CN1859032A - Antenna subset selecting method based on orthogonal component - Google Patents

Abstract

This invention relates to a method for selecting antenna subsets based on orthogonal components, which selects few antennas making the volume of chanels the largest from multiple receiving antennas and connects them to the RF link for communication, at the beginning of the communication, the emission end transmits training sequences and the receiving end can test the state information of all channels by them and we can compute the optimum combination of the receive antennas based on the orthogonality among vectors of each line of channel matrix.

Description

A kind of antenna subset system of selection based on quadrature component

One, technical field

The present invention relates to a kind of reception antenna system of selection that is used under multiple-input and multiple-output (MIMO) system, specifically a kind of antenna subset system of selection based on quadrature component.

Two, technical background

It line options technology is to simplify the main means of complicated multiaerial system, is the focus that antenna system is used and studied.Compare with a single aerial system, multiple-input and multiple-output (MIMO) system also makes the wireless channel capacity be greatly improved in opposing in the multipath fading, and this impels people that mimo system is carried out extensively and profoundly research.Though use many antennas to improve systematic function greatly, owing to need a large amount of expensive radio frequency (RF) circuit, thereby cause the realization cost of system too high and complexity is too big.For improving systematic function to greatest extent and reducing the hardware cost of system and the complexity of system, can use day line options technology is the limited a large amount of antenna of radio circuit assembling, therefrom choose one group of antenna of channel capacity maximum is transmitted and received, the specific implementation process is seen Fig. 1.

Antenna selecting method in the mimo system has carried out a large amount of research.Wherein optimal selection mode is exactly to select the combination that can make the channel capacity maximum from all possible combination of antennas.Yet this method need be carried out when selecting each time

Inferior computing when the antenna number is very big, will can't reach real-time signal processing too greatly because of amount of calculation.Therefore, people have proposed the antenna selecting method of the low suboptimum of series of computation complexity.The simplest antenna selecting method that is based on channel capable vector mould value (NBS) in these antenna system of selection, it is that the row of selecting mould value maximum from all row of channel matrix is formed new channel submatrix.Though the NBS method is calculated simple, performance is unsatisfactory.So poplar-Se Ke Joy (Yang-Seok Choi) and An Deruo Abbortsford gross profit generation (A.F.Molisch) have proposed the fast selecting method of a class based on correlation between each row of channel matrix, it selects two row of correlation maximum from channel matrix, cast out the wherein less row of mould value then.This step is sustained up to N _R-n _RRow is removed.Can obtain the channel submatrix of each row mould value maximum and each line-to-line correlation minimum by this method.Yet this method need be calculated the correlation between all row, and amount of calculation is bigger, and to compare system capacity loss bigger with best practice.Recently, the week-Se Ke Parker (Joo-Seok Park) and all Parkers (Dong-JoPark) proposed a kind of fast selecting method based on irrelevance between mould value and the capable vector of channel, and computation complexity is further reduced, and performance also is greatly improved.Under special circumstances, for example when selecting two antennas at receiving terminal, this method has almost obtained the power system capacity that the optimal selection method can reach; When but elected selecting antennas number further increased, still there was bigger capacitance loss in this method.

Three, summary of the invention

At the defective of prior art, the invention provides a kind of antenna subset system of selection based on quadrature component.

As shown in Figure 2, get two row vectors arbitrarily from the channel matrix H that receiving terminal records, be expressed as h1, h2, the vectorial h1 that wherein goes can be decomposed into the parallel component with respect to h2

And quadrature component h1 _H2 ^⊥, promptly

If correlation is more little between h1, h2 two row vectors, then component The mould value just more little, h1 _H2 ^⊥The mould value big more, promptly two vectors are tending towards quadrature more.

In like manner, from remaining capable vector, get delegation's vector arbitrarily and be designated as h3, when the correlation of the 3rd the vectorial h3 of row and preceding two row vectorial h1, h2 more hour, h3 is tending towards perpendicular to h1 more simultaneously also perpendicular to h2, promptly be tending towards the vector space formed perpendicular to h1, h2 more, then h3 is with respect to the quadrature component h3 of h1 and h2 _H1 ^⊥With h3 _H2 ^⊥And amplitude big more.In like manner can know the situation of multidirectional amount by inference.

The pairing reception antenna of delegation of selecting channel mould value maximum in the channel matrix that receiving terminal records is article one reception antenna, calculate then the antenna that the capable vector of the channel of all the other antenna correspondences selected relatively the capable vector of channel quadrature component and the mould value, get the new antenna that adds of maximum conduct, carry out successively, up to the identical end of selecting with the rf chain way of antenna number, concrete system of selection is:

(1) antenna subset is from empty set, selects to meet desired antenna and add in the antenna subset from non-selected antenna at every turn.

(2) method of employing cycle calculations, the result of previous calculations gained is all used in each selection, simplifies amount of calculation.

(3) adopt the method for channel mould value maximum when selecting article one reception antenna, calculate the mould value of the capable vector of channel of all reception antenna correspondences, the antenna of selecting mould value maximum wherein is as article one reception antenna.

(4) line options is a choice criteria with each row of channel quadrature component between vector other day, the capable vector of channel that calculates earlier every non-selected antenna correspondence has respectively been selected quadrature component between the capable vector of antenna channel with respect to each, with elder generation's addition of its quadrature component and then delivery value, with the size of mould value standard as the antenna of selecting to be fit to.

The present invention can be used in current 3G and the B3G communication system choice criteria to a small amount of radio circuit of a large amount of antenna assignment.

Four, description of drawings

Fig. 1 is a system architecture diagram of the present invention.

Fig. 2 is the graph of a relation between vector of the present invention.

Fig. 3 is different n _RThe time the interruption capacity, N _T=3, N _R=8, SNR=20dB interrupts the volumetric properties curve during 10% interruption rate.

Fig. 4 is N _T=2, N _R=8, n _R=N _TCumulative distribution function and system break capacity relationship curve when reaching SNR=20dB.

Fig. 5 is N _T=3, N _R=8, n _R=N _TCumulative distribution function and system break capacity relationship curve when reaching SNR=20dB.

Fig. 6 is N _T=2, N _R=8, n _R=N _T, 10% interruption rate, the system break volumetric properties relation curve during different signal to noise ratio.

Fig. 7 is N _T=3, N _R=8, n _R=N _T, 10% interruption rate, the system break volumetric properties relation curve during different signal to noise ratio.

Wherein, 1, signal processing and coding unit, 2, radio frequency link, the radio frequency commutation circuit of 3, distributing radio frequency link for reception antenna, 4, signal processing and decoding unit, 5, the input of transmission signals, 6, selected antenna subset receives and processing signals after output.Interruption rate represents not reach the probability of certain channel capacity grade; The interruption capacities chart is shown in the channel capacity under certain interruption rate.

Five, embodiment

Embodiment:

A kind of antenna subset system of selection based on quadrature component, the pairing reception antenna of delegation of selecting channel mould value maximum in the channel matrix that receiving terminal records is article one reception antenna, calculate then the antenna that the capable vector of the channel of all the other antenna correspondences selected relatively the capable vector of channel quadrature component and the mould value, get the new antenna that adds of maximum conduct, carry out successively, up to the identical end of selecting with the rf chain way of antenna number, concrete system of selection is:

(1) antenna subset is from empty set, selects to meet desired antenna and add in the antenna subset from non-selected antenna at every turn.

(2) method of employing cycle calculations, the result of previous calculations gained is all used in each selection, simplifies amount of calculation.

(3) adopt the method for channel mould value maximum when selecting article one reception antenna, calculate the mould value of the capable vector of channel of all reception antenna correspondences, the antenna of selecting mould value maximum wherein is as article one reception antenna.

(4) line options is a choice criteria with each row of channel quadrature component between vector other day, the capable vector of channel that calculates earlier every non-selected antenna correspondence has respectively been selected quadrature component between the capable vector of antenna channel with respect to each, with elder generation's addition of its quadrature component and then delivery value, with the size of mould value standard as the antenna of selecting to be fit to.

Wherein,

1) channel vector h _kFor the k in the channel matrix H is capable, wherein k be S set=1,2 ..., N _RIn certain element.Order set K is an empty set.

2) choose the capable h of mould value maximum among the H _{K (1)}, k (1) is removed from the S set, add among the set K.

3) in other step of this method, get pairing each the row h of S set _j(j ∈ S), calculate it with respect to the set K corresponding to each the row quadrature component and ${\mathrm{\α}}_j=\underset{k\left(i\right)\∈K}{\mathrm{\Σ}}(h_j-\frac{\⟨h_j,h_{k\left(i\right)}\⟩}{{\left|\right|h_{k\left(i\right)}\left|\right|}^2}{h}_{k\left(i\right)}),$ Wherein＜h _j, h _{K (i)}

Be vectorial h _jAnd h _{K (i)}Inner product.All (j ∈ S) are got and make α _jThe capable h of mould value maximum _j, it is removed in S set, add among the set K.Continue this circulation, the element number in set K is n _RTill individual.

By the performance of emulation experiment checking the method for the invention, we have provided the optimal selection algorithm simultaneously, based on the selection algorithm of mould value, based on relevant selection algorithm, based on the selection algorithm of mould value and irrelevance and the performance curve of stochastic selection algorithm.The hypothesis channel is the flat rayleigh fading channel of quasistatic in the emulation.

That Fig. 3 provides is different choice number of antennas n _RUnder interruption capacity (outage capacity) performance curve, suppose N _T=3, N _R=8, SNR=20dB, and 10% interruption rate.Work as n _R≤ 2 o'clock, new algorithm proposed by the invention was all obtained the interruption capacity of near optimal with best based on the algorithm performance of mould value and irrelevance, but works as n _RThe new algorithm of this paper proposition in＞2 o'clock is better than the algorithm performance based on mould value and irrelevance.

That Fig. 4 describes is N _T=2, N _R=8, n _R=N _T, the cumulative distribution function under the SNR=20dB and the relation of power system capacity.Can see, work as n _R=N _T=2 o'clock, along with reducing of interruption rate, new algorithm with based on the algorithm capacity of mould value and irrelevance all near optimal selection, be much better than performance simultaneously based on the algorithm and the stochastic selection algorithm of mould value.Fig. 5 is that Fig. 4 is at n _R=N _TPerformance under=3 situations compares, and as can be seen, when elected selecting antennas number increased, the performance of new algorithm was near the optimal selection algorithm always.And other algorithm is bigger with the increase channel capacity loss of number of transmit antennas.

The system break volumetric properties that Fig. 6 has provided under the different signal to noise ratio (snr)s compares, and supposes N _T=2, N _R=8, n _R=N _T, 10% interruption rate, Fig. 7 are that Fig. 6 is at n _R=N _TPerformance curve under=3.As can be seen, with the increase of SNR, the channel capacity of new algorithm approaches optimum always, works as n _R=N _T=3 o'clock, new algorithm was compared with other algorithms, and performance advantage is along with the increase of signal to noise ratio becomes more and more obvious.

Claims (1)

1, a kind of antenna subset system of selection based on quadrature component, it is characterized in that, the pairing reception antenna of delegation of selecting channel mould value maximum in the channel matrix that receiving terminal records is article one reception antenna, calculate then the antenna that the capable vector of the channel of all the other antenna correspondences selected relatively the capable vector of channel quadrature component and the mould value, get the new antenna that adds of maximum conduct, carry out successively, up to the identical end of selecting with the rf chain way of antenna number, concrete system of selection is:

(1) antenna subset is from empty set, selects to meet desired antenna and add in the antenna subset from non-selected antenna at every turn;

(2) method of employing cycle calculations, the result of previous calculations gained is all used in each selection, simplifies amount of calculation;

(3) adopt the method for channel mould value maximum when selecting article one reception antenna, calculate the mould value of the capable vector of channel of all reception antenna correspondences, the antenna of selecting mould value maximum wherein is as article one reception antenna;

(4) line options is a choice criteria with each row of channel quadrature component between vector other day, the capable vector of channel that calculates earlier every non-selected antenna correspondence has respectively been selected quadrature component between the capable vector of antenna channel with respect to each, with elder generation's addition of its quadrature component and then delivery value, with the size of mould value standard as the antenna of selecting to be fit to.

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