CN102684767B - Multi-carrier MISO system based on three-dimensional mutual-complementing code - Google Patents

Abstract

A multi-carrier MISO (Multiple Input, Single Output) system based on a three-dimension mutual-complementing code relates to an MISO system, and aims to solve the problem that a conventional MISO system is poor in multi-path interference resistance and multi-user interference resistance. Each user k adopts a three-dimensional mutual-complementing code as a signature code, each three-dimensional mutual-complementing code consists of NT two-dimensional mutual-complementing codes, and for each user k, the working procedures of the system comprises the steps as follows: step I, at a transmitting end, data to be sent is modulated to NT paths of modulation signals by utilizing a transmitter of the MISO system, and then the NT paths of modulation signals are transmitted to wireless signal channels via NT antennae; and steps II, at a receiving end, the transmitters of the MISO system is utilized to receive the NT paths of modulation signals transmitted to the wireless signal channels in the step I with one antenna. The system is applicable to the field of wireless communication.

Description

The communication means of the multicarrier MISO system based on three-dimensional complementary code

Technical field

The present invention relates to a kind of MISO system, particularly a kind of communication means of the multicarrier MISO system based on three-dimensional complementary code.

Background technology

1998, the SiavashM.Alamouti of Harvard University proposed a simple double antenna MISO (Multiple Inputs, Single Output) system and has realized transmit diversity.Then the system that VahidTarokh, Hamid Jafarkhani and A.R.Calderbank propose script Alamouti, is integrated into general form, and expansion transmitting terminal can not only be used the form of two antennas.MISO system has adopted many antennas at transmitting terminal, has realized space diversity.The advantage of this system has been to introduce " space " this new dimension, has increased transmission rate, has reduced error probability, thereby improved the availability of frequency spectrum in the situation that not increasing frequency spectrum resource or transmitting power.

Space Time Coding is the coded system that current MISO system is commonly used to implementation space diversity, and common coding has STBC (Space-time Block Code), STTC (Space-Time Trellis Code) and STDC (Space-Time Differential Code) etc.But Space Time Coding is not considered the multipath in environment and is disturbed the impact on system, thereby under the environment that exists multipath to disturb, the possibility that Space Time Coding is realized is little.Simultaneously, although some paper has been discussed the orthogonality between multi-user, many antennas, but all rest on the orthogonality of symbol level (Symbol-Level), do not discuss the orthogonality of chip-level (Chip-Level), the situation in the time of can only being slow fading for channel response.In decode procedure, receiving terminal only, when receiving the full detail of Space Time Coding, just can be decoded, thereby cannot realize instant decoding.

In current wireless communication technology, complete complementary code is the code with perfect auto-correlation and their cross correlation, can effectively resist multipath and disturb and multi-user interference.And because complete complementary code has the orthogonality of chip-level (Chip-Level), because needn't be limited to the constant restriction of channel conditions in a plurality of sign bit elementary times, thereby can realize the decoding in the very fast time, solve in time the information that we need.

Summary of the invention

The object of the invention is, in order to solve the problem of current MISO system opposing multipath interference and multi-user interference ability, to have proposed a kind of communication means of the multicarrier MISO system based on three-dimensional complementary code.

The communication means of a kind of multicarrier MISO system based on three-dimensional complementary code of the present invention, each user k adopts a three-dimensional complementary code as signed codevector, and each three-dimensional complementary code comprises N _tindividual two-dimentional mutual-complementing code, for each user k, the process of the multicarrier MISO system works based on three-dimensional complementary code comprises the steps:

Step 1: at transmitting terminal, utilize the transmitter of MISO system that Data Modulation to be sent is become to N _troad modulation signal, then by N _troad modulation signal N _troot antenna transmission is to wireless channel;

Step 2: at receiving terminal, utilize the receiver of MISO system with being transmitted to the N of wireless channel in 1 antenna reception step 1 _troad modulation signal.

The invention has the advantages that:

(1) maximum number of user that three-dimensional complementary code of the present invention can be supported is identical with subcode number with maximum antenna number, is all M=2 ^k(k=1,2 ...); Code length is M ^r(r=2,3 ...).Restriction between having cut off mutually between the code length of three-dimensional complementary code and subcode number, can distinguish arbitrary extension, has better practicality.

(2) three-dimensional complementary code of the present invention has desirable autocorrelation performance, and the expression formula of auto-correlation relation is:

$\left\{\begin{array}{cc}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\mathrm{\ρ}(S_{k,m}^{\left(n_t\right)};i)=\mathrm{MN}& i=0\\ \underset{m=1}{\overset{M}{\mathrm{\Σ}}}\mathrm{\ρ}(S_{k,m}^{\left(n_t\right)};i)=\mathrm{MN}& i\≠0\end{array}\right.---\left(10\right)$

K=1 wherein, 2 ..., K; Nt=1,2 ..., NT

When displacement is in the situation of odd number displacement, we can prove that its auto-correlation condition meets, displacement be 0 o'clock its correlation and reach peak, when displacement is not 0, its correlation sum is 0; When displacement is even number displacement, meeting equally in displacement is that 0 o'clock correlation reaches peak, and when displacement is non-vanishing, correlation is 0.Two subcodes in same three-dimensional complementary code have perfect correlation properties, and two subcodes in two three-dimensional complementary codes have perfect correlation properties equally respectively.

(3) three-dimensional complementary code of the present invention has desirable their cross correlation, and the expression formula of their cross correlation is:

$\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\mathrm{\ρ}(S_{k,m},S_{k^{\′},m};i)=0$ I is arbitrary value (11)

K wherein, k'=1,2 ..., K; K ≠ k'

The subcode of different user is under the condition of even number displacement, and cross-correlation function sum is zero; Under the condition of odd number displacement, cross correlation value sum is also 0.Fully meet correlated condition, this mutual-complementing code can be resisted multi-user interference effectively.

(4), because three-dimensional complementary code of the present invention has desirable auto-correlation cross-correlation feature, the communication means of the multicarrier MISO system based on three-dimensional complementary code of the present invention can eliminate multiple access interference completely and multipath disturbs.

(5) communication means of the multicarrier MISO system based on three-dimensional complementary code of the present invention can be realized Space Time Coding and multiple access access by a kind of special spread spectrum simultaneously, not only reduced the complexity of system, more the further global optimization of system provides good platform.

Accompanying drawing explanation

Fig. 1 is the communication means overall structure schematic diagram of the described multicarrier MISO system based on three-dimensional complementary code of the present invention.

Fig. 2 is the structural representation of transmitter of MISO system of the communication means of the described multicarrier MISO system based on three-dimensional complementary code of the present invention. representative of consumer k is at antenna n _ton m subcode, wherein k ∈ 1,2 ..., K}, K is number of users; n _t∈ 1,2 ..., N _t, N _tfor antenna number; M ∈ 1,2 ..., and M}, M is subcode number.

Fig. 3 is the structural representation of receiver of MISO system of the communication means of the described multicarrier MISO system based on three-dimensional complementary code of the present invention.

Embodiment

Embodiment one: in conjunction with Fig. 1, present embodiment is described, the communication means of the multicarrier MISO system based on three-dimensional complementary code of the present invention, user k adopts a three-dimensional complementary code as signed codevector, and each three-dimensional complementary code comprises N _tindividual two-dimentional mutual-complementing code, for user k, the process of the multicarrier MISO system works based on three-dimensional complementary code comprises the steps:

Step 1: at transmitting terminal, utilize the transmitter of MISO system that Data Modulation to be sent is become to N _troad modulation signal, then by N _troad modulation signal N _troot antenna transmission is to wireless channel;

Step 2: at receiving terminal, utilize the receiver of MISO system with being transmitted to the N of wireless channel in 1 antenna reception step 1 _troad modulation signal.

MISO system based on three-dimensional complementary code comprises k user, and each user's transmitter comprises N _ttransmit antennas, receiver comprises a reception antenna.In this system, each user adopts a three-dimensional complementary code as its signed codevector, realizes multiple access access and Space Time Coding simultaneously.A three-dimensional complementary code comprises N _tindividual traditional two-dimentional mutual-complementing code, each two-dimentional mutual-complementing code comprises M spread spectrum subsequence.

Embodiment two: present embodiment is to the further illustrating of the communication means of the multicarrier MISO system based on three-dimensional complementary code described in embodiment one,

The production method of described three-dimensional complementary code comprises the steps:

The first step: adopt orthogonal matrix A and the B that two dimensions are 2 * 2 to construct the sequence C that 2 length are 4 ₁and C ₂:

$\begin{array}{c}{C}_1=(b_{11}{A}_1,b_{12}{A}_2)=(c_{11},c_{12},c_{13},c_{14})\\ C_2=(b_{21}{A}_1,b_{22}{A}_2)=(c_{21},c_{22},c_{23},c_{24})\end{array}---\left(1\right)$

Wherein, the expression formula of orthogonal matrix A is:

$A=\left[\begin{array}{c}{A}_1\\ A_2\end{array}\right]=\left(\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right);\left|a_{\mathrm{ij}}\right|=1---\left(2\right)$

I wherein, j=1,2;

The expression formula of orthogonal matrix B is:

$B=\left(\begin{array}{cc}{b}_{11}& b_{12}\\ b_{21}& b_{22}\end{array}\right);\left|b_{\mathrm{ij}}\right|=1---\left(3\right)$

I wherein, j=1,2;

The orthogonal matrix A that two dimensions are 2 * 2 and the norm of each element in B are the plural numbers for 1;

Second step: 2 sequence C that length is 4 that the first step is obtained ₁and C ₂with 2 * 2 orthogonal dimension matrixes construct N _t* 4 sequences that length is 4:

$\begin{array}{c}{E}_{\mathrm{ij}}^{\left(n_t\right)}=(C_{i1}{d}_{j1}^{\left(n_t\right)},C_{i2}{d}_{j2}^{\left(n_t\right)},C_{i3}{d}_{j1}^{\left(n_t\right)},C_{i4}{d}_{j2}^{\left(n_t\right)})\\ =(e_{\mathrm{ij}1}^{\left(n_t\right)},e_{\mathrm{ij}2}^{\left(n_t\right)},e_{\mathrm{ij}3}^{\left(n_t\right)},e_{\mathrm{ij}4}^{\left(n_t\right)})\end{array}----\left(4\right)$

Wherein, i, j=1,2; n _t=1,2 ..., N _t;

N _tfor number of transmit antennas;

Each mutual-complementing code of above-mentioned generation has two subcodes, is respectively with

Orthogonal matrix expression formula be:

$D^{\left(n_t\right)}=\left(\begin{array}{cc}{d^{\left(n_t\right)}}_{11}& {d^{\left(n_t\right)}}_{12}\\ {d^{\left(n_t\right)}}_{21}& {d^{\left(n_t\right)}}_{22}\end{array}=\right);\left|{d^{\left(n_t\right)}}_{\mathrm{ij}}\right|=1---\left(5\right)$

I wherein, j=1,2; n _t=1,2 ..., N _t;

Order this N _tindividual matrix sum is orthogonal matrix D:

$D=\underset{n_t=1}{\overset{N_T}{\mathrm{\Σ}}}{D}^{\left(n_t\right)}=\underset{n_t=1}{\overset{N_T}{\mathrm{\Σ}}}\left(\begin{array}{cc}{d^{\left(n_t\right)}}_{11}& {d^{\left(n_t\right)}}_{12}\\ {d^{\left(n_t\right)}}_{21}& {d^{\left(n_t\right)}}_{22}\end{array}\right)=\left(\begin{array}{cc}\underset{n_t=1}{\overset{N_T}{\mathrm{\Σ}}}{d^{\left(n_t\right)}}_{11}& \underset{n_t=1}{\overset{N_T}{\mathrm{\Σ}}}{d^{\left(n_t\right)}}_{12}\\ \underset{n_t=1}{\overset{N_T}{\mathrm{\Σ}}}{d^{\left(n_t\right)}}_{21}& \underset{n_t=1}{\overset{N_T}{\mathrm{\Σ}}}{d^{\left(n_t\right)}}_{22}\end{array}\right)=\left(\begin{array}{cc}{d}_{11}& d_{12}\\ d_{21}& d_{22}\end{array}\right)---\left(6\right)$

The 3rd step: by described N _tthe sequence that * 4 length is 4 adopts mutually to be inserted the mode of arranging and forms a sequence:

$\begin{array}{c}{F}_i=(e_{i11},e_{i21};e_{i12},e_{i22};...;e_{{i12}^{r-1}},e_{{i22}^{r-1}})\\ =(f_{i1},f_{i2},...,f_{{i2}^r})\end{array}---\left(7\right)$

I=1 wherein, 2; The initial value of r is 3;

Sequence length in formula (7) is consistent with the length of mutual-complementing code in formula (5), and the code length of the mutual-complementing code in formula (5) is 2 ^r-1, a code has two subcodes;

And by the sequence F obtaining ₁, F ₂replace the sequence C in second step ₁and C ₂the basic code of the mutual-complementing code constructing:,

$\begin{array}{c}{E}_{11}^{\left(n_t\right)}={T_1}^{\left(n_t\right)}=[T_{11}^{\left(n_t\right)},T_{12}^{\left(n_t\right)},T_{13}^{\left(n_t\right)},T_{14}^{\left(n_t\right)}]\\ E_{12}^{\left(n_t\right)}={T_2}^{\left(n_t\right)}=[T_{21}^{\left(n_t\right)},T_{22}^{\left(n_t\right)},T_{23}^{\left(n_t\right)},T_{24}^{\left(n_t\right)}]\\ E_{21}^{\left(n_t\right)}={T_3}^{\left(n_t\right)}=[T_{31}^{\left(n_t\right)},T_{32}^{\left(n_t\right)},T_{33}^{\left(n_t\right)},T_{34}^{\left(n_t\right)}]\\ E_{22}^{\left(n_t\right)}={T_4}^{\left(n_t\right)}=[T_{41}^{\left(n_t\right)},T_{42}^{\left(n_t\right)},T_{43}^{\left(n_t\right)},T_{44}^{\left(n_t\right)}]\end{array}---\left(8\right)$

Wherein: n _t=1,2 ..., N _t; Basic code comprises 4 codes: each code also comprises 4 subcodes;

The code F producing by formula (7) ₁, F ₂replace the C in formula (6) ₁and C ₂carry out computing, producing extended length is the expansion three-dimensional complementary code of 2 times of original code lengths.Be labeled as equally n wherein _t=1,2 ..., N _t.By each regard a code as, then it is cut apart, each code is divided into four subcodes, these four codes that produce in formula (8) are the basic code of mutual-complementing code, each code of this basic code separates four subcodes, and each subcode length is a chip lengths (chip).

The 4th step: the basic code producing according to the 3rd step, in the situation that not changing subcode length, the number of expansion subcode:

Wherein, j=0,1 ..., (L/2-1),

for the complementation of T, and L=2 ^r(R>=2 and R are integer) represents the number of the code before expansion.

Often carry out one extension, in new code, contained subcode number will become original two times, and the sum of the code comprising with stylish code also can become original two times.The length of new code is consistent with true form, and it is controlled that the length that the extended mode that the present invention proposes can not change subcode makes subcode length always.

Embodiment three: present embodiment is to be to the different of the communication means of the multicarrier MISO system based on three-dimensional complementary code described in embodiment two, in the production method of described three-dimensional complementary code, repeatedly carry out the 3rd step, every execution once, 2 times of the extended length of the basic code of the mutual-complementing code constructing.

We can also expand the length of subcode, utilize the sequence obtaining in formula (7) replace producing the sequence C of mutual-complementing code originally ₁, C ₂, then the operation in doing a formula (6) just can construct the complete complementary code of 2 times of extended length by this sequence and orthogonal matrix D according to such mode, subcode extended length is gone down but can not change the subcode number comprising in each yard.The length of the mutual-complementing code subcode producing like this will be expanded down with 2 index, becomes 2 chip lengths, 4 chip lengths, 8 chip lengths etc.But the subcode number of each basic code remains 4.

Embodiment four: in conjunction with Fig. 2, present embodiment is described, present embodiment is to the further illustrating of the communication means of the multicarrier MISO system based on three-dimensional complementary code described in embodiment one,

The emission process of the transmitter of MISO system is:

Step 1: data to be sent are carried out to information source coding, obtain polarization nonreturn to zero code;

Step 2: adopt N in three-dimensional complementary code _tthe polarization nonreturn to zero code that the two-dimentional mutual-complementing code of group obtains step 1 respectively carries out complementary spread spectrum, every group of corresponding data that obtain after the spread spectrum of M road of two dimension mutual-complementing code; N _tfor positive integer;

Step 3: the data after the every group of corresponding M road spread spectrum obtaining of two dimension mutual-complementing code obtaining in step 2 are adopted respectively to the different carrier wave in M road $\sqrt{\frac{2}{T_b}}\cos \left(2\mathrm{\π}{f}_{1}t\right),\sqrt{\frac{2}{T_b}}\cos \left(2\mathrm{\π}{f}_{2}t\right),...,\sqrt{\frac{2}{T_b}}\cos \left(2\mathrm{\π}{f}_{M}t\right)$ Modulate, obtain M road modulation signal; M is positive integer;

Step 4: respectively every group of M road modulation signal corresponding to two dimension mutual-complementing code obtaining in step 3 carried out to equal gain combining, obtain N _troad modulation signal, by described N _troad modulation signal passes through respectively N _ttransmit antennas is sent to wireless channel.

In the structural representation of the MISO system transmitter of the MISO system based on three-dimensional complementary code, representative of consumer k is at antenna n _ton m subcode, wherein k ∈ 1,2 ..., K}, K is number of users; n _t∈ 1,2 ..., NT}, N _tfor antenna number; M ∈ 1,2 ..., and M}, M is subcode number.First the data of transmitting terminal copy N _tpart, with implementation space, send diversity.Every part of copy adopts respectively a two-dimentional mutual-complementing code in three-dimensional complementary code to carry out complementary spread spectrum, and the M part copy that is about to these data adopts M subcode in mutual-complementing code to carry out respectively spread spectrum, and is modulated to the carrier wave f of M different frequency ₁, f ₂..., f _mupper, last equal gain combining, and send.

Embodiment five: in conjunction with Fig. 3, present embodiment is described, present embodiment is to the further illustrating of the communication means of the multicarrier MISO system based on three-dimensional complementary code described in embodiment one, two, three or four,

The receiving course of the receiver of MISO system is:

Step 5: pass through N by a reception antenna receiver/transmitter _tthe N of root antenna transmission _troad modulation signal, the signal that reception antenna receives is r (t), adopts N _tgroup band pass filter carries out filtering to the signal r (t) receiving respectively, obtains N _troad frequency is f ₁, f ₂..., f _mfiltering signal;

Step 6: step 5 Zhong Mei road filtering signal is the N of the three-dimensional complementary code corresponding with transmitting terminal respectively _torganize two-dimentional mutual-complementing code and carry out despreading, the signal after despreading adopts the carrier wave of respective frequencies to carry out demodulation again, obtains the signal after the demodulation of M road;

Step 7: the despread signal on the M road in step 6 is obtained every group is respectively a bit time T _bunder carry out integration, obtain the integration data of M road integral result;

Step 8: the M road integral result in the every group of integration data obtaining in step 7 is added, obtains a road and be added rear data, N _tgroup integration data obtains N altogether _tdata after road is added;

Step 9: the N that step 8 is obtained _tafter road is added, data are carried out equal gain combining, obtain a road and merge rear data;

Step 10: merge the initial data that rear data are adjudicated rear acquisition transmitting terminal transmission by obtaining Yi road in step 9.

In the structural representation of the MISO system receiver of the MISO system based on three-dimensional complementary code, receiving terminal receives by an antenna, wherein r ₁, r ₂..., r _mthe signal of receiving for receiving terminal.Because transmitting terminal modulates the signal to M carrier wave f ₁, f ₂..., f _mupper, so reception signal is divided into M road by M band pass filter at receiving terminal, then carry out demodulation.Data after demodulation enter correlator, adopt respectively a two-dimentional mutual-complementing code in three-dimensional complementary code to carry out complementary despreading, being about to M group data adopts respectively M subcode in mutual-complementing code to carry out respectively despreading, finally the signal of variant antenna is added together with identical weight, namely according to the mode of equal gain combining, merge, and enter decision device and adjudicate.

Claims (4)

1. the communication means of the multicarrier MISO system based on three-dimensional complementary code, user k adopts a three-dimensional complementary code as signed codevector, and each three-dimensional complementary code comprises N _tindividual two-dimentional mutual-complementing code, for user k, the process of the multicarrier MISO system works based on three-dimensional complementary code comprises the steps:

Step 1: at transmitting terminal, utilize the transmitter of MISO system that Data Modulation to be sent is become to N _troad modulation signal, then by N _troad modulation signal N _troot antenna transmission is to wireless channel;

Step 2: at receiving terminal, utilize the receiver of MISO system with being transmitted to the N of wireless channel in 1 antenna reception step 1 _troad modulation signal;

It is characterized in that, the production method of three-dimensional complementary code comprises the steps:

The first step: adopt orthogonal matrix A and the B that two dimensions are 2 * 2 to construct the sequence C that 2 length are 4 ₁and C ₂:

Wherein, the expression formula of orthogonal matrix A is:

I wherein, j=1,2; Subscript i represents that i is capable, and subscript j represents j row;

The expression formula of orthogonal matrix B is:

Second step: 2 sequence C that length is 4 that the first step is obtained ₁and C ₂with 2 * 2 orthogonal dimension matrixes construct N _t* 4 sequences that length is 4:

Wherein, i, j=1,2; n _t=1,2 ..., N _t; with represent respectively with

Orthogonal matrix expression formula be:

I wherein, j=1,2; n _t=1,2 ..., N _t;

And this N _tit is orthogonal matrix that individual matrix sum D also requires:

The 3rd step: by described N _tthe sequence that * 4 length is 4 adopts mutually to be inserted the mode of arranging and forms a sequence:

I=1 wherein, 2; The initial value of r is 3; represent respectively and by the sequence F obtaining ₁, F ₂replace the sequence C in second step ₁and C ₂, the basic code of the mutual-complementing code constructing:

Wherein: n _t=1,2 ..., N _t; Basic code comprises 4 codes: each code also comprises 4 subcodes, with for subcode;

The 4th step: the basic code producing according to the 3rd step, in the situation that not changing subcode length, the number of expansion subcode:

Wherein, j=0,1 ..., L/2-1,

for the complementation of T, and L=2 ^r, R>=2 and R are integer, represent the number of the code before expansion.

2. the communication means of the multicarrier MISO system based on three-dimensional complementary code according to claim 1, is characterized in that, repeatedly carries out the 3rd step, every execution once, 2 times of the extended length of the basic code of the mutual-complementing code constructing.

3. the communication means of the multicarrier MISO system based on three-dimensional complementary code according to claim 1, is characterized in that, the emission process of the transmitter of MISO system is:

Step 1: data to be sent are carried out to information source coding, obtain polarization nonreturn to zero code;

Step 2: adopt N in three-dimensional complementary code _tthe polarization nonreturn to zero code that the two-dimentional mutual-complementing code of group obtains step 1 respectively carries out complementary spread spectrum, every group of corresponding data that obtain after the spread spectrum of M road of two dimension mutual-complementing code;

Step 3: the data after the every group of corresponding M road spread spectrum obtaining of two dimension mutual-complementing code obtaining in step 2 are adopted respectively to the different carrier wave in M road modulate, obtain M road modulation signal;

Step 4: respectively every group of M road modulation signal corresponding to two dimension mutual-complementing code obtaining in step 3 carried out to equal gain combining, obtain N _troad modulation signal, by described N _troad modulation signal passes through respectively N _ttransmit antennas is sent to wireless channel.

4. according to the communication means of the multicarrier MISO system based on three-dimensional complementary code described in claim 1,2 or 3, it is characterized in that, the receiving course of the receiver of MISO system is:

Step 5: pass through N by a reception antenna receiver/transmitter _tthe N of root antenna transmission _troad modulation signal, the signal that reception antenna receives is r (t), adopts N _tgroup band pass filter carries out filtering to the signal r (t) receiving respectively, obtains N _troad frequency is f ₁, f ₂..., f _mfiltering signal;

Step 6: step 5 Zhong Mei road filtering signal is the N of the three-dimensional complementary code corresponding with transmitting terminal respectively _torganize two-dimentional mutual-complementing code and carry out despreading, the signal after despreading adopts the carrier wave of respective frequencies to carry out demodulation again, obtains the signal after the demodulation of M road;

Step 7: the despread signal on the M road in step 6 is obtained every group is respectively a bit time T _bunder carry out integration, obtain the integration data of M road integral result;

Step 8: the M road integral result in the every group of integration data obtaining in step 7 is added, obtains a road and be added rear data, N _tgroup integration data obtains N altogether _tdata after road is added;

Step 9: the N that step 8 is obtained _tafter road is added, data are carried out equal gain combining, obtain a road and merge rear data;

Step 10: merge the initial data that rear data are adjudicated rear acquisition transmitting terminal transmission by obtaining Yi road in step 9.