CN106254036A - A kind of detection method being layered under supercomposed coding generalized spatial modulation system - Google Patents

Abstract

The present invention is claimed a kind of generalized space modulation (SCM GSM) system using layering supercomposed coding; belong to wireless communication technology field; by using hierarchical coding modulation (SCM) technology on constellation point; meet different service quality (QoS) requirement of different pieces of information business on same transmission time slot, meet the multiple business demand of following 5G system more flexibly.Constellation modulation principle based on SCM, receiving terminal proposes layered weighting (ILD) algorithm of a kind of iteration, the method effectively reduces the searching times of signal detection, and maximum likelihood (ML) detection of system bit error rate (BER) performance near-optimization.

Description

A kind of detection method being layered under supercomposed coding generalized spatial modulation system

Technical field

The invention belongs to wireless communication technology field, particularly relate to be layered superimposing technique in generalized spatial modulation system Application.

Background technology

Spatial modulation (Spatial Modulation, SM) is as the multi-antenna transmitting transmission scheme of a kind of novelty, originally Input bit is constituted a kind of mapping relations with launching antenna serial number, carries certain transmission information, and lead in radio communication Territory obtains and pays close attention to widely.But owing to traditional SM technology is all that it passes by activating transmission antenna transmission data Defeated speed is significantly lower than the space multiplexing technique in conventional MIMO system.In order to meet the demand of following two-forty, generalized space Modulation (Generalized Spatial Modulation, GSM) technology is proposed out.

As the extension of SM technology, the core concept of GSM scheme is, arbitrary delivery time activates many transmitting antennas and sends Bit information, a portion bit information is mapped on constellation modulation figure, and remaining bit is mapped to what antenna index number was constituted In space dimension.Compared to SM technology, GSM can improve spectrum efficiency further.GSM technology mainly has two kinds of different realities at present Execute scheme: the first scheme is single data stream transmission, and the most activation antennas transmit identical symbol；The second is many data Streaming scheme, the most activation antennas transmit different symbols.The former is a kind of diversity technique, can be used for lifting system Bit error rate (Bit Error Ratio, BER) performance, the latter is then the combination of spatial reuse and SM technology, it is possible to increase be The spectrum efficiency of system.So, GSM technology can well be compromised between spectrum efficiency and BER performance, with SM technology phase Ratio, has more preferable motility.

But in gsm system, the bit information that each activation antenna sends is by bit information by monolayer modulating mode It is mapped in equably on MPSK, or MQAM planisphere.Signaling point in these planispheres equal-probability distribution at equal intervals, from capacity From the perspective of optimization, this pattern is not optimum, limits systematic function to a certain extent.Meanwhile, coded modulation is logical Cross the extension of signal constellation (in digital modulation) figure and obtain more high transformation property, but in two-forty system, system decoding complexity is also a weight The Consideration wanted.Gsm system transmitting terminal uses the modulation of M system non-linear bit symbol, and receiving terminal uses best performance Maximum-likelihood algorithm (Maximum Likelihood, ML) carries out signal detection, and its system decoding complexity is Along with the increase of M, computation complexity is exponentially incremented by.Therefore, the modulation scheme at gsm system employing high-order is extremely difficult.

Within 1997, proposed a kind of new coded modulation scheme by Duan et al.: be layered supercomposed coding scheme (Superposition Coded Modulation, SCM) is due to its outstanding performance and cheap overhead, this skill Art is once proposing to be immediately exposed to the extensive concern of all circles.SCM technology greatly simplify the composition of available numeral, and owing to compiling Code process is linear, and the decoding complexity of receiving terminal also can be relatively low.Particularly needs transmit simultaneously data, voice, In the multimedia business transmission of video information, hierarchical coding can provide optimal resource allocation mode and the biography of optimum for system Defeated speed.As in mimo systems, different number can be provided according to the significance level of the information of transmission by hierarchical coding modulation According to transmission quality.Meanwhile, SCM technology can excavate the optimum utilization of system resource, and therefore it is as a kind of power save " green " encoding scheme of type, is just being widely used in each research field of wireless communication technology.

Along with going deep into of research, SCM technology is the most gradually applied to SM field, simultaneously the various detection algorithm of receiving terminal also by Propose, as linear minimum mean-squared error based on iteration (Linear minimum mean square error, LMMSE) detects And Sphere Decoding (Improved sphere decoding, the ISD) detection etc. improved.This linear modulating-coding structure, Meet the needs of following 5G system multiple business the most flexibly, and can effectively reduce receiving terminal by the decoded mode of layering Decoding complexity.But SCM technology is all based on SM system mostly at present, and SCM technology is applied to gsm system by the rarest research In；Especially, nobody relates to receiving terminal corresponding signal detection scheme especially.

Special instruction, the parameter of channel model is as follows: have N at one_tRoot launches antenna, N_rThe tradition of root reception antenna In GSM-MIMO system, it is assumed that delivery time activates N_aRoot antenna transmission modulation symbol, the most now system hasPlant and wait The antenna combination of choosing.And according to the bit mapping scheme of gsm system, the bit information of the input of transmitting terminal is divided into two parts, First bit demultiplexing is modulated in MPSK/MQAM constellation, and another bit is used for determining to select where to organize antenna combination, wherein N_cTable Show that bit maps required antenna combination number.Bit maps for convenience, will only need in gsm systemPlant sky Line combines, and remains N-N_cPlant antenna combination to be not used by.Existing ML Optimum Detection needs to carry out full search code book, its Detection complexity is high.

Summary of the invention

Present invention seek to address that above problem of the prior art.Propose one and effectively reduce system complexity, also Detection method under the layering supercomposed coding generalized spatial modulation system of good systematic function is provided.Technical scheme As follows:

A kind of detection method being layered under supercomposed coding generalized spatial modulation system, it comprises the following steps:

101, first SCM-GSM system is used at transmitting terminal, and by bit information waiting for transmission through serioparallel exchange Cheng Xing Seat point modulation and spatial modulation two parts, spatial index modulation is still for the combination selecting transmission antenna to index, but constellation point Modulating part will use SCM technology；

102, at receiving terminal, it is proposed that the layered weighting ILD algorithm of a kind of iteration, mainly by successively using interference to disappear Except method carries out signal interpretation.

Further, the channel model parameters that described SCM-GSM system transmitting terminal uses is: have N_tRoot launches antenna, N_r Root reception antenna, it is assumed that delivery time activates N_aRoot antenna transmission modulation symbol, the most now system hasPlant candidate's Antenna combination.The bit information of the input of transmitting terminal is divided into two parts, first bit demultiplexing to adjust in MPSK/MQAM constellation System, another bit is used for determining to select where to organize antenna combination, wherein N_cRepresent that bit maps required antenna combination number.

Further, the transmitting terminal constellation modulating part of described step 101 uses SCM technology to specifically include: by different QoS The bit information required is layered, and the bit information that qos requirement is high or priority is high carries out absolute coding modulation on upper strata, The information that qos requirement is low or priority is low carries out absolute coding modulation at low layer.

Further, bit information waiting for transmission is become constellation point modulation and space through serioparallel exchange by described step 101 Index modulation two parts, spatial index modulation is still for the combination selecting transmission antenna to index, but constellation point modulating part will Use SCM technology, specifically include:

The bit being used for constellation modulation on every activation antenna is passed through serioparallel exchange again, obtains L road bit information, wherein Each road bit information is equivalent to a modulating layer, and the information of each layer is encoded by identical encoder, and output sequence is c_i, c_i B is obtained after interleaver_i, and each layer of interleaving mode difference；Finally, b_iConstellation mapping is carried out by corresponding modulation system, To modulation symbol s_i, wherein i represents i-th layer；Line after finally the information of every activation antenna transmitting is weighted by each layer modulation symbol Property superposition,

$x^j=\underset{i=1}{\overset{L}{\Σ}}{\mathrm{\ρ}}_i^j{s}_i^j,(j=0,...,N_a)---\left(1\right)$

Wherein, wherein j represents that jth root activates antenna, and L is the number of plies, s_iIt is the symbol after modulation, ρ_iIt is i-th layer of weighting system Number, value is shown below

${\mathrm{\ρ}}_i=\frac{2^{L-l}}{\sqrt{{\mathrm{\Σ}}_{i=1}^L{\left(2^{i-1}\right)}^2}}---\left(2\right)$

Finally, through N_t×N_rDimension wireless channel Η transmission, and each element of Η obey variance be 1, average be 0 Multiple Gauss distribution, receive signal model can be expressed as

Y=Hx+n (3)

Y ∈ N in formula_rThe received signal vector of × 1, n ∈ N_r× 1, and average be 0, variance be δ²Multiple Gauss additivity white noise Sound vector,x∈N_t× 1, represent and send symbolic vector.

Further, the layered weighting ILD algorithm of described step 102 receiving terminal iteration specifically includes:

Assume kth (k < N_c) plant antenna combination be used to transmit modulation symbol, then Η can be equivalent to N_r×N_aThe channel of dimension Matrix Η_k, Η_kComprise and matrix Η activates the N that antenna is corresponding_aRow, can be reduced to so receiving signal model

$y=H_{k}x+n=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}{x}^j+n---\left(4\right)$

And bring into (1) launch obtain

$y=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}({\mathrm{\&rho;}}_1^j{x}_1^j+...+{\mathrm{\&rho;}}_i^j{x}_i^j+...+{\mathrm{\&rho;}}_L^j{x}_L^j)+n---\left(7\right)$

According to (2) formula, each layer weight coefficient meets ρ₁>…>ρ_l>…>ρ_L；

(7) formula is input in ground floor signal detector, carries out signal interpretation according to the detection criteria of (8) formula, obtain The modulation symbol collection of ground floor

$\begin{array}{c}(\hat{k},{\hat{s}}_1)=\arg \underset{k\&Element;I,s_1\&Element;S_1}{\min }\left|\right|y-H_k{s}_1|{|}_F^2\\ =\arg \underset{k\&Element;I,s_1\&Element;S_1}{\min }\left|\right|y-H_k{\mathrm{\&rho;}}_1{s}_1|{|}_F^2\end{array}---\left(8\right)$

Wherein I represents antenna index set, S₁Represent the modulation symbol vector set of ground floor；

Ground floor is detectedIt is brought in second layer detector, obtains according to (9) formula

${\hat{s}}_2=\arg \underset{\hat{k},s_2\&Element;S_2}{\min }\left|\right|y-H_{\hat{k}}({\mathrm{\&rho;}}_1{s}_1+{\mathrm{\&rho;}}_2{s}_2)|{|}_F^2---\left(9\right)$

Wherein the antenna index in (9) formula has determined as kth kind, S₂Represent the modulation symbol vector set of the second layer, CompriseIndividual element；

The just second layer detectsIt is brought in third layer detector, uses same principle to obtain with the second layer To the last detect last modulation symbol

${\hat{s}}_L=\arg \underset{\hat{k},s_L\&Element;S_L}{\min }\left|\right|y-H_{\hat{k}}({\mathrm{\&rho;}}_1{s}_1+...+{\mathrm{\&rho;}}_L{s}_L)|{|}_F^2---\left(10\right)$

S_LRepresent the modulation symbol vector set of L layer, comprise equallyIndividual element；The modulation that finally will obtain Symbolic vectorCarry out bit decoding.

Advantages of the present invention and having the beneficial effect that:

The present invention is at the gsm system of high-speed transfer, in order to meet the multiple business demand of following 5G system more neatly, SCM is applied to the constellation modulating part of GSM by this patent, devises a kind of new mimo system based on layering supercomposed coding Spatial modulation (SCM-GSM) system, the program, compared to traditional GSM technology, can meet the most of the same trade or business under same transmission time slot Different service quality (Quality of Service, the QoS) requirement of business.Meanwhile, receiving terminal has invented the detection of a kind of novelty Layered weighting (Iterative layered detection, the ILD) scheme of algorithm iteration, compared to the ML of best performance Detection, along with the increase of constellation order of modulation, receiving terminal decoding complexity is become linear increment, and IDL algorithm from exponential increasing BER performance approximation ML detection.Therefore, the detection scheme efficient balance of invention systematic function and complexity.

Accompanying drawing explanation

Fig. 1 is the planisphere that the present invention provides preferred embodiment two superimposed coded modulation principle.

Fig. 2 is based on SCM technology generalized spatial modulation system model.

The flow chart of Fig. 3 iteration layered weighting algorithm.

Fig. 4 be launch antenna number be 8, reception antenna is 8, activate antenna be 2, the number of plies is 2, and spectrum efficiency is 8bit/s/ Under Hz, the iteration layered weighting BER performance of different number of times and the comparison diagram of ML.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, detailed Carefully describe.Described embodiment is only a part of embodiment of the present invention.

Technical scheme is as follows:

First, in order to allow, reader is clearer understands the program, enters two basic conceptions used in the present invention here Row explanation.

(1) SCM technology: its core concept is to be layered by the bit information that different QoS requires, qos requirement high or The bit information that priority is high carries out absolute coding modulation on upper strata, and the information that qos requirement is low or priority is low is entered at low layer Row absolute coding is modulated.The constellation point diagram (4/16QAM) that accompanying drawing 1 is modulated for two layer encoding, carries out independent volume by two-layer QPSK Linear superposition after code modulation, is equivalent to 16QAM planisphere.

(2) SCM-GSM system: bit information waiting for transmission as shown in Figure 2, is first passed through string by transmitting terminal system block diagram And it being converted into constellation point modulation and spatial index modulates two parts, spatial index modulation is still for selecting transmission antenna to index Combination, but constellation point modulating part will use SCM technology.The bit of constellation modulation will be used for again by string on every activation antenna And change, obtaining L road bit information, each of which road bit information is equivalent to a modulating layer, and the information of each layer passes through phase Same encoder (Turbo coding/convolutional encoding) encodes, and output sequence is c_i, c_iB is obtained after interleaver_i, and each layer of friendship Knit mode different.Finally, b_iCarry out constellation mapping by corresponding modulation system (MPSK/MQAM), obtain modulation symbol s_i, wherein i Represent i-th layer.Linear superposition after finally the information of every activation antenna transmitting is weighted by each layer modulation symbol.

$x^j=\underset{i=1}{\overset{L}{\&Sigma;}}{\mathrm{\&rho;}}_i^j{s}_i^j,(j=0,...,N_a)---\left(1\right)$

Wherein, wherein j represents that jth root activates antenna, and L is the number of plies, s_iIt is the symbol after modulation, ρ_iIt is i-th layer of weighting system Number, value is shown below.

${\mathrm{\&rho;}}_i=\frac{2^{L-l}}{\sqrt{{\mathrm{\&Sigma;}}_{i=1}^L{\left(2^{i-1}\right)}^2}}---\left(2\right)$

Finally, through N_t×N_rDimension wireless channel Η transmission, and each element of Η obey variance be 1, average be 0 Multiple Gauss distribution, receive signal model can be expressed as

Y=Hx+n (3)

Y ∈ N in formula_rThe received signal vector of × 1, n ∈ N_r× 1, and average be 0, variance be δ²Multiple Gauss additivity white noise Sound vector,x∈N_t× 1, represent and send symbolic vector.

Assume kth (k < N_c) plant antenna combination be used to transmit modulation symbol, then Η can be equivalent to N_r×N_aThe channel of dimension Matrix Η_k, Η_kComprise and matrix Η activates the N that antenna is corresponding_aRow, can be reduced to so receiving signal model

$y=H_{k}x+n=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}{x}^j+n---\left(4\right)$

According to the reception signal model after simplifying, the ML detection algorithm of GSM-MIMO system can be to be written as form

$(\hat{k},\hat{s})=\arg \underset{k\&Element;I,s\&Element;S}{min}\left|\right|y-H_{k}s|{|}_F^2---\left(5\right)$

Wherein I represents antenna index set, and S represents all modulation symbol vector set, and the combination of sets of I with S containsIndividual element.Therefore, ML detection algorithm needs to carry outSecondary exhaustive search, it is clear that such detection scheme has There is the highest computation complexity.

The present invention utilizes the SCM technical advantage that the modulation of transmitting terminal constellation point uses, it is proposed that a kind of new signal detection is calculated Method, iteration layered weighting.Mainly by successively using interference elimination method to carry out signal interpretation, both effectively reduced system Complexity, also provides for good systematic function.As shown in Figure 3, the derivation of equation of specific algorithm is such as algorithm testing process block diagram Under.

Based on N above_tRoot launches antenna, N_rThe GSM-MIMO system model of root reception antenna, wherein N_aRoot antenna is swashed Apply flexibly in transmission modulation symbol.(1) formula above is substituted into (4) Shi Ke get.

$\begin{array}{c}y=H_{k}x+n=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}{x}^j+n\\ =\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}\left(\underset{i=1}{\overset{L}{\&Sigma;}}{\mathrm{\&rho;}}_i^j{x}_i^j\right)+n\end{array}---\left(6\right)$

(6) are launched, can obtain；

$y=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}({\mathrm{\&rho;}}_1^j{x}_1^j+...+{\mathrm{\&rho;}}_i^j{x}_i^j+...+{\mathrm{\&rho;}}_L^j{x}_L^j)+n---\left(7\right)$

According to (2) formula, each layer weight coefficient meets ρ₁>…>ρ_l>…>ρ_L.Therefore, the constellation mapping that ground floor is corresponding Point Euclidean distance is relatively big, the strongest capacity of resisting disturbance.

(7) formula is input in ground floor signal detector, carries out signal interpretation according to the detection criteria of (8) formula, obtain The modulation symbol collection of ground floor

$\begin{array}{c}(\hat{k},{\hat{s}}_1)=\arg \underset{k\&Element;I,s_1\&Element;S_1}{\min }\left|\right|y-H_k{s}_1|{|}_F^2\\ =\arg \underset{k\&Element;I,s_1\&Element;S_1}{\min }\left|\right|y-H_k{\mathrm{\&rho;}}_1{s}_1|{|}_F^2\end{array}---\left(8\right)$

Wherein I represents antenna index set, S₁Represent the modulation symbol vector set of ground floor.Especially, I and S₁Group Intersection containsIndividual element.Therefore, ground floor decoding needs are carried outSecondary search, relative to ML Poor search complexity greatly reduce.

Ground floor is detectedIt is brought in second layer detector, obtains according to (9) formula

${\hat{s}}_2=\arg \underset{\hat{k},s_2\&Element;S_2}{\min }\left|\right|y-H_{\hat{k}}({\mathrm{\&rho;}}_1{s}_1+{\mathrm{\&rho;}}_2{s}_2)|{|}_F^2---\left(9\right)$

Wherein the antenna index in (9) formula has determined as kth kind, S₂Represent the modulation symbol vector set of the second layer, CompriseIndividual element.Therefore, second layer decoding needs are carried outSecondary search.

The just second layer detectsIt is brought in third layer detector, uses same principle to obtain with the second layer To the last detect last modulation symbol

${\hat{s}}_L=\arg \underset{\hat{k},s_L\&Element;S_L}{\min }\left|\right|y-H_{\hat{k}}({\mathrm{\&rho;}}_1{s}_1+...+{\mathrm{\&rho;}}_L{s}_L)|{|}_F^2---\left(10\right)$

Antenna index in above formula has also determined that, S_LRepresent the modulation symbol vector set of L layer, comprise equallyIndividual element.Therefore, it is also desirable to carry outSecondary search.The modulation symbol vector that finally will obtainCarry out Bit decoding.

Decoding from ground floor to L layer, whole process needs to carry out altogetherSecondary search, Compared to ML'sSecondary poor search, the searching times of layered weighting is significantly reduced.Especially, along with order of modulation Increase, i.e. number of plies L increase, the searching times of layered weighting linearly increases.

In order to promote system BER performance further, it is contemplated that the search volume of the second layer to L layer is only adjusted with this layer of constellation The exponent number of system is relevant, activates antenna combination and is determined by ground floor.The present invention proposes a kind of layered weighting scheme based on iteration, For convenience of statement, definition ite is iteration factor, and algorithm concrete steps are expressed as follows:

(1) first carry out the glossary of symbols detection of ground floor according to formula (8), we choose ite candidate set intersection here,

(2) by first time iterationThe modulation symbol vector of candidate combinationsSubstitute into second layer decoder, according to Formula (9) above, (10) carry out second to the decoding of L layer, drawing the modulation symbol vector of correspondenceWith

(3) it is iterated, by second time iterationHybrid modulation symbolic vectorSubstitute into the second layer and L layer is translated Code device, repeats step (2), draws the modulation symbol vector of correspondenceWith

(4) until i-th te timeThe modulation symbol vector of combinationSubstitute into second layer decoder, repeat step (2) modulation symbol vector of correspondence, is drawnWith

(5) iterate to L layer every time, this modulation symbol collection corresponding to iteration can be obtained to sending according to formula (10) Minimum euclidean distance between signalEuclidean distance minimum is chosen in ite iteration, Corresponding modulation symbol vectorIt is exactly last required, then willCarry out corresponding bit decoding.

From above, iterations is the most, and system BER performance is the best.By theory analysis and Computer Simulation, iteration Number of times and activation antenna index collection N_cThere is relation with number of plies L, work as ite=N_cDuring L, the BER performance the most closely ML's of system Full search, whole iterative process needs to carry outSecondary search.Therefore, IDL detection altogether need into OKSecondary search, compared to ML'sSecondary search, the searching times of IDL decreases A lot, the BER performance approximation ML of its system.

Below in conjunction with accompanying drawing (table), the present invention done more detailed narration, in order to those skilled in the art is better understood from The present invention.Special instruction, description below is based on N_t=8, N_r=8, N_a=2 and the SCM-GSM of constellation point modulation employing L=2 System, spectrum efficiency η of this system=8bit/s/Hz.Now, system has N=28 kind antenna combination mode, and we choose it In 16 kinds, i.e. N_c=16.The constellation point modulation of two-layer all uses QSPK to modulate, and can obtain according to formula (2)The mapping table being modulated rear weight of ground floor is as shown in table 1.

Constellation mapping table after the weighting of table 1 ground floor

In like manner, the mapping table of second layer constellation modulation rear weight is as shown in table 2.

Constellation mapping table after the weighting of table 2 second layer

The modulation symbol vector collection combination of antenna index collection I and each layer will be activated.

Table 3 antenna index collection and modulation symbol combination table

According to above step (1) Suo Shu, first the signal y received is input in the detector of ground floor, now, As shown in Table 1, it would be desirable to doSecondary search, now we select the candidate combinations of 32 kinds of iteration Collection.Understand according to step (2), choose one group of candidate set intersection therein and be updated in second layer detector, we have determined that Activate the compound mode of antenna, so having only to activate antenna to 16 kinds of corresponding constellations modulation symbols of lower search corresponding Number.Understand with (4) according to step (3), remaining 31 kinds of iteration Candidate Sets are substituted in second layer detection with same principle, finally According to step (5), choose the modulation symbol vector that Euclidean distance is minimumCarry out bit decoding.

Therefore, whole iteration layered weighting process needs to carry out 768 (256+16 × 32) secondary search.ML detection is used to need Carry outSecondary search.Meanwhile, every time search needs to carry out 16 complex multiplications and once plural modulus Computing, and the computing that 16 plural numbers add.Explanation ILD detection algorithm for more adding system is substantially reduced computation complexity, and table 4 is united Real number needed for having counted each of which is taken advantage of and real addition number of times.Especially, a CM computing 4 real number methods of needs, one Secondary plural number adds 2 real adds of computing needs.As can be seen from the table, relative to ML algorithm, the complexity of ILD detection algorithm reduces 81.25%.

Table 4ILD algorithm and ML algorithm complex compare

Learn from Fig. 4, as ite=1, the BER performance of system substantially in the straight line of a level, when ite=16, During ite=20, the BER performance of system has and promotes significantly.Special ratio as ite=32, the ILD detection algorithm BER of proposition Can detect close to ML completely, but its computation complexity is well below ML algorithm.

The above embodiment is interpreted as being merely to illustrate the present invention rather than limiting the scope of the invention.? After the content of the record having read the present invention, the present invention can be made various changes or modifications by technical staff, and these equivalences become Change and modify and fall into the scope of the claims in the present invention equally.

Claims (5)

1. the detection method being layered under supercomposed coding generalized spatial modulation system, it is characterised in that comprise the following steps:

101, first use SCM-GSM system at transmitting terminal, and bit information waiting for transmission is become constellation point through serioparallel exchange Modulation and spatial modulation two parts, spatial modulation part is still for the combination selecting transmission antenna to index, but constellation point modulation Part will use SCM technology；

102, at receiving terminal, it is proposed that the layered weighting ILD algorithm of a kind of iteration, mainly by successively using interference elimination side Method carries out signal interpretation.

Detection method under layering supercomposed coding generalized spatial modulation system the most according to claim 1, it is characterised in that The channel model parameters that described SCM-GSM system transmitting terminal uses is: have N_tRoot launches antenna, N_rRoot reception antenna, it is assumed that send out The moment is sent to activate N_aRoot antenna transmission modulation symbol, the most now system hasPlant the antenna combination of candidate.Transmitting terminal The bit information of input is divided into two parts, first bit demultiplexing to modulate in MPSK/MQAM constellation, and another bit is used for certainly Determine where selection organizes antenna combination, wherein N_cRepresent that bit maps required antenna combination number.

Detection method under layering supercomposed coding generalized spatial modulation system the most according to claim 1 and 2, its feature exists In, the transmitting terminal constellation modulating part of described step 101 uses SCM technology to specifically include: bit information different QoS required Being layered, the bit information that qos requirement is high or priority is high carries out absolute coding modulation on upper strata, qos requirement low or The information that priority is low carries out absolute coding modulation at low layer.

Detection method under layering supercomposed coding generalized spatial modulation system the most according to claim 3, it is characterised in that Bit information waiting for transmission is become constellation point modulation and spatial modulation two parts through serioparallel exchange by described step 101, and space is adjusted System is still for the combination selecting transmission antenna to index, but constellation point modulating part will use SCM technology, specifically include:

The bit being used for constellation modulation on every activation antenna is passed through serioparallel exchange again, obtains L road bit information, each of which Road bit information is equivalent to a modulating layer, and the information of each layer is encoded by identical encoder, and output sequence is c_i, c_iPass through B is obtained after interleaver_i, and each layer of interleaving mode difference；Finally, b_iCarry out constellation mapping by corresponding modulation system, adjusted Symbol s processed_i, wherein i represents i-th layer；Finally the information of every activation antenna transmitting is linearly folded after being weighted by each layer modulation symbol Add,

$x^j=\underset{i=1}{\overset{L}{\&Sigma;}}{\mathrm{\&rho;}}_i^j{s}_i^j,(j=0,...,N_a)---\left(1\right)$

Wherein, wherein j represents that jth root activates antenna, and L is the number of plies, s_iIt is the symbol after modulation, ρ_iIt is i-th layer of weight coefficient, takes Value is shown below

${\mathrm{\&rho;}}_i=\frac{2^{L-l}}{\sqrt{{\&Sigma;}_{i=1}^L{\left(2^{i-1}\right)}^2}}---\left(2\right)$

Finally, through N_t×N_rThe wireless channel Η transmission of dimension, and each element of Η obey variance be 1, average be 0 answer Gauss distribution, receiving signal model can be expressed as

Y=Hx+n (3)

Y ∈ N in formula_rThe received signal vector of × 1, n ∈ N_r× 1, and average be 0, variance be δ²Multiple Gauss additive white noise to Amount,x∈N_t× 1, represent and send symbolic vector.

Detection method under layering supercomposed coding generalized spatial modulation system the most according to claim 4, it is characterised in that The layered weighting ILD algorithm of described step 102 receiving terminal iteration specifically includes:

Assume kth (k < N_c) plant antenna combination be used to transmit modulation symbol, then Η can be equivalent to N_r×N_aThe channel matrix of dimension Η_k, Η_kComprise and matrix Η activates the N that antenna is corresponding_aRow, can be reduced to so receiving signal model

$y=H_{k}x+n=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}{x}^j+n---\left(4\right)$

And bring into (1) launch obtain

$y=\underset{j=1}{\overset{N_a}{\&Sigma;}}{h}_{k,j}({\mathrm{\&rho;}}_1^j{x}_1^j+...+{\mathrm{\&rho;}}_i^j{x}_i^j+...+{\mathrm{\&rho;}}_L^j{x}_L^j)+n---\left(7\right)$

According to (2) formula, each layer weight coefficient meets ρ₁>…>ρ_l>…>ρ_L；

(7) formula is input in ground floor signal detector, carries out signal interpretation according to the detection criteria of (8) formula, obtain first The modulation symbol collection of layer

$\begin{array}{c}(\hat{k},{\hat{s}}_1)=\arg \underset{k\&Element;I,s_1\&Element;S_1}{\min }\left|\right|y-H_k{s}_1|{|}_F^2\\ =\arg \underset{k\&Element;I,s_1\&Element;S_1}{\min }\left|\right|y-H_k{\mathrm{\&rho;}}_1{s}_1|{|}_F^2\end{array}---\left(8\right)$

Wherein I represents antenna index set, S₁Represent the modulation symbol vector set of ground floor；

Ground floor is detectedIt is brought in second layer detector, obtains according to (9) formula

${\hat{s}}_2=\arg \underset{\hat{k},s_2\&Element;S_2}{\min }\left|\right|y-H_{\hat{k}}({\mathrm{\&rho;}}_1{s}_1+{\mathrm{\&rho;}}_2{s}_2)|{|}_F^2---\left(9\right)$

Wherein the antenna index in (9) formula has determined as kth kind, S₂Represent the modulation symbol vector set of the second layer, compriseIndividual element；

The just second layer detectsIt is brought in third layer detector, uses same principle to obtain with the second layerUntil Finally detect last modulation symbol

${\hat{s}}_L=\arg \underset{\hat{k},s_L\&Element;S_L}{\min }\left|\right|y-H_{\hat{k}}({\mathrm{\&rho;}}_1{s}_1+...+{\mathrm{\&rho;}}_L{s}_L)|{|}_F^2---\left(10\right)$

S_LRepresent the modulation symbol vector set of L layer, comprise equallyIndividual element；The modulation symbol that finally will obtain VectorCarry out bit decoding.