CN102984734A - 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 radio communication reception technique 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, surpass 50% speech business and surpass 70% data service and occur in the indoor environment, comprise family, office, coffee shop, shopping square etc.But because the penetration loss of wall, the macro base station network is difficult to satisfy well the demand of indoor communications.For addressing this problem, Home eNodeB (femtocell) technology has been arisen at the historic moment.Home eNodeB claims again Femto cell, is called Home eNode B in Long Term Evolution (English full name is Long Term Evolution, is called for short LTE in the 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 indoor covering problem, has the characteristics such as access is simple, low-power consumption, low cost.Home eNodeB is linked into the network of telecom operators by broadband modes such as Digital Subscriber Line or optical fiber.

The number of users of Home eNodeB support is 4 to 8.Adopt virtual multiple-input and multiple-output (Virtual MIMO, Virtual Multiple Input Multiple Output) technology in the transmission of up link.The single antenna that is about to a plurality of different users is combined, the same time transmits, (English full name is: Multiple Input Multiple Output to consist of virtual MIMOs with many reception antennas of Home eNodeB, the Chinese translation is: multiple-input and multiple-output, be called for short in the literary composition: MIMO), just being equivalent to unique user at the receiving terminal transmitting terminal, to dispose many antennas the same, so be called virtual MIMO.Since virtual MIMO is to allow different user transmit simultaneously, the different systematic function that so different user's matching methods just can produce.Therefore, user's marriage problem is necessary in the research Home eNodeB.A good matching method will be very significantly improved the performance of system.

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

Summary of the invention

Technical problem: technical problem to be solved by this invention is: user's matching method of the virtual multiple-input and multiple-output of a kind of Home eNodeB is provided, 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 may further comprise the steps:

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

Step 20): i wheel day line options: take turns at i – 1 on the basis of day line options, in the user who does not add the pairing antenna sets, select a user's antenna to add the pairing antenna sets, and make the growth of user's average error bit rate in the pairing antenna sets

Minimize; I represents that day which of line options take turns, and i is the integer more than or equal to 2, and the initial value of i is 2;

Step 30): more added the antenna number N in the pairing antenna sets _qCount N with reception antenna _RSize, if N _q＜N _R, then execution in step 40); Otherwise execution in 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 the selection of 2+p wheel antenna, p represents to return step 20) number of times; Otherwise execution in step 50);

Step 50): pairing is finished, and all users' antenna sends data simultaneously in the Home eNodeB notice pairing antenna sets when begin next dispatching cycle.

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

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

2. the performance of BER that effectively prevents the user sharply worsens.Step 40 in method of the present invention) in, by growth rate η (i) and the control growth factor η that compares average error bit rate _cSize, decide subsequent step.By the size of control growth factor is set, can control neatly the growth rate of user's average error bit rate in the pairing process, prevent that user's BER performance from sharply worsening.

Description of drawings

Fig. 1 is flow chart of the present invention.

Fig. 2 is the bit error rate curve chart that method of the present invention is 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 may further comprise the steps:

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

In step 10), select the first transmit antennas after, an element among the vectorial Q of order pairing indication (1)

Wherein, n ₁The sequence number of antenna is chosen in expression.The number of users N of Home eNodeB is preferably 4 to 8.

Step 20): i wheel day line options: on the basis of i – 1 polling selecting antennas, in the user who does not add the pairing antenna sets, select a user's antenna to add the pairing antenna sets, and make the growth of user's average error bit rate in the pairing antenna sets

Minimize; I represents that day which of line options take turns, and i is the integer more than or equal to 2, and the initial value of i is 2.

In step 20) in,

After referring to i wheel day line options, the growth of the average error bit rate that the average error bit rate of having matched the user is taken turns with respect to i – 1,

I is the integer more than or equal to 2.Behind the i polling selecting antennas, an element among the order pairing vectorial Q of indication (i)

Wherein, n _iThe sequence number of antenna is chosen in expression.

Step 30): more added the antenna number N in the pairing antenna sets _qCount N with reception antenna _RSize, if N _q＜N _R, then execution in step 40); Otherwise execution in 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 the selection of 2+p wheel antenna, p represents to return step 20) number of times; Otherwise execution in step 50).

In step (4), after η (i) refers to i wheel day line options, the growth rate that user's the average error bit rate of having matched is taken turns with respect 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): pairing is finished, and all users' antenna sends data simultaneously in the Home eNodeB notice pairing antenna sets when begin next dispatching cycle.

In step 50) in, after pairing is finished, the optimal case that the pairing vectorial Q of indication (i) namely matches, N _TThe antenna sum that=i namely participates in matching.

Said method is according to each user's channel condition, and take bit error rate as target, the method for seeking optimum pairing antenna sets can be expressed as follows:

$Q=\arg \underset{Q\∈B_n}{\min }\mathrm{\Δ}\stackrel{\‾}{\mathrm{BER}}=\arg \underset{Q\∈B_n}{\min }\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{q}_n\mathrm{\Δ}\stackrel{\‾}{{\mathrm{BER}}_n}---\left(1\right)$

And satisfy condition 1:

$\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{q}_n\≤N_R,q_n\∈\left\{\mathrm{0,1}\right\}---\left(2\right)$

And condition 2:

η(i)≤η _c (3)

Wherein, Q is the pairing indication vector of N * 1, and N is the total number of users amount in the Home eNodeB; N the element q of Q _nSatisfy: if nth user's antenna is selected as pairing, q then _n=1, otherwise, q _n=0; B _nIt is the set of all possible indication vector; N _RThe quantity of Home eNodeB reception antenna; η _cGrowth control coefrficient for bit error rate;

Represent the variation of user's average error bit rate in the whole pairing process, it satisfies following formula:

$\mathrm{\Δ}\stackrel{\‾}{\mathrm{BER}}=\underset{i=2}{\overset{N_T}{\mathrm{\Σ}}}\mathrm{\Δ}\stackrel{\‾}{\mathrm{BER}\left(i\right)}---\left(4\right)$

Wherein, N _TWhen the expression pairing is finished, participate in the antenna amount of pairing;

After representing that i wheel is sought the pairing antenna and finished, matched the variation of antenna average error bit rate, as the formula (5); After η (i) refers to i wheel day line options, the growth rate that user's the average error bit rate of having matched is taken turns with respect to i – 1, as the formula (6);

$\mathrm{\Δ}\stackrel{\‾}{\mathrm{BER}\left(i\right)}=\stackrel{\‾}{\mathrm{BER}\left(i\right)}-\stackrel{\‾}{\mathrm{BER}(i-1)}---\left(5\right)$

$\mathrm{\η}\left(i\right)=\frac{\mathrm{\Δ}\stackrel{\‾}{\mathrm{BER}\left(i\right)}}{\stackrel{\‾}{\mathrm{BER}(i-1)}}---\left(6\right)$

Wherein,

After representing that i wheel searching pairing antenna is finished, the average error bit rate of having matched antenna, as the formula (7):

$\stackrel{\‾}{\mathrm{BER}\left(i\right)}=\frac{1}{i}\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{\mathrm{BER}}_{n_j}\left(i\right)---\left(7\right)$

Wherein,

After representing that the i wheel is sought the pairing antenna, among the i that has the matched user, j user's bit error rate.It satisfies formula (8):

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

Wherein, N _MinThe mean value of the adjacent constellation point quantity of each constellation point among the expression modulation figure; M ₀The number of constellation point among the expression modulation figure; Q () expression Q function, its formula is

Wherein, z represents integration variable; Coefficient ξ=3/[R (M ₀-1)], R represents user's chnnel coding code check; G _cExpression user's channel coding gain;

Represent j the pairing user without inclined to one side Signal to Interference plus Noise Ratio, Be expressed as:

${\mathrm{SINR}}_{n_j}=\frac{{\mathrm{\&sigma;}}_{a_{{\mathrm{<figure-callout\; id="2"\; label="n\; j"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}_j}}^2}{{\mathrm{\&sigma;}}_{e_{n_j}}^2}-1---\left(9\right)$

Wherein,

It is the variance of j pairing user's signal;

Be the variance of j pairing user's error, satisfy formula (10):

${\mathrm{\&sigma;}}_{{\mathrm{<figure-callout\; id="2"\; label="e\; n\; j"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">e</figure-callout>}}_{n_j}}^2=\frac{1}{M}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{\mathrm{\&Sigma;}}_{n_j{n}_j}^2\left[m\right]---\left(10\right)$

Wherein, 1≤j≤i, 0≤m≤M – 1, M are number of subcarriers, intermediate variable

Satisfy formula (11):

$\left[\begin{array}{cccc}{\mathrm{\&Sigma;}}_{n_1{n}_1}^2\left[m\right]& {\mathrm{\&Sigma;}}_{n_1{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}_2}^2\left[m\right]& ...& {\mathrm{\&Sigma;}}_{n_1{n}_i}^2\left[m\right]\\ {\mathrm{\&Sigma;}}_{n_2{n}_1}^2\left[m\right]& {\mathrm{\&Sigma;}}_{n_2{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}_2}^2\left[m\right]& ...& {\mathrm{\&Sigma;}}_{n_2{n}_i}^2\left[m\right]\\ ...& ...& ...& ...\\ {\mathrm{\&Sigma;}}_{n_i{n}_1}^2\left[m\right]& {\mathrm{\&Sigma;}}_{n_i{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}_2}^2\left[m\right]& ...& {\mathrm{\&Sigma;}}_{n_i{n}_i}^2\left[m\right]\end{array}\right]={\mathrm{\&sigma;}}_n^2{\left(H^H\right[m\left]H\right[m]+\frac{{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}{{\mathrm{\&sigma;}}_{a_{n_j}}^2}{I}_i)}^{-1}---\left(11\right)$

Wherein, H ^-κ[m] represents H[m] conjugate transpose;

It is the additive noise variance; I ₂Expression i rank unit matrix; H[m] be the frequency domain channel matrix of user on subcarrier m that participates in pairing in the pairing of i wheel, satisfy formula (12):

$H\left[m\right]=\left[\begin{array}{cccc}{H}_{n_{1}1}\left[m\right]& H_{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2}1}\left[m\right]& ...& H_{n_{i}1}\left[m\right]\\ H_{n_{1}2}\left[m\right]& {\mathrm{<figure-callout\; id="2"\; label="H\; n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">H</figure-callout>}}_{n_{}}\left[m\right]& ...& H_{n_{i}2}\left[m\right]\\ ..& ...& ...& ...\\ H_{n_1{N}_R}\left[m\right]& H_{n_2{N}_R}\left[m\right]& ...& H_{n_i{N}_R}\left[m\right]\end{array}\right]---\left(12\right)$

Wherein,

Be illustrated on the subcarrier m channel complex gain between j pairing antenna and the r root reception antenna, 1≤j≤i, 1≤r≤N _R

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

Embodiment 1:

8 user's mobile device UE are arranged in the simulating scenes of embodiment 1, and 1 Home eNodeB.Antenna of each UE configuration, Home eNodeB has two antennas.According to channel conditions the UE antenna is carried out suitable pairing, with the antenna formation virtual MIMO of family.UE in the simulating scenes is set to the low speed mobile status of 1m/s.

Channel circumstance and the link parameter of emulation are as follows: channel adopts 7 footpath EPA models, and noise power is got-3dB, and the polarization angle of reception antenna is (45 °, 45 °).The subcarrier mapping mode is centralized, adopts conventional CP, contains 7 SC-FDMA symbols in each time slot.System bandwidth is 20MHz, and 1MHz is respectively reserved as the protection bandwidth in two ends, and remaining 18MHz bandwidth assignment is to UE.The LTE sub-carriers is spaced apart 15kHz, and each Resource Block comprises 12 subcarriers at frequency domain, so UE can be assigned to 100 Resource Block, i.e. the quantity M=1200 of subcarrier.IFFT after the corresponding subcarrier mapping counts and then is set to 2048 points, and 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 _cBe 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.

8 users are arranged in the simulating scenes of embodiment, so vectorial Q (0)=[00000000] is indicated in the pairing before the pairing, adopt antenna that the method for poll selects the 1st user as transmitting antenna after Q (1)=[10000000].

The 2nd takes turns selection pairing antenna, even an element among the pairing vectorial Q of indication (2) Choose antenna n ₂Criterion be the growth that makes average error bit rate

Minimize.Got by formula (5) and formula (7): $\mathrm{\&Delta;}\stackrel{\&OverBar;}{\mathrm{BER}\left(2\right)}=\stackrel{\&OverBar;}{\mathrm{BER}\left(2\right)}-\stackrel{\&OverBar;}{\mathrm{BER}\left(1\right)}=\frac{1}{2}({\mathrm{BER}}_{n_1}\left(2\right)+{\mathrm{BER}}_{n_2}\left(2\right))-{\mathrm{BER}}_{n_1}\left(1\right).$ Got by formula (8): ${\mathrm{BER}}_{n_2}\left(2\right)=\frac{N_{\min }}{{\log }_2{M}_0}Q\left(\sqrt{\mathrm{\&xi;}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="SINR\; n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">SINR</figure-callout>}}_{n_{}}\&CenterDot;G_c}\right).$ 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 to calculate n ₂=2,3 ..., 7,8 o'clock respectively

Then must obtain first corresponding

With n ₂=5 is example, formula (9):

Wherein

Can be obtained by formula (10) and formula (11), that is:

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

$\left[\begin{array}{cc}{\mathrm{\&Sigma;}}_{11}^2\left[m\right]& {\mathrm{\&Sigma;}}_{15}^2\left[m\right]\\ {\mathrm{\&Sigma;}}_{51}^2\left[m\right]& {\mathrm{\&Sigma;}}_{55}^2\left[m\right]\end{array}\right]={\mathrm{\&sigma;}}_n^2{\left(H^H\right[m\left]H\right[m]+\frac{{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002403311200021.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}{{\mathrm{\&sigma;}}_{a_2}^2}{I}_2)}^{-1}$

Wherein, H[m] be the frequency domain channel matrix on subcarrier m that user 1 and user 5 consist of.So just calculated n ₂=2,3 ..., 7,8 o'clock, each

Corresponding value in like manner calculates corresponding

Value and

Value, more corresponding at last

Value, choose antenna n corresponding to minimum value ₂As the 2nd antenna of taking turns pairing.Suppose that result the 2nd takes turns the user's 6 who chooses antenna pairing, namely

Then vectorial Q (2)=[10000100] are indicated in the 2nd pairing of taking turns after pairing finishes.

Then, judge the antenna number N that has added pairing _qCount N with reception antenna _RSize.Because N _q=N _R=2, do not satisfy N _q＜N _RCondition, so pairing finishes.The optimal case that the pairing of this moment indicates vectorial Q (2) namely to match, N _T=2 namely participate in the antenna sum of pairing.Home eNodeB notifies the user antenna of all selected pairings to send simultaneously data when begin next dispatching cycle.

As shown in Figure 2, by Matlab emulation, the performance of BER of traditional SA matching method and the SA matching method based on bit error rate of the present invention is compared.Transverse axis represents signal to noise ratio, and unit is decibel, and the longitudinal axis represents bit error rate.Among Fig. 2, represent the simulation result of traditional SA matching method with the lines of circle.The simulation result that represents matching method of the present invention with the lines of del.As seen 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 obviously is better than traditional SA matching method.

The personage who knows this area will understand, although described specific embodiment for the ease of explaining here, can make various changes in the situation that does not deviate from spirit and scope of the invention.Therefore, except claims, can not be used for restriction the present invention.

Claims (4)

1. user's matching method of the virtual multiple-input and multiple-output of Home eNodeB is characterized in that the method may further comprise the steps:

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

Step 20): i wheel day line options: take turns at i – 1 on the basis of day line options, in the user who does not add the pairing antenna sets, select a user's antenna to add the pairing antenna sets, and make the growth of user's average error bit rate in the pairing antenna sets

Minimize; I represents that day which of line options take turns, and i is the integer more than or equal to 2, and the initial value of i is 2;

Step 30): more added the antenna number N in the pairing antenna sets _qCount N with reception antenna _RSize, if N _q＜N _R, then execution in step 40); Otherwise execution in 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 the selection of 2+p wheel antenna, p represents to return step 20) number of times; Otherwise execution in step 50);

Step 50): pairing is finished, and all users' antenna sends data simultaneously in the Home eNodeB notice pairing antenna sets when begin next dispatching cycle.

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 step 20) in,

After referring to i wheel day line options, the average error bit rate of having matched the user is taken turns the growth of pairing user's average error bit rate with respect to i – 1,

3. user's matching method of the virtual multiple-input and multiple-output of Home eNodeB according to claim 1, it is characterized in that, in the described step (4), after η (i) refers to i wheel day line options, the average error bit rate of having matched the user is taken turns the growth rate of pairing user's average error bit rate with respect to i – 1

η _cIt is a constant.

4. 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.

Images