CN101483478A - MIMO communication system based on relay and communication method thereof - Google Patents

Abstract

The present invention discloses a multi-input multi-output communication system based on relay and a communication method thereof, and belongs to the field of wireless communication. The structure of the invention comprises a transmitter, a forwarding device and a receiver. The forwarding device is composed of relays. Each relay equally comprises a phase rotator and an amplitude amplifier. The communication method comprises the following steps: executing preprocessing to the signal to be transmitted by the transmitter for obtaining the column vector signal before transmission; amplifying the received signal by the amplitude amplifier of each relay in the forwarding device, adjusting the phase of received signal by the phase rotator; and executing amplitude weighting and phase rotating to the duplicate copies of a plurality of received channel by two maximal ratio combiners in the receiver. The system and method of the invention have higher spectrum efficiency and better probability capability. Each replay independently processes and forwards the received signal. The complexity and feedback expenditure of cooperative processing are reduced.

Description

A kind of multiple-input-multiple-output communication system and communication means thereof based on relaying

Technical field

The present invention relates to a kind of multiple-input-multiple-output communication system, relate in particular to a kind of multiple-input-multiple-output communication system and communication means thereof, belong to wireless communication field based on relaying.

Background technology

Multiple-input and multiple-output (MIMO) communication technology attains full development in recent years.It is to utilize space resources to realize a kind of effective means of high-rate link transmission, can under the situation that does not increase extra spectrum and power, significantly increase the transmission rate and the reliability of communication system, be acknowledged as one of key technology in the next generation mobile communication.The research of point-to-point multi-antenna transmitting transferring technology reaches its maturity, and it can improve the validity of spectrum efficiency, link reliability and power utilization effectively by spatial reuse gain, diversity gain and array gain.

Yet along with the raising to communicating requirement, as two-forty, high quality-of-service (QoS) requirement, high coverage rate etc., traditional MIMO technique table reveals many defectives: the sub-district coverage rate is narrow, has coverage hole or blind spot; Because the bad channel conditions of near-far interference and Cell Edge User makes transmission rate not high; Under the crowded situation in sub-district, the adjacent cell flow of balance is difficulty relatively, and all are the center with the base station, base station complexity height; Strong to the base station dependence, limited by number of antennas, the user diversity degree is low.

For solving top problem, aspect network configuration, introduced relaying, and introducing is considered to and can significantly improves network transmission performance in not obvious change backbone network structure based on the distributed proccessing of relaying in link transmission and scheduling, solves the problem that Cellular Networks exists.Studies show that many antennas MIMO technology can be used in base station and relay and improve the overall performance of system effectively, the suitable combination of relay transmission and many antennas MIMO technology can improve system spectral efficiency, and transfer of data more efficiently is provided.Yet these achievements in research only are to study the communication performance of MIMO relay system from information-theoretical angle, how not to point out specific implementation.

In the MIMO communication system based on many relayings, a plurality of relay wells are distributed on the different positions, the forwarding received signal that how to make a plurality of relaying cooperations, and do not need centralized central controller to unify to handle, do not need the exchanges data of relay well and channel information exchange to become very important problem yet.At present, also there is not good implementation.

Summary of the invention

The present invention is that many relay systems acquisition good wireless communication performances that distributed collaborative is handled propose a kind of multiple-input-multiple-output communication system and communication means thereof based on relaying.

A kind of multiple-input-multiple-output communication system based on relaying, comprise transmitter, retransmission unit and receiver, transmitter passes to receiver by retransmission unit with signal after receiving the input data, the receiver dateout, described retransmission unit is made up of an independent K relaying, each relaying all comprises a phase rotation device and an amplitude amplifier, and wherein K is a natural number.

A kind of communication means based on above-mentioned multiple-input-multiple-output communication system based on relaying comprises the steps:

(1) receiver is estimated first jumping and the response of second hop channel;

(2) receiver carries out the high specific merging according to second hop channel response that estimates to second hop channel, obtains second hop channel response of equivalence;

(3) receiver is according to first jumping and the second hop channel information is calculated as follows the common scalar factor of each relaying of estimating:

$\mathrm{\ξ}=\sqrt{\frac{P_2}{{d_r}^H\mathrm{diag}(H_1{d}_1{d_1}^H{H_1}^H+{{\mathrm{\σ}}_1}^2{I}_K)d_r}}$

(4) receiver is broadcast to each relaying to the corresponding feedback of the common scalar factor ξ of each relaying that calculates;

(5) each relaying is estimated first hop channel;

(6) each relaying receives the equivalence second hop channel fading factor b from the receiver feedback separately respectively _i

(7) each relaying is given transmitter the first hop channel feedback information that has estimated;

(8) transmitter receives the feedback information about first hop channel from each relaying;

(9) transmitter is according to first hop channel response H ₁The transmitter computes preprocessor $d_{}$ ${}_1=\sqrt{P_1}{\mathrm{<figure-callout\; id="1"\; label="v"\; filenames="A200910025576E00101.png,A200910025576E00102.png"\; state="\{\{state\}\}">v</figure-callout>}}_1;$

(10) each relaying amplifies the amplitude of carrying out of received signal separately by following formula:

$\left|\frac{a_i{b}_i}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)}\right|,i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;K$

(11) each relaying independently carries out the phase place rotation by following formula to received signal separately:

$\&angle;\left(\frac{a_i^{*}{b}_i^{*}}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)}\right),i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;K$

(12) each relaying is according to the common scalar factor ξ of the correspondence that receives, to all corresponding ξ of amplification of signal that will transmit separately doubly;

(13) receiver carries out the high specific merging second time based on the equivalent channel of whole system after received signal has experienced high specific merging for the first time;

Wherein: P ₂The total power constraint of-all relayings, d _rThe common phase vectors of forming of-all relayings, H ₁The response of-the first hop channel, σ ₁ ², σ ₂ ²-be respectively the additive white Gaussian noise variance of first hop channel and second hop channel, I _K-unit matrix, a _i-equivalent first hop channel the fading factor, v ₁-to first hop channel response H ₁Carry out singular value decomposition and obtain the unit character vector of eigenvalue of maximum correspondence, P ₁The maximum power of-transmitter, K-relaying number, K is a natural number, a _i ^*, b _i ^*-be respectively the conjugation of the equivalent first hop channel fading factor and the conjugation of the equivalent second hop channel fading factor.

The present invention proposes the distributed forwarding scheme of a kind of a plurality of cooperative relays, it is receiver calculates all relayings according to current channel response common scalar factor, and its feedback is broadcast to all relayings, each relaying is according to first jumping and second jump that the equivalent channel fading factor amplifies the receive channel amplitude of carrying out separately and phase place is rotated separately; The mode of each relaying collaborative process is only to need the first own jumping and the second hop channel information and any channel information of not needing other relayings, the any exchanges data that does not more need relay well has greatly reduced the complexity of collaborative process and the expense that channel switch is brought.

Description of drawings

Fig. 1 is that system of the present invention forms structural representation, and among the figure: M represents that the antenna number that is equipped with on the transmitter, N represent the antenna number that is equipped with on the receiver.

Fig. 2 is a communication means flow chart of the present invention.

Fig. 3-Figure 11 is under the different antenna configurations of transmitter, the receiver situation different with the cooperative relays number, the simulation result figure under different signal to noise ratios, Fig. 3: MIMO=4*4*1, total base station power 20dB, all relaying gross power 20dB; Fig. 4: MIMO=4*4*1, total base station power 10dB, all relaying gross power 10dB; Fig. 5: MIMO=4*4*1, total base station power 0dB, all relaying gross power 0dB; Fig. 6: MIMO=4*4*2, total base station power 20dB, all relaying gross power 20dB; Fig. 7: MIMO=4*4*2, total base station power 10dB, all relaying gross power 10dB; Fig. 8: MIMO=4*4*2, total base station power 0dB, all relaying gross power 0dB; Fig. 9: MIMO=4*4*4, total base station power 20dB, all relaying gross power 20dB; Figure 10: MIMO=4*4*4, total base station power 10dB, all relaying gross power 10dB; Figure 11: MIMO=4*4*4, total base station power 0dB, all relaying gross power 0dB.

Embodiment

As shown in Figure 1, a kind of multiple-input-multiple-output communication system based on relaying, comprise transmitter, retransmission unit and receiver, transmitter passes to receiver by retransmission unit with signal after receiving the input data, the receiver dateout, described retransmission unit is made up of an independent K relaying, each relaying all comprises a phase rotation device and an amplitude amplifier, on transmitter, be equipped with M root antenna, on receiver, be equipped with N root antenna, wherein: K, M and N are natural numbers, include two maximal ratio combiners in receiver.

As shown in Figure 2, a kind of communication means based on above-mentioned multiple-input-multiple-output communication system based on relaying comprises the steps:

(1) receiver is estimated first jumping and the response of second hop channel;

(2) first maximal ratio combiner of receiver carries out the high specific merging according to second hop channel response that estimates to second hop channel, obtains second hop channel response of equivalence;

(3) receiver is according to first jumping and the second hop channel information is calculated as follows the common scalar factor of each relaying of estimating:

$\mathrm{\&xi;}=\sqrt{\frac{P_2}{{d_r}^H\mathrm{diag}(H_1{d}_1{d_1}^H{H_1}^H+{{\mathrm{\&sigma;}}_1}^2{I}_K)d_r}}$

(4) receiver is broadcast to each relaying to the corresponding feedback of the common scalar factor ξ of each relaying that calculates;

(5) each relaying is estimated first hop channel;

(6) each relaying receives the equivalence second hop channel fading factor b from the receiver feedback separately respectively _i

(7) each relaying is given transmitter the first hop channel feedback information that has estimated;

(8) transmitter receives the feedback information about first hop channel from each relaying;

(9) transmitter is according to first hop channel response H ₁The transmitter computes preprocessor $d_{}$ ${}_1=\sqrt{P_1}{\mathrm{<figure-callout\; id="1"\; label="v"\; filenames="A200910025576E00101.png,A200910025576E00102.png"\; state="\{\{state\}\}">v</figure-callout>}}_1;$

(10) each relaying amplifies the amplitude of carrying out of received signal separately by following formula:

$\left|\frac{a_i{b}_i}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)}\right|,i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;K$

(11) each relaying independently carries out the phase place rotation by following formula to received signal separately:

$\&angle;\left(\frac{a_i^{*}{b}_i^{*}}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)}\right),i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;K$

(12) each relaying is according to the common scalar factor ξ of the correspondence that receives, to all corresponding ξ of amplification of signal that will transmit separately doubly;

(13) receiver has experienced after for the first time high specific merges in received signal, and second maximal ratio combiner carries out merging based on the high specific second time of the equivalent channel of whole system;

Wherein: P ₂The total power constraint of-all relayings, d _rThe common phase vectors of forming of-all relayings, H ₁The response of-the first hop channel, σ ₁ ², σ ₂ ²-be respectively the additive white Gaussian noise variance of first hop channel and second hop channel, I _K-unit matrix, a _i-equivalent first hop channel the fading factor, v ₁-to first hop channel response H ₁Carry out singular value decomposition and obtain the unit character vector of eigenvalue of maximum correspondence, P ₁The maximum power of-transmitter, K-relaying number, K is a natural number, a _i ^*, b _i ^*-be respectively the conjugation of the equivalent first hop channel fading factor and the conjugation of the equivalent second hop channel fading factor.

Many relayings collaboration type is transmitted to handle and is realized by following steps:

A. each relaying obtains the equivalent channel of first hop channel and transmitter preprocessor by channel estimating $a=H_1{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="A200910025576E00101.png,A200910025576E00102.png"\; state="\{\{state\}\}">d</figure-callout>}}_1=\left(\begin{array}{c}{a}_1\\ \&CenterDot;\&CenterDot;\&CenterDot;\\ a_K\end{array}\right);$

B. the processing of response of second hop channel and receiver obtains the equivalent second hop channel b=u ^HH ₂, wherein: u is the maximal ratio combiner of receiver;

C. calculating the forwarding separately of each relaying handles: $\mathrm{\&xi;}\frac{a_i^{*}{b}_i^{*}}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)},i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;K;$

D. each relaying multiply by at separately received signal I=1,2 ... K is transmitted to receiver simultaneously at next time slot;

E. receiver carries out high specific to the received signal and merges, the design of maximal ratio combiner be by to second hop channel response carry out first row of the left singular matrix that singular value decomposition obtains, this is listed as corresponding eigenvalue of maximum.

Fig. 3-Figure 11 has provided the different antenna configurations of transmitter, receiver respectively under the situation of different signal to noise ratios, and the distributed collaborative processing scheme of being carried and relay well do not have the cumulative distribution function curve of the scheme of cooperation.As seen under the situation of identical antenna configurations and identical cooperative relays number, traversal capacity of the present invention is all apparently higher than the scheme that does not have cooperation, and the outage probability performance under any speed all obviously is better than not have the scheme of cooperating.

Claims (2)

1, a kind of multiple-input-multiple-output communication system based on relaying, comprise transmitter, retransmission unit and receiver, transmitter passes to receiver by retransmission unit with signal after receiving the input data, the receiver dateout, it is characterized in that: described retransmission unit is made up of an independent K relaying, each relaying all comprises a phase rotation device and an amplitude amplifier, and wherein K is a natural number.

2, a kind of communication means based on the described multiple-input-multiple-output communication system based on relaying of claim 1 is characterized in that comprising the steps:

(1) receiver is estimated first jumping and the response of second hop channel;

(2) receiver carries out the high specific merging according to second hop channel response that estimates to second hop channel, obtains second hop channel response of equivalence;

(3) receiver is according to first jumping and the second hop channel information is calculated as follows the common scalar factor of each relaying of estimating:

$\mathrm{\&xi;}=\sqrt{\frac{P_2}{{d_r}^H\mathrm{diag}(H_1{d}_1{d_1}^H{H_1}^H+{{\mathrm{\&sigma;}}_1}^2{I}_K)d_r}}$

(4) receiver is broadcast to each relaying to the corresponding feedback of the common scalar factor ξ of each relaying that calculates;

(5) each relaying is estimated first hop channel;

(6) each relaying receives the equivalence second hop channel fading factor b from the receiver feedback separately respectively _i

(7) each relaying is given transmitter the first hop channel feedback information that has estimated;

(8) transmitter receives the feedback information about first hop channel from each relaying;

(9) transmitter is according to first hop channel response H ₁The transmitter computes preprocessor $d_1=\sqrt{P_1}{v}_1;$

(10) each relaying amplifies the amplitude of carrying out of received signal separately by following formula:

$\left|\frac{a_i{b}_i}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)}\right|,$ i＝1，2，…K

(11) each relaying independently carries out the phase place rotation by following formula to received signal separately:

$\&angle;\left(\frac{{a_i}^{*}{b_i}^{*}}{{{\mathrm{\&sigma;}}_1}^2{\left|b_i\right|}^2+\frac{{{\mathrm{\&sigma;}}_2}^2}{P_2}({\left|a_i\right|}^2+{{\mathrm{\&sigma;}}_1}^2)}\right),i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;K$

(12) each relaying is according to the common scalar factor ξ of the correspondence that receives, to all corresponding ξ of amplification of signal that will transmit separately doubly;

(13) receiver carries out the high specific merging second time based on the equivalent channel of whole system after received signal has experienced high specific merging for the first time;

Wherein: P ₂The total power constraint of one all relayings, d _rThe common phase vectors of forming of-all relayings, H ₁The response of-the first hop channel, σ 1 ², σ ₂ ²-be respectively the additive white Gaussian noise variance of first hop channel and second hop channel, I _K-unit matrix, a _i-equivalent first hop channel the fading factor, v ₁-to first hop channel response H ₁Carry out singular value decomposition and obtain the unit character vector of eigenvalue of maximum correspondence, P ₁The maximum power of-transmitter, K-relaying number, K is a natural number, a _i ^*, b _i ^*-be respectively the conjugation of the equivalent first hop channel fading factor and the conjugation of the equivalent second hop channel fading factor.

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