e _N] ^TBe corresponding noise vector.

The array vector of l subcarrier of user k is:

a _{K, l}=[a _{K, l, 1}, K, a _{K, l, N}] ^T[formula 5]

Each subcarrier of MC-DS-CDMA transmission plan is carried independent user information, and the testing process of the arbitrary sub-carrier signal of arbitrary user all is identical, and therefore the detection of the arbitrary sub-carrier signal of arbitrary user only is discussed.Be without loss of generality, suppose that (1≤l≤L) individual subcarrier signals is a desired signal to the 1st user l.

The signal times that each array element is received is with the subcarrier cos (ω corresponding with the transmitting terminal modulation system _lT), just can realize the separation of each sub-carrier signal.To l subcarrier signals of BPSK modulation system user that array antenna is isolated be:

x _l(t)＝[x _l，1(t)，L，x _l，N(t)] ^T＝r(t)cos(ω _lt)

=[r ₁(t) cos (ω _lT), L, r _N(t) cos (ω _lT)] ^T[formula 6]

2, despreading and matched filter processing

Isolated sub-carrier signal is carried out despreading and matched filter processing, realize the despreading of subscriber signal, obtain the matched filtering output of user's sub-carrier signal.Base station array antenna n (=1, L, N) individual array element is output as the matched filtering of i bit of the 1st l sub-carrier signal of user:

$y_{1,l,n}\left(i\right)=\frac{1}{T_b}{\&Integral;}_{(i-1)T_b+{\mathrm{\&tau;}}_{1,l}}^{i{T}_b+{\mathrm{\&tau;}}_{1,l}}{x}_{l,n}\left(t\right)c_1(t-{\mathrm{\&tau;}}_{1,l})\mathrm{dt}$ [formula 7]

All array elements of base station are output as the matched filtering of i bit of the 1st l sub-carrier signal of user:

$y_{1,l}\left(i\right)={[y_{1,l,1}\left(i\right),y_{1,l,2}\left(i\right),L,y_{1,l,N}\left(i\right)]}^T=\frac{1}{T_b}{\&Integral;}_{(i-1)T_b+{\mathrm{\&tau;}}_{1,l}}^{{\mathrm{iT}}_b+{\mathrm{\&tau;}}_{1,l}}{x}_l{c}_1(t-{\mathrm{\&tau;}}_{1,l})\mathrm{dt}$

[formula 8]

Wherein, m _{1, l}(i), n _{1, l}(i) represent total interference and noise signal respectively.

The noise of system and interference characteristic have significant effects to the performance that the spatial domain that is proposed merges method of reseptance.Below system noise and interference are analyzed.

1) noise

Noise item can provide as follows:

$n_{1,l}\left(i\right)=\frac{1}{T_b}{\&Integral;}_{(i-1)T_b+{\mathrm{\&iota;}}_{1,l}}^{i{T}_b+{\mathrm{\&tau;}}_{1,l}}e\left(t\right)c_1(t-{\mathrm{\&tau;}}_{1,l})\mathrm{dt}$ [formula 9]

Its variance is

${\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">N</figure-callout>}}^2=\frac{N_0}{2T_b}$ [formula 10]

2) disturb

The MC-DS-CDMA transmission plan owing to the orthogonality between each subcarrier, is therefore only existed multiple access to insert and disturbs m _{1, l}(i), can provide as follows:

$\&CenterDot;\underset{g=1}{\overset{G}{\mathrm{\&Sigma;}}}{c}_{1,g}[b_{k,l,(g-1)}{R}_g\left({\mathrm{\&tau;}}_{k,l}^{\&prime;}\right)+b_{k,l,g}{R}_g(T_c-{\mathrm{\&tau;}}_{k,l}^{\&prime;})]$ [formula 11]

Wherein, τ _{K, l}' be the relative time delay of k the individual subcarrier of user l ' with respect to l subcarrier of first user; R _gBe the partial auto correlation of chip waveform (τ), be defined as follows:

$R_g\left(\mathrm{\&tau;}\right)=\frac{1}{T_c}{\&Integral;}_0^{\mathrm{\&tau;}}g(t+T_c-\mathrm{\&tau;})g\left(t\right)\mathrm{dt},0\&le;\mathrm{\&tau;}\&le;T_c$ [formula 12]

3, the spatial domain of signal merges

Below the correlation properties of disturbing are further analyzed, draw optimum and suboptimum merging weight or weight vector that the received signal spatial domain merges.Disturb correlation properties to comprise auto-correlation and their cross correlation.

1) auto-correlation

Vector m _{1, l}(i) element m _{1, l, n}(i) can be regarded as a series of independent Gaussian stochastic variables.Therefore, their auto-correlation function can approximate evaluation be:

$E\left\{m_{1,l,n}\left(i\right)m_{1,l,n}^{*}(i+h)\right\}\&cong;{\mathrm{\&sigma;}}_I^2\mathrm{\&delta;}\left(h\right),1\&le;n\&le;N$ [formula 13]

Wherein, () ^*Be conjugate operation, δ (h) is the delta function.

Can get its variance is:

${\mathrm{\&sigma;}}_I^2=\underset{k=2}{\overset{K}{\mathrm{\&Sigma;}}}{P}_{k,l}\frac{{\mathrm{\&sigma;}}_{k,l}^2}{G}(R_g^2\left({\mathrm{\&tau;}}_{k,l}^{\&prime;}\right)+R_g^2(T_c-{\mathrm{\&tau;}}_{k,l}^{\&prime;}))$ [formula 14]

Suppose τ _{K, l}' be evenly distributed on [0, T _c], g (t) is to be T the duration _cSquare wave, to formula 14 [0, T _c] on ask average, can obtain:

${\mathrm{\&sigma;}}_I^2=\underset{k=2}{\overset{K}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&sigma;}}_{k,\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}{3G}{P}_{k,l}$ [formula 15]

2) cross-correlation

m _{1, l, n}(i) and m _{1, l, n '}(i) cross-correlation between is that the spatial domain of received signal on different array element n and n ' is relevant.It can be derived out by the cross-correlation function of linear array, and the cross-correlation function of linear array is expressed as follows:

$E\left\{a_{k,l}\left(t\right)a_{k,l}^H(t+\mathrm{\&tau;})\right\}=J_0\left(2\mathrm{\&pi;}{f}_d\mathrm{\&tau;}\right)\&CenterDot;R_{k,l}$ [formula 16]

Wherein, () ^HThe expression conjugate transpose, f _dIt is maximum Doppler frequency-shift.R _{K, l}Be l subcarrier array vector of expression user k a _{K, l}The N of correlation * N Hermitian Toeplitz matrix, its real part and imaginary part can be expressed as respectively:

$\mathrm{Re}\left\{R_{k,l}(n^{\&prime;},n)\right\}=J_0\left(r_{k,l}(n^{\&prime;},n)\right)+2\underset{q=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{J}_{2q}\left(r_{k,l}(n^{\&prime;},n)\right)\&CenterDot;\cos \left(2q{\mathrm{\&theta;}}_{k,l}\right)$ [formula 17]

$\mathrm{Im}\left\{R_{k,l}(n^{\&prime;},n)\right\}=2\underset{q=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{J}_{2q+1}(r_{k,l}(n^{\&prime;},n)\&CenterDot;\sin \left((2q+1){\mathrm{\&theta;}}_{k,l}\right))$ [formula 18]

J _qBe first kind q rank Bessel functions,

r _{K, l}(n ', n)=2 π d|n '-n|/λ _{K, l}[formula 19]

3) total interference plus noise correlation matrix

Definition interference correlation matrix M (h) is:

$M\left(i\right)=E\left\{m_{1,l}\left(i\right)m_{1,l}^H(i+h)\right\}=\mathrm{M\&delta;}\left(h\right)$ [formula 20]

Matrix M can be derived by formula 15,

$M=\underset{k=2}{\overset{K}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&sigma;}}_{k,\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}{3G}{P}_{k,l}{a}_{k,l}{a}_{k,l}^H=\frac{(M-1)}{3G}\&CenterDot;E\left\{{\mathrm{\&sigma;}}_{k,l}^2{P}_{k,l}{a}_{k,}\right\}$ [formula 21]

Have the identical signal power channel fading identical if further suppose each subcarrier of each user, P is promptly arranged with experience _{K, l}=P _l, ${\mathrm{\&sigma;}}_{k,\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2={\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2,$ The distribution function f (θ) of each user's sub-carrier signal angle of arrival is equally distributed within [0,2 π], and formula 21 can further be expressed as:

$M=\frac{(M-1)}{3G}{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2\&CenterDot;P_l\&CenterDot;{\&Integral;}_{\mathrm{\&theta;}}a\left(\mathrm{\&theta;}\right)a^H\left(\mathrm{\&theta;}\right)\&CenterDot;f\left(\mathrm{\&theta;}\right)\mathrm{d\&theta;}$

$=\frac{(M-1)}{3G}{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2\&CenterDot;P_l\&CenterDot;{\&Integral;}_{\mathrm{\&theta;}}R\left(\mathrm{\&theta;}\right)f\left(\mathrm{\&theta;}\right)\mathrm{d\&theta;}$ [formula 22]

R (θ) is the matrix in formula 17 and the formula 18, and the element of the n ' row n row of matrix M is:

$m_{n^{\&prime;},n}=\frac{(M-1)}{3G}{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="H071B9375X20071016E000012.png"\; state="\{\{state\}\}">l</figure-callout>}}^2\&CenterDot;P_l\&CenterDot;J_0\left(r(n^{\&prime;},n)\right)$ [formula 23]

Therefore, total interference plus noise correlation matrix is:

$R_T=E\left\{(m_{1,l}+n_{1,l}){(m_{1,l}+n_{1,l})}^H\right\}=M+{\mathrm{\&sigma;}}_N^{2}I$ [formula 24]

In the formula, I is a unit matrix.

R _TDetermining the optimum weight vector that merges in spatial domain of following formula, promptly the optimum weight vector that merges in the spatial domain of the 1st l subcarrier of user is:

$w_{1,l,\mathrm{opt}}=\mathrm{\&alpha;}{R}_T^{-1}{a}_{1,l}^{*}$ [formula 25]

Wherein, a _{1, l} ^*Be the complex conjugate of the 1st l subcarrier array response vector of user, α is a constant, can be taken as 1.

Work as R _TWhen approaching unit matrix, interference plus noise and white noise can be considered to sky the time, promptly have

$R_T=M+{\mathrm{\&sigma;}}_N^{2}I=({\mathrm{\&sigma;}}_I^2+{\mathrm{\&sigma;}}_N^2)I{=\mathrm{\&sigma;}}^{2}I$ [formula 26]

Wherein, σ _l ²Be defined in formula 15, σ _N ²It is the noise variance that is shown in formula 10.Like this, can obtain suboptimum spatial domain merging weight vector is:

$w_{1,l}=[w_{1,l,1}\left(i\right),K,w_{1,l,N}\left(i\right)]=\mathrm{\&alpha;}{a}_{1,l}^{*}\left(i\right)$ [formula 27]

The present invention only uses the suboptimum spatial domain of having simplified to merge weight vector, compare with the optimum merging, systematic function descends little, but because suboptimum spatial domain combined vector only need be known the knowledge of user's subcarrier array vector, do not merge the contrary of the necessary interference plus noise correlation matrix of weight vector and do not need to calculate optimum spatial domain, greatly reduce the complexity that weight vector calculates.

L subcarrier signals of the 1st user is that the conclusive judgement variable is through the output that the spatial domain merges i the bit in back:

$z_{1,l}\left(i\right)=w_{1,l}^T\left(i\right)y_{1,l}\left(i\right)=\sqrt{P_{1,l}}{\mathrm{\&rho;}}_{1,l}{b}_{k,l,i}\left|a_{1,l}\left(i\right)\right|+{\mathrm{\&eta;}}_{1,l}\left(i\right)$ [formula 28]

Wherein, $\left|a_{1,l}\right|=\frac{a_{1,l}^H\&CenterDot;a_{1,l}}{\sqrt{a_{1,l}^H\&CenterDot;a_{1,l}}},$ η _{1, l}(i) merge for the spatial domain that the back is disturbed and noise item with.

5, the judgement of signal

The present invention utilizes simple polarity decision method to adjudicate to resulting conclusive judgement variable, obtains the court verdict of user's sub-carrier signal.To the BPSK modulation system, be:

$z_{1,l}\left(i\right)=\left\{\begin{array}{c}1,z_{1,l}\left(i\right)>0\\ -1,z_{1,l}\left(i\right)<0\end{array}\right.$ [formula 29]

Embodiment 2:

Method of the present invention is applicable to the array antennas mobile communication system of any employing MC-DS-CDMA transmission plan.

The arbitrary subcarrier l of arbitrary user k array antenna MC-DS-CDMA system up-link spatial domain with reference to Fig. 1 merges the reception structured flowchart, and a kind of concrete steps of array antenna MC-DS-CDMA system up-link method of reseptance comprise:

Step 1, the signal r that array antenna the 1st array element is received ₁(t) ..., the signal r that N array element is received _N(t) send into the 1st respectively ..., N the pairing carrier signal separation module of array element (1-1) ..., (1-N) in, N carrier separation module finished the input signal subcarrier cos (ω corresponding with the transmitting terminal modulation system _lThe computing of t) multiplying each other realizes the separation of sub-carrier signal, correspondence the 1st ..., l subcarrier signals of N user that array element is isolated is respectively: x _{L, 1}(t)=r ₁(t) cos (ω _lT) ..., x _{L, N}(t)=r _N(t) cos (ω _lT);

Step 2 is with signal x _{L, 1}(t) send into the despreading and the matched filtering module (2-1) that connect behind the carrier signal separation module (1-1) and carry out despreading and matched filter processing, obtain the matched filtering output of the arbitrary subcarrier l of the user k i bit signal of corresponding the 1st array element: $y_{k,l,1}\left(i\right)=\frac{1}{T_b}{\&Integral;}_{(i-1)T_b+{\mathrm{\&tau;}}_{k,l}}^{i{T}_b+{\mathrm{\&tau;}}_{k,l}}{x}_{l,1}\left(t\right)c_k(t-{\mathrm{\&tau;}}_{k,l})\mathrm{dt};$

，…，

Simultaneously, with signal x _{L, N}Send into the despreading and the matched filtering module (2-N) that connect behind the carrier signal separation module (1-N) and carry out despreading and matched filter processing, obtain the matched filtering output of the arbitrary subcarrier l of the user k i bit signal of corresponding N array element: $y_{k,l,N}\left(i\right)=\frac{1}{T_b}{\&Integral;}_{(i-1)T_b+{\mathrm{\&tau;}}_{k,j}}^{i{T}_b+{\mathrm{\&tau;}}_{k,l}}{x}_{l,N}\left(t\right)c_k(t-{\mathrm{\&tau;}}_{k,l})\mathrm{dt};$

Step 3, with despreading and matched filtering module (2-1) ..., the signal y that (2-N) is exported _{K, l, 1}(i) ..., y _{K, l, N}(i) send into the spatial domain and merge module (3), obtain vector y _{K, l}(i)=y _{K, l, 1}(i), L, y _{K, l, N}(i)] ^T, merge weight vector w by the spatial domain _{K, l}=[w _{K, l, 1}(i), K, w _{K, l, N}(i)], the spatial domain of finishing l sub-carrier signal of user k merges, and obtains the conclusive judgement variable of l sub-carrier signal of user k $z_{k,l}\left(i\right)=w_{k,l}^T\left(i\right)y_{k,l}\left(i\right);$

Step 4 is with the conclusive judgement variable z of l sub-carrier signal of user k _{K, l}Send into signal decision module (4) and carry out polarity decision, obtain the court verdict of the arbitrary subcarrier l of arbitrary user k signal.

Fig. 2 provided a kind of array antenna MC-DS-CDMA system up-link method of reseptance that adopts the present invention to propose adopt optimum respectively and suboptimum merging weight vector and array antenna array number not simultaneously error rate of system to the simulation result of number of users.The array element distance of the even linear battle array that is adopted in simulation process is λ/2, and each subcarrier signals power of user is identical, and Normalized Signal/Noise Ratio is E _b/ N ₀=10dB, sub-carrier number and spread processing gain are 64, the angle of arrival of all user's sub-carrier signals is separate, and evenly distributes between [0,2 π].

The bit error rate performance of system is very approaching when adopting optimum and suboptimum merging weight vector as can be seen from Figure 2, it is very little to the performance impact of system to show that the employing suboptimum merges weight vector, but because the suboptimum spatial domain merges the knowledge that weight vector only need be known user's subcarrier array vector, do not merge the contrary of the necessary interference plus noise correlation matrix of weight vector and do not need to calculate optimum spatial domain, greatly reduce the complexity that weight vector calculates.Simultaneously, after adopting the array antenna of many array elements, the performance of system is greatly improved than the MC-DS-CDMA system that adopts single antenna, and array number more the multisystem performance improve just significantly more, show that the effect of the inventive method is very remarkable.

Claims (3)

1. array antenna MC-DS-CDMA method for receiving uplink is characterized in that may further comprise the steps:

Step 1, the signal r that array antenna the 1st array element is received ₁(t) ..., the signal r that N array element is received _N(t) send into the 1st respectively ..., N the pairing carrier signal separation module of array element (1-1) ..., (1-N) in, N carrier separation module finished the input signal subcarrier cos (ω corresponding with the transmitting terminal modulation system _lThe computing of t) multiplying each other realizes the separation of sub-carrier signal, correspondence the 1st ..., l subcarrier signals of N user that array element is isolated is respectively: x _{L, 1}(t)=r ₁(t) cos (ω _lT) ..., x _{L, N}(t)=r _N(t) cos (ω _lT);

Step 2 is with signal x _{L, 1}(t) send into the despreading and the matched filtering module (2-1) that connect behind the carrier signal separation module (1-1) and carry out despreading and matched filter processing, obtain the matched filtering output of the arbitrary subcarrier l of the user k i bit signal of corresponding the 1st array element:

，…，

Simultaneously, with signal x _{L, N}Send into the despreading and the matched filtering module (2-N) that connect behind the carrier signal separation module (1-N) and carry out despreading and matched filter processing, obtain the matched filtering output of the arbitrary subcarrier l of the user k i bit signal of corresponding N array element:

Step 3, with despreading and matched filtering module (2-1) ..., the signal y that (2-N) is exported _{K, l, 1}(i) ..., y _{K, l, N}(i) send into the spatial domain and merge module (3), obtain vector y _{K, l}(i)=[y _{K, l, 1}(i) ..., y _{K, l, N}(i)] ^T, merge weight vector w by the spatial domain _{K, l}=[w _{K, l, 1}(i) ..., w _{K, l, N}(i)], the spatial domain of finishing l sub-carrier signal of user k merges, and obtains the conclusive judgement variable of l sub-carrier signal of user k

Step 4 is with the conclusive judgement variable z of l sub-carrier signal of user k _{K, l}Send into signal decision module (4) and carry out polarity decision, obtain the court verdict of the arbitrary subcarrier l of arbitrary user k signal;

ω in the step in the above _lBe the angular frequency of l subcarrier of user, τ _{K, l}Be the time delay of l subcarrier of user k, T _bBe bit period, c _kIt is the frequency expansion sequence of user k.

2. according to the described a kind of array antenna MC-DS-CDMA method for receiving uplink of claim 1, it is characterized in that spatial domain in the step 3 merges to be based on suboptimum and to merge that weight vector carries out that the weight vector of l sub-carrier signal spatial domain merging of user k is

Wherein, a _{K, l} ^*Be the complex conjugate of l subcarrier array response vector of user k, α is a constant, is taken as 1.

3. array antenna MC-DS-CDMA up link receiving system is characterized in that comprising:

What connect after each array element of array antenna finishes the corresponding subcarrier of input signal and transmitting terminal modulation system multiplication mutually, realizes the carrier signal separation module that sub-carrier signal separates;

With the sub-carrier signal of isolated each array element send into connect behind each carrier signal separation module carry out despreading and matched filter processing, obtain the despreading and the matched filtering module of the pairing user's subcarrier of each array element bit signal matched filtering output;

Obtain vector, and merge weight vector by the spatial domain, finish each array element matched filter output signal spatial domain and merge, the spatial domain that obtains user's sub-carrier signal conclusive judgement variable merges module;

The conclusive judgement variable of user's sub-carrier signal is carried out polarity decision, obtain the signal decision module of arbitrary user's sub-carrier signal court verdict;

At first, each array element received signal of array antenna is sent into the carrier signal separation module that connects after each array element of array antenna, finish the corresponding subcarrier of input signal and transmitting terminal modulation system multiplication mutually, realize the separation of sub-carrier signal; Secondly, the sub-carrier signal of isolated each array element of institute is sent into despreading and the matched filtering module that connects behind each carrier signal separation module, carry out despreading and matched filter processing, the matched filtering that obtains the pairing user's subcarrier of each array element bit signal is exported; Then, the parallel spatial domain of sending into of the pairing user's subcarrier of each array element bit signal matched filtering output is merged module, obtain vector, and merge weight vector by the spatial domain, finish each array element matched filter output signal spatial domain and merge, obtain user's sub-carrier signal conclusive judgement variable; The conclusive judgement variable of user's sub-carrier signal is sent into the signal decision module carry out polarity decision, obtain the court verdict of arbitrary user's sub-carrier signal;

The carrier signal separation module that connects after each array element of array antenna, despreading and matched filtering module are connected in series successively, pairing despreading of each array element afterwards and matched filtering module are parallel again joins with spatial domain merging module, and the spatial domain merges module and connects the signal decision module at last again.

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