CN103095402A - Method and device for updating channel quality indicator - Google Patents

Abstract

The invention provides a method and a device for updating a channel quality indicator. The method for updating the channel quality indicator mainly comprises the following steps: confirming an assessment valve of an inter-cell interference power corresponding to a user experience (UE) according to a channel state information (CSI) feedback by the UE and a precoding matrix of a collaborative cell, wherein the assessment valve of the inter-cell interference power corresponding to the UE is greater than or equal to a true valve of the inter-cell interference power corresponding to the UE; confirming a signal power corresponding to the UE according to the CSI feedback by the UE; carrying out channel quality indicator updating according to the assessment valve of the inter-cell interference power corresponding to the UE and the signal power corresponding to the UE; and carrying out user scheduling for the UE according to the updated channel quality indicator. According to the method for updating the channel quality indicator, phenomenon that the channel quality indicator of the UE is over estimated is effectively avoided, so that the block error rate in data transmission is greatly reduced.

Description

Upgrade the method and apparatus of channel quality indication

Technical field

The present invention relates to wireless communication technology, particularly upgrade the method and apparatus of channel quality indication (CQI).

Background technology

In coordinate multipoint (CoMP) transmission, for example, coordinate multipoint one by one cooperative scheduling/cooperative beam be shaped in (CoMP-CS/CB) transmission, the renewal of CQI will be carried out according to the channel condition information (CSI) of subscriber equipment (UE) feedback in base station (eNB), and then carry out user's scheduling according to the CQI after upgrading.But the CSI that can know from UE due to the base station is very limited, so can't the CQI of UE accurately be upgraded, also, the CQI of UE is often over-evaluated or underestimated in the base station, thereby can't realize accurate user's scheduling.Especially when the CQI of UE is over-evaluated, after carrying out user's scheduling according to the CQI that is over-evaluated, to adopt higher modulation coding mode (MCS) to carry out transfer of data to this UE, this often causes data transmission fails, cause very high Block Error Rate (BLER), also can cause simultaneously mass data to retransmit, thereby greatly reduce network throughput.

Summary of the invention

In order to address the above problem, embodiments of the invention provide the method and apparatus that upgrades the channel instruction indication, indicate situation about being over-evaluated with the channel quality of avoiding UE occurring, thereby greatly reduce the Block Error Rate in transfer of data.

The method of the renewal channel quality indication that the embodiment of the present invention provides comprises:

Determine the valuation of the presence of intercell interference power that described UE is corresponding according to the pre-coding matrix of the CSI of UE feedback and cooperation cell, wherein, the valuation of the presence of intercell interference power that described UE is corresponding is more than or equal to the actual value of presence of intercell interference power corresponding to described UE;

Determine according to the CSI of described UE feedback the signal power that described UE is corresponding;

The valuation of the presence of intercell interference power corresponding according to described UE and signal power are carried out channel quality indication renewal, and according to the channel quality indication after upgrading, described UE are carried out user's scheduling.

Wherein, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: under the condition of hypothesis UE receiver and interference channel coupling, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

Under the condition of hypothesis UE receiver and interference channel coupling, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein, Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

Perhaps, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: under the condition that the pre-coding matrix of hypothesis interference channel and cooperation cell can farthest mate, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

Under the condition that the pre-coding matrix of supposing interference channel and cooperation cell can farthest mate, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}3}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}{\left(\underset{k=1}{\overset{n_r}{\mathrm{\Σ}}}{\mathrm{\σ}}_k\cos {\mathrm{\α}}_k\right)}^2,$

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, α _kBe angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming; The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

Said method further comprises: according to the transfer of data of UE as a result the ACK/NACK feedback to angle variables α _kDo the self adaptation adjustment.

When UE is equipped with two antennas, according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}\mathrm{3,2}\mathrm{Tx}@\mathrm{UE}}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}({\mathrm{\σ}}_1^2+{\mathrm{\σ}}_2^2){\sin }^2\mathrm{\β},$

Determine that residential quarter corresponding to described UE build the valuation of interference power, wherein, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, β is angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

Said method further comprises: according to the transfer of data of UE as a result the ACK/NACK feedback angle variables β is done the self adaptation adjustment.

According to the transfer of data of UE as a result the ACK/NACK feedback angle variables β done the self adaptation adjustment comprise: initialization angle variables β is

When user feedback NACK, with first step delta of value increase of angle variables β, even β=β+Δ, and guarantee When user feedback ACK, the value of angle variables β is reduced second a step-length δ, even β=β-δ, and guarantee β 〉=0; Wherein, described the first step delta and the second step-length δ are between 0 He Between two constant values.Wherein, described the first step delta and the second step-length δ satisfy

Or, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: under the condition that the pre-coding matrix of hypothesis UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

Wherein, under the condition that the pre-coding matrix of supposing UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And Representative feature beam forming direction.

The device of the described renewal channel quality indication of the embodiment of the present invention comprises:

The presence of intercell interference power determining unit, determine the valuation of the presence of intercell interference power that described UE is corresponding for the pre-coding matrix of the channel condition information CSI that feeds back according to user terminal UE and cooperation cell, the valuation of the presence of intercell interference power that wherein, described UE is corresponding is more than or equal to the actual value of presence of intercell interference power corresponding to described UE;

The signal power determining unit is used for determining according to the CSI of this UE feedback the signal power that this UE is corresponding;

Channel quality indication updating block is used for the presence of intercell interference power valuation corresponding according to this UE and signal power and carries out the CQI renewal, makes the base station to carry out user's scheduling to this UE according to the CQI after upgrading.

Wherein, the presence of intercell interference power determining unit is under the condition of hypothesis UE receiver and interference channel coupling, and the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.Wherein, the presence of intercell interference power determining unit is according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein, Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

Perhaps, the presence of intercell interference power determining unit is under the condition that the pre-coding matrix of hypothesis interference channel and cooperation cell can farthest mate, and the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.Wherein, the presence of intercell interference power determining unit is according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}3}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}{\left(\underset{k=1}{\overset{n_r}{\mathrm{\Σ}}}{\mathrm{\σ}}_k\cos {\mathrm{\α}}_k\right)}^2,$

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, α _kBe angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.Wherein, the presence of intercell interference power determining unit comprises: the angle variables adjusting module, be used for according to the transfer of data of UE as a result the ACK/NACK feedback to angle variables α _kDo the self adaptation adjustment.

When UE was equipped with two antennas, the presence of intercell interference power determining unit was according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}\mathrm{3,2}\mathrm{Tx}@\mathrm{UE}}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}({\mathrm{\σ}}_1^2+{\mathrm{\σ}}_2^2){\sin }^2\mathrm{\β},$

Determine that residential quarter corresponding to described UE build the valuation of interference power, wherein, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, β is angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.Wherein, the presence of intercell interference power determining unit comprises: the angle variables adjusting module, be used for according to the transfer of data of UE as a result the ACK/NACK feedback angle variables β is done the self adaptation adjustment.

Or, the presence of intercell interference power determining unit is under the condition that the pre-coding matrix of hypothesis UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, and the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.Wherein, the presence of intercell interference power determining unit is according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein, Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

As previously mentioned, in the method and apparatus of the renewal channel instruction indication that the embodiment of the present invention provides, the base station is carrying out guaranteeing when presence of intercell interference (ICI) power is estimated that presence of intercell interference power valuation corresponding to determined certain UE is more than or equal to the actual value of presence of intercell interference power corresponding to this UE, thereby the channel quality indication of the UE after guaranteeing to upgrade can not over-evaluated, to reduce the Block Error Rate in transfer of data.

Description of drawings

Fig. 1 is the flow chart of the described CQI update method of the embodiment of the present invention;

Fig. 2 is the described CQI updating device of embodiment of the present invention internal structure schematic diagram.

Embodiment

In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.

When carrying out channel quality indication (CQI) renewal in the base station according to the CSI of UE feedback, at first the base station carries out to this UE according to the pre-coding matrix of the CSI of a certain UE feedback in self coverage and cooperation cell that presence of intercell interference power is estimated and signal power is estimated, and then the presence of intercell interference power and signal power corresponding according to this UE that estimates carries out the CQI renewal of this UE.Because the base station can be very limited from the CSI that UE is known, therefore the base station is inaccurate for the suffered Interference Estimation of coming each residential quarter in the self feed back set of UE, be also that the base station is estimated inaccurate to presence of intercell interference power corresponding to this UE, thereby can't realize the accurate renewal of the CQI of UE, the situation that the CQI of UE is over-evaluated or underestimates often occur.Especially when the CQI of UE is over-evaluated, user's scheduling will be carried out according to the CQI that is over-evaluated in the base station, result is will adopt higher MCS to carry out transfer of data to this UE, this often causes bust this, cause very high Block Error Rate, also can cause simultaneously the serious consequence that mass data retransmits and network throughput reduces greatly.

For this reason, embodiments of the invention provide the method for upgrading CQI, occur effectively to avoid the situation that CQI is over-evaluated.The method is completed by the base station usually.

Fig. 1 has shown the flow process of the method for the described renewal of the present embodiment CQI, and as shown in Figure 1, the method comprises the steps:

Step 101: determine the valuation of the presence of intercell interference power that this UE is corresponding according to the pre-coding matrix of the CSI of UE feedback and cooperation cell, the valuation of the presence of intercell interference power that wherein, determined this UE is corresponding is more than or equal to the actual value of presence of intercell interference power corresponding to this UE;

Step 102: determine the signal power that this UE is corresponding according to the CSI of this UE feedback;

Just comprise CQI information in CSI due to the UE feedback, therefore, in this step, can directly determine according to the CQI information of UE feedback the signal power that this UE is corresponding.Need to prove, the CQI information of UE feedback is not considered from the interference within cooperation, therefore, need to carry out CQI of the present invention and upgrade.

Step 103: the valuation of the presence of intercell interference power corresponding according to this UE and signal power are carried out the CQI renewal, and according to the CQI after upgrading, this UE are carried out user's scheduling.

In this step, the valuation of the presence of intercell interference power corresponding according to this UE and signal power are carried out concrete grammar that CQI upgrades can be with reference to the relevant motion of 3GPP.

can find out from said method, due to the valuation of the presence of intercell interference power that determined UE is corresponding in above-mentioned steps 101 actual value more than or equal to presence of intercell interference power corresponding to this UE, the interference power from cooperation cell that namely is subject to more than or equal to this UE, make the actual value that is less than or equal to CQI through the CQI after the described method renewal of step 103, also namely use the CQI that the method can obtain relatively guarding, namely can obtain the lower bound of actual CQI, thereby effectively avoided the situation that CQI is over-evaluated to occur, the problems such as the high Block Error Rate that solution causes because CQI over-evaluates and mass data re-transmission.

The below will describe described CSI and the pre-coding matrix of the cooperation cell method of determining the presence of intercell interference power valuation that this UE is corresponding according to UE feedback of above-mentioned steps 101 in detail.

For convenience of description, definition UE reception antenna number is n _r, for some data flow, its power normalization linear receiver is g.The total transmitted power of cooperation cell is P _t, order adds up to r _c, the pre-coding matrix of cooperation cell base station is W _c, the cooperation cell base station is H to user's wireless channel _c, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

Channel gain during the representative feature beam forming; And

Representative feature beam forming direction.The actual value of the presence of intercell interference that in this case, UE is corresponding can calculate by following formula (1).

$P_{\mathrm{ICI}}^{\mathrm{real}}=\frac{P_t}{r_c}g{H}_c{W}_c{W}_c^H{H}_c^H{g}^H---\left(1\right)$

Can obtain the expression formula shown in following formula (2) to above-mentioned formula (1) through the derivation of equation.

$P_{\mathrm{ICI}}^{\mathrm{real}}=\frac{P_t}{r_c}\underset{k=1}{\overset{n_r}{\mathrm{\Σ}}}\underset{l=1}{\overset{n_r}{\mathrm{\Σ}}}{\mathrm{\σ}}_k{\mathrm{\σ}}_l\cos {\mathrm{\α}}_k\cos {\mathrm{\α}}_l\left|v_k^H{W}_c{W}_c^H{v}_l\right|\cos ({\mathrm{\θ}}_k-{\mathrm{\θ}}_l+{\mathrm{\φ}}_{\mathrm{kl}})---\left(2\right)$

Wherein, ${\mathrm{gu}}_k={\cos \mathrm{\α}}_k\·e^{{\mathrm{j\θ}}_k},{\mathrm{gu}}_l=\cos {\mathrm{\α}}_l\·e^{{\mathrm{j\θ}}_l},v_k^H{W}_c{W}_c^H{v}_l=\left|v_k^H{W}_c{W}_c^H{v}_l\right|e^{j{\mathrm{\φ}}_{\mathrm{kl}}},$

θ _k，θ _l∈[0，2π)，k，l＝1，...，n _r。

According to the CSI of UE feedback, the base station can know that the total transmitted power of cooperation cell in above-mentioned formula (2) is P _t, order adds up to r _c, pre-coding matrix is W _cAnd

With But, because the CSI of UE feedback is limited, so the base station can not be known

With (the perhaps α in above-mentioned formula (2) _k, α _lAnd θ _k, θ _l), k, l=1 ..., n _rThereby, can't accurately calculate the actual value of disturbing between the UE respective cell, also namely can't estimate to entirely accurate the suffered interference from cooperation cell of UE.

In the present embodiment, for the CQI that obtains to guard estimates, the base station need to guarantee the valuation of determined presence of intercell interference power more than or equal to the actual value of presence of intercell interference power corresponding to this UE when determining the valuation of presence of intercell interference power, also namely determine the upper bound of presence of intercell interference power actual value.Particularly, can adopt one of following three kinds of methods to realize.

Method 1

Under the condition of hypothesis UE receiver and interference channel coupling, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.Each data flow of namely supposing receiver g and cooperation cell is mated fully, and ignores

Phase place, even also α _k=α _l=θ _k-θ _l+ φ _kl=0, k, l=1 ..., n _r, at this moment, satisfy cos σ _k=cos σ _l=cos (θ _k-θ _l+ φ _kl)=1 can obtain shown in the following formula of the upper limit (3) of presence of intercell interference power corresponding to UE.

$P_{\mathrm{ICI}}^{\mathrm{scheme}1}=\frac{P_t}{r_c}\underset{k=1}{\overset{n_r}{\mathrm{\Σ}}}\underset{l=1}{\overset{n_r}{\mathrm{\Σ}}}{\mathrm{\σ}}_k{\mathrm{\σ}}_l\left|v_k^H{W}_c{W}_c^H{v}_l\right|---\left(3\right)$

The valuation that above-mentioned formula (3) is determined the presence of intercell interference power that UE is corresponding namely can be used in the base station.The valuation of the presence of intercell interference power that the UE that obviously, calculates by above-mentioned formula (3) is corresponding

Actual value more than or equal to presence of intercell interference power corresponding to this UE

Method 2

Under the condition that the pre-coding matrix of hypothesis UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.In the method, the following formula of base station applies (4) is determined the valuation of the presence of intercell interference power that UE is corresponding.

$P_{\mathrm{ICI}}^{\mathrm{scheme}2}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}{\left(\underset{k=1}{\overset{n_r}{\mathrm{\Σ}}}{\mathrm{\σ}}_k\right)}^2---\left(4\right)$

The valuation of the presence of intercell interference power that the UE that obviously, calculates by above-mentioned formula (4) is corresponding

Actual value more than or equal to presence of intercell interference power corresponding to this UE

Ten thousand methods 3

Under the condition that the pre-coding matrix of hypothesis interference channel and cooperation cell can farthest mate, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.The multinomial on the computing formula equation shown in formula (2) the right is done further amplification can obtain following formula (5), the valuation that following formula (5) is determined the presence of intercell interference power that UE is corresponding can be used in the base station.Obviously, due to the value of cosine function less than or equal to 1, the valuation of the presence of intercell interference power that the UE that calculates by following formula (5) is corresponding

Actual value more than or equal to presence of intercell interference power corresponding to this UE

$P_{\mathrm{ICI}}^{\mathrm{scheme}3}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}{\left(\underset{k=1}{\overset{n_r}{\mathrm{\Σ}}}{\mathrm{\σ}}_k\cos {\mathrm{\α}}_k\right)}^2---\left(5\right)$

Wherein,

K=1 ..., n _rObviously, for n is arranged _rThe user of root reception antenna, total n _rIndividual angle parameter.At this moment, the base station can utilize the transfer of data result feedback (ACK/NACK) of UE to this n _rIndividual angle parameter α _kCarry out adaptive adjustment.

Especially, with two antenna n _r=2 is example, at this moment, can notice vectorial u ₁⊥ u ₂, i.e. vectorial u ₁And u ₂Be quadrature, thereby satisfy

At this moment, above-mentioned formula (5) can further be derived as following formula (6).

$P_{\mathrm{ICI}}^{\mathrm{scheme}\mathrm{3,2}\mathrm{Tx}@\mathrm{UE}}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}({\mathrm{\σ}}_1^2+{\mathrm{\σ}}_2^2){\sin }^2\mathrm{\β}---\left(6\right)$

Wherein, $\mathrm{\β}={\mathrm{\α}}_1+\arctan \frac{{\mathrm{\σ}}_1}{{\mathrm{\σ}}_2}.$

In the method, the base station can pre-determine the value of angle variables β, and then determines the valuation of the presence of intercell interference power that this UE is corresponding according to above-mentioned formula (6).As an alternative solution, at first the base station also can utilize transfer of data result (ACK/NACK) feedback of UE to do the self adaptation adjustment to angle variables β, and then the valuation of determining the presence of intercell interference power that this UE is corresponding according to the angle variables β after adjusting and above-mentioned formula (6).Particularly, the method for self adaptation adjustment angle variables β comprises the steps:

Step 1, initialization angle variables β is

Step 2 is carried out following self adaptation adjustment according to the transfer of data result (ACK/NACK) of user feedback to angle beta, specifically comprises:

A) when user feedback NACK, with first step delta of value increase of angle beta, even β=β+Δ, and guarantee

B) when user feedback ACK, the value of angle beta is reduced second a step-length δ, even β=β is one δ, and guarantee β 〉=0.

Wherein, above-mentioned the first step delta and the second step-length δ are between 0 He

Between two constant values, these two values can equate, also can be unequal.Preferably, in order to return back to rapidly the upper bound of presence of intercell interference power corresponding to UE when data transmission fault (NACK) occurs, usually make $0<\mathrm{\&delta;}<\mathrm{\&Delta;}<\frac{\mathrm{\&pi;}}{2}.$

The method of corresponding above-mentioned renewal channel quality indication, embodiments of the invention also disclose a kind of channel quality indication updating device that is applied in the base station, and the internal structure of this device mainly comprises as shown in Figure 2:

Presence of intercell interference power determining unit 201, determine the valuation of the presence of intercell interference power that this UE is corresponding for the pre-coding matrix of the CSI that feeds back according to UE and cooperation cell, the valuation of the presence of intercell interference power that wherein, determined this UE is corresponding is more than or equal to the actual value of presence of intercell interference power corresponding to this UE;

Signal power determining unit 202 is used for determining according to the CSI of this UE feedback the signal power that this UE is corresponding;

Channel quality indication updating block 203 is used for the presence of intercell interference power valuation corresponding according to this UE and signal power and carries out the CQI renewal, makes the base station to carry out user's scheduling to this UE according to the CQI after upgrading.

Particularly, above-mentioned presence of intercell interference power determining unit 201 can be passed through the valuation that one of said method 1, method 2 and method 3 described methods are determined the presence of intercell interference power that UE is corresponding.

When using said method 2 and determine the valuation of the presence of intercell interference power that UE is corresponding, above-mentioned presence of intercell interference power determining unit 201 comprises: the angle variables adjusting module, be used for according to the transfer of data of UE as a result the ACK/NACK feedback to angle variables α _kDo the self adaptation adjustment;

When using the valuation of presence of intercell interference power corresponding to the definite UE of said method 3, above-mentioned presence of intercell interference power determining unit 201 comprises:

The angle variables adjusting module, be used for according to the transfer of data of UE as a result the ACK/NACK feedback angle variables β is done the self adaptation adjustment;

Presence of intercell interference power determination module is used for determining according to above-mentioned formula (6) valuation of the presence of intercell interference power that described UE is corresponding.

can find out from above-mentioned channel quality indication updating device, due to the valuation of presence of intercell interference power corresponding to the UE that is determined by presence of intercell interference power determining unit 201 actual value more than or equal to presence of intercell interference power corresponding to this UE, the interference power from cooperation cell that namely is subject to more than or equal to this UE, make CQI after channel quality indication updating block 203 upgrades be less than or equal to the actual value of CQI, the CQI that also namely can obtain relatively guarding, it is the lower bound of actual CQI, thereby effectively avoided the situation that CQI is over-evaluated to occur, the problems such as the high Block Error Rate that solution causes because CQI over-evaluates and mass data re-transmission.

The above is only preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of making, is equal to replacement, improvement etc., within all should being included in the scope of protection of the invention.

Claims (22)

1. a method of upgrading the channel quality indication, is characterized in that, comprising:

Determine the valuation of the presence of intercell interference power that described UE is corresponding according to the pre-coding matrix of the channel condition information CSI of user terminal UE feedback and cooperation cell, the valuation of the presence of intercell interference power that wherein, described UE is corresponding is more than or equal to the actual value of presence of intercell interference power corresponding to described UE;

Determine according to the CSI of described UE feedback the signal power that described UE is corresponding;

The valuation of the presence of intercell interference power corresponding according to described UE and signal power are carried out channel quality indication renewal, and according to the channel quality indication after upgrading, described UE are carried out user's scheduling.

2. method according to claim 1, wherein, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: under the condition of hypothesis UE receiver and interference channel coupling, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

3. method according to claim 2, wherein, under the condition of hypothesis UE receiver and interference channel coupling, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

4. method according to claim 1, wherein, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: under the condition that the pre-coding matrix of hypothesis interference channel and cooperation cell can farthest mate, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

5. method according to claim 4, wherein, under the condition that the pre-coding matrix of supposing interference channel and cooperation cell can farthest mate, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}3}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}{\left(\underset{k=1}{\overset{n_r}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_k\cos {\mathrm{\&alpha;}}_k\right)}^2,$ Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, α _kBe angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

6. method according to claim 5 wherein, further comprises: according to the transfer of data of UE as a result the ACK/NACK feedback to angle variables α _kDo the self adaptation adjustment.

7. method according to claim 4, wherein, when UE is equipped with two antennas, according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}\mathrm{3,2}\mathrm{Tx}@\mathrm{UE}}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}({\mathrm{\&sigma;}}_1^2+{\mathrm{\&sigma;}}_2^2){\sin }^2\mathrm{\&beta;},$

Determine that residential quarter corresponding to described UE build the valuation of interference power, wherein, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, β is angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein, Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

8. method according to claim 7 wherein, further comprises: according to the transfer of data of UE as a result the ACK/NACK feedback angle variables β is done the self adaptation adjustment.

9. method according to claim 8, wherein, according to the transfer of data of UE as a result the ACK/NACK feedback angle variables β done the self adaptation adjustment comprise:

Initialization angle variables β is

When user feedback NACK, with first step delta of value increase of angle variables β, even β=β+Δ, and guarantee

When user feedback ACK, the value of angle variables β is reduced second a step-length δ, even β=β-δ, and guarantee β 〉=0; Wherein, described the first step delta and the second step-length δ are between 0 He

Between two constant values.

10. method according to claim 9, wherein, described the first step delta and the second step-length δ satisfy $0<\mathrm{\&delta;}<\mathrm{\&Delta;}<\frac{\mathrm{\&pi;}}{2}.$

11. method according to claim 1, wherein, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: under the condition that the pre-coding matrix of hypothesis UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

12. method according to claim 11, wherein, under the condition that the pre-coding matrix of supposing UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, determine that according to the CSI of UE feedback and the pre-coding matrix of cooperation cell the valuation of the presence of intercell interference power that described UE is corresponding comprises: according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming; The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

13. a device that upgrades the channel quality indication is characterized in that, comprising:

The presence of intercell interference power determining unit, determine the valuation of the presence of intercell interference power that described UE is corresponding for the pre-coding matrix of the channel condition information CSI that feeds back according to user terminal UE and cooperation cell, the valuation of the presence of intercell interference power that wherein, described UE is corresponding is more than or equal to the actual value of presence of intercell interference power corresponding to described UE;

The signal power determining unit is used for determining according to the CSI of this UE feedback the signal power that this UE is corresponding;

Channel quality indication updating block is used for the presence of intercell interference power valuation corresponding according to this UE and signal power and carries out the CQI renewal, makes the base station to carry out user's scheduling to this UE according to the CQI after upgrading.

14. device according to claim 13, wherein, the presence of intercell interference power determining unit is under the condition of hypothesis UE receiver and interference channel coupling, and the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

15. device according to claim 14, wherein, the presence of intercell interference power determining unit is according to formula Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

16. device according to claim 13, wherein, the presence of intercell interference power determining unit is under the condition that the pre-coding matrix of hypothesis interference channel and cooperation cell can farthest mate, and the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

17. device according to claim 16, wherein, the presence of intercell interference power determining unit is according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}3}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}{\left(\underset{k=1}{\overset{n_r}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_k\cos {\mathrm{\&alpha;}}_k\right)}^2,$ Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, α _kBe angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein, Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

18. device according to claim 17, wherein, the presence of intercell interference power determining unit comprises: the angle variables adjusting module, be used for according to the transfer of data of UE as a result the ACK/NACK feedback to angle variables α _kDo the self adaptation adjustment.

19. device according to claim 16, wherein, when UE was equipped with two antennas, the presence of intercell interference power determining unit was according to formula $P_{\mathrm{ICI}}^{\mathrm{scheme}\mathrm{3,2}\mathrm{Tx}@\mathrm{UE}}=\frac{P_t}{r_c}\underset{k,l}{\max }\left\{\right|v_k^H{W}_c{W}_c^H{v}_l\left|\right\}({\mathrm{\&sigma;}}_1^2+{\mathrm{\&sigma;}}_2^2){\sin }^2\mathrm{\&beta;},$

Determine that residential quarter corresponding to described UE build the valuation of interference power, wherein, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, β is angle variables, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

20. device according to claim 19, wherein, the presence of intercell interference power determining unit comprises: the angle variables adjusting module, be used for according to the transfer of data of UE as a result the ACK/NACK feedback angle variables β is done the self adaptation adjustment.

21. device according to claim 13, wherein, the presence of intercell interference power determining unit is under the condition that the pre-coding matrix of hypothesis UE receiver and interference channel coupling and interference channel and cooperation cell can farthest mate, and the CSI that feeds back according to UE and the pre-coding matrix of cooperation cell are determined the valuation of the presence of intercell interference power that described UE is corresponding.

22. device according to claim 21, wherein, the presence of intercell interference power determining unit is according to formula

Determine the valuation of the presence of intercell interference power that described UE is corresponding, wherein, n _rBe the reception antenna number of UE, P _tBe the total transmitted power of cooperation cell, r _cBe order sum, W _cBe the pre-coding matrix of cooperation cell base station, H _cBe the cooperation cell base station wireless channel to described UE, its singular value decomposition is H _c=U _c∑ _cV _c ^H, wherein,

Coupling receive direction during the representative feature beam forming;

The channel gain of representative feature beam forming direction; And

Representative feature beam forming direction.

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