CN101630967B - Method for obtaining channel quality in multi-input multi-output system - Google Patents

Abstract

The invention discloses a method for obtaining channel quality in a multi-input multi-output (MIMO) system, which is used for a receiving terminal to compute the channel quality. The method is used for the receiving terminal to obtain channel quality information in the MIMO system, wherein the receiving terminal estimates the influence of current interference on the channel quality according to the past interference cut off at one current time interval, and obtains the channel quality information. By adopting the method for obtaining the channel quality in a multi-input multi-output system, the receiving terminal can obtain exacter channel quality information and feed back the information to a transmission terminal when multi-layer interference happens, and also can obtain better estimation effect when a codebook does not exist.

Description

Method for obtaining channel quality in multi-input multi-output

Technical field

The present invention relates to wireless communication field, be specifically related to the computational methods of CQI (CQI) in a kind of multiple-input and multiple-output (MIMO) system.

Background technology

In wireless communications, if use many antennas at transmitting terminal (eNB), then the mode of spatial reuse can be taked to improve transmission rate, namely different data are launched in the different antennae position of transmitting terminal on identical running time-frequency resource.Also use many antennas at receiving terminal (UE), then the resource of all antennas all can be distributed to same user when single user.This above transmission form is referred to as Single User MIMO (SU-MIMO).In addition also can when multi-user by the Resourse Distribute in different antennae space to different user, this transmission form is called multiuser MIMO (MU-MIMO).

Above-mentioned Single User MIMO and multiuser MIMO both of these case, transmitting terminal all needs the channel information according to each user (CSI) to carry out Resources allocation and determines the method for transmitting.Receiving terminal can be obtained out by channel estimating each dual-mode antenna between channel information, then by information feed back to eNB.

In an actual situation, because feedback needs by system resource, information is carried out quantification and is just fed back by general UE.At Long Term Evolution (Long Time Evolution, LTE) in system, the feedback system of the information after quantification, mainly comprise CQI (Channel Quality Indicator, CQI), pre-coding matrix index (Precoding Matrix Index, PMI) and order instruction (RankIndicator, RI).In addition, transmitting terminal also can carry out estimating channel information from alternate manner, such as, estimate descending channel information with channel reciprocity from up channel information.

Receiving terminal can calculate Signal to Interference plus Noise Ratio (SINR) by channel and Interference Estimation, CQI is exactly generally the SINR after quantizing, below under the scene of SU-MIMO spatial reuse (Spatial Multiplexing), by the computational methods of SINR during least mean-square error (MMSE) receiver.

When transmitting terminal and receiving terminal have 2 antennas, the channel between transmitting terminal and receiving terminal is the matrix H of a 2x2, and is when 2 in order, and precoding W is also the matrix of a 2x2, the channel after precoding processing then:

F=[f ₁f ₂]=HW formula (1)

Wherein, f ₁for the equivalent channel vector of ground floor, f ₂for the equivalent channel vector of the second layer.

The vector of the signal that receiving terminal receives to be vectorial y, the n of a 2x1 be also a 2x1, represents interference and noise that 2 antennas receive, and s ₁and s ₂then the data symbol at different numeral stream respectively:

Y=f ₁s ₁+ f ₂s ₂+ n formula (2)

In use MMSE receiver situation, the Signal to Interference plus Noise Ratio (SINR) of numeral stream (stream) 1 and numeral stream 2 respectively:

$\mathrm{stream}1=f_1^{*}{\hat{R}}_{\mathrm{nn},2}^{-1}{f}_1$ Formula (3)

$\mathrm{stream}2=f_2^{*}{\hat{R}}_{\mathrm{nn},1}^{-1}{f}_2$ Formula (4)

Wherein,

${\hat{R}}_{\mathrm{nn},k}=\underset{i}{\overset{\mathrm{num\; int}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+f_k{f}_k^{*}+N_{o}I,$ Num int represents the number of interfered cell;

H _ipresence of intercell interference (inter-cell interference);

H _i ^*h _itransposed matrix;

N _oi is the white noise of Gaussian Profile;

Then be the interference for k stream and noise covariance matrix, comprise the co-channel interference f between numeral stream _k.

For the LTE of Release 8, precoding is all make a reservation for from the code book of standard, when SU-MIMO, accurately can know the interference between numeral stream, so also more accurately can calculate CQI when SINR calculates.But under the dual-stream beamforming (Beamforming) that Release 9 supports, precoding is that receiving terminal calculates, and receiving terminal just accurately can not know the interference between numeral stream, and the calculating of CQI may have deviation with during actual transmission.

Under multi-user's double fluid Beamforming scene, when there being two users to do spatial reuse, compare time the account form of SINR is 2 with SU-MIMO order, just each numeral stream is occupied by different users, and interference just can be said to the interference of multi-user.

The signal received at user 1 receiving terminal is:

y＝f ₁s ₁+f ₂s ₂+n

When user 1 is with MMSE receiver, the Signal to Interference plus Noise Ratio (SINR) of user 1 is:

$\mathrm{MMSE\; SINR\; for\; User}1=f_1^{*}{\hat{R}}_{\mathrm{nn},2}^{-1}{f}_1,$ Wherein ${\hat{R}}_{\mathrm{nn},k}=\underset{i}{\overset{\mathrm{numInt}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+f_k{f}_k^{*}+N_{o}I.$

Because the different antennae position of transmitting terminal on identical running time-frequency resource, launches different data to multi-user, each user can produce interference to other user.Although the interference of each user can be reduced with certain methods (such as broken zero etc.), in an actual situation, because quantize and other various error, certain multi-user interference all can be had to exist at receiving terminal.When there being multi-user interference, because the pairing of multi-user carries out at transmitting terminal, receiving terminal is generally difficult to the prediction doing following interference, so the accuracy of CQI is general all lower.

When MU-MIMO, although receiving terminal accurately can not know the interference of following multi-user, also the interference that multi-user brings can be considered roughly when CQI calculates.One of them method all precodings of likely matching with oneself is all done the calculating of a SINR, then does average.Such as in Release 8, the code book of 2 antennas is:

Be when 1 in each user's order, have the selection of 4 numerals.If transmitting terminal allows nonopiate pairing, then each user just has 3 numerals to match, and that is has the possibility of 3 disturbances.In that case, then can calculate each possibility remakes on average:

${\mathrm{SINR}}_{\mathrm{MU}}=\frac{1}{S-1}\underset{w_k\∈{\mathrm{Cint}}_n}{\overset{S-1}{\mathrm{\Σ}}}{f}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\left({\mathrm{Hw}}_k\right){\left({\mathrm{Hw}}_k\right)}^{*})}^{-1}{f}_1,$ Wherein ${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{num\; int}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I.$

Wherein S is the quantity of numeral, namely equals 4; W _kit is the precoding of interference.The estimation can will one, work being disturbed general like this, but this method is only for the situation having code book, and if do not have code book, the precoding of interference can have a lot of possibility, and that just cannot do a prediction.

Summary of the invention

Technical problem to be solved by this invention, is that needs provide a kind of method for obtaining channel quality in multi-input multi-output, carries out the calculating of channel quality for receiving terminal.

In order to solve the problems of the technologies described above, the invention provides a kind of method for obtaining channel quality in multi-input multi-output, channel quality information is obtained for receiving terminal in described multi-input multi-output system, wherein, described receiving terminal on the impact of channel quality, obtains described channel quality information according to the current interference of passing interference estimation within current time interval.

Preferably, described estimation, is comprised and being estimated by public guide frequency or demodulation pilot frequency.

Preferably, described receiving terminal is according to the described channel quality of described passing interference estimation, comprise the mean value that calculates described passing interference and estimate described channel quality according to described mean value, or estimating described channel quality by carrying out filtration to the multi-user interference in the described time interval.

Preferably, described channel quality information, comprises Signal to Interference plus Noise Ratio or CQI.

Preferably, described receiving terminal on the impact of channel quality, obtains described channel quality information, in multiuser mimo system, for the user m ' in M user, Signal to Interference plus Noise Ratio SINR according to the current interference of described passing interference estimation _{mU, i}for:

${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(k\right)f_{\mathrm{int},m}{\left(k\right)}^{*})}^{-1}{f}_{m^{\′}};$

Channel quality indicator CQI _{mU, i}for:

CQI _MU，m′＝Q(SINR _MU，m′)；

Wherein,

T is the described time interval, and t is current time;

F _{m '}for the equivalent channel vector of layer m ';

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{num\; int}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

F _{int, m}k () represents the interference that the user m after precoding processing obtained according to described demodulation pilot frequency produces;

Q (x) expression carries out quantization operations to x.

Preferably, when described T is 1, ${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(t\right)f_{\mathrm{int},m}{\left(t\right)}^{*})}^{-1}{f}_{m^{\′}}.$

Preferably, under multi-user's dual-stream beamforming pattern, described receiving terminal is estimated channel matrix according to public guide frequency and is obtained the equivalent channel vector f of ground floor according to described channel matrix ₁, according to the equivalent channel vector f of described ground floor ₁obtain single user clear channel quality indicator CQI _{sU, 1}; The mean value of multi-user interference is calculated, according to described mean value and f according to described demodulation pilot frequency ₁, obtain described CQI _{sU, 1}with the difference of multi-user channel quality designator;

Described channel quality information comprises described CQI _{sU, 1}with difference.

Preferably, described in ${\mathrm{CQI}}_{\mathrm{SU},1}=Q\left(f_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{f}_1\right);$

Described $\mathrm{\Δ}{\mathrm{CQI}}_{\mathrm{SM}}={\mathrm{CQI}}_{\mathrm{SU},1}-Q\left(f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1\right).$

Preferably, the method comprises further:

Described receiving terminal is by described CQI _{sU, 1}and difference feeds back to described transmitting terminal.

Preferably, described receiving terminal estimates according to described demodulation pilot frequency the equivalent channel vector obtaining ground floor according to the equivalent channel vector of described ground floor acquisition has multi-user interference and single user glitch-free channel quality indicator difference Δ CQI _sM; The channel quality indicator CQI of the transmit diversity form of Release 8 port 5 is estimated according to described public guide frequency _tXD;

Described channel quality information comprises described Δ CQI _sMwith CQI _tXD.

Preferably, described in $\mathrm{\Δ}{\mathrm{CQI}}_{\mathrm{SM}}=Q\left({\hat{f}}_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_1-{\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1\right).$

Preferably, the method comprises further:

Described receiving terminal is by described Δ CQI _sMwith CQI _tXDfeed back to described transmitting terminal.

Preferably, described f _{m '}equal Hw _{m '}, be by precoding processing after user m ' equivalent channel vector, precoding w _{m '}based on codebook selecting.

Preferably, the method comprises further:

Described receiving terminal feeds back described channel quality information based on code book.

Preferably, according to described passing interference, described receiving terminal estimates that current interference is on the impact of channel quality, obtain described channel quality information, bilayer for single user multi-input multi-output system transmits, when the quantity of public guide frequency port is no less than number of transmit antennas, described receiving terminal estimates channel matrix according to public guide frequency, obtains the equivalent channel vector of the equivalent channel vector sum second layer of ground floor, and calculate the mean value of interlayer interference according to described demodulation pilot frequency according to described channel matrix; According to the equivalent channel vector of described ground floor, the equivalent channel vector of the second layer and mean value, obtain the CQI of ground floor and the CQI of the second layer.

Preferably, the Signal to Interference plus Noise Ratio SINR of ground floor _{sU, 1}for:

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1,$

The channel quality indicator CQI of described ground floor _{sU, 1}for:

CQI _SU，1＝Q(SINR _SU，1)；

The Signal to Interference plus Noise Ratio SINR of the second layer _{sU, 2}for:

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_2,$

The channel quality indicator CQI of the described second layer _{sU, 2}for:

CQI _SU，2＝Q(SINR _SU，2)；

Wherein:

T is the described time interval, and t is current time;

F _ifor the equivalent channel vector of layer i;

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{num\; int}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

F _intk () represents the interlayer interference obtained according to described demodulation pilot frequency;

Q (x) expression carries out quantization operations to x.

Preferably, when described T is 1,

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+f_{\mathrm{int}}\left(t\right)f_{\mathrm{int}}{\left(t\right)}^{*})}^{-1}{f}_1;$

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+f_{\mathrm{int}}\left(t\right)f_{\mathrm{int}}{\left(t\right)}^{*})}^{-1}{f}_2.$

Preferably, the method comprises further:

After described receiving terminal obtains described channel quality information, by described CQI _{sU, 1}and CQI _{sU, 2}feed back to described transmitting terminal.

Preferably, according to described passing interference, described receiving terminal estimates that current interference is on the impact of channel quality, obtain described channel quality information, bilayer for single user multi-input multi-output system transmits, when the quantity of public guide frequency port is less than number of transmit antennas, described receiving terminal obtains the equivalent channel vector of the equivalent channel vector sum second layer of ground floor according to demodulation pilot frequency; And obtain ground floor according to the equivalent channel of described ground floor vector and there is no interlayer interference and having the ground floor channel quality indicator difference of interlayer interference, there is no interlayer interference according to the equivalent channel vector acquisition second layer of the described second layer and having the second layer channel quality indicator difference of interlayer interference.

Preferably, described ground floor channel quality indicator difference Δ CQI ₁for:

$\mathrm{\Δ}{\mathrm{CQI}}_1=Q\left({\hat{f}}_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_1-{\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1\right);$

Described second layer channel quality indicator difference Δ CQI ₂for:

$\mathrm{\Δ}{\mathrm{CQI}}_2=Q\left({\hat{f}}_2^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_2-{\hat{f}}_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_2\right);$

Wherein:

T is the described time interval, and t is current time;

represent the equivalent channel vector of the described ground floor obtained according to described demodulation pilot frequency estimation, represent the equivalent channel vector of the described second layer obtained according to described demodulation pilot frequency estimation;

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{num\; int}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

F _intk () represents the interlayer interference obtained according to described demodulation pilot frequency;

Q (x) expression carries out quantization operations to x.

Preferably, the method comprises further:

Described receiving terminal is according to the channel quality indicator CQI of the transmit diversity form of Release 8 port 5 _tXD, described Δ CQI ₁and Δ CQI ₂, feed back described channel quality information to described transmitting terminal.

Preferably, described receiving terminal is according to described Δ CQI ₁with Δ CQI ₂obtain CQI mean value Δ CQI, by described CQI _tXDdescribed transmitting terminal is fed back to the difference of described Δ CQI; Or

Described receiving terminal is by described CQI _tXDwith described Δ CQI ₁difference, and described CQI _tXDwith described Δ CQI ₂difference feed back to described transmitting terminal;

Wherein said Δ CQI=(Δ CQI ₁+ Δ CQI ₂)/2.

Compared with prior art, the method for obtaining channel quality in multi-input multi-output that the present invention proposes, receiving terminal can obtain channel quality information feed back to transmitting terminal more accurately when there being multilayer to disturb, do not having also can obtain in code book situation to estimate effect preferably.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of first method in first embodiment of the invention;

Fig. 2 is the schematic flow sheet of second method in first embodiment of the invention;

Fig. 3 is the schematic flow sheet of fourth way in second embodiment of the invention;

Fig. 4 is the schematic flow sheet of the 5th mode in second embodiment of the invention;

Fig. 5 is the schematic flow sheet that transmitting terminal of the present invention carries out according to the channel quality information that receiving terminal feeds back transmitting.

Embodiment

Describe embodiments of the present invention in detail below with reference to drawings and Examples, to the present invention, how application technology means solve technical problem whereby, and the implementation procedure reaching technique effect can fully understand and implement according to this.

In the present invention, receiving terminal is when calculating and feed back CQI or SINR, the impact of current interference on CQI or SINR is estimated according to passing interference, such as being averaged by the end of working as the interference in previous T time interval to passing, estimating current channel quality information according to this mean value.After obtaining channel quality information, by the channel quality information feedback of acquisition to transmitting terminal, transmitting terminal carries out the transmission with receiving terminal according to this channel quality information.

Estimate current interference according to passing interference, wherein a kind of method carrys out Estimation and Measurement by pilot tone.A kind of demodulation pilot frequency (Demodulation Reference Signal is comprised in the standard of LTE, DMRS), it is the dedicated pilot that transmitting terminal (eNB) is launched each receiving terminal (UE), this pilot tone needs through precoding processing when launching, the same with data precoding.As long as therefore UE knows which layer the channel of oneself is positioned at, just can learn that other layer is all interference, Interference Estimation can be realized from the DMRS of interfere with layer.

Below be divided into MU-MIMO and SU-MIMO that the computational methods being estimated CQI by DMRS are described respectively.

For MU-MIMO situation

When MU-MIMO, if total M user, then CQI and SINR of user m ' is respectively:

${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(k\right)f_{\mathrm{int},m}{\left(k\right)}^{*})}^{-1}{f}_{m^{\′}}$ Formula (5)

CQI _{mU, m '}=Q (SINR _{mU, m '}) formula (6)

Wherein, t represents current time, and T represents the time interval;

f _int，m(t)＝H _int，m(t)w _int，m(t)；

Wherein, represent the mean value of multi-user interference in T time interval.

Q (x) expression in formula (6) carries out quantization operations to x.

Wherein f _{int, m}(t)=H _{int, m}(t) w _{int, m}(t) be through precoding processing after multi-user interference, can obtain according to DMRS.Interference in this period of time before current time to T time section is averaging processing, or multi-user interference before current time T time section can be filtered with filter.Certainly, T also can equal 1, does not namely do average, only does Interference Estimation according to current DMRS, and both T equaled 1 up-to-date style (5) and is expressed as:

${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(t\right)f_{\mathrm{int},m}{\left(t\right)}^{*})}^{-1}{f}_{m^{\′}}$ Formula (5-1)

It should be noted that, carry out interference filter by filter, and T equals 1 expression and do not do average treatment, is equally applicable to SU-MIMO situation.

Under the scene of multi-user, interference is mainly with the co-channel interference that community other users produce, and these interference are all through precoding processing, so the size of interference all depends on eNB with change.For different e NB, adopt different pairings and precoding processing, thus produce different interference.By to the statistics disturbed before, can know that eNB produces the probable strength of interference, thus an estimation is done on the impact of CQI.

For SU-MIMO situation

When SU-MIMO, if double-deck transmission, the calculating of CQI and SINR of ground floor can be write as:

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1$ Formula (7)

CQI _{sU, 1}=Q (SINR _{sU, 1}) formula (8)

Wherein f _int(t)=H (t) w ₂(t).

Wherein, represent the mean value of multi-user interference in T time interval.

Wherein, H (t) w ₂(t) be by precoding processing after interlayer interference, can obtain from DMRS.The same with the scene of multi-user, the interference in this period of time before current time to T time section is averaging processing, or can disturbs by the multilayer that filter filters before current time T time section.

For the second layer, computational methods are the same with ground floor, that is:

The Signal to Interference plus Noise Ratio SINR of the second layer in double-deck transmission _{sU, 2}and channel quality indicator CQI _{sU, 2}be respectively:

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_2$ Formula (7-1)

CQI _{sU, 2}=Q (SINR _{sU, 2}) formula (8-1)

Wherein:

F _ifor the equivalent channel vector of layer i;

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{num\; int}}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

Q (x) expression carries out quantization operations to x;

Wherein f _int(t)=H (t) w ₁(t), H (t) w ₁(t) be by precoding processing after interlayer interference, can obtain from DMRS.

Wherein, represent the mean value of multi-user interference in T time interval.

Certainly, T also can equal 1, does not namely do average, only does Interference Estimation according to current DMRS, and both T equaled 1 up-to-date style (7) and is expressed as:

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+f_{\mathrm{int}}\left(t\right)f_{\mathrm{int}}{\left(t\right)}^{*})}^{-1}{f}_1$ Formula (7-2)

Formula (7-1) is expressed as:

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+f_{\mathrm{int}}\left(t\right)f_{\mathrm{int}}{\left(t\right)}^{*})}^{-1}{f}_2$ Formula (7-3)

Embodiment is utilized how to calculate channel quality by demodulation pilot frequency to explanation below.

First embodiment

In LTE Release 8, based on the transmission of single antenna port 5, belong to a kind of application of single current wave beam forming (Beamforming, BF) technology.In order to strengthen the performance of descending non-code book transmission means, a kind of new transmission means is proposed in the enhancing version Release 9 of LTE, belong to the non-codebook space multiplex mode that a kind of order is 2, namely have employed the transmission of two antenna ports of double-current BF technology.

Under single user double fluid BF scene, because be not the mode based on code book, eNB oneself can determine the method for precoding processing.Although eNB generally makes two-layer precoding vector orthogonalization, due to the various errors of real system, when signal arrives UE time, the interference of interlayer is difficult to avoid, and can carry out the calculating of CQI in this case by the average method of interference:

The CQI of ground floor is:

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1$ Formula (9)

CQI _{sU, 1}=Q (SINR _{sU, 1}) formula (10)

Wherein f _int(t)=H (t) w ₂(t).

The CQI of the second layer is:

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_2$ Formula (11)

CQI _{sU, 2}=Q (SINR _{sU, 2}) formula (12)

Wherein f _int(t)=H (t) w ₁(t).

When receiving terminal feedback SINR or CQI (being described to feed back CQI), include following first, second and third totally three kinds of modes:

First method

UE directly feeds back two CQI, i.e. CQI _{sU, 1}and CQI _{sU, 2}.

Fig. 1 is that in SU-MIMO system, receiving terminal feedback channel quality information is to the schematic flow sheet of the first method of transmitting terminal when the quantity of public guide frequency CRS (Common Reference Signal) port (port) is no less than number of transmit antennas.As shown in Figure 1, this flow process mainly comprises the steps:

Step S110, UE estimate channel matrix H according to public guide frequency CRS (Common Reference Signal);

Step S120, UE obtain two characteristic vectors according to this channel matrix H;

Step S130, UE obtain the equivalent channel vector f of ground floor according to these two characteristic vectors ₁with the equivalent channel vector f of the second layer ₂;

Step S140, UE calculate the mean value of interlayer interference according to DMRS;

Step S150, UE are according to this mean value and this f ₁and f ₂, obtain ground floor channel quality indicator CQI _{sU, 1}with second layer channel quality indicator CQI _{sU, 2};

Step S160, UE are by this CQI _{sU, 1}and CQI _{sU, 2}feed back to transmitting terminal.

Second method

Above-mentioned first method is the channel can knowing all antennas based on UE, this needs the quantity of CRS port to be no less than number of transmit antennas, such as in Release 8, the quantity of maximum CRS is 4, if transmitting terminal has 8 antennas, now above-mentioned first method is then inapplicable.

When the quantity of CRS port (port) is less than number of transmit antennas, (use CQI here to feed back CQI by the transmit diversity form of the transmission of approximate Release 8 port 5 _tXDrepresent), then based on average interlayer interference, CQI is turned down, obtain the equivalent channel vector f of ground floor according to DMRS ₁with the equivalent channel vector f of the second layer ₂, use respectively at this with represent the equivalent channel vector f of the ground floor estimated according to DMRS ₁with the equivalent channel vector f of the second layer ₂, so the SINR of ground floor when there being interlayer interference is:

${\mathrm{SINR}}_{\mathrm{SU},1}={\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1$ Formula (13)

Ground floor is not having interlayer interference and is having the ground floor CQI difference of interlayer interference to be:

$\mathrm{\Δ}{\mathrm{CQI}}_1=Q\left({\hat{f}}_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_1-{\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1\right)$ Formula (14)

Use the process the same with ground floor, can obtain the second layer CQI difference of the second layer when not having interlayer interference and have interlayer interference is:

$\mathrm{\Δ}{\mathrm{CQI}}_2=Q\left({\hat{f}}_2^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_2-{\hat{f}}_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_2\right)$ Formula (15)

Calculate the CQI mean value of ground floor CQI difference and second layer CQI difference:

Δ CQI=(Δ CQI ₁+ Δ CQI ₂)/2 formula (16)

According to CQI _tXDand this CQI mean value obtains CQI estimated value:

CQI _e=CQI _tXD-Δ CQI formula (17)

Receiving terminal is by this CQI estimated value CQI _efeed back to transmitting terminal, so just the interlayer interference estimated all can be reflected in CQI _ein computational process.Transmitting terminal eNB receives CQI _eafter estimate that two characteristic vectors of channel do the adjustment of CQI between different layers according to eNB oneself again.Fig. 2 is the schematic flow sheet of the above-mentioned second method of the present invention.As shown in Figure 2, this flow process mainly comprises the steps:

Step S210, UE estimate the channel quality indicator CQI of the transmit diversity form of Release 8 port 5 according to public guide frequency CRS _tXD;

Step S220, UE estimate the equivalent channel vector of ground floor according to DMRS with the equivalent channel vector of the second layer

Step S230, UE are according to being somebody's turn to do calculate ground floor there is no interlayer interference and having the ground floor CQI difference DELTA CQI of interlayer interference ₁;

Step S240, UE are according to being somebody's turn to do calculate the second layer there is no interlayer interference and having the second layer CQI difference DELTA CQI of interlayer interference ₂;

Step S250, according to this ground floor CQI difference DELTA CQI ₁with second layer CQI difference DELTA CQI ₂obtain CQI mean value Δ CQI=(Δ CQI ₁+ Δ CQI ₂)/2;

Step S260, UE are according to this CQI _tXDand CQI mean value Δ CQI obtains CQI estimated value CQI _e=CQI _tXD-Δ CQI feedback is to transmitting terminal.

Third Way

Compared with aforesaid second method, Third Way after acquisition ground floor CQI difference and second layer CQI difference, according to ground floor CQI difference and second layer CQI difference, and CQI _tXDobtain:

Ground floor CQI estimated value is:

CQI _1E=CQI _tXD-Δ CQI ₁formula (18)

Second layer CQI estimated value is:

CQI _2E=CQI _tXD-Δ CQI ₂formula (19)

Receiving terminal is by this ground floor CQI estimated value CQI _1Eand second layer CQI estimated value CQI _2Efeed back to transmitting terminal.

Second embodiment

Double fluid BF also can support multiuser MIMO, and each user only accounts for a stream (order is 1).First embodiment requires that the order of single user channel is 2, if the order of channel is 1, then needs multiuser MIMO to do spatial reuse.If the order of channel is 1 do not have again user to match, then need the single current BF adopting single user.In this single current BF pattern, support the switching of dynamic single user single current BF and multi-user BF, the present embodiment adopts the feedback method of differential CQI.

First the CQI of single current BF is calculated:

${\mathrm{CQI}}_{\mathrm{SU},1}=Q\left({\mathrm{SINR}}_{\mathrm{SU},1}\right)=Q\left(f_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{f}_1\right)$ Formula (20)

And then the difference DELTA CQI calculated between single current BF and double-current BF _sD:

${\mathrm{\ΔCQI}}_{\mathrm{SD}}={\mathrm{CQI}}_{\mathrm{SU},1}-Q\left({\mathrm{SINR}}_{\mathrm{MU}}\right)$

$={\mathrm{CQI}}_{\mathrm{SU},1}-Q\left(f_1^{*}({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*}{)}^{-1}{f}_1\right)$ Formula (21)

Receiving terminal is by this Δ CQI _sDafter feeding back to transmitting terminal eNB, if eNB finds two users to match, can from CQI _{sU, 1}with Δ CQI _sDcalculate the CQI of multi-user _mU=CQI _{sU, 1}-Δ CQI _sDif do not have user to match and just use CQI _{sU, 1}do the transmission of single user.

When receiving terminal feedback SINR or CQI (being described to feed back CQI), include the following 4th and the 5th totally two kinds of modes:

Fourth way

The manner utilizes the mode of difference to feed back CQI, supports the switching of dynamic single user and multi-user, such as, when order is 1, because only have one deck, do not have the interference of multilayer, and the glitch-free CQI of single user is:

${\mathrm{CQI}}_{\mathrm{SU},1}=Q\left({\mathrm{SINR}}_{\mathrm{SU},1}\right)=Q\left(f_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{f}_1\right)$ Formula (22)

The difference of itself and multi-user CQI is:

${\mathrm{\ΔCQI}}_{\mathrm{SM}}={\mathrm{CQI}}_{\mathrm{SU},1}-Q\left({\mathrm{SINR}}_{\mathrm{MU}}\right)$

$={\mathrm{CQI}}_{\mathrm{SU},1}-Q\left(f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1\right)$ Formula (23)

Because the CQI of multi-user is the CQI lower than single user, therefore Δ CQI _sMpositive number, at quantification Δ CQI _sMin time, can feed back with the bit more a little less than CQI, such as CQI _{sU, 1}be quantize with 5 bits, can quantize with 3 bits.

Fig. 3 is the schematic flow sheet of the above-mentioned fourth way of the present invention.As shown in Figure 3, this flow process mainly comprises the steps:

Step S310, UE estimate channel matrix H according to public guide frequency CRS;

Step S320, UE obtain a characteristic vector the strongest according to this channel matrix H;

Step S330, UE obtain the equivalent channel vector f of ground floor according to this strongest characteristic vector ₁;

Step S340, UE calculate the mean value of multi-user interference according to DMRS

Step S350, UE are according to this f ₁, obtain single user clear channel quality indicator CQI _{sU, 1};

Step S360, UE are according to this mean value and this f ₁, obtain this single user clear channel quality indicator CQI _{sU, 1}with the difference DELTA CQI of multi-user CQI _sM;

Step S370, UE are by this CQI _{sU, 1}with Δ CQI _sMfeed back to transmitting terminal.

5th mode

The manner is the equivalent channel vector f that cannot obtain ground floor at UE from CRS ₁when (such as the quantity of CRS port is no less than number of transmit antennas), can estimate to obtain the equivalent channel vector f of ground floor according to DMRS ₁, use at this represent the amount estimated according to DMRS, so CQI noiseless with single user _{sU, 1}difference be:

$\mathrm{\Δ}{\mathrm{CQI}}_{\mathrm{SM}}=Q\left({\hat{f}}_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_1-{\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1\right)$ Formula (24)

In this case, receiving terminal uses the CQI of the transmit diversity form of the transmission of Release 8 port 5 to transmitting terminal feedback _tXDand this Δ CQI _sM.

Fig. 4 is the schematic flow sheet of above-mentioned 5th mode of the present invention.As shown in Figure 4, this flow process mainly comprises the steps:

Step S410, UE estimate the channel quality indicator CQI of the transmit diversity form of Release 8 port 5 according to public guide frequency CRS _tXD;

Step S420, UE estimate the equivalent channel vector of ground floor according to DMRS

Step S430, UE are according to the equivalent channel vector of this ground floor calculate and there is no multi-user interference and the CQI difference DELTA CQI having multi-user interference _sM;

Step S440, UE are by this CQI _tXDand this Δ CQI _sMfeed back to transmitting terminal.

It should be noted that, above-mentioned first embodiment can be mixed with the second embodiment, and Fig. 2 is channel the highest order when being 2, and transmitting terminal carries out the schematic flow sheet transmitted according to the channel quality information that receiving terminal feeds back.As shown in Figure 2, when the first embodiment is mixed with the second embodiment, transmitting terminal carries out transmitting mainly comprising the steps: according to the channel quality that receiving terminal feeds back

Step S210, receiving terminal UE calculate the order of channel;

Step S220, judges whether the order of this channel is 1, is for 1 goes to step S230, otherwise goes to step S250;

Step S230, UE calculate single user clear channel quality indicator CQI _{sU, 1};

Step S240, UE calculate this single user clear channel quality indicator CQI _{sU, 1}with the difference DELTA CQI of multi-user channel quality designator, and by this single user clear channel quality indicator CQI _{sU, 1}and this difference DELTA CQI feedback is to transmitting terminal eNB, goes to step S260;

Step S250, UE calculate double-deck channel quality, obtain ground floor channel quality indicator CQI _{sU, 1}and second layer channel quality indicator CQI _{sU, 2}, and by this ground floor channel quality indicator CQI _{sU, 1}and second layer channel quality indicator CQI _{sU, 2}feed back to transmitting terminal, go to step S290;

Step S260, transmitting terminal is attempted carrying out multi-user's pairing, and whether successfully judges pairing, successful then go to step S270, otherwise goes to step S280;

Step S270, transmitting terminal adopts multi-user's double fluid BF to carry out information transmission;

Step S280, transmitting terminal adopts single user single current BF to carry out information transmission;

Step S290, transmitting terminal adopts single user double fluid BF to carry out information transmission.

3rd embodiment

The pattern 5 of the Release 8 of LTE, supports the transmission of the multiuser MIMO based on code book.In Release 10 version strengthening Long Term Evolution (LTE-Advanced), UE also can based on code book when feedback CQI and PMI, but in order to strengthen the performance of MU-MIMO, the transmission of non-code book multiuser MIMO when eNB transmission, still can be supported.Under this scheme, because be also that application DMRS carrys out demodulation, so the execution mode of multi-user's double fluid BF, also DMRS can be adopted equally estimate interference.With multi-user's double fluid BF difference, mainly can be multiplexing more than two users.Be exactly below when there being M user, the CQI computational methods of user m ':

${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(k\right)f_{\mathrm{int},m}{\left(k\right)}^{*})}^{-1}{f}_{m^{\′}}$ Formula (25)

CQI _{mU, m '}=Q (SINR _{mU, m '}) formula (26)

Wherein f _{int, m}(t)=H _{int, m}(t) w _{int, m}(t).

Wherein H _{int, m}(t) w _{int, m}(t) be by precoding processing after from user m produce interference, can obtain according to DMRS.The interference of all users is added up, and then reoperate time is average (such as formula in (25) shown in be the average treatment of time), obtain such as formula the channel quality information shown in (26).Time be on average by the estimation now with the interference between before T calculate one average, or the multi-user interference before can filtering with filter.

Certainly, when time interval T is 1, formula (25) is:

${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(k\right)f_{\mathrm{int},m}{\left(k\right)}^{*})}^{-1}{f}_{m^{\′}}$ Formula (25-1)

Wherein f _{m '}=Hw _{m '}be by precoding processing after user m ' equivalent channel vector, precoding w _{m '}select based on code book.

Although the execution mode disclosed by the present invention is as above, the execution mode that described content just adopts for the ease of understanding the present invention, and be not used to limit the present invention.Technical staff in any the technical field of the invention; under the prerequisite not departing from the spirit and scope disclosed by the present invention; any amendment and change can be done what implement in form and in details; but scope of patent protection of the present invention, the scope that still must define with appending claims is as the criterion.

Claims (21)

1. a method for obtaining channel quality in multi-input multi-output, channel quality information is obtained for receiving terminal in described multi-input multi-output system, it is characterized in that, described receiving terminal on the impact of channel quality, obtains described channel quality information according to the current interference of passing interference estimation within current time interval; The impact of the current interference of described estimation on channel quality comprises:

Under multi-user's dual-stream beamforming pattern, estimate channel matrix according to public guide frequency, and calculate the mean value of multi-user interference according to demodulation pilot frequency;

Bilayer for single user multi-input multi-output system transmits, and when the quantity of public guide frequency port is less than number of transmit antennas, obtains equivalent channel vector, and calculate the mean value of interlayer interference according to demodulation pilot frequency according to demodulation pilot frequency;

Bilayer for single user multi-input multi-output system transmits, and when the quantity of public guide frequency port is no less than number of transmit antennas, estimates channel matrix according to public guide frequency, and calculates the mean value of interlayer interference according to demodulation pilot frequency.

2. the method for claim 1, is characterized in that:

Described receiving terminal, according to the described channel quality of described passing interference estimation, also comprises and estimates described channel quality according to described mean value, or estimate described channel quality by carrying out filtration to the multi-user interference in the described time interval.

3. method as claimed in claim 2, is characterized in that:

Described channel quality information, comprises Signal to Interference plus Noise Ratio or CQI.

4. method as claimed in claim 3, is characterized in that:

Described receiving terminal on the impact of channel quality, obtains described channel quality information, in multiuser mimo system, for the user m' in M user, Signal to Interference plus Noise Ratio SINR according to the current interference of described passing interference estimation _{mU, i}for:

${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)m=1}{\overset{t}{\mathrm{\Σ}}}\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(k\right)f_{\mathrm{int},m}{\left(k\right)}^{*})}^{-1}{f}_{m^{\′}};$

Channel quality indicator CQI _{mU, i}for:

CQI _MU,m'＝Q(SINR _MU,m')；

Wherein,

T is the described time interval, and t is current time;

F _m'for the equivalent channel vector of layer m';

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{nu}\min t}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

represent channel disturbance and noise covariance matrix;

F _{int, m}k () represents the interference that the user m after precoding processing obtained according to described demodulation pilot frequency produces;

Q (x) expression carries out quantization operations to x.

5. method as claimed in claim 4, is characterized in that:

When described T is 1, ${\mathrm{SINR}}_{\mathrm{MU},m^{\′}}=f_{m^{\′}}^{*}{({\hat{R}}_{\mathrm{nn}}+\underset{m=1,m\≠m^{\′}}{\overset{M}{\mathrm{\Σ}}}{f}_{\mathrm{int},m}\left(t\right)f_{\mathrm{int},m}{\left(t\right)}^{*})}^{-1}{f}_{m^{\′}}.$

6. method as claimed in claim 4, is characterized in that:

Under multi-user's dual-stream beamforming pattern, described receiving terminal also comprises after estimating channel matrix according to public guide frequency: the equivalent channel vector f obtaining ground floor according to described channel matrix ₁, according to the equivalent channel vector f of described ground floor ₁obtain single user clear channel quality indicator CQI _{sU, 1}; Also comprise calculate the mean value of multi-user interference according to described demodulation pilot frequency after: according to described mean value and f ₁, obtain described CQI _{sU, 1}with the difference DELTA CQI of multi-user channel quality designator _sM;

Described channel quality information comprises described CQI _{sU, 1}with difference DELTA CQI _sM.

7. method as claimed in claim 6, is characterized in that:

Described ${\mathrm{CQI}}_{\mathrm{SU},1}=Q\left(f_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{f}_1\right);$

Described ${\mathrm{\ΔCQI}}_{\mathrm{SM}}={\mathrm{CQI}}_{\mathrm{SU},1}-Q\left(f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1\right);$

F _intk () represents the interlayer interference obtained according to described demodulation pilot frequency.

8. method as claimed in claim 6, it is characterized in that, the method comprises further:

Described receiving terminal is by described CQI _{sU, 1}and difference DELTA CQI _sMfeed back to transmitting terminal.

9. method as claimed in claim 4, is characterized in that:

Described receiving terminal estimates according to described demodulation pilot frequency the equivalent channel vector obtaining ground floor according to the equivalent channel vector of described ground floor acquisition has multi-user interference and single user glitch-free channel quality indicator difference Δ CQI _sM; The channel quality indicator CQI of the transmit diversity form of Release 8 port 5 is estimated according to described public guide frequency _tXD;

Described channel quality information comprises described Δ CQI _sMwith CQI _tXD.

10. method as claimed in claim 9, is characterized in that:

Described ${\mathrm{\ΔCQI}}_{\mathrm{SM}}=Q({\hat{f}}_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_1-{\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1).$

11. methods as claimed in claim 9, it is characterized in that, the method comprises further:

Described receiving terminal is by described Δ CQI _sMwith CQI _tXDfeed back to transmitting terminal.

12. methods as claimed in claim 4, is characterized in that:

Described f _m'equal be by precoding processing after user m ' equivalent channel vector, precoding based on codebook selecting.

13. methods as claimed in claim 12, it is characterized in that, the method comprises further:

Described receiving terminal feeds back described channel quality information based on code book.

14. methods as claimed in claim 3, is characterized in that:

According to described passing interference, described receiving terminal estimates that current interference is on the impact of channel quality, obtain described channel quality information, bilayer for single user multi-input multi-output system transmits, when the quantity of public guide frequency port is no less than number of transmit antennas, described receiving terminal also comprises after estimating channel matrix according to public guide frequency: the equivalent channel vector obtaining the equivalent channel vector sum second layer of ground floor according to described channel matrix, and the mean value calculating interference according to demodulation pilot frequency refers to the mean value calculating interlayer interference according to described demodulation pilot frequency; According to the equivalent channel vector of described ground floor, the equivalent channel vector of the second layer and mean value, obtain the CQI of ground floor and the CQI of the second layer.

15. methods as claimed in claim 14, is characterized in that:

The Signal to Interference plus Noise Ratio SINR of ground floor _{sU, 1}for:

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_1,$

The channel quality indicator CQI of described ground floor _{sU, 1}for:

CQI _SU,1＝Q(SINR _SU,1)；

The Signal to Interference plus Noise Ratio SINR of the second layer _{sU, 2}for:

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{f}_2,$

The channel quality indicator CQI of the described second layer _{sU, 2}for:

CQI _SU,2＝Q(SINR _SU,2)；

Wherein:

T is the described time interval, and t is current time;

F _ifor the equivalent channel vector of layer i;

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{un}\min t}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

represent channel disturbance and noise covariance matrix;

F _intk () represents the interlayer interference obtained according to described demodulation pilot frequency;

Q (x) expression carries out quantization operations to x.

16. methods as claimed in claim 15, is characterized in that:

When described T is 1,

${\mathrm{SINR}}_{\mathrm{SU},1}=f_1^{*}{({\hat{R}}_{\mathrm{nn}}+f_{\mathrm{int}}\left(t\right)f_{\mathrm{int}}{\left(t\right)}^{*})}^{-1}{f}_1;$

${\mathrm{SINR}}_{\mathrm{SU},2}=f_2^{*}{({\hat{R}}_{\mathrm{nn}}+f_{\mathrm{int}}\left(t\right)f_{\mathrm{int}}{\left(t\right)}^{*})}^{-1}{f}_2;$

17. methods as claimed in claim 15, it is characterized in that, the method comprises further:

After described receiving terminal obtains described channel quality information, by described CQI _{sU, 1}and CQI _{sU, 2}feed back to transmitting terminal.

18. methods as claimed in claim 3, is characterized in that:

According to described passing interference, described receiving terminal estimates that current interference is on the impact of channel quality, obtain described channel quality information, bilayer for single user multi-input multi-output system transmits, when the quantity of public guide frequency port is less than number of transmit antennas, described receiving terminal obtains the equivalent channel vector of the equivalent channel vector sum second layer of ground floor according to demodulation pilot frequency; And obtain ground floor according to the equivalent channel of described ground floor vector and there is no interlayer interference and having the ground floor channel quality indicator difference of interlayer interference, there is no interlayer interference according to the equivalent channel vector acquisition second layer of the described second layer and having the second layer channel quality indicator difference of interlayer interference.

19. methods as claimed in claim 18, is characterized in that:

Described ground floor channel quality indicator difference Δ CQI ₁for:

${\mathrm{\ΔCQI}}_1=Q({\hat{f}}_1^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_1-{\hat{f}}_1^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_1);$

Described second layer channel quality indicator difference Δ CQI ₂for:

${\mathrm{\ΔCQI}}_2=Q({\hat{f}}_2^{*}{\hat{R}}_{\mathrm{nn}}^{-1}{\hat{f}}_2-{\hat{f}}_2^{*}{({\hat{R}}_{\mathrm{nn}}+\frac{1}{T}\underset{k=t-(T-1)}{\overset{t}{\mathrm{\Σ}}}{f}_{\mathrm{int}}\left(k\right)f_{\mathrm{int}}{\left(k\right)}^{*})}^{-1}{\hat{f}}_2);$

Wherein:

T is the described time interval, and t is current time;

represent the equivalent channel vector of the described ground floor obtained according to described demodulation pilot frequency estimation, represent the equivalent channel vector of the described second layer obtained according to described demodulation pilot frequency estimation;

${\hat{R}}_{\mathrm{nn}}=\underset{i}{\overset{\mathrm{nu}\min t}{\mathrm{\Σ}}}{H}_i{H_i}^{*}+N_{o}I;$

Num int represents the number of interfered cell;

H _irepresent presence of intercell interference;

H _i ^*represent H _itransposed matrix;

N _oi represents the white noise of Gaussian Profile;

represent channel disturbance and noise covariance matrix;

F _intk () represents the interlayer interference obtained according to described demodulation pilot frequency;

Q (x) expression carries out quantization operations to x.

20. methods as claimed in claim 19, it is characterized in that, the method comprises further:

Described receiving terminal is according to the channel quality indicator CQI of the transmit diversity form of Release 8 port 5 _tXD, described Δ CQI ₁and Δ CQI ₂, feed back described channel quality information to transmitting terminal.

21. methods as claimed in claim 20, is characterized in that:

Described receiving terminal is according to described Δ CQI ₁with Δ CQI ₂obtain CQI mean value Δ CQI, by described CQI _tXDdescribed transmitting terminal is fed back to the difference of described Δ CQI; Or

Described receiving terminal is by described CQI _tXDwith described Δ CQI ₁difference, and described CQI _tXDwith described Δ CQI ₂difference feed back to described transmitting terminal;

Wherein said Δ CQI=(Δ CQI ₁+ Δ CQI ₂)/2.