CN1901434A - Multiple-in and multiple-out communication method of signal asynchronous transmission - Google Patents

Abstract

This invention discloses a MIMO communication method for signal asynchronous emission characterizing that it applies a hierachical empty time code structure and an emitter delayes signals of different emission antennas and emits them asynchronously, a receiver applies an asynchronous MIMO test method to test signals, in which, the gain brought with time delay hierarchy is used by different time dealy to emission signals at the emission end and at the receiving end, the receiving hierarchy is increased by the MIMO test method to increase the link quality of the MIMO system.

Description

A kind of multiple-in and multiple-out communication method of signal asynchronous emission

Technical field

The invention belongs to communication technical field, particularly the communication means of the many antennas of use in the communication technology.

Background technology

(Multiple Input Multiple Output, MIMO) communication means all is based on signal Synchronization emission in existing multiple-input, multiple-output.Because the MIMO communication means has good spectrum efficiency, higher system capacity and communication quality preferably, it is one of key technology of new generation of wireless communication system.

The MIMO communication means adopts the Space Time Coding technology, and use therein empty time-code mainly contains two big classes: based on the space-time trellis codes of transmit diversity (Space Time Trellis Codes, STTC) and Space-Time Block Coding (Space Time Block Codes, STBC); Based on the hierarchical space-time code of non-transmit diversity (Layered Space Time Codes, LSTC).

Space-time trellis codes is a kind of design of taking all factors into consideration chnnel coding, modulation, transmit diversity and receive diversity, and the coded system of bigger coding gain, the availability of frequency spectrum and diversity gain can be provided.The performance of space-time trellis codes is fine, but its complexity of decoding is quite high.Particularly, when number of transmit antennas fixedly the time, the decoding complex degree of space-time trellis codes (trellis state by decoder is measured several times) increases with transmission rate exponentially level.In view of this, Alamouti has proposed a kind of simple two antennas transmit diversity schemes, and has provided comparatively simple decoding algorithm.People such as Tarkh are therefrom inspired, and use orthogon theory, and this scheme is generalized to the transmit diversity systems with any number of transmit antennas, have proposed Space-Time Block Coding thus.Space-Time Block Coding is compared with space-time trellis codes, though performance decreases, decoding complex degree is much smaller.

Hierarchical space-time code is that the information source data are divided into several parallel sub data flows, and the technology that they are encoded independently and modulate is not so it is based on transmit diversity.People such as the Foschini of Bell Laboratory have at first proposed a kind of diagonal angle hierarchical space-time code (Diagonally Bell Labs Layered Space-Time Wireless Communication Architecture, D-BLAST), emission information is carried out Space Time Coding according to diagonal, under Rayleigh fading environment independently, this structure has obtained huge theoretical capacity, its capacity is with the number linear growth of transmitting antenna, can reach 90% shannon capacity, though D-BLAST has preferably characteristic and hierarchical structure when empty, but its defective is exactly that complexity is too high, is not suitable for using.Empty time-code H-BLAST (Horizontal BLAST) of horizontal slice and vertical layered space-time code V-BLAST (Vertical BLAST) have been proposed subsequently. though the decoding of H-BLAST is simple, and characteristic is poor during its sky; And the better performances of V-BLAST, decoding complexity is little, therefore is used widely.System based on the V-BLAST structure has carried out experimental verification in the laboratory, under the environment of indoor slow fading, the spectrum efficiency of this system is up to 40bit/s/Hz.

Introduce general structure and detection algorithm below based on the MIMO communication system of hierarchical space-time code structure.

Based on the mimo system schematic diagram of hierarchical space-time code structure as shown in Figure 1, form by transmitter schematic diagram and receiver schematic diagram.Transmitter comprises: emission data module 1, demixing time space 2, D/A converter module 3, radio frequency processing 1 module 4, M transmitting antenna 5, wherein radio frequency processing 1 module 4 comprises M radio frequency processing submodule, and the radio frequency processing submodule on the different transmit antennas can be different.Receiver comprises: N reception antenna 6, radio frequency processing 2 modules 7, analog-to-digital conversion module 8, MIMO detection module 9, decoder module 10 and restore data module 11 when layering is empty, wherein radio frequency processing 2 modules 7 comprise N radio frequency processing submodule, and the radio frequency processing submodule on the different reception antennas can be different.

There is the signal detection algorithm of numerous maturations based on the MIMO communication means of hierarchical space-time code structure, as maximum likelihood algorithm, zero forcing algorithm, least-mean-square error algorithm or the like.Be example below with the zero forcing algorithm, introduce signal detection algorithm based on the MIMO communication means of hierarchical space-time code structure.

As shown in Figure 1, emission data 1 become parallel M circuit-switched data symbols streams at first by demixing time space module 2 with the emission digital coding, through after the wireless channel, received simultaneously by N reception antenna at receiving terminal, the signal that receives is carried out ZF detect, at last data are exported.

We are defined as a=(a equivalence base band transmit M n dimensional vector n ₁a ₂A _M) ^T, a _kThe data of representing k transmitting antenna, corresponding received signal vector is r=(r ₁r ₂R _N) ^T, can be expressed as

r＝Ha+N (1)

Wherein h _{I, j}The channel fading factor of expression from j transmitting antenna to i reception antenna supposed different h _IjBetween separate, N represents the Gaussian noise vector of receiving terminal.The ZF detection method of directly inverting is expressed as follows, and the estimated value  of the vector that transmits is

＝a+H ^N (2)

Wherein, () ^The Moore-Penrose of representing matrix is contrary.The principle of this method is directly to the channel matrix operation of inverting, and the signal phasor that receives with this inverse matrix premultiplication is deciphered each component more simultaneously then, and the advantage of this method is simple, and complexity is low, and shortcoming is that the decoding effect is relatively poor.Content sees G.D.Golden for details, C.J.Foschini, " Detection algorithmand initial laboratory results using V-BLAST space-time communication architecture ", IEEEECTRONICS LETTERS 7 ^ThJan 1999, Vol.35 No.1.

Existing multiple-in and multiple-out communication method all is based on the signal Synchronization emission.For the multiple-in and multiple-out communication method that adopts hierarchical space-time code, because signal is launched simultaneously at transmitting terminal, transmitting terminal does not have the gain that delay diversity brings, and the receive diversity degree of receiving terminal is lower, thereby has influenced link-quality and power system capacity.At the shortcoming of existing multiple-in and multiple-out communication method, also do not provide a kind of signal asynchronous emission multiple-in and multiple-out communication method at present known document, patent and the relevant publication.

Summary of the invention

Deficiency at the multiple-in and multiple-out communication method that has the signal Synchronization emission now, the multiple-in and multiple-out communication method that the purpose of this invention is to provide a kind of signal asynchronous emission, according to communication means of the present invention, transmit and the asynchronous MIMO of receiver detects by transmitter is asynchronous, can improve the link-quality of mimo systems, reduce the error rate, improve systematic function.

In order to describe content of the present invention easily, at first following term is done one and explain, as Fig. 2, shown in Figure 3:

1) demixing time space technology: be meant the input data are carried out the demixing time space modulation, form the output of multichannel data symbols streams;

2) frame forming tech: be meant the Frame output of the data symbol stream of input being formed a plurality of certain-lengths;

3) delay technique: the Frame that is meant the certain-length that will import was exported after delay a period of time;

4) add the protection spacer techniques: be meant that the Frame afterbody to input adds the protection interval of certain hour length, its objective is the interference of avoiding between frame and the frame;

5) matched filtering technique: be meant the signal on the different transmit antennas is mated, so that the signal on the differentiation different transmit antennas;

6) data sampling technology: be meant input signal is sampled, the different discrete constantly sampled values of output;

Decoding technique when 7) layering is empty: will import the demodulation of decoding when data are carried out the layering sky and obtain restore data.

The demixing time space technology can be the V-BLAST coding techniques, also can be H-BLAST coding techniques or D-BLAST coding techniques.

Decoding technique can be the V-BLAST decoding technique when layering was empty, also can be H-BLAST decoding technique or D-BLAST decoding technique.

The multiple-in and multiple-out communication method of a kind of signal asynchronous emission provided by the invention, it comprises step of transmitting and receiving step;

A kind of transmitter of multiple-in and multiple-out communication method of signal asynchronous emission has M (M is a positive integer) individual transmitting antenna (as Fig. 2, shown in Figure 5), and described step of transmitting comprises:

Step 1: demixing time space

Adopt the demixing time space technology, the emission data of importing 1 are encoded to the parallel data symbol stream output in M road;

Step 2: framing

Adopt frame forming tech, the M circuit-switched data symbols streams of step 1 output is formed the Frame output of a plurality of certain-lengths respectively.Each Frame length equates that the length of described Frame is more than or equal to 2, and the length of Frame is by factor decisions such as requirement of receiver complexity and error rate of system performance requirement on the engineering.Specifically be expressed as: establish that i data symbol is b on k the antenna _k(i), k=1 wherein ..., M, the length of Frame is S, promptly comprises S data symbol, S 〉=2.The framing step is combined into the Frame output that a plurality of length are S with every circuit-switched data symbol, and a Frame of k circuit-switched data symbol correspondence comprises S symbol, i.e. b _k(0), b _k(1) ..., b _k(S-1);

Step 3: time-delay

Adopt delay technique, will carry out time delay respectively by each Frame on the M road of step 2 output, be τ the time of delay of establishing k the Frame on the transmitting antenna _k, the data frame delays τ on the k road then _k, k=1 wherein ..., M.Require the delay time T of every frame data _kLess than several symbol periods, i.e. 0≤τ _k＜Δ T _s(Δ is the positive integer greater than 0); Time delay τ on the different branch _kCan be all unequal, or part is unequal, and have one group of optimum delay τ ₁, τ ₂..., τ _MMake the error rate of system best performance; τ on the engineering _kSize is determined by factors such as system spectrum utilance, error rate of system performance requirements;

Step 4: add protection at interval

Adopt to add the protection spacer techniques, the protection that the afterbody of each Frame of step 3 output is added certain hour length at interval.Can zero setting in this protection at interval, also can place other and can avoid the data disturbed between frame and the frame.Protection interlude length is by the time of delay of every circuit-switched data and the availability of frequency spectrum decision of system on the engineering.Suppose the τ that delayed time on the k road _kFrame after to increase time span be T _GkProtection at interval, require τ _k+ T _Gk=τ _m+ T _Gm, k, m ∈ 1,2 ..., M} as shown in Figure 4, is an example with the frame data on each antenna, supposes 0≤τ ₁＜τ ₂＜...＜τ _M＜T _s, in order to eliminate the interference between frame and the frame, then the protection on k transmitting antenna need be satisfied T at interval _Gk〉=τ _M-τ _kSo the minimum protection on M transmitting antenna can be zero at interval;

Step 5: digital-to-analogue conversion

The digital signal on the M road of step 4 output is converted to the analog signal output of M road;

Step 6: emission radio frequency processing

The M road analog signal of step 5 output is carried out radio frequency processing, obtain to satisfy the M road signal of launch requirements, launch from M transmitting antenna.

Be example with frame data on each transmitting antenna, adopt the method for zero setting in the protection at interval,, obtain can being expressed as corresponding to the low pass equivalence complex baseband signal of transmitting antenna k through after the step 1,2,3,4:

$s_k\left(t\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\Σ}}}{b}_k\left(i\right)g(t-{\mathrm{iT}}_s-{\mathrm{\τ}}_k),k=1,\·\·\·,M---\left(3\right)$

Wherein, b _k(i) be corresponding to the symbol of launching in i symbol duration of k transmitting antenna, b _k(i)=0, i  0,1 ..., S-1}; E _sBe symbol energy, the expression transmitting antenna adopts the form of average power allocation in the formula (4), and the transmitting power of each transmitting antenna is

T _sBe data b _k(i) cycle of a symbol; G (t) is the equivalent complex radical band waveform of transmitting antenna, and g (t) satisfies: g (t)=0, t  [0, T _s), ${\left|\right|g\left(t\right)\left|\right|}^2={\∫}_0^{T_s}g*\left(t\right)g\left(t\right)\mathrm{dt}=1,$ Wherein subscript * represents complex conjugate.

The receiver of supposing a kind of multiple-in and multiple-out communication method of signal asynchronous emission has N (N is a positive integer) individual reception antenna (as Fig. 3, shown in Figure 6), and described receiving step comprises:

Step 7: received RF is handled

The signal that reception antenna 6 is received obtains N baseband signal r after handling through received RF _j(t), j=1 ..., N;

As shown in Figure 3, the signal r behind j reception antenna of receiver 6 process received RF treatment steps 7 _j(t) be:

$r_j\left(t\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\Σ}}}\underset{k=1}{\overset{M}{\mathrm{\Σ}}}{b}_k\left(i\right)h_{j,k}\left(i\right)g(t-{\mathrm{iT}}_s-{\mathrm{\τ}}_k)+n_j\left(t\right)---\left(5\right)$

Wherein, h _{J, k}(i) be the i channel fading factor from k transmitting antenna to j reception antenna constantly, n _j(t) be j the additivity white complex gaussian noise on the reception antenna.

Step 8: matched filtering

N baseband signal r to step 7 output _j(t), j=1 ..., N carries out matched filter processing, as shown in Figure 3, and the baseband signal r on j reception antenna _j(t) by M matched filter, output M road signal.In like manner, the baseband signal on N reception antenna by behind M the matched filter, obtains M * N road signal respectively altogether.This step is expressed as follows: received signal r _j(t) constantly be output as by l behind the matched filter of transmitting antenna m (positive integer of 1≤m≤M)

$y_j^m\left(l\right)={\∫}_{{\mathrm{lT}}_s+{\mathrm{\τ}}_m}^{(l+1)T_s+{\mathrm{\τ}}_m}{r}_j\left(t\right)g*(t-{\mathrm{lT}}_s-{\mathrm{\τ}}_m)\mathrm{dt},m=1,\·\·\·M---\left(6\right)$

(5) formula (6) formula of bringing into is obtained:

$y_j^m\left(l\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\Σ}}}\underset{k=1}{\overset{M}{\mathrm{\Σ}}}{h}_{j,k}\left(i\right)b_k\left(i\right){\∫}_{l{T}_s+{\mathrm{\ι}}_m}^{(l+1)T_s+{\mathrm{\τ}}_m}g(t-{\mathrm{iT}}_s-{\mathrm{\τ}}_k)g*(t-{\mathrm{lT}}_s-{\mathrm{\τ}}_m)\mathrm{dt}$

$+{\∫}_{{\mathrm{lT}}_s+{\mathrm{\τ}}_m}^{(l+1)T_s+{\mathrm{\τ}}_m}{n}_j\left(t\right)g*(t-{\mathrm{lT}}_s-{\mathrm{\τ}}_m)\mathrm{dt}$ (7)

If

$R_{m,k}(l-i)={\∫}_{{\mathrm{lT}}_s+{\mathrm{\τ}}_m}^{(l+1)T_s+{\mathrm{\τ}}_m}g(t-{\mathrm{iT}}_s-{\mathrm{\τ}}_k)g*(t-{\mathrm{lT}}_s-{\mathrm{\τ}}_m)\mathrm{dt}---\left(8\right)$

$n_j^m\left(l\right)={\∫}_{\mathrm{lT}+{\mathrm{\τ}}_m}^{(l+1)T+{\mathrm{\τ}}_m}{n}_j\left(t\right)g*(t-\mathrm{lT}-{\mathrm{\τ}}_m)\mathrm{dt}---\left(9\right)$

Then (7) formula can be reduced to

$y_j^m\left(l\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\Σ}}}\underset{k=1}{\overset{M}{\mathrm{\Σ}}}{R}_{m,k}(l-i)h_{j,k}\left(i\right)b_k\left(i\right)+n_j^m\left(l\right)---\left(10\right)$

Step 9: data sampling

Adopt the signal of data sampling technology, constantly sample continuously, obtain a plurality of discrete sampled values at t to matched filter output in the step 8.This step is expressed as: for the output signal of m matched filter at t=(l+1) T+ τ _m(l=0 ..., S-1, τ _mBe the time delay of signal on m the transmitting antenna) S sampled value y of acquisition _j ^m(0), y _j ^m(1) ..., y _j ^m(S-1), m=1 ..., M, j=1 ..., N, the sampled value difference that the signal on the different reception antennas obtains by data sampling.

Step 10: asynchronous MIMO detects

At first, the sampled value y to obtaining through data sampling step 9 on j the reception antenna _j ^m(l) (m=1 ..., M, j=1 ..., N, l=0 ..., S-1) carry out data combination and obtain corresponding matrix expression, specifically be expressed as follows:

Introduce M _T* M _TChannel correlation matrix R (l-i), its element is R _{M, k}(l-i).R (l-i) satisfies:

R (l-i)=R ^H(i-l) (11) wherein () ^HThe expression complex-conjugate transpose.

By g (t)=0, and t  [0, T _s) and 0≤τ _k＜Δ T _s,

R(l-i)＝0， |l-i|＞Δ (12)

If j reception antenna at the diagonal angle channel matrix of the corresponding time slot of l symbol is

h _j(l)＝diag{h _j，1(l)，h _j，2(l)，…，h _j，M(l)} (13)

J reception antenna matched filter banks be at l=0, and 1 ..., S-1 output type (10) constantly can be expressed as vector form

$y_j\left(l\right)=\sqrt{\frac{E_s}{M_T}}\underset{i=0}{\overset{S-1}{\mathrm{\Σ}}}R(l-i)h\left(i\right)b\left(i\right)+n_j\left(l\right)---\left(14\right)$

Wherein $y_j\left(l\right)={(y_j^1\left(l\right),y_j^2\left(l\right),\·\·\·,y_j^M\left(l\right))}^T,$ b(i)＝(b ₁(i)，b ₂(i)，…，b _M(i)) ^T，

$n_j\left(l\right)={(n_j^1\left(l\right),n_j^2\left(l\right),\·\·\·,n_j^M\left(l\right))}^T.$

Following wushu (14) is expressed as more succinct matrix form.Definition

H _j＝diag{h _j(0)，h _j(1)，…，h _j(S-1)} (16)

$Y_j={(y_j^T\left(0\right),y_j^T\left(1\right),\·\·\·,y_j^T(S-1))}^T---\left(17\right)$

b＝(b ^T(0)，b ^T(1)，…，b ^T(S-1)) ^T (18)

$n_j={(n_j^T\left(0\right),n_j^T\left(1\right),\·\·\·,n_j^T(S-1))}^T---\left(19\right)$

R is SM _T* SM _TPiece symmetry Toeplitz matrix, H _jBe SM _T* SM _TDiagonal matrix.Like this, carry out matched filtering, the signal Y that extracts from symbol time slot 0 to S-1 at reception antenna j _jCan be expressed as:

$Y_j=\sqrt{\frac{E_s}{M}}R{H}_{j}b+n_j---\left(20\right)$

Following formula is the sampled value y on j the reception antenna _j ^m(l) (m=1 ..., M, j=1 ..., N, l=0 ..., S-1) carry out the matrix expression that obtains after the data combination.In like manner, carry out to obtain N different matrix expression after the data combination through the sampled value of data sampling step 9 acquisition on N reception antenna.

Then, this N matrix expression is carried out high specific merges, specifically be expressed as follows:

Matrix expression to N different reception antenna correspondence carries out the associating matrix expression that the high specific merging can get N reception antenna

$Y=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{H}_j^H{Y}_j$

$=\sqrt{\frac{E_s}{M}}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{H}_j^{H}R{H}_{j}b+\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{H}_j^H{n}_j$ (21)

If $H=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{H}_j^{H}R{H}_j,$ $N=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{H}_j^H{n}_j,$ Then following formula can turn to

$Y=\sqrt{\frac{E_s}{M}}\mathrm{Hb}+N---\left(22\right)$

At last, associating matrix expression (22) based on N reception antenna, utilize methods such as direct ZF (ZF:Zero-Forcing), ordering interference cancellation can recover the estimated value  of symbol b, other any detection methods that recover estimated value  also are applicable to detection step of the present invention.

Step 11: decoding when layering is empty

Decoding technique when adopting layering empty, the estimated value  decoding of the symbol that step 10 is obtained, data are restored.

Through after the above step, just can realize the multiple-in and multiple-out communication method of signal asynchronous emission provided by the invention.

Need to prove:

M circuit-switched data symbols streams in the step 1 is corresponding to M transmitting antenna;

The pairing radio frequency processing process of different transmit antennas can be different in the step 5;

The purpose that received RF is handled in the step 7 makes signal r exactly _j(t) can satisfy the processing requirements of late-class circuit;

The pairing radio frequency processing process of different reception antennas can be different in the step 7;

The course of work of the present invention:

As Fig. 2, shown in Figure 3, the emission data at first obtain M circuit-switched data symbols streams through demixing time space module 2 codings; M circuit-switched data symbols streams passes through that to form a plurality of length into frame module 12 be the Frame of S then; Submodule in each circuit-switched data frame process time delay module 13 carries out time-delay separately; Each circuit-switched data frame process interpolation protection interval module 14 after the process time-delay is added protection interval separately behind Frame; Treated then Frame is launched from transmitting antenna through D/A converter module 3 and radio frequency processing 3 modules 15 backs.Reception antenna 6 obtains N received signal r by radio frequency processing 4 modules 16 after receiving signal _j(t), j=1 ..., N, received signal r _j(t) carry out matched filtering by transmitting on 17 pairs of different antennae of matched filter pack module, the signal after the coupling is sampled by data sampling module 18, obtains one group of sampled value y _j ^m(0), y _j ^m(1) ..., y _j ^m(S-1), m=1 ..., M, j=1 ..., N, the sampled value difference that the signal on the different reception antennas obtains by data sampling module 18.The sampled value of data sampling module 18 outputs is imported asynchronous MIMO detection module, earlier the sampled value on j the reception antenna is combined into the expression matrix form, again the matrix expression on the different reception antennas being carried out high specific merges, obtain the estimated value of symbol then, decoding obtains restore data during at last by the layering sky.

Innovation part of the present invention: in the existing multiple-in and multiple-out communication method, signal all is a synchronized transmissions, and adopts the detection method of MIMO to recover to transmit.The multiple-in and multiple-out communication method of a kind of signal asynchronous emission that the present invention proposes by carrying out different time-delays to transmitting, makes the asynchronous emission that transmits, and adopts corresponding asynchronous MIMO detection method to recover to transmit at receiving terminal.The asynchronous emission of transmitting terminal signal has utilized delay diversity, and the asynchronous MIMO detection algorithm of receiving terminal has increased the receive diversity degree, can improve the link-quality of mimo systems, reduces the error rate, improves systematic function.

Essence of the present invention: the multiple-in and multiple-out communication method of a kind of signal asynchronous emission that the present invention proposes, it is characterized in that adopting the hierarchical space-time code structure, transmitter to the signal delay on the different transmit antennas after asynchronous emission, receiver adopts asynchronous MIMO detection method that signal is detected.At transmitting terminal by carrying out different time-delays to transmitting, the gain that has utilized delay diversity to bring; Adopt asynchronous MIMO detection algorithm at receiving terminal, increased the receive diversity degree, can improve the link-quality of mimo systems, reduce the error rate, improve systematic function.

Advantage of the present invention is: the multiple-in and multiple-out communication method of a kind of signal asynchronous emission that the present invention proposes, keeping the existing MIMO communication means availability of frequency spectrum height that adopts hierarchical space-time code, on the big basis of power system capacity, introduced delay diversity, increased the receive diversity degree, further reduce the error rate, can improve link-quality and overall system performance.

In sum, the multiple-in and multiple-out communication method of a kind of signal asynchronous emission that the present invention proposes by at transmitting terminal the signal on the different transmit antennas being carried out time delay, makes signal asynchronous emission; Adopt asynchronous MIMO detection method to recover signal at receiver.Transmitting terminal has been introduced the delay diversity to the different delay of the signal on the different transmit antennas, and the asynchronous MIMO detection algorithm of receiving terminal has increased the receive diversity degree, can improve the link-quality of mimo systems, reduces the error rate, improves systematic function.

Description of drawings

Fig. 1 is existing mimo system schematic diagram based on the hierarchical space-time code structure

Wherein, the 1st, the emission data module, the 2nd, the demixing time space module, the 3rd, D/A converter module, the 4th, radio frequency processing 1 module 4,5th, transmitting antenna, the 6th, reception antenna, the 7th, radio frequency processing 2 modules, the 8th, analog-to-digital conversion module, the 9th, MIMO detection module, the 10th, decoder module when layering is empty, the 11st, the restore data module, TX1 represents transmitting antenna 1, and TXk represents transmitting antenna k, TXM represents transmitting antenna M, RX1 represents reception antenna 1, and RXk represents reception antenna k, and RXN represents reception antenna N, D/A represents digital-to-analogue conversion, A/D represents analog-to-digital conversion, and radio frequency 1_1 represents the 1st submodule of radio frequency processing 1 module, and radio frequency 1_k represents k submodule of radio frequency processing 1 module, radio frequency 1_M represents M submodule of radio frequency processing 1 module, radio frequency 2_1 represents the 1st submodule of radio frequency processing 2 modules, and radio frequency 2_k represents k submodule of radio frequency processing 2 modules, and radio frequency 2_N represents N submodule of radio frequency processing 2 modules.Fig. 2 is the asynchronous multiple-in and multiple-out communication method transmitter schematic diagram that transmits of the present invention

Wherein, the 1st, emission data module, the 2nd, demixing time space module; the 12nd, become frame module, the 13rd, time delay module, the 14th, add the protection interval module; the 3rd, D/A converter module; the 15th, radio frequency processing 3 modules, the 5th, transmitting antenna, TX1 are represented transmitting antenna 1; TXk represents transmitting antenna k; TXM represents transmitting antenna M, and D/A represents digital-to-analogue conversion, τ ₁Represent the delay of signal on the 1st transmitting antenna, τ _kRepresent the delay of signal on k the transmitting antenna, τ _MRepresent the delay of signal on M the transmitting antenna, radio frequency 3_1 represents the 1st submodule of radio frequency processing 3 modules, and radio frequency 3_k represents k submodule of radio frequency processing 3 modules, and radio frequency 3_M represents M submodule of radio frequency processing 3 modules.

Fig. 3 is the asynchronous multiple-in and multiple-out communication method receiver schematic diagram that transmits of the present invention

Wherein, the 6th, reception antenna, the 16th, radio frequency processing 4 modules, the 17th, matched filter pack module, the 18th, data sampling module, the 19th, asynchronous MIMO detection module, the 10th, decoder module when layering is empty, the 11st, restore data module, r ₁(t) signal through obtaining after the radio frequency processing on the 1st reception antenna of expression, r _N(t) signal through obtaining after the radio frequency processing on the 1st reception antenna of expression, y _j ^m(l) (m=1 ..., M, j=1 ..., N, l=0 ..., S-1) signal on j reception antenna of expression through transmitting antenna m matched filter after at the l sampling in the moment, t=(l+1) T+ τ _m(m=1 ..., the signal behind M) the expression process transmitting antenna m matched filter is in the different l sampling time constantly.

Fig. 4 is the asynchronous schematic diagram that transmits of the present invention

Wherein, τ _k(k=1 ..., the M) delay of signal on k transmitting antenna of expression, T _Gk(k=1 ..., M) be the protection interlude length of adding on k the transmitting antenna, b _k(i) (k=1 ..., M, i=0 ..., S-1) be the symbol of emission in i symbol duration of k transmitting antenna.

Fig. 5 is the emission schematic process flow diagram of the asynchronous multiple-in and multiple-out communication method that transmits of the present invention

Fig. 6 is the reception schematic process flow diagram of the asynchronous multiple-in and multiple-out communication method that transmits of the present invention

Embodiment:

The multiple-in and multiple-out communication method of a kind of signal asynchronous emission provided by the invention comprises the transmitter and receiver two large divisions, as Fig. 2, shown in Figure 3.Provide an embodiment of this method below, number of transmit antennas M=2, reception antenna is counted N=2, and the frame length of Frame is S=2, E _s=1, adopt average power allocation, the base band pulse waveform adopts square wave, and the time-delay of transmitting antenna is respectively τ ₁=0, τ ₂=0.6T _s, T _s=1 μ s, the protection interval T of interpolation _G1=0.6T _s, T _G2=0, data are zero in the protection at interval.

Under the situation of above-mentioned parameter, the specific implementation step of the multiple-in and multiple-out communication method of a kind of signal asynchronous emission provided by the invention is described below, transmitter as shown in Figure 2:

At transmitting terminal, the emission data through demixing time space 2, become frame module 12, time delay module 13 and add protection interval module 14 after, on the transmitting antenna 1 and the equivalence of the low pass on the transmitting antenna 2 complex baseband signal can be expressed as respectively:

$s_1\left(t\right)=\sqrt{\frac{1}{2}}\underset{i=0}{\overset{1}{\mathrm{\Σ}}}{b}_1\left(i\right)g(t-{\mathrm{iT}}_s)---\left(23\right)$

$s_2\left(t\right)=\sqrt{\frac{1}{2}}\underset{i=0}{\overset{1}{\mathrm{\Σ}}}{b}_2\left(i\right)g(t-{\mathrm{iT}}_s-0.6T_s)---\left(24\right)$

Send in the wireless channel after the signal process radio frequency processing step on transmitting antenna 1 and the transmitting antenna 2.

Receiver as shown in Figure 3, at receiving terminal, by obtaining received signal r after the radio frequency processing step ₁(t) and r ₂(t), be expressed as follows:

$r_1\left(t\right)=\sqrt{\frac{1}{2}}\underset{i=0}{\overset{1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{2}{\mathrm{\&Sigma;}}}{b}_k\left(i\right){\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="A20051002128900211.png,A20051002128900212.png"\; state="\{\{state\}\}">h</figure-callout>}}_{1,k}\left(i\right)g(t-{\mathrm{iT}}_s-{\mathrm{\&tau;}}_k)+n_1\left(t\right)---\left(25\right)$

$r_2\left(t\right)=\sqrt{\frac{1}{2}}\underset{i=0}{\overset{1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{2}{\mathrm{\&Sigma;}}}{b}_k\left(i\right)h_{2,k}\left(i\right)g(t-{\mathrm{iT}}_s-{\mathrm{\&tau;}}_k)+n_2\left(t\right)---\left(26\right)$

After matched filter pack module 17 and data sampling module 18, m matched filter can be expressed as follows in l sampled value constantly on reception antenna 1 and the reception antenna 2:

$y_1^m\left(l\right)=\sqrt{\frac{1}{2}}\underset{i=0}{\overset{1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{2}{\mathrm{\&Sigma;}}}{R}_{m,k}(l-i){\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="A20051002128900211.png,A20051002128900212.png"\; state="\{\{state\}\}">h</figure-callout>}}_{1,k}\left(i\right)b_k\left(i\right)+n_1^m\left(l\right)---\left(27\right)$

$y_2^m\left(l\right)=\sqrt{\frac{1}{2}}\underset{i=0}{\overset{1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{2}{\mathrm{\&Sigma;}}}{R}_{m,k}(l-i)h_{2,k}\left(i\right)b_k\left(i\right)+n_2^m\left(l\right)---\left(28\right)$

After the sampled value of reception antenna 1 and reception antenna 2 was imported asynchronous MIMO detection module, the matrix expression that is reassembled into through data can be expressed as respectively:

${\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="A20051002128900211.png,A20051002128900212.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1=\sqrt{\frac{1}{2}}R{H}_{1}b+n_1---\left(29\right)$

$Y_2=\sqrt{\frac{1}{2}}R{H}_{2}b+n_2---\left(30\right)$

Each variable-definition of following formula is shown in (15) formula～(19) formula.The signal of reception antenna 1 and reception antenna 2 are carried out high specific to be merged and can get

$Y=\sqrt{\frac{1}{2}}\mathrm{Hb}+N---\left(31\right)$

Carrying out ZF at last detects the estimated value  recover signal and is expressed as follows

＝b+H ^N (32)

The estimated value  of the signal data that are restored behind the decoder module 10 when empty by layering.

The embodiment of the multiple-in and multiple-out communication method of above-mentioned a kind of signal asynchronous emission can adopt the C Programming with Pascal Language to realize, by Computer Simulation as can be known, compare with the multiple-in and multiple-out communication method of existing signal Synchronization emission, it has the link-quality that improves mimo systems, reduce the error rate, improve advantages such as systematic function.

Claims (1)

1, a kind of multiple-in and multiple-out communication method of signal asynchronous emission is characterized in that it comprises step of transmitting and receiving step;

A kind of transmitter of multiple-in and multiple-out communication method of signal asynchronous emission has the individual transmitting antenna of M (M is a positive integer), and described step of transmitting comprises:

Step 1: demixing time space

Adopt the demixing time space technology, the emission data of importing (1) are encoded to the parallel data symbol stream output in M road, wherein the demixing time space technology can be the V-BLAST coding techniques, also can be H-BLAST coding techniques or D-BLAST coding techniques;

Step 2: framing

Adopt frame forming tech, the M circuit-switched data symbols streams of step 1 output is formed the Frame output of a plurality of certain-lengths respectively; Each Frame length equates that the length of described Frame is more than or equal to 2, and the length of Frame is by factor decisions such as requirement of receiver complexity and error rate of system performance requirement on the engineering; Specifically be expressed as: establish that i data symbol is b on k the antenna _k(i), k=1 wherein ..., M, the length of Frame is S, promptly comprises S data symbol, S 〉=2; The framing step is combined into the Frame output that a plurality of length are S with every circuit-switched data symbol, and a Frame of k circuit-switched data symbol correspondence comprises S symbol, i.e. b _k(0), b _k(1) ..., b _k(S-1);

Step 3: time-delay

Adopt delay technique, will carry out time delay respectively by each Frame on the M road of step 2 output, be τ the time of delay of establishing k the Frame on the transmitting antenna _k, the data frame delays τ on the k road then _k, k=1 wherein ..., M; Require the delay time T of every frame data _kLess than several symbol periods, i.e. 0≤τ _k＜Δ T _s(Δ is the positive integer greater than 0); Time delay τ on the different branch _kCan be all unequal, or part is unequal, and have one group of optimum delay τ ₁, τ ₂..., τ _MMake the error rate of system best performance; τ on the engineering _kSize is determined by factors such as system spectrum utilance, error rate of system performance requirements;

Step 4: add protection at interval

Adopt to add the protection spacer techniques, the protection that the afterbody of each Frame of step 3 output is added certain hour length at interval; Can zero setting in this protection at interval, also can place other and can avoid the data disturbed between frame and the frame; Protection interlude length is by the time of delay of every circuit-switched data and the availability of frequency spectrum of system requiring decision on the engineering; Suppose the τ that delayed time on the k road _kFrame after to increase time span be T _GkProtection at interval, require τ _k+ T _Gk=τ _m+ T _Gm, k, m ∈ 1,2 ..., M};

Step 5: digital-to-analogue conversion

The digital signal on the M road of step 4 output is converted to the analog signal output of M road;

Step 6: emission radio frequency processing

The M road analog signal of step 5 output is carried out radio frequency processing, obtain to satisfy the M road signal of launch requirements, launch from M transmitting antenna, wherein the pairing radio frequency processing process of different transmit antennas can be different;

Be example with frame data on each transmitting antenna, adopt the method for zero setting in the protection at interval,, obtain can being expressed as corresponding to the low pass equivalence complex baseband signal of transmitting antenna k through after the step 1,2,3,4:

$s_k\left(t\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\&Sigma;}}}{b}_k\left(i\right)g(t-{\mathrm{iT}}_s-{\mathrm{\&tau;}}_k),k=1,\&CenterDot;\&CenterDot;\&CenterDot;,M---\left(1\right)$

Wherein, b _k(i) be corresponding to the symbol of launching in i symbol duration of k transmitting antenna, $b_k\left(i\right)=0,i\&NotElement;\{\mathrm{0,1},\&CenterDot;\&CenterDot;\&CenterDot;,S-1\};$ E _sBe symbol energy, the expression transmitting antenna adopts the form of average power allocation in the formula (1), and the transmitting power of each transmitting antenna is Transmitting antenna of the present invention also can adopt other power division forms; T _sBe data b _k(i) cycle of a symbol; G (t) is the equivalent complex radical band waveform of transmitting antenna, and g (t) satisfies: $g\left(t\right)=0,t\&NotElement;[0,T_s),$ ${\left|\right|g\left(t\right)\left|\right|}^2={\&Integral;}_0^{T_s}{g}^{*}\left(t\right)g\left(t\right)\mathrm{dt}=1,$ Wherein subscript * represents complex conjugate;

A kind of receiver of multiple-in and multiple-out communication method of signal asynchronous emission has the individual reception antenna of N (N is a positive integer), and described receiving step comprises:

Step 7: received RF is handled

The signal that reception antenna 6 is received obtains N baseband signal r after handling through received RF _j(t), j=1 ..., N, the pairing radio frequency processing process of different reception antennas can be different; Signal r behind j reception antenna of receiver 6 process received RF treatment steps 7 _j(t) be:

$r_j\left(t\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{M}{\mathrm{\&Sigma;}}}{b}_k\left(i\right)h_{j,k}\left(i\right)g(t-i{T}_s-{\mathrm{\&tau;}}_k)+n_j\left(t\right)---\left(2\right)$

Wherein, h _{J, k}(i) be the i channel fading factor from k transmitting antenna to j reception antenna constantly, n _j(t) be j the additivity white complex gaussian noise on the reception antenna;

Step 8: matched filtering

N baseband signal r to step 7 output _j(t), j=1 ..., N carries out matched filter processing, the baseband signal r on j reception antenna _j(t) by M matched filter, output M road signal; In like manner, the baseband signal on N reception antenna by behind M the matched filter, obtains M * N road signal respectively altogether; This step is expressed as follows: received signal r _j(t) constantly be output as by l behind the matched filter of transmitting antenna m (positive integer of 1≤m≤M)

$y_j^m\left(l\right)={\&Integral;}_{l{T}_s+{\mathrm{\&tau;}}_m}^{(l+1)T_s+{\mathrm{\&tau;}}_m}{r}_j\left(t\right)g^{*}(t-{\mathrm{lT}}_s-{\mathrm{\&tau;}}_m)\mathrm{dt},m=1,\&CenterDot;\&CenterDot;\&CenterDot;M---\left(3\right)$

(2) formula (3) formula of bringing into is obtained:

$y_j^m\left(l\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{M}{\mathrm{\&Sigma;}}}{h}_{j,k}\left(i\right)b_k\left(i\right){\&Integral;}_{{\mathrm{lT}}_s+{\mathrm{\&tau;}}_m}^{{(l+1)T}_s+{\mathrm{\&tau;}}_m}g(t-{\mathrm{iT}}_s-{\mathrm{\&tau;}}_k)g^{*}(t-l{T}_s-{\mathrm{\&tau;}}_m)\mathrm{dt}$

$+{\&Integral;}_{{\mathrm{lT}}_s+{\mathrm{\&tau;}}_m}^{{(l+1)T}_s+{\mathrm{\&tau;}}_m}{n}_j\left(t\right)g^{*}(t-{\mathrm{lT}}_s-{\mathrm{\&tau;}}_m)\mathrm{dt}$ (4)

If

$R_{m,k}(l-i)={\&Integral;}_{{\mathrm{lT}}_s+{\mathrm{\&tau;}}_m}^{{(l+1)T}_s+{\mathrm{\&tau;}}_m}g(t-{\mathrm{iT}}_s-{\mathrm{\&tau;}}_k)g^{*}(t-{\mathrm{lT}}_s-{\mathrm{\&tau;}}_m)\mathrm{dt}---\left(5\right)$

$n_j^m\left(l\right)={\&Integral;}_{{\mathrm{lT}}_s+{\mathrm{\&tau;}}_m}^{{(l+1)T}_s+{\mathrm{\&tau;}}_m}{n}_j\left(t\right)g^{*}(t-{\mathrm{lT}}_s-{\mathrm{\&tau;}}_m)\mathrm{dt}---\left(6\right)$

Then (4) formula can be reduced to

$y_j^m\left(l\right)=\sqrt{\frac{E_s}{M}}\underset{i=0}{\overset{S-1}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{M}{\mathrm{\&Sigma;}}}{R}_{m,k}(l-i)h_{j,k}\left(i\right)b_k\left(i\right)+n_j^m\left(l\right)---\left(7\right)$

Step 9: data sampling

Adopt the signal of data sampling technology, constantly sample continuously, obtain a plurality of discrete sampled values at t to matched filter output in the step 8; This step is expressed as: for the output signal of m matched filter of j reception antenna at t=(l+1) T+ τ _m(l=0 ..., S-1, τ _mBe the time delay of signal on m the transmitting antenna) S sampled value y of acquisition _j ^m(0), y _j ^m(1) ..., y _j ^m(S-1), m=1 ..., M, j=1 ..., N, the sampled value difference that the signal on the different reception antennas obtains by data sampling;

Step 10: asynchronous MIMO detects

At first, the sampled value y to obtaining through data sampling step 9 on j the reception antenna _j ^m(l) (m=1 ..., M, j=1 ..., N, l=0 ..., S-1) carry out data combination and obtain corresponding matrix expression, specifically be expressed as follows:

Introduce M _T* M _TChannel correlation matrix R (l-i), its element is R _{M, k}(l-i); R (l-i) satisfies:

R(l-i)＝R ^H(i-l) (8)

Wherein () ^HThe expression complex-conjugate transpose;

By $g\left(t\right)=0,t\&NotElement;[0,T_s)$ And 0≤τ _k＜Δ T _s,

R(l-i)＝0，|l-i|＞Δ (9)

If j reception antenna at the diagonal angle channel matrix of the corresponding time slot of l symbol is

h _j(l)＝diag{h _j，1(l)，h _j，2(l)，…，h _j，M(l)} (10)

A j reception antenna M matched filter be at l=0, and 1 ..., S-1 output type (7) constantly can be expressed as vector form

$y_j\left(l\right)=\sqrt{\frac{E_s}{M_T}}\underset{i=0}{\overset{S-1}{\mathrm{\&Sigma;}}}R(l-i)h_j\left(i\right)b\left(i\right)+n_j\left(l\right)---\left(11\right)$

Wherein $y_j\left(l\right)={(y_j^1\left(l\right),y_j^2\left(l\right),\&CenterDot;\&CenterDot;\&CenterDot;,y_j^M\left(l\right))}^T,$ b(i)＝(b ₁(i)，b ₂(i)，…，b _M(i)) ^T，

$n_j\left(l\right)={(n_j^1\left(l\right),n_j^2\left(l\right),\&CenterDot;\&CenterDot;\&CenterDot;,n_j^M\left(l\right))}^T;$

Following handle (11) formula is expressed as more succinct matrix form; Definition

H _j＝diag{h _j(0)，h _j(1)，…，h _j(S-1)} (13)

$Y_j={(y_j^T\left(0\right),y_j^T\left(1\right),\&CenterDot;\&CenterDot;\&CenterDot;,y_j^T(S-1))}^T---\left(14\right)$

b＝(b ^T(0)，b ^T(1)，…，b ^T(S-1)) ^T (15)

$n_j={(n_j^T\left(0\right),n_j^T\left(1\right),\&CenterDot;\&CenterDot;\&CenterDot;,n_j^T(S-1))}^T---\left(16\right)$

Be SM _T* SM _TPiece symmetry Toeplitz matrix, H _jBe SM _T* SM _TDiagonal matrix; Carry out matched filtering from symbol time slot 0 to S-1 at reception antenna j, extract-signal sampling value Y _jCan be expressed as:

Following formula is the sampled value y on j the reception antenna _j ^m(l) (m=1 ..., M, j=1 ..., Nl=0 ..., S-1) carry out the matrix expression that obtains after the data combination; In like manner, carry out to obtain N different matrix expression after the data combination through the sampled value of data sampling step 9 acquisition on N reception antenna;

Then, this N matrix expression is carried out high specific merges, specifically be expressed as follows:

Matrix expression to N different reception antenna correspondence carries out the associating matrix expression that the high specific merging can get N reception antenna

$Y=\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{H}_j^H{Y}_j$

(18)

If

$N=\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{H}_j^H{n}_j,$ Then following formula can turn to

$Y=\sqrt{\frac{E_s}{M}}\mathrm{Hb}+N---\left(19\right)$

At last, based on the associating matrix expression (19) of N reception antenna, utilize methods such as direct ZF (ZF:Zero-Forcing), ordering interference cancellation can recover the estimated value of symbol b Other any estimated values that recover Detection method also be applicable to detection step of the present invention;

Step 11: decoding when layering is empty

Decoding technique when adopting layering empty, the estimated value of the symbol that step 10 is obtained Decoding, the data that are restored, decoding technique can be the V-BLAST decoding technique when wherein layering was empty, also can be H-BLAST decoding technique or D-BLAST decoding technique.

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