CN103326812B - The method and apparatus of quantized channel status information - Google Patents

Abstract

The present invention discloses the method and apparatus of a kind of quantized channel status information. According to one embodiment of the invention, it provides the method providing codewords indexes from subscriber equipment to base station, and this base station is configured with N_tRoot beam antenna. The method comprises: according to estimated channel matrix, and subscriber equipment determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion, r=1, and 2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna; And the codewords indexes of code word is sent to base station. The present invention uses non-permanent mould code book, compared to permanent mould code book, it comprises the problem of unbalanced power between each antenna element, is remarkably improved the performance of system.

Description

The method and apparatus of quantized channel status information

Technical field

The present invention is the method and apparatus about a kind of quantized channel status information, especially with respect to the method and apparatus of quantized channel status information in a kind of wireless communication system.

Background technology

It is known that channel condition information (CSI, ChannelStateInformation) quantifies to be a key issue in frequency division multiplexing (FDD, FrequencyDivisionDuplex) system. Wherein for beam antenna, its channel quantitative and feedback problem then richer challenge. With common directed circular antenna array (CAA, Circularantennaarray) for example, owing to arriving angle (DoA, DegreeofArrival) different, each antenna is to identical subscriber equipment (UE, UserEquipment) there is different antenna gains, as fluctuated between the floor level (e.g. ,-15dB) less than-1dB to antenna gain.

But, industry is now widely used is the code book for omnidirectional antenna, and it cannot reflect the unbalanced power problem between the antenna element of beam antenna. Thus, the problem needing in the industry the quantized channel status information solving beam antenna badly.

Summary of the invention

It is an object of the present invention to provide the method and apparatus of quantized channel status information in a kind of wireless communication system, it is applicable to beam antenna configuration, can feed back the unbalanced power problem between the antenna element of beam antenna.

According to one embodiment of the invention, it provides a kind of method, and it provides codewords indexes information from subscriber equipment to base station, and this base station is configured with N_tRoot beam antenna. The method comprises: according to estimated channel matrix, and subscriber equipment determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion, r=1, and 2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna; And the codewords indexes information of code word is sent to base station.

In one embodiment of this invention, this non-permanent mould code book is the predefined code book for omnidirectional antenna configuration and the product of the diagonalizable matrix quantifying vector of each antenna element amplitude of variation in reflection beam antenna. In one embodiment, non-permanent mould code book comprises two-stage feedback arrangement; Corresponding predefined code book comprises the first code book and the second code book, and wherein the first code book comprises broad-band channel direction estimation information, and the second code book comprises sub-band channel direction estimation information. The first order feedback of non-permanent mould code book is determined with the diagonalizable matrix of the vector of the amplitude definition of each antenna element in beam antenna by the first code book of predefined code book. The second level feedback of non-permanent mould code book is determined by the second code book of predefined code book.

According to another embodiment of the present invention, it provides a kind of method that code word is determined in base station. The method comprises: reception order is the index information of the code word in the non-permanent mould code book of r, r=1, and 2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna; And the index information according to code word determines code word.

According to another embodiment of the present invention, it provides the subscriber equipment providing codewords indexes information to base station. This subscriber equipment comprises: code word determines device; According to estimated channel matrix, subscriber equipment determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion, r=1,2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna; And codewords indexes information transmitting apparatus, the codewords indexes information of code word is sent to base station.

One embodiment of the invention also provides for a kind of base station, comprises: codewords indexes information receiver; Reception order is the index information of the code word in the non-permanent mould code book of r, r=1,2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna; And code word determines device, determine code word according to the index information of code word.

Non-permanent mould (non-constantmodulus) code book provided by the invention is applicable to beam antenna configuration, can the unbalanced power of feeding back antenna; Compared to permanent mould code book, there is the system performance gain of highly significant and limited additional feedback expense.

Accompanying drawing explanation

Fig. 1 is that subscriber equipment provides codewords indexes information to the flow chart of base station according to an embodiment of the invention;

Fig. 2 is that the flow chart of code word is determined in base station according to an embodiment of the invention;

Fig. 3 is system structure block chart for quantized channel status information according to an embodiment of the invention.

Detailed description of the invention

Spirit for a better understanding of the present invention, it is described further by the part preferred embodiment below in conjunction with the present invention.

The method and apparatus for quantized channel status information of the present invention, uses non-permanent mould code book for beam antenna. This non-permanent mould code book reflects the unbalanced power information between each beam antenna, thus quantized channel status information more accurately.

According to one embodiment of the invention, enter to have more in (MIMO, MultipleInputMultipleOutput) system at downlink more, base station, it is equipped with N_tRoot beam antenna, as can be configured to directed circular antenna array etc. For each order r, r=0,1 ..., N_t, build the non-permanent mould code book of correspondence respectively, wherein this non-permanent mould code book is configured by for omnidirectional antenna, and the predefined code book such as omnidirectional's circle aerial array is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna. There is the non-permanent mould code book of different order, and code book is established rules really, is stored respectively in base station and subscriber equipment, for quantized channel status information. Subscriber equipment provides the codewords indexes information of quantized channel status information to base station, based on the codewords indexes information received, base station determines that code word obtains channel condition information. When index information in code word does not comprise the order information of the code book of its correspondence, subscriber equipment also needs to send this order information to base station.

Concrete, as it is shown in figure 1, subscriber equipment provides the codewords indexes information of quantized channel status information to base station by up-link. In step 100, according to estimated channel matrix, subscriber equipment determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion; This non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna as previously mentioned. Such as, this non-permanent mould code book is the predefined code book for omnidirectional antenna configuration and the product of the diagonalizable matrix quantifying vector of each antenna element amplitude of variation in reflection beam antenna. Then, the codewords indexes information of this code word is sent to base station by subscriber equipment in a step 101.

Accordingly, in base station side. As in figure 2 it is shown, the index information of the code word received in step 200 base station in the non-permanent mould code book that order is r; Then in step 201, code word is determined according to the index information of the code word received, thus obtaining channel condition information.

The non-permanent mould code book of the present invention can use the arbitrary code book for omni-directional antenna arrays to quantify the channel condition information of beam antenna. According to one embodiment of the invention, this non-permanent mould code book can be the code book comprising two-stage feedback arrangement, and the corresponding predefined code book for omnidirectional antenna configuration comprises the first code book and the second code book; Wherein the first code book comprises broad-band channel direction estimation information, and the second code book comprises sub-band channel direction estimation information. The first order feedback of non-permanent mould code book can be determined with the diagonalizable matrix of the vector of the amplitude definition of each antenna element in beam antenna by the first code book of predefined code book, and second level feedback also can be determined by the second code book of predefined code book. It is typically longer than in view of the feedback cycle of first order feedback arrangement or equal to second level feedback arrangement, reflects that the unbalanced information of each antenna power is generally only embodied in first order feedback arrangement and just may be used. That is, the second level feedback of non-permanent mould code book can directly use the second code book of predefined code book.

So, the non-permanent mould code book with two-stage feedback arrangement comprises two pre-coding matrix indexes (PrecodingMatrixIndicator), is respectively used to the channel performance of instruction system broad and the channel performance of subband and/or short-term. Compared with LTERel-10 code book, when it can not increase the feedback overhead of pre-coding matrix index, significant raising systematic function. Pre-coding matrix index as understood by those skilled in the art and codewords indexes are same concept, can be used alternatingly in the present invention.

Below for a non-permanent mould code book with two-stage feedback arrangement, how channel condition information is quantified by demonstration one embodiment of the invention further, namely produces the non-permanent mould code book with above-mentioned two-stage feedback arrangement for quantized channel status information. Those skilled in the art can grasp the generation of the non-permanent mould code book of first order feed-back structure easily based on this generation of non-permanent mould code book with two-stage feedback arrangement, repeats no more herein.

According to one embodiment of the invention, the unbalanced power of each beam antenna is measured by the signal power of downlink channel, thus obtaining the amplitude of each antenna. Then for N_tRoot beam antenna, by the amplitude definition one of each antenna vector

Assuming that this beam antenna is directed circular array configuration, its predefined code book preferably uses the code book for omnidirectional's circular array.

N for omnidirectional's circular array configuration_tRoot antenna, wherein the azimuth of n-th antenna is ��_n. Due to the uniform distribution on same circumference of each antenna, ��_nIt is represented by:

${\mathrm{\θ}}_n=\frac{2\mathrm{\π}}{N_t}n,n=\mathrm{0,1},\·\·\·N_t-1$

The electromagnetic angle of departure (AoD, AngleofDeparture) of this Base Transmitter is expressed as (��, ��), wherein the electromagnetic horizontal azimuth of �� and �� respectively this Base Transmitter and the elevation angle. Then base station has following form to the principal eigenvector of the channel matrix between subscriber equipment:

$v={[e^{-j\frac{2\mathrm{\πR}}{\mathrm{\λ}}\sin \mathrm{\β}\cos (\mathrm{\α}-{\mathrm{\θ}}_0)},e^{-j\frac{2\mathrm{\πR}}{\mathrm{\λ}}\sin \mathrm{\β}\cos (\mathrm{\α}-{\mathrm{\θ}}_1)},\·\·\·,e^{-j\frac{2\mathrm{\πR}}{\mathrm{\λ}}\sin \mathrm{\β}\cos (\mathrm{\α}-{\mathrm{\θ}}_{\mathrm{Nt}-1})}]}^T---\left(1\right)$

Wherein �� �� [0,2 ��), �� �� [0, ��), R be uniform circular array row radius, �� is the electromagnetic wavelength of Base Transmitter.

In the present embodiment, the predefined code book with two-stage feedback arrangement of the present invention is built based on this channel matrix. For each order rr=0,1 ..., N_t, build corresponding predefined code book, the predefined code book of variant order r, comprise corresponding first code book C₁With the second code book C₂. Wherein the first code book C₁Comprise some first code word W₁, represent one group of wave beam (beam) to broad-band channel direction estimation, such as M adjacent wave beam; And the second code book C₂Comprise some second code word W₂, it selects the first code word W₁In a wave beam be used for portray sub-band channel direction.

Can by �� on whole phase space respectively uniform quantization be N number of value, it may be assumed that

$\mathrm{\α}=\frac{2\mathrm{\πn}}{N},n=\mathrm{0,1},\·\·\·,N-1;$

For the sake, elevation angle �� is set toThen the first code book C₁In the first code word W₁In beam table be shown as:

$b_n={[e^{-j\frac{2\mathrm{\πR}}{\mathrm{\λ}}\cos (\frac{2\mathrm{\πn}}{N}-{\mathrm{\θ}}_0)},e^{-j\frac{2\mathrm{\πR}}{\mathrm{\λ}}\cos (\frac{2\mathrm{\πn}}{N}-{\mathrm{\θ}}_1)},\·\·\·,e^{-j\frac{2\mathrm{\πR}}{\mathrm{\λ}}\cos (\frac{2\mathrm{\πn}}{N}-{\mathrm{\θ}}_{N_t-1})}]}^T,n=\mathrm{0,1},\·\·\·,N-1---\left(2\right)$

When the first code word W₁When comprising M adjacent beams, then the first code book C₁In kth the first code word W₁It is expressed as:

$W_1^{\left(k\right)}=\left[\begin{array}{cccc}{b}_{\frac{\mathrm{Mk}}{2}\mathrm{mod}N}& b_{(\frac{\mathrm{Mk}}{2}+1)\mathrm{mod}N}& \·\·\·& b_{(\frac{\mathrm{Mk}}{2}+M-1)\mathrm{mod}N}\end{array}\right],k=\mathrm{0,1},\·\·\·,\frac{2(N-M)}{M}+1---\left(3\right)$

In the present embodiment, k represents the first code word W₁Index, and encoded according to need after carry out storing and transmitting.

First code word W₁The first code book C₁It is

$C_1=\{W_1^{\left(0\right)},W_1^{\left(1\right)},W_1^{\left(2\right)},\·\·\·,W_1^{(\frac{2(N-M)}{M}+1)}\}---\left(4\right)$

The first order feedback of non-according to an embodiment of the invention permanent mould code book contains unbalanced power information, and namely this first order feedback arrangement is determined with the diagonalizable matrix of the vector of the amplitude definition of each antenna element in beam antenna by the first code book predefining code book. The first code book that can make predefined code book is multiplied with the diagonalizable matrix of the vector of the amplitude definition of each in beam antenna, then kth the first code word F in the first order feedback of this non-permanent mould code book₁It is expressed as:

${F_1}^{\left(k\right)}=\mathrm{diag}\left({\tilde{p}}_{1x{N}_t}\right)x{W_1}^{\left(k\right)}\text{---}\left(5\right)$

Set order in the present embodiment as 1 to N_tThe first code book C₁All identical, then the non-permanent mould code book of different orders is also identical.

Second code word W₂It it is the first code word W selecting there is corresponding order₁In a wave beam, i.e. string in equation (3). Therefore, order is the second code book C of 1₂In i-th the second code word W₂It is

$W_2^{\left(i\right)}=\frac{1}{\sqrt{N_t}}\left[{\tilde{e}}_i\right],i=\mathrm{0,1},\·\·\·,M-1---\left(6\right)$

WhereinBe be except i+1 element 0 M*1 basis vector. Accordingly, this order is the second code book C of 1₂It is expressed as:

C₂={ W₂ ⁽⁰⁾, W₂ ⁽¹⁾..., W₂ ^(M-1)}

(7)

For having the second code book C of higher order r₂, then its i-th second code word W₂ ⁽ⁱ⁾It is expressed as:

In the present embodiment, i represents the second code word W₂Index, and encoded according to need after carry out storing and transmitting.

In the present embodiment, non-permanent mould code book mainly reflects long-term unbalanced power information, thus its second level feedback can directly use the second code book C in predefined code book₂. Namely order is the second level feedback of the non-permanent mould code book of r, its i-th the second code word F₂ ⁽ⁱ⁾It is expressed as:

The last code word F of non-permanent mould code book is based on the first code word F of first order feedback₁The second code word F with second level feedback₂Determine. The final predefined code book being 1 for order, can be F according to its code word F of one embodiment of the invention₁With F₂It is multiplied, namely

F=F₁F₂

(10)

The present invention also provides for the device for quantized channel status information, and it uses non-permanent mould code book for beam antenna.

Fig. 3 illustrates the system block diagram of the device of quantized channel status information according to an embodiment of the invention, and within the system, subscriber equipment 30 provides codewords indexes information to base station 40, and this base station 40 is configured with N_tThe antenna of root orientation circular array configuration. Subscriber equipment 30 comprises: code word determines device 300, and it is according to estimated channel matrix, determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion, r=1, and 2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in reflection beam antenna by the predefined code book configured for omnidirectional antenna; And codewords indexes information transmitting apparatus 301, the codewords indexes information of code word is sent to base station.

Accordingly, base station 40 comprises: codewords indexes information receiver 400, and its order receiving subscriber equipment 30 offer is the index information of the code word of the non-permanent mould code book of r; And code word determines device 401, determine code word based on the codewords indexes information received.

Below by way of the emulation to system-level performance, highlight the advantage compared to permanent mould code book when the present invention is applied to beam antenna further.

In Table 1, compare multi-user and enter to have more in (MU-MIMO, MultipleUser-MultipleInputMultipleOutput) pattern more, 8 antennas of the directed circular array configuration systematic function when using two kinds of different circular array code books. One of them is non-according to an embodiment of the invention permanent mould code book, and oneself considers unbalanced power problem; Another code book does not then account for unbalanced power problem, is called permanent mould code book.

As a comparison, benchmark MIMO mode adopts Rel.8 two antenna single user to enter to have more (SU-MIMO, SingleUser-MultipleInputMultipleOutput) pattern more. According to table 1, compared to Rel.8 two antenna SU-MIMO, the non-permanent mould code book of 8 antennas can obtain community average gain and the 214% cell edge gain of 147%, and performance surpasses permanent mould code book.

The system layer simulation result of table 18 antenna direction circular array antenna configuration

Table 2 compares two kinds of feedback overheads with the circular array code book of two-stage feedback. Visible, for the reflection unbalanced long-term characteristic of antenna gain, non-according to an embodiment of the invention permanent mould circular array code book only introduces about 2%, very limited amount of additional feedback expense.

Table 2 feedback overhead compares

The technology contents of the present invention and technical characterstic have revealed that as above, but those of ordinary skill in the art are still potentially based on teachings of the present invention and announcement and do all replacements without departing substantially from spirit of the present invention and modification. Therefore, protection scope of the present invention should be not limited to the content that embodiment is disclosed, and should include the various replacement without departing substantially from the present invention and modification, and is contained by present patent application claims.

Claims (16)

1. the method providing codewords indexes information from subscriber equipment to base station, described base station is configured with N_tRoot beam antenna; Described method comprises:

According to estimated channel matrix, described subscriber equipment determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion, r=1,2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in the described beam antenna of reflection by the predefined code book configured for omnidirectional antenna; And

The codewords indexes information of described code word is sent to described base station.

2. the method for claim 1, it is characterised in that this non-permanent mould code book is the product of the predefined code book for omnidirectional antenna configuration and the diagonalizable matrix of the quantization vector reflecting each antenna element amplitude of variation in described beam antenna.

3. the method as described in one of claim 1 or 2, it is characterised in that described non-permanent mould code book comprises two-stage feedback arrangement; Corresponding described predefined code book comprises the first code book and the second code book, and wherein said first code book comprises broad-band channel direction estimation information, and described second code book comprises sub-band channel direction estimation information.

4. method as claimed in claim 3, it is characterised in that the first order feedback of described non-permanent mould code book is determined with the diagonalizable matrix of the vector of the amplitude definition of each antenna element in described beam antenna by the first code book of described predefined code book.

5. method as claimed in claim 3, it is characterised in that the second level feedback of described non-permanent mould code book is determined by the second code book of described predefined code book.

6. the method that code word is determined in base station, described base station is configured with N_tRoot beam antenna; Described method comprises:

Reception order is the index information of the code word in the non-permanent mould code book of r, r=1,2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in the described beam antenna of reflection by the predefined code book configured for omnidirectional antenna; And

Index information according to described code word determines described code word.

7. method as claimed in claim 6, it is characterised in that this non-permanent mould code book is the predefined code book for omnidirectional antenna configuration and the product of the diagonalizable matrix quantifying vector of each antenna element amplitude of variation in the described beam antenna of reflection.

8. the method as described in one of claim 6 or 7, it is characterised in that described non-permanent mould code book comprises two-stage feedback arrangement; Corresponding described predefined code book comprises the first code book and the second code book, and wherein said first code book comprises broad-band channel direction estimation information, and described second code book comprises sub-band channel direction estimation information.

9. method as claimed in claim 8, it is characterised in that the first order feedback of described non-permanent mould code book is determined with the diagonalizable matrix of the vector of the amplitude definition of each antenna element in described beam antenna by the first code book of described predefined code book.

10. method as claimed in claim 8, it is characterised in that the second level feedback of described non-permanent mould code book is determined by the second code book of described predefined code book.

11. a subscriber equipment, providing codewords indexes information to base station, described base station is configured with N_tRoot beam antenna; Described subscriber equipment comprises:

Code word determines device; According to estimated channel matrix, described subscriber equipment determines the code word in the non-permanent mould code book that order is r based on a predetermined criterion, r=1,2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in the described beam antenna of reflection by the predefined code book configured for omnidirectional antenna; And

Codewords indexes information transmitting apparatus, sends the codewords indexes information of described code word to described base station.

12. subscriber equipment as claimed in claim 11, it is characterised in that this non-permanent mould code book be the predefined code book for omnidirectional antenna configuration with by the product of the diagonalizable matrix quantifying vector of each antenna element amplitude of variation in described beam antenna.

13. the subscriber equipment as described in one of claim 11 or 12, it is characterised in that described non-permanent mould code book comprises two-stage feedback arrangement; Corresponding described predefined code book comprises the first code book and the second code book, and wherein said first code book comprises broad-band channel direction estimation information, and described second code book comprises sub-band channel direction estimation information.

14. a base station, it is configured with N_tRoot beam antenna; Described base station comprises:

Codewords indexes information receiver; Reception order is the index information of the code word in the non-permanent mould code book of r, r=1,2 ... N_t; Wherein this non-permanent mould code book is determined with the quantization vector of each antenna element amplitude of variation in the described beam antenna of reflection by the predefined code book configured for omnidirectional antenna; And

Code word determines device, determines described code word according to the index information of described code word.

15. base station as claimed in claim 14, it is characterised in that this non-permanent mould code book is the predefined code book for omnidirectional antenna configuration and the product of the diagonalizable matrix quantifying vector of each antenna element amplitude of variation in the described beam antenna of reflection.

16. the base station as described in one of claims 14 or 15, it is characterised in that described non-permanent mould code book comprises two-stage feedback arrangement; Corresponding described predefined code book comprises the first code book and the second code book, and wherein said first code book comprises broad-band channel direction estimation information, and described second code book comprises sub-band channel direction estimation information.