CN102984734B - Home base station imaginary multi-input and multi-output user matching method - Google Patents

Abstract

The invention discloses a home base station imaginary multi-input and multi-output user matching method including step 10, a first round antenna choosing, adopting a polling method to choose an antenna of a user as a first transmitting antenna from N users of a home base station and adding the first transmitting antenna to a matching antenna group, step 20: an I round antenna choosing: choosing an antenna of a user which does not join in the matching antenna group to join the matching antenna group and minimizing the increase of average bit error rate of users in the matching antenna group, step 30: comparing the number of the antennas Nq in the matching antenna group with the number of receiving antennas NR, if NR is bigger, carrying out step 40, if not carrying out step 50, step 40: comparing a growth rate of the average bit error rate eta (I )with a rise control ratio eta c , if eta (I ) is less than or equal to eta c, returning to step 20 for a 2+p round antenna choosing, if not carrying step 50, step 50: completing matching. Bit error rate performance can be improved by the method.

Description

User's matching method of the virtual multiple-input and multiple-output of a kind of Home eNodeB

Technical field

The present invention relates to wireless communication receiver technical field, specifically, relate to user's matching method of the virtual multiple-input and multiple-output of a kind of Home eNodeB.

Background technology

According to investigations, the speech business more than 50% and the data service more than 70% occur in indoor environment, comprise family, office, coffee shop, shopping square etc.But due to the penetration loss of wall, macro base station network is difficult to the demand meeting indoor communications well.For addressing this problem, Home eNodeB (femtocell) technology has been arisen at the historic moment.Home eNodeB, also known as Femto cell, is called Home eNode B in Long Term Evolution (English full name is Long Term Evolution, is called for short LTE in literary composition) system, is called for short HeNB.Home eNodeB is a kind of compact low power base station, and coverage is 10-50m, is mainly used in solving in-door covering problem, has the features such as access is simple, low-power consumption, low cost.Home eNodeB is linked into the network of telecom operators by the wide band system such as Digital Subscriber Line or optical fiber.

The number of users of Home eNodeB support is 4 to 8.Virtual multiple-input and multiple-output (Virtual MIMO, Virtual Multiple Input Multiple Output) technology is adopted in the transmission of up link.Single antenna by multiple different user is combined, the same time transmits, (English full name is: Multiple Input Multiple Output to form virtual MIMO with many reception antennas of Home eNodeB, Chinese translation is: multiple-input and multiple-output, be called for short in literary composition: MIMO), just being equivalent to unique user at receiving terminal transmitting terminal, to be configured with multiple antennas the same, therefore be called virtual MIMO.Since virtual MIMO allows different user transmit simultaneously, the different systematic function that so different user's matching methods just can produce.Therefore, the marriage problem studying user in Home eNodeB is necessary.An excellent matching method, is very significantly improved making the performance of system.

Traditional simulated annealing method (SA, Simulated Annealing) is a kind of asymptotic optimality matching method.The process of pairing is divided into some wheel and carries out by it, and each is taken turns and selects an antenna, until negative growth appears in power system capacity according to the principle of maximize system capacity.User's pairing energy that this method is applied to macro base station obtains good performance of BER.But when Home eNodeB, because the antenna distance of Home eNodeB receiver is less, channel relevancy increases greatly, the performance of BER of SA method is caused to decline.

Summary of the invention

Technical problem: technical problem to be solved by this invention is: the user's matching method providing the virtual multiple-input and multiple-output of a kind of Home eNodeB, improves the performance of BER of user's pairing.

Technical scheme: for solving the problems of the technologies described above, user's matching method of the virtual multiple-input and multiple-output of a kind of Home eNodeB that the present invention adopts, the method comprises the following steps:

Step 10): the 1st takes turns a day line options: adopt polling method to choose the antenna of a user as the first transmit antennas in N number of user of Home eNodeB, adds in pairing antenna sets; N be more than or equal to 3 integer;

Step 20): i-th takes turns a day line options: take turns on the basis of day line options at i – 1, selects the antenna of a user to add pairing antenna sets, and make the growth of the average error bit rate of user in pairing antenna sets in the user not adding pairing antenna sets minimize; I represents that day which of line options is taken turns, i be more than or equal to 2 integer, the initial value of i is 2;

Step 30): more add the antenna number N in pairing antenna sets _qwith reception antenna number N _rsize, if N _q<N _r, then step 40 is performed); Otherwise perform step 50);

Step 40): compare the growth rate η (i) of average error bit rate and the control growth factor η of bit error rate _csize, if η (i)≤η _c, then return step 20), carry out 2+p and take turns the selection of antenna, p represent return step 20) number of times; Otherwise perform step 50);

Step 50): matched, in Home eNodeB notice pairing antenna sets, the antenna of all users sends data when next dispatching cycle starts simultaneously.

Beneficial effect: compared with prior art, the present invention has the following advantages:

1. improve the performance of BER of user's pairing.Method of the present invention combines the English full name of BER(: Bit Error Rate, and Chinese translation is: bit error rate, is called for short BER in literary composition) advantage of pairing and SA method.It ensure that each user has lower BER performance on the one hand; On the other hand, do not take in from total optimization, each takes turns pairing is all seek locally optimal solution on the basis of last round of pairing, thus obtains approximate total optimization solution with lower complexity.Matching method of the present invention is applicable to the channel circumstance of Home eNodeB, can improve the average error bit rate of user.

2. effectively prevent the performance of BER of user from sharply worsening.Step 40 in method of the present invention) in, by comparing the growth rate η (i) of average error bit rate and control growth factor η _csize, decide subsequent step.By arranging the size controlling growth factor, the growth rate of user's average error bit rate in pairing process can be controlled neatly, prevent the BER performance of user from sharply worsening.

Accompanying drawing explanation

Fig. 1 is flow chart of the present invention.

Fig. 2 is the bit error rate curve chart of method of the present invention compared with traditional simulated annealing method.

Embodiment

Below in conjunction with accompanying drawing, the solution of the present invention is described in detail.

As shown in Figure 1, user's matching method of the virtual multiple-input and multiple-output of a kind of Home eNodeB of the present invention, comprises the following steps:

Step 10): the 1st takes turns a day line options: adopt polling method to choose the antenna of a user as the first transmit antennas in N number of user of Home eNodeB, adds in pairing antenna sets; N be more than or equal to 3 integer.

In step 10), after selecting the first transmit antennas, an element in the order pairing vectorial Q of instruction (1) wherein, n ₁represent the sequence number choosing antenna.The number of users N of Home eNodeB is preferably 4 to 8.

Step 20): i-th takes turns a day line options: on the basis of i – 1 polling selecting antennas, selects the antenna of a user to add pairing antenna sets, and make the growth of the average error bit rate of user in pairing antenna sets in the user not adding pairing antenna sets minimize; I represents that day which of line options is taken turns, i be more than or equal to 2 integer, the initial value of i is 2.

In step 20) in, after finger i-th takes turns day line options, the growth of the average error bit rate that the average error bit rate of having matched user is taken turns relative to i – 1, i be more than or equal to 2 integer.After i-th polling selecting antennas, an element in the vectorial Q (i) of order pairing instruction wherein, n _irepresent the sequence number choosing antenna.

Step 30): more add the antenna number N in pairing antenna sets _qwith reception antenna number N _rsize, if N _q<N _r, then step 40 is performed); Otherwise perform step 50).

Step 40): compare the growth rate η (t) of average error bit rate and the control growth factor η of bit error rate _csize, if η (i)≤η _c, then return step 20), carry out 2+p and take turns the selection of antenna, p represent return step 20) number of times; Otherwise perform step 50).

In step (4), η (i) refer to i-th take turns day line options after, the growth rate that the average error bit rate of having matched user is taken turns relative to i – 1, η _cit is a constant.η _ccan change as required, limit the growth rate η (i) of average error bit rate.

Step 50): matched, in Home eNodeB notice pairing antenna sets, the antenna of all users sends data when next dispatching cycle starts simultaneously.

In step 50) in, after having matched, the optimal case that namely the vectorial Q (i) of pairing instruction matches, N _tnamely=i participates in the antenna sum matched.

Said method, according to the channel condition of each user, take bit error rate as target, and the method finding optimum pairing antenna sets can be expressed as follows:

$Q=\arg \underset{Q\&Element;B_n}{\min }\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}}=\arg \underset{Q\&Element;B_n}{\min }\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{q}_n\mathrm{\&Delta;}\stackrel{\&OverBar;}{{\mathrm{BER}}_n}---\left(1\right)$

And satisfy condition 1:

$\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{q}_n\&le;N_R,q_n\&Element;\left\{\mathrm{0,1}\right\}---\left(2\right)$

And condition 2:

η(i)≤η _c (3)

Wherein, Q is the pairing instruction vector of N × 1, and N is the total number of users amount in Home eNodeB; The n-th element q of Q _nmeet: if the antenna of nth user is selected as pairing, then q _n=1, otherwise, q _n=0; B _nit is the set of all possible instruction vector; N _rthe quantity of Home eNodeB reception antenna; η _cfor the growth control coefrficient of bit error rate; represent the change of user's average error bit rate in whole pairing process, it meets following formula:

$\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}}=\underset{i=2}{\overset{N_T}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}\left(i\right)}---\left(4\right)$

Wherein, N _twhen representing that pairing completes, participate in the antenna amount of pairing; represent i-th take turns and find pairing antenna terminates after, matched the change of antenna average error bit rate, as the formula (5); η (i) refer to i-th take turns day line options after, the growth rate that the average error bit rate of having matched user is taken turns relative to i – 1, as the formula (6);

$\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}\left(i\right)}=\stackrel{\&OverBar;}{\mathrm{BER}\left(i\right)}-\stackrel{\&OverBar;}{\mathrm{BER}(i-1)}---\left(5\right)$

$\mathrm{\&eta;}\left(i\right)=\frac{\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}\left(i\right)}}{\stackrel{\&OverBar;}{\mathrm{BER}(i-1)}}---\left(6\right)$

Wherein, represent i-th take turns and find pairing antenna completes after, matched the average error bit rate of antenna, as the formula (7):

$\stackrel{\&OverBar;}{\mathrm{BER}\left(i\right)}=\frac{1}{i}\underset{j=1}{\overset{i}{\mathrm{\&Sigma;}}}{\mathrm{BER}}_{n_j}\left(i\right)---\left(7\right)$

Wherein, after expression i-th is taken turns and found pairing antenna, in i the user matched, the bit error rate of a jth user.It meets formula (8):

${\mathrm{BER}}_{n_j}\left(i\right)=\frac{N_{\min }}{{\log }_2{M}_0}Q\left(\sqrt{\mathrm{\&xi;}\&CenterDot;{\mathrm{SINR}}_{n_j}\&CenterDot;G_c}\right)---\left(8\right)$

Wherein, N _minrepresent the mean value of the adjacent constellation point quantity of each constellation point in modulation figure; M ₀represent the number of constellation point in modulation figure; Q () represents Q function, and its formula is wherein, z represents integration variable; Coefficient ξ=3/ [R (M ₀-1)], R represents the chnnel coding code check of user; G _crepresent the channel coding gain of user; represent jth match user without inclined Signal to Interference plus Noise Ratio, be expressed as:

${\mathrm{SINR}}_{n_j}=\frac{{\mathrm{\&sigma;}}_{a_{n_j}}^2}{{\mathrm{\&sigma;}}_{e_{n_j}}^2}-1---\left(9\right)$

Wherein, it is the variance of the signal of a jth pairing user; be the variance of the error of a jth pairing user, meet formula (10):

${\mathrm{\&sigma;}}_{e_{n_j}}^2=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\mathrm{\&Sigma;}}_{n_j{n}_j}^2\left[m\right]---\left(10\right)$

Wherein, 1≤j≤i, 0≤m≤M – 1, M is number of subcarriers, intermediate variable meet formula (11):

$\left[\begin{array}{cccc}{\mathrm{\&Sigma;}}_{n_1{n}_1}^2\left[m\right]& {\mathrm{\&Sigma;}}_{n_1{n}_2}^2\left[m\right]& ...& {\mathrm{\&Sigma;}}_{n_1{n}_i}^2\left[m\right]\\ {\mathrm{\&Sigma;}}_{n_2{n}_1}^2\left[m\right]& {\mathrm{\&Sigma;}}_{n_2{n}_2}^2\left[m\right]& ...& {\mathrm{\&Sigma;}}_{n_2{n}_i}^2\left[m\right]\\ ...& ...& ...& ...\\ {\mathrm{\&Sigma;}}_{n_i{n}_1}^2\left[m\right]& {\mathrm{\&Sigma;}}_{n_i{n}_2}^2\left[m\right]& ...& {\mathrm{\&Sigma;}}_{n_i{n}_i}^2\left[m\right]\end{array}\right]={\mathrm{\&sigma;}}_n^2{\left(H^H\right[m\left]H\right[m]+\frac{{\mathrm{\&sigma;}}_n^2}{{\mathrm{\&sigma;}}_{a_{n_j}}^2}{I}_i)}^{-1}---\left(11\right)$

Wherein, H ^-κ[m] represents the conjugate transpose of H [m]; it is additive noise variance; I ₂represent i rank unit matrix; H [m] be i-th take turns in pairing participate in match the frequency domain channel matrix of user on subcarrier m, meet formula (12):

$H\left[m\right]=\left[\begin{array}{cccc}{H}_{n_{1}1}\left[m\right]& H_{n_{2}1}\left[m\right]& ...& H_{n_{i}1}\left[m\right]\\ H_{n_{1}2}\left[m\right]& H_{n_{2}2}\left[m\right]& ...& H_{n_{i}2}\left[m\right]\\ ..& ...& ...& ...\\ H_{n_1{N}_R}\left[m\right]& H_{n_2{N}_R}\left[m\right]& ...& H_{n_i{N}_R}\left[m\right]\end{array}\right]---\left(12\right)$

Wherein, represent on subcarrier m, the channel complex gain of jth between pairing antenna and r root reception antenna, 1≤j≤i, 1≤r≤N _r.

Exemplify an embodiment below, but protection scope of the present invention is not limited to described embodiment.

Embodiment 1:

8 user's mobile device UE are had in the simulating scenes of embodiment 1, and 1 Home eNodeB.Each UE configures an antenna, and Home eNodeB has two antennas.According to channel conditions, suitable pairing is carried out to UE antenna, form virtual MIMO with the antenna of family.UE in simulating scenes is set to the low mobility state of 1m/s.

Channel circumstance and the link parameter of emulation are as follows: channel adopts 7 footpath EPA models, and noise power gets-3dB, and the polarisation angles of reception antenna is (-45 °, 45 °).Subcarrier mapping mode is centralized, adopts conventional CP, containing 7 SC-FDMA symbols in each time slot.System bandwidth is 20MHz, and each reserved 1MHz in two ends is as protection bandwidth, and remaining 18MHz bandwidth assignment is to UE.LTE sub-carriers is spaced apart 15kHz, and each Resource Block comprises 12 subcarriers on frequency domain, therefore UE can be assigned to 100 Resource Block, i.e. the quantity M=1200 of subcarrier.IFFT after corresponding subcarrier maps counts, and be set to 2048 points, sample frequency is 30.72MHz.Maximum Doppler frequency offset is f _d=v × f _c/ c=6.67Hz, wherein the movement speed v of UE is 1m/s, carrier frequency f _cfor 2GHz, light velocity c is 3 × 10 ⁸m/s.Coded system is the Turbo code of code check R=1/3, and modulation system is QPSK.

Have 8 users in the simulating scenes of embodiment, therefore the pairing before pairing indicates vectorial Q (0)=[00000000], adopt the antenna of method choice the 1st user of poll as Q after transmitting antenna (1)=[10000000].

2nd takes turns selection pairing antenna, even an element in the pairing vectorial Q of instruction (2) choose antenna n ₂criterion be the growth making average error bit rate minimize.Obtained by formula (5) and formula (7): $\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}\left(2\right)}=\stackrel{\&OverBar;}{\mathrm{BER}\left(2\right)}-\stackrel{\&OverBar;}{\mathrm{BER}\left(1\right)}=\frac{1}{2}({\mathrm{BER}}_{n_1}\left(2\right)+{\mathrm{BER}}_{n_2}\left(2\right))-{\mathrm{BER}}_{n_1}\left(1\right).$ Obtained by formula (8): ${\mathrm{BER}}_{n_2}\left(2\right)=\frac{N_{\min }}{{\log }_2{M}_0}Q\left(\sqrt{\mathrm{\&xi;}\&CenterDot;{\mathrm{SINR}}_{n_2}\&CenterDot;G_c}\right).$ Wherein, N _min=2, M ₀=4, $\mathrm{\&xi;}=\frac{3}{R(M_0-1)}=3,$ G _c＝4.7dB。N ₂possible value be one of remaining 7 antennas, namely need calculate n ₂=2,3 ..., 7, each when 8 then must first obtain corresponding with n ₂=5 is example, formula (9): wherein can be obtained by formula (10) and formula (11), that is:

${\mathrm{\&sigma;}}_{e_5}^2=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\mathrm{\&Sigma;}}_{55}^2\left[m\right]$

$\left[\begin{array}{cc}{\mathrm{\&Sigma;}}_{11}^2\left[m\right]& {\mathrm{\&Sigma;}}_{15}^2\left[m\right]\\ {\mathrm{\&Sigma;}}_{51}^2\left[m\right]& {\mathrm{\&Sigma;}}_{55}^2\left[m\right]\end{array}\right]={\mathrm{\&sigma;}}_n^2{\left(H^H\right[m\left]H\right[m]+\frac{{\mathrm{\&sigma;}}_n^2}{{\mathrm{\&sigma;}}_{a_2}^2}{I}_2)}^{-1}$

Wherein, the frequency domain channel matrix on subcarrier m that forms for user 1 and user 5 of H [m].So just calculate n ₂=2,3 ..., 7, when 8, respectively corresponding value, in like manner calculates corresponding value and value, finally more corresponding value, choose the antenna n that minimum value is corresponding ₂the antenna of pairing is taken turns as the 2nd.Suppose that result the 2nd takes turns the antenna pair of the user 6 chosen, namely then the 2nd take turns pairing terminate after pairing indicate vectorial Q (2)=[10000100].

Then, the antenna number N having added pairing is judged _qwith reception antenna number N _rsize.Due to N _q=N _r=2, do not meet N _q<N _rcondition, therefore pairing terminate.The optimal case that pairing now indicates vectorial Q (2) namely to match, N _tnamely=2 participate in the antenna sum matched.Home eNodeB notifies that the user antenna of all selected pairings sends data when next dispatching cycle starts simultaneously.

As shown in Figure 2, emulated by Matlab, the performance of BER of traditional SA matching method and the SA matching method based on bit error rate of the present invention is contrasted.Transverse axis represents signal to noise ratio, and unit is decibel, and the longitudinal axis represents bit error rate.In Fig. 2, the lines with circle represent the simulation result of traditional SA matching method.Lines with del represent the simulation result of matching method of the present invention.Visible under each signal to noise ratio, the bit error rate of matching method of the present invention is starkly lower than the bit error rate of traditional SA matching method.Therefore, the performance of BER of method of the present invention is obviously better than traditional SA matching method.

The personage knowing this area will understand, although describe specific embodiment for the ease of explaining here, can make various change when not deviating from spirit and scope of the invention.Therefore, except as by the appended claims, can not be used for limiting the present invention.

Claims (2)

1. user's matching method of the virtual multiple-input and multiple-output of Home eNodeB, it is characterized in that, the method comprises the following steps:

Step 10): the 1st takes turns a day line options: adopt polling method in N number of user of Home eNodeB, to choose the antenna of a user as the first transmit antennas, adds in pairing antenna sets; N be more than or equal to 3 integer;

Step 20): i-th takes turns a day line options: take turns on the basis of day line options at i – 1, selects the antenna of a user to add pairing antenna sets, and make the growth of the average error bit rate of user in pairing antenna sets in the user not adding pairing antenna sets minimize; I represents that day which of line options is taken turns, i be more than or equal to 2 integer, the initial value of i is 2;

Step 30): more add the antenna number N in pairing antenna sets _qwith reception antenna number N _rsize, if N _q<N _r, then step 40 is performed); Otherwise perform step 50);

Step 40): compare the growth rate η (i) of average error bit rate and the control growth factor η of bit error rate _csize, if η (i)≤η _c, then return step 20), carry out 2+p and take turns the selection of antenna, p represent return step 20) number of times; Otherwise perform step 50);

Step 50): matched, in Home eNodeB notice pairing antenna sets, the antenna of all users sends data when next dispatching cycle starts simultaneously;

Described step 20) in, refer to i-th take turns day line options after, the average error bit rate of user of having matched takes turns the growth of average error bit rate of pairing user relative to i – 1,

In described step (40), η (i) refer to i-th take turns day line options after, the average error bit rate of user of having matched takes turns the growth rate of average error bit rate of pairing user relative to i – 1, η _cit is a constant.

2. user's matching method of the virtual multiple-input and multiple-output of Home eNodeB according to claim 1, is characterized in that, described N is 4 to 8.