CN100492956C - Space-time block code MT-CDMA system uplink transmitting and receiving method - Google Patents

Abstract

This invention relates to one division group code MT-CDMA system upper linkage emission and receive method, which comprises the following steps: emission step to process series change on each user data flow; cross space division coding through 2 times2 data block; processing time zone expansion on each path data flow; processing rapid Fourier change; adding and emission; receive step to receive each antenna signal for rapid Fourier change; expanding each user each load wave signal for expanding and matching filter; then for space decoding and then merging the multi-path signal time zone; merging the parallel signals to get user final judgment variables on each sub-wave; modulating final judgment variables to recover the user data signal on each load wave; then recovering the user data flow.

Description

A kind of space-time block code MT-CDMA system uplink 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).Usually, the sub-carrier number of MC-CDMA and MC-DS-CDMA scheme is identical with the length of frequency expansion sequence, and the MT-CDMA scheme adopts longer frequency expansion sequence and than the sub-carrier number of frequency expansion sequence length much less, two kinds of schemes of MT-CDMA scheme and other are compared to have and are suppressed the good and emission of multiple access jamming performance, advantage that the receiver complexity is low like this, will obtain important use in the future mobile communications architecture.But existing MT-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.

Summary of the invention

The present invention is the performance that further improves the MT-CDMA system, emission and method of reseptance that a kind of Space-Time Block Coding with multiple-input and multiple-output (MIMO) (STBC) technology is applied to the MT-CDMA system up-link have been proposed, under the situation of not sacrificing frequency resource, improved the performance of MT-CDMA system significantly.

Emission of a kind of space-time block code MT-CDMA of the present invention (STBC-MT-CDMA) system up-link and the technical scheme that the recipient sends out 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, the signal that each antenna is received carries out the fast fourier transform (FFT) corresponding with transmitting terminal fast fourier inverse transformation (IFFT), recovers each subcarrier signals;

(2) signal to each footpath of each subcarrier of each user all carries out despreading corresponding with transmitting terminal and matched filter processing, obtains each footpath signal after despreading of each subcarrier of each user;

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

(4) time domain that decoded output signal carries out multipath signal when empty to each footpath of each subcarrier of each user merges, and obtains the signal after each subcarrier multipath of each user merges;

(5) signal of the same subcarrier of same user after multipath on each reception antenna merges carried out the spatial domain again and merge, obtain the conclusive judgement variable of user at each sub-carrier signal;

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

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

Below method of the present invention is discussed.

1. transmit

Investigation has the emission process of K user's STBC-MT-CDMA system up-link.Each user adopts the BPSK modulation, has identical transmitting power S and data rate 1/T _bData flow after the user modulation 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 of 2n and 2n+1

With

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:

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

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, Be corresponding m and cut generally that G is the spread processing gain.

With

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 MT-CDMA, owing to adopt longer frequency expansion sequence, what each subcarrier experienced is frequency selective fading channels.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:

$h_{k,i,j,P}\left(t\right)=\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{\mathrm{\β}}_{k,i,j,p,l}{e}^{{\mathrm{j\γ}}_{k,i,j,p,l}}\mathrm{\δ}(t-t_{k,j})$ [formula 3]

Wherein, L is the distinguishable multipath number of channel,

Be complex channel coefficient,

Be the amplitude gain of channel,

Be the phase gain of channel, t _{K, l}Be multidiameter delay, 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 multi-path decline is quasi-static, have

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

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

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

$r_j\left(t\right)=\sqrt{2S}\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{i=1}{\overset{2}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{\mathrm{\β}}_{k,i,j,p,l}{a}_{k,i,p}(t-t_{k,l}-{\mathrm{\τ}}_{k,i,j})c_k(t-t_{k,l}-{\mathrm{\τ}}_{k,i,j})$ [formula 5]

Wherein, τ _{K, i, j}Be the propagation delay of user k from i transmitting antenna to j reception antenna.

For the signal on p subcarrier l of the user k footpath 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 wave l footpath signal of user k are output as on j reception antenna:

$y_{k,j,p,l}^{\left(n\right)}={\∫}_{{\mathrm{nT}}_s+t_{k,l}}^{(n+1)T_s+t_{k,l}}{r}_j\left(t\right)\exp [-j\left(2\mathrm{\π}{f}_{p}t\right)]c_k(t-t_{k,l})\mathrm{dt}$ [formula 6]

Use respectively

With

Be illustrated on j the reception antenna, decoding delay unit and conjugate operation units were in the output in two continuous symbol cycles when p carrier wave l footpath of user k signal was empty With

Merge coefficient, decoding merges and adopts high specific (MRC) merging criterion when empty.To Merge Scenarios of the present invention, p carrier wave 2n of user k and 2n+1 bit

With

The conclusive judgement variable be respectively:

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

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

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

Decoding merges the high specific merging criterion that is adopted, merge coefficient during to the present invention's sky

With 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 parallel serial conversion.

Beneficial effect of the present invention:

STBC-MT-CDMA scheme proposed by the invention is compared with MT-CDMA system in the past, owing to obtained empty time emission and receive diversity gain, its link performance is that the error rate significantly reduces, the spectrum efficiency and the capacity of system then are significantly improved, and the performance of improving the MT-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 code MT-CDMA system uplink;

Fig. 2 is the receiving course figure of the arbitrary user k of space-time block code MT-CDMA system uplink;

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;

Fig. 6 decoding when empty merges adopts high specific to merge respectively and the simulation result of BER performance when waiting gain (EGC) merging.

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 code MT-CDMA system uplink 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

With

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:

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 (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:

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

With reference to the receiving course of the arbitrary user k of a kind of space-time block code MT-CDMA system uplink 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, signal process and the corresponding fast fourier transform of transmitting terminal fast fourier inverse transformation (IFFT) (FFT) 21 that each antenna receives, recover the signal on each subcarrier, the signal on the arbitrary subcarrier p that is recovered is:

r _j(t)exp[-j(2π?f _p ^t)]

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

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

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

Wherein, t _{K, l}It is multidiameter delay;

(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 decoding merge cells when a delay unit, conjugate operation units and are empty 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 l footpath signal was empty:

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

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

Wherein,

With

Represent the merge coefficient that decoding delay unit and conjugate operation units when p subcarrier l footpath of user k signal that j antenna receive is empty exports in two continuous symbol 2n and 2n+1 cycle respectively, merge the merging of employing high specific, merge coefficient

With

Be respectively:

With

(4) time domain that decoded output signal carries out multipath signal when empty to each footpath of each subcarrier of each user merges 24, and the output signal that the arbitrary subcarrier p of user k multipath signal time domain merges latter two successive bits 2n and 2n+1 is respectively:

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

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

(5) signal of the same subcarrier of same user after multipath on each reception antenna merges carried out the spatial domain again and merge 25, 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:

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

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

(6) the conclusive judgement variable to each sub-carrier signal carries out BPSK demodulation 26, recovers the data-signal of user on each subcarrier;

(7) signal that is recovered is carried out parallel serial conversion 27 and recover user's data stream.

Be to estimate the performance of a kind of space-time block code MT-CDMA system uplink emission of the present invention and method of reseptance, the error rate (BER) of the STBC-MT-CDMA system that 2 transmitting antennas, 2 reception antennas are proposed down and former MT-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 is 16, and spreading gain is 512, and error rate thresholding is 10 ^-3

Fig. 3 has provided two BER of system performances to signal to noise ratio E _b/ N ₀Simulation result; Fig. 4 has provided 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 code MT-CDMA scheme that is proposed to compare the BER performance that has improved system significantly with former MT-CDMA scheme.

Fig. 5 has provided two system bandwidth efficient to signal to noise ratio E _b/ N ₀Simulation result.Can clearly be seen that from Fig. 5 the space-time block code MT-CDMA scheme that employing proposes compares with former MT-CDMA scheme, improved the bandwidth efficiency of system or the capacity of system significantly.

Fig. 6 has provided empty time decoding and has merged and adopt high specific to merge respectively and the simulation result of the BER performance of suggesting plans during equal gain combining.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 decoding merged the merging of employing high specific when empty, the mode that decoding merging employing high specific merges when therefore empty is suitable.

Claims (3)

1. a space-time block code MT-CDMA system uplink is launched and method of reseptance, it is characterized in that emission and the receiving course of arbitrary user k, 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

With 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:

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 transmitting antenna is:

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

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, signal process and the corresponding fast fourier transform of transmitting terminal fast fourier inverse transformation (21) that each antenna receives, recover the signal on each subcarrier, the signal on the arbitrary subcarrier p that is recovered is:

r _j(t)exp[-j(2πf _pt)]

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

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

$y_{k,j,p,l}^{\left(n\right)}={\∫}_{{\mathrm{nT}}_s+t_{k,l}}^{(n+1)T_s+t_{k,l}}{r}_j\left(t\right)\exp [-j\left({2\mathrm{\πf}}_{p}t\right)]c_k(t-t_{k,l})\mathrm{dt}$

Wherein, t _{K, l}It is multidiameter delay;

(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 decoding merge cells when a delay unit, conjugate operation units and are empty 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 l footpath signal was empty:

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

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

Wherein,

With

The merge coefficient that delay unit and conjugate operation units export in two continuous symbol 2n and 2n+1 cycle of representing respectively to decode when p subcarrier l footpath of user k signal that j antenna receive is empty;

(4) time domain that decoded output signal carries out multipath signal when empty to each footpath of each subcarrier of each user merges (24), and the output signal that the arbitrary subcarrier p of user k multipath signal time domain merges latter two successive bits 2n and 2n+1 is respectively:

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

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

(5) signal of the same subcarrier of same user after multipath on each reception antenna merges carried out the spatial domain again and merge (25), 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:

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

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

(6) the conclusive judgement variable to each sub-carrier signal carries out BPSK demodulation (26), recovers the data-signal of user on each subcarrier;

(7) signal that is recovered is carried out parallel serial conversion (27) and recover user's data stream.

2. according to described a kind of space-time block code MT-CDMA system uplink emission of claim 1 and method of reseptance, it is characterized in that receiving step (3) merging that decoding delay unit and conjugate operation units exports in two continuous symbol 2n and 2n+1 cycle when empty to p subcarrier l of user k footpath signal adopts high specific merging, merge coefficient

With

Be respectively:

With

Wherein,

β _{K, 1, j, p, l}Be the amplitude gain of p subcarrier of k user from the 1st transmitting antenna to j reception antenna channel,

β _{K, 2, j, p, l}Be the amplitude gain of p subcarrier of k user from the 2nd transmitting antenna to j reception antenna channel;

Be signal on p subcarrier l of the user k footpath from the 2nd transmitting antenna to the phase shift j reception antenna,

Be signal on p subcarrier l of the user k footpath from the 1st transmitting antenna to the phase shift j reception antenna.

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