CN1758576A - Uplink chain emitting and receiving method of space time block code its-DS-CDMA system - Google Patents

Abstract

A method for emitting and receiving up link of space hour block code in MC-DC-CDMA system includes emitting steps as carrying out series-parallel transform for each user data stream, applying 2 x 2 orthogonal space hour block coding for data block stream, carrying out fast Fourier transform and airspace spread spectrum for sub data stream, then adding for emitting; receiving steps as carrying out fast Fourier transform for signal received by each antenna, carrying out dispreading and filtering treatment as well as airspace decoding for each sub carrier signal and each sub carrier signal being dispread, carrying out airspace combination and BPSK demodulation to restore data signal then restoring user data stream by carrying out parallel-series transform.

Description

A kind of Space-Time Block Coding MC-DS-CDMA system up-link emission and method of reseptance

Technical field

The invention belongs to multicarrier (MC) code division multiple access (CDMA) cell mobile communication systems multiple-input and multiple-output (MIMO) 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 principal modes of multitone modulation CDMA (MT-CDMA).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.But existing MC-DS-CDMA scheme also is difficult to satisfy future mobile communications to high-transmission quality, spectral efficient and jumbo requirement at the aspects such as the error rate, spectrum efficiency and capacity of system.

Space-Time Block Coding (STBC) technology of using multiple-input and multiple-output (MIMO) in mobile communication system is to improve the effective ways of mobile communication system data wireless links transmission rate, transmission quality and the availability of frequency spectrum.

Summary of the invention

The present invention is a radio link performance of improving the MC-DS-CDMA system, uplink transmit and method of reseptance that a kind of Space-Time Block Coding technology with multiple-input and multiple-output is applied to the MC-DS-CDMA system have been proposed, under the situation of not sacrificing frequency resource, improved the performance of MC-DS-CDMA system significantly.

Emission of a kind of Space-Time Block Coding MC-DS-CDMA of the present invention (STBC-MC-DS-CDMA) system up-link and reception technique scheme may further comprise the steps:

A. step of transmitting:

(1) each user forms P channel parallel data stream through the serial to parallel conversion of the data flow process 1:P of BPSK modulation, and forming length is the parallel data block of P;

(2) data block stream through 2 * 2 orthogonal space time group coding after, form two paths of data piece stream, will be dispensed on emission respectively on two transmitting antennas;

(3) the P way data flow of each circuit-switched data piece stream all being used length is that the spreading code of G carries out the time domain spread spectrum, and different users adopts different spreading codes;

(4) the P road parallel signal behind the time domain spread spectrum is carried out fast fourier inverse transformation (IFFT), each road signal is modulated on the corresponding subcarrier;

(5) launch after the P way carrier signal addition after will modulating.

B. receiving step:

(1) signal that receives of each antenna comprises the stack of the signal and the noise of each user, each transmitting antenna, and the signal that each antenna is received carries out the fast fourier transform corresponding with transmitting terminal (FFT), recovers each subcarrier signals;

(2) each subcarrier signals of each user is all carried out despreading corresponding with transmitting terminal and matched filter processing, obtain the signal after each subcarrier despreading of each user;

(3) signal after each the subcarrier despreading of each user that obtains is all carried out corresponding with transmitting terminal decoding when empty, decoding comprises a delay unit, a conjugate operation units and a time domain merge cells when empty, obtains the output signal of two successive bits of each subcarrier of each user when empty after the decoding;

(4) signal to same user decoding output when each reception antenna is overhead carries out the spatial domain merging again, obtains the conclusive judgement variable of user at each sub-carrier signal;

(5) the conclusive judgement variable to each sub-carrier signal carries out the BPSK demodulation, recovers the data-signal of user on each subcarrier;

(6) data-signal that is recovered is carried out and go here and there conversion and recover user's data stream.

Below emission of the present invention and receiving course are discussed, with the concrete implication of illustrating emission of the present invention and each step of method of reseptance and the meaning of related symbol.

1. transmit

Investigate the emission process of above-mentioned STBC-MC-DS-CDMA system up-link.Supposing the system has K user, and each user adopts the BPSK modulation, has identical transmitting power S and data rate 1/T _bCustomer traffic is at first carried out the serial to parallel conversion of 1:P, form P channel parallel data stream, forming length is the parallel data block of P, and n data block is expressed as $b_k^{\left(n\right)}=[b_{k,1}^{\left(n\right)}.....b_{k,P}^{\left(n\right)}{]}^T,$ Wherein, () ^TThe expression transposition, the symbol period T behind the serial to parallel conversion _s=PT _bTwo continuous data block b of 2n and 2n+1 _k ⁽²ⁿ⁾And b _k ⁽²ⁿ⁺¹⁾Space Time Coding output 2P * 2 matrixes below forming:

$\left(\begin{array}{cc}{a}_{k,1}^{(2n+1)}& a_{k,1}^{\left(2n\right)}\\ a_{k,2}^{(2n+1)}& a_{k,2}^{\left(2n\right)}\end{array}\right)=\frac{1}{\sqrt{2}}\left(\begin{array}{cc}{-b}_k^{(2n+1)}& b_k^{\left(2n\right)}\\ b_k^{\left(2n\right)}& b_k^{(2n+1)}\end{array}\right)$ [formula 1]

Wherein, $a_{k,i}^{\left(n\right)}=[a_{k,i,1}^{\left(n\right)}...a_{k,i,P}^{\left(n\right)}{]}^T,$ I=1,2, represent n the data block of k user's correspondence on i transmitting antenna,

It is the normalization coefficient of emission symbol energy.

To above-mentioned emission process, the signal that k user launched on i transmitting antenna can be expressed as:

$s_{k,i}\left(t\right)=\sqrt{2S}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}{a}_{k,i,p}\left(t\right)c_k\left(t\right)\exp \left(j\right(2\mathrm{\π}{f}_{p}t)$ [formula 2]

In the formula, $a_{k,i,p}\left(t\right)={\mathrm{\Σ}}_{n=-\∞}^{\∞}{a}_{k,i,p}^{\left(n\right)}{g}_{T_s}(t-{\mathrm{nT}}_s)$ Represent the p that k user's correspondence launched on i transmitting antenna (the individual data flow of 1≤p≤P), wherein, a _{K, i, p} ⁽ⁿ⁾N the data bit that expression is corresponding. $c_k\left(t\right)={\mathrm{\Σ}}_{m=1}^G{c}_k^{\left(m\right)}{g}_{T_c}(t-{\mathrm{mT}}_c)$ Be k user's spreading code waveform, c _k ^(m)Be corresponding m and cut generally that G is the spread processing gain.g _Ts(t) and g _Tc(t) be respectively be defined in [0, T _s) and [0, T _c) on square wave.

2. channel

To the system that makes up based on MC-DS-CDMA, what each subcarrier experienced is frequency non-selective fading channel.P subcarrier of k user from i transmitting antenna to j (j=1,2 ..., J) low-pass impulse response of channel can be expressed as between the reception antenna:

$h_{k,i,j,p}\left(t\right)={\mathrm{\β}}_{k,i,j,p}{e}^{j{\mathrm{\γ}}_{k,i,j,p}}\mathrm{\δ}\left(t\right)$ [formula 3]

Wherein, β _{K, i, j, p}e ^{J γ k, i, j, p}Be complex channel coefficient, β _{K, i, j, p}Be the amplitude gain of channel, γ _{K, i, j, p}Be the phase gain of channel, δ (t) is the delta function.Because the scheme that is proposed is used for the high-speed radio transmission, can suppose at two mark space [2nT _s(2n+1) T _s] channel fading is quasi-static, have

${\mathrm{\β}}_{k,i,j,p}^{\left(2n\right)}\≈{\mathrm{\β}}_{k,i,j,p}^{(2n+1)}={\mathrm{\β}}_{k,i,j,p}$

${\mathrm{\γ}}_{k,i,j,p}^{\left(2n\right)}\≈{\mathrm{\γ}}_{k,i,j,p}^{(2n+1)}={\mathrm{\γ}}_{k,i,j,p}$ [formula 4]

3. received signal

To up link, experienced formula 3 described channels after, can be expressed as in the received signal of j antenna of receiving terminal:

$r_j\left(t\right)=\sqrt{2S}\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{i=1}{\overset{2}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}{\mathrm{\β}}_{k,i,j,p}{a}_{k,i,p}(t-{\mathrm{\τ}}_{k,i,j})c_k(t-{\mathrm{\τ}}_{k,i,j})$

[formula 5]

Wherein, τ _{K, i, j}For the propagation delay of user k from i transmitting antenna to j reception antenna, to different k, i, j supposes τ _{K, i, j}Be independently. _{K, i, j, p}(t)=(γ _{K, i, j, p}-2 π f _pτ _{K, i, j}) mod2 π be p sub-carrier signal of user k from i transmitting antenna to j (j=1 ..., the J) phase shift between individual reception antenna, η _j(t) expression additive white Gaussian noise.

4. the demodulation of signal

Be without loss of generality, suppose that user k is a desired user, makes τ _{K, i, j}=0.To above-mentioned receiving course, the despreading and the matched filtering of n symbol of p the carrier signal of user k are output as on j reception antenna:

$y_{k,j,p}^{\left(n\right)}={\∫}_{{\mathrm{nT}}_s}^{{(n+1)T}_s}{r}_j\left(t\right)\exp (-j2\mathrm{\π}{f}_{p}t)c_k\left(t\right)\mathrm{dt}$ [formula 6]

Use α respectively _{K, j, p, 1} ⁽²ⁿ⁾, α _{K, j, p, 2} ⁽²ⁿ⁾And α _{K, j, p, 1} ⁽²ⁿ⁺¹⁾, α _{K, j, p, 2} ⁽²ⁿ⁺¹⁾Be illustrated on j the reception antenna, decoding was at the output y in two continuous symbol cycles when p carrier signal of user k was empty _{K, j, p} ⁽²ⁿ⁾(y _{K, j, p} ^(2n+l)) ^*Merge coefficient, merge to adopt the high specific merging criterion.To Merge Scenarios of the present invention, b _{K, p} ⁽²ⁿ⁾And b _{K, p} ⁽²ⁿ⁺¹⁾The conclusive judgement variable be respectively:

$Y_{k,p}^{\left(2n\right)}=\underset{j=1}{\overset{J}{\mathrm{\Σ}}}\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{\left(2n\right)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{\left(2n\right)}\}$ [formula 7]

$Y_{k,p}^{(2n+1)}=\underset{j=1}{\overset{J}{\mathrm{\Σ}}}\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{(2n+1)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{(2n+1)}\}$ [formula 8]

In the formula, () ^*The expression complex conjugate.

To high specific merging criterion of the present invention, merge coefficient α _{K, j, p, 1} ⁽²ⁿ⁾, α _{K, j, p, 2} ⁽²ⁿ⁾And α _{K, j, p, 1} ⁽²ⁿ⁺¹⁾, α _{K, j, p, 2} ⁽²ⁿ⁺¹⁾Be respectively:

[formula 9]

With

[formula 10]

Resulting conclusive judgement variable is carried out BPSK to be separated and is in harmonious proportion the information data that promptly obtains desired user k behind the serial to parallel conversion.

Beneficial effect of the present invention:

STBC-MC-DS-CDMA scheme proposed by the invention organically is applied to the MC-DS-CDMA system with the Space-Time Block Coding technology of multiple-input and multiple-output, empty time emission and receive diversity gain have been obtained, under the condition of same band, compare with MC-DS-CDMA system in the past, the error rate of system significantly reduces, the spectrum efficiency of system and capacity have then obtained improving significantly, and the performance of improving the MC-DS-CDMA system is had significant effect.

Description of drawings

Fig. 1 is the emission process figure of the arbitrary user k of Space-Time Block Coding MC-DS-CDMA system up-link;

Fig. 2 is the receiving course figure of the arbitrary user k of Space-Time Block Coding MC-DS-CDMA system up-link;

Fig. 3 is the comparisons of two error rate of systems (BER) to the signal to noise ratio simulation result;

Fig. 4 is the comparisons of two error rate of systems (BER) to the number of users simulation result;

Fig. 5 is the comparisons of two system bandwidth efficient to the signal to noise ratio simulation result;

The simulation result of BER performance when Fig. 6 adopts high specific merging and equal gain combining respectively for time domain merges.

Embodiment

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

With reference to the emission process of the arbitrary user k of a kind of Space-Time Block Coding MC-DS-CDMA system up-link of Fig. 1, concrete steps comprise:

(1) binary signal of information source 10 generations of arbitrary user k, through BPSK modulation 11, the data flow of generation forms the P channel parallel data and flows through the serial to parallel conversion 12 of 1:P, and forming length is the parallel data block of P, and n data block is expressed as $b_k^{\left(n\right)}=[b_{k,1}^{\left(n\right)}.....b_{k,P}^{\left(n\right)}{]}^T,$ Wherein, () ^TThe expression transposition;

(2) two continuous data block b _k ⁽²ⁿ⁾And b _k ⁽²ⁿ⁺¹) orthogonal space time group coding 13 through 2 * 2,2P * 2 matrixes below forming:

$\left(\begin{array}{cc}{a}_{k,1}^{(2n+1)}& a_{k,1}^{\left(2n\right)}\\ a_{k,2}^{(2n+1)}& a_{k,2}^{\left(2n\right)}\end{array}\right)=\frac{1}{\sqrt{2}}\left(\begin{array}{cc}-b_k^{(2n+1)}& b_k^{\left(2n\right)}\\ b_k^{\left(2n\right)}& b_k^{(2n+1)}\end{array}\right)$

Wherein, $a_{k,i}^{\left(n\right)}=[a_{k,i,1}^{\left(n\right)}...a_{k,i,P}^{\left(n\right)}{]}^T,$ I=1,2, represent n the data block of k user's correspondence on i transmitting antenna,

It is the normalization coefficient of emission symbol energy;

(3) P channel parallel data stream is the time domain spread spectrum 14 of the spreading code of G through length, obtains the signal of user k correspondence behind arbitrary road p spread spectrum on i the transmitting antenna and is:

α _k，j，p(t)c _k(t)

Wherein, c _k(t) be k user's spreading code waveform;

(4) the P road parallel signal behind the time domain spread spectrum is modulated to each road signal on the corresponding subcarrier through fast fourier inverse transformation (IFFT) 15, obtains the signal of user k correspondence on modulation successor one subcarrier p on i the transmitting antenna to be:

$\sqrt{2S}{a}_{k,i,p}\left(t\right)c_k\left(t\right)\exp \left(j2\mathrm{\π}{f}_{p}t\right)$

Wherein, S is a user emission power, f _pIt is the frequency of p subcarrier;

(5) P road, modulation back subcarrier signals is launched on the antenna of correspondence through addition 16 backs, and the signal that user k launches on i transmitting antenna can be expressed as:

$s_{k,i}\left(t\right)=\sqrt{2S}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}{a}_{k,i,p}\left(t\right)c_k\left(t\right)\exp \left(j\right(2\mathrm{\π}{f}_{p}t)$

With reference to the receiving course of the arbitrary user k of a kind of Space-Time Block Coding MC-DS-CDMA system up-link of Fig. 2, concrete steps comprise:

(1) signal that receives of each antenna comprises the stack of the signal and the noise of each user, each transmitting antenna, the signal that each antenna receives is through the fast fourier transform (FFT) 21 corresponding with transmitting terminal, recover the signal on each subcarrier, the signal on the arbitrary subcarrier p that is recovered is:

r _j(t)exp(-j2πf _pt)

Wherein, r _j(t) be received signal on j antenna of receiving terminal;

(2) each subcarrier signals of each user is all passed through the despreading corresponding with transmitting terminal and matched filtering 22 and is handled, and obtains the signal after each subcarrier despreading of each user, and the signal of n bit is after the despreading of the arbitrary subcarrier p of user k and the matched filter processing:

$y_{k,j,p}^{\left(n\right)}={\∫}_{{\mathrm{nT}}_s}^{{(n+1)T}_s}{r}_j\left(t\right)\exp (-2\mathrm{\π}{f}_{p}t)c_k\left(t\right)\mathrm{dt}$

(3) signal after each the subcarrier despreading of each user that obtains is all carried out corresponding with transmitting terminal decoding 23 when empty, decoding comprises a delay unit, a conjugate operation units and a time domain merge cells when empty, and the output signal of two successive bits 2n of decoding and 2n+1 was respectively when the arbitrary subcarrier p of user k was empty:

$\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{\left(2n\right)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{\left(2n\right)}\}$

$\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{(2n+1)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{(2n+1)}\}$

Wherein, α _{K, j, p, 1} ⁽²ⁿ⁾, α _{K, j, p, 2} ⁽²ⁿ⁾And α _{K, j, p, 1} ⁽²ⁿ⁺¹⁾, α _{K, j, p, 2} ⁽²ⁿ⁺¹⁾Represent that respectively decoding when p sub-carrier signal of user k that j antenna receive is empty exports the time domain merge coefficient of 2n and 2n+1 bit;

(4) signal to same user decoding output when each reception antenna is overhead carries out spatial domain merging 24 again, obtains the conclusive judgement variable of user at each sub-carrier signal, and the 2n of p subcarrier of user k and the conclusive judgement variable of 2n+1 bit are respectively:

$Y_{k,p}^{\left(2n\right)}=\underset{j=1}{\overset{J}{\mathrm{\Σ}}}\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{\left(2n\right)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{\left(2n\right)}\}$

$Y_{k,p}^{(2n+1)}=\underset{j=1}{\overset{J}{\mathrm{\Σ}}}\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{(2n+1)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{(2n+1)}\}$

(5) the conclusive judgement variable to each sub-carrier signal carries out BPSK demodulation 25, recovers the data-signal of user on each subcarrier;

(6) signal that is recovered is carried out parallel serial conversion 26 and recover user's data stream.

Be to estimate the performance of the emission of a kind of Space-Time Block Coding MC-DS-CDMA of the present invention system up-link and method of reseptance, the error rate (BER) of the STBC-MC-DS-CDMA system that big line 2 reception antennas of 2 emissions are proposed down and former MC-DS-CDMA system and bandwidth efficiency have carried out Computer Simulation and have compared.In order to compare, supposing the system has identical bandwidth, data rate and channel parameter.In the emulation, spreading code has adopted pseudorandom (PN) sign indicating number, and carrier number and spreading gain are 128, and error rate thresholding is 10 ^-3

Fig. 3 has provided two BER of system performances to signal to noise ratio E _s/ N ₀Simulation result; Fig. 4 provides the simulation result of two BER of system performances to number of users.From Fig. 3 and Fig. 4, can be clear that, adopt the Space-Time Block Coding MC-DS-CDMA scheme that is proposed to compare the BER performance that has improved system significantly with former MC-DS-CDMA scheme.

Fig. 5 has provided two system bandwidth efficient to signal to noise ratio E _s/ N ₀Simulation result.Can clearly be seen that from Fig. 5 the Space-Time Block Coding MC-DS-CDMA scheme that employing proposes compares with former MC-DS-CDMA scheme, improved the bandwidth efficiency of system or the capacity of system significantly.

Fig. 6 has provided the simulation result of the BER performance of suggesting plans when high specific merging and equal gain combining are adopted in the time domain merging respectively.As can be seen from Figure 6, the BER performance of system when the BER performance of system will obviously be better than adopting equal gain combining when adopting high specific to merge, so the mode that the time domain merging adopts high specific to merge is suitable.

Claims (2)

1. a Space-Time Block Coding MC-DS-CDMA system up-link is launched and method of reseptance, it is characterized in that arbitrary user's (k) emission and receiving course, may further comprise the steps:

A. step of transmitting:

(1) binary signal of the information source of arbitrary user k (10) generation, through BPSK modulation (11), the data flow of generation forms the P channel parallel data and flows through the serial to parallel conversion (12) of 1:P, and forming length is the parallel data block of P, and n data block is expressed as

$b_k^{\left(n\right)}={[b_{k,1}^{\left(n\right)}.....b_{k,P}^{\left(n\right)}]}^T,$ Wherein, () ^TThe expression transposition;

(2) two continuous data block b _k ⁽²ⁿ) and b _k ⁽²ⁿ⁺¹⁾Orthogonal space time group coding (13) through 2 * 2,2P * 2 matrixes below forming:

$\left(\begin{array}{cc}{a}_{k,1}^{(2n+1)}& a_{k,1}^{\left(2n\right)}\\ a_{k,2}^{(2n+1)}& a_{k,2}^{\left(2n\right)}\end{array}\right)=\frac{1}{\sqrt{2}}\left(\begin{array}{cc}-b_k^{(2n+1)}& b_k^{\left(2n\right)}\\ b_k^{\left(2n\right)}& b_k^{(2n+1)}\end{array}\right)$

Wherein, $a_{k,i}^{\left(n\right)}={[a_{k,i,1}^{\left(n\right)}...a_{k,i,P}^{\left(n\right)}]}^T$ N the data block of (i=1,2) k user's correspondence of expression on i transmitting antenna, It is the normalization coefficient of emission symbol energy;

(3) P channel parallel data stream is the time domain spread spectrum (14) of the spreading code of G through length, obtains the signal of user k correspondence behind arbitrary road p spread spectrum on i the transmitting antenna and is:

a _{K, i, p}(t) c _k(t) wherein, c _k(t) be k user's spreading code waveform;

(4) the P road parallel signal behind the time domain spread spectrum is modulated to each road signal on the corresponding subcarrier through fast fourier inverse transformation (15), obtains the signal of user k correspondence on modulation successor one subcarrier p on i the transmitting antenna to be:

$\sqrt{2S}{a}_{k,i,p}\left(t\right)c_k\left(t\right)\exp \left(j2\mathrm{\π}{f}_{p}t\right)$

Wherein, S is a user emission power, f _pIt is the frequency of p subcarrier;

(5) P road, modulation back subcarrier signals is launched on the antenna of correspondence through addition (16) back, and the signal indication that user k launches on i the big line of emission is:

$s_{k,i,p}\left(t\right)=\sqrt{2S}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}{a}_{k,i,p}\left(t\right)c_k\left(t\right)\exp \left(j2\mathrm{\π}{f}_{p}t\right)$

B. receiving step:

(1) signal that receives of each antenna comprises the stack of the signal and the noise of each user, each transmitting antenna, the signal that each antenna receives is through the fast fourier transform (21) corresponding with transmitting terminal, recover the signal on each subcarrier, the signal on the arbitrary subcarrier p that is recovered is:

r _j(t) exp (j2 π f _pT) wherein, r _j(t) be received signal on j antenna of receiving terminal;

(2) each subcarrier signals of each user is all passed through despreading corresponding with transmitting terminal and matched filtering (22) processing, obtain the signal after each subcarrier despreading of each user, the signal of n bit is after the despreading of the arbitrary subcarrier p of user k and the matched filter processing:

$y_{k,j,p}^{\left(2\right)}={\∫}_{n{T}_s}^{(n+1)T_s}{r}_j\left(t\right)\exp (-2\mathrm{\π}{f}_{b}t)c_k\left(t\right)\mathrm{dt}$

(3) signal after each the subcarrier despreading of each user that obtains is all carried out corresponding with transmitting terminal decoding (23) when empty, decoding comprises a delay unit, a conjugate operation units and a time domain merge cells when empty, and the output signal of two successive bits 2n of decoding and 2n+1 was respectively when the arbitrary subcarrier p of user k was empty:

$\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{\left(2n\right)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{\left(2n\right)}\}$

$\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{(2n+1)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{(2n+1)}\}$

Wherein, α _{K, j, p, 1} ⁽²ⁿ⁾, α _{K, j, p, 2} ⁽²ⁿ⁾And α _{K, j, p, 1} ⁽²ⁿ⁺¹⁾, α _{K, j, p, 2} ⁽²ⁿ⁺¹⁾Represent that respectively decoding when p sub-carrier signal of user k that j antenna receive is empty exports the time domain merge coefficient of 2n and 2n+1 bit;

(4) signal to same user decoding output when each reception antenna is overhead carries out spatial domain merging (24) again, obtain the conclusive judgement variable of user at each sub-carrier signal, the 2n of p subcarrier of user k and the conclusive judgement variable of 2n+1 bit are respectively:

$Y_{k,p}^{\left(2n\right)}=\underset{j=1}{\overset{J}{\mathrm{\Σ}}}\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{\left(2n\right)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{\left(2n\right)}\}$

$Y_{k,p}^{(2n+1)}=\underset{j=1}{\overset{J}{\mathrm{\Σ}}}\mathrm{Re}\{y_{k,j,p}^{\left(2n\right)}{\mathrm{\α}}_{k,j,p,1}^{(2n+1)}+{\left(y_{k,j,p}^{(2n+1)}\right)}^{*}{\mathrm{\α}}_{k,j,p,2}^{(2n+1)}\}$

(5) the conclusive judgement variable to each sub-carrier signal carries out BPSK demodulation (25), recovers the data-signal of user on each subcarrier;

(6) signal that is recovered is carried out parallel serial conversion (26) and recover user's data stream.

2. according to described a kind of Space-Time Block Coding MC-DS-CDMA system up-link emission of claim 1 and method of reseptance, the time domain of two continuous 2n of decoding output and 2n+1 bit merges the merging of employing high specific, merge coefficient α when it is characterized in that claim 1 receiving step (3) to p sub-carrier signal sky of user k _{K, j, p, 1} ⁽²ⁿ⁾, α _{K, j, p, 2} ⁽²ⁿ⁾And α _{K, j, p, 1} ⁽²ⁿ⁺¹⁾, α _{K, j, p, 2} ⁽²ⁿ⁺¹⁾Be respectively:

With

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