WO2010031268A1

WO2010031268A1 - Antennae diversity method and apparatus

Info

Publication number: WO2010031268A1
Application number: PCT/CN2009/072552
Authority: WO
Inventors: 姜静; 王衍文; 于辉
Original assignee: 中兴通讯股份有限公司
Priority date: 2008-09-22
Filing date: 2009-06-30
Publication date: 2010-03-25
Also published as: CN101686072A

Abstract

An antennae diversity method and apparatus are applied in the Long-Term Evolution Advanced system including eight antennae. The method includes: setting up a space-time encoding matrix: S, wherein S₁ and S₂ are symbols before being encoded, the rows of the matrix stand for adjacent times or adjacent frequencies, the columns stand for weighting vectors, and the weight 1 and weight 2 are preset by the base station or generated adaptively; encoding with the encoding matrix to obtain the diversity processed symbols Y, wherein Y=W*S, W is the beamforming weighting matrix, W and W₁ and W₂are the weighting vectors for the first and second beam respectively both with a dimension of 8×1.

Description

Antenna diversity method and device

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to an antenna diversity method and apparatus. BACKGROUND In a Long-Term Evolution (LTE) system, when the downlink antenna is 2 antennas, the diversity mode is Space Frequency Block Codes (SFBC), and the coding matrix is as follows. 1 shows: antenna 2

Frequency 1

Frequency 2

S=

In the downlink, the diversity mode is also defined as frequency switching diversity (SFBC + Frequency Switch Time Division, SFBC + FSTD). The coding matrix is shown in Equation 2: Antenna 1 Antenna 2 Antenna 3 Antenna 4

Frequency 1 s ₁ 0 - s; 0

Frequency 2 s ₂ 0 0

Frequency 3 0 0 - - s;

Frequency 4 0

s= ^ 4 0 si 2 In the LTE-Advanced system, in order to improve the downlink data transmission rate and spectrum utilization, up to 8 transmit antennas can be used in the downlink, but in the related art, it is not provided. The diversity mode under 8 antennas. SUMMARY OF THE INVENTION The present invention has been made in view of the problem that the related art does not provide a diversity mode under 8 antennas. To this end, the present invention is directed to an antenna diversity method and apparatus to solve the above problems. According to an aspect of the invention, an antenna diversity method is provided. The antenna diversity method according to the present invention is applied to a long-term evolution advanced system including 8 antennas, weight 1 weight 2 frequency/time 1

Frequency/Time 2 S ₂ S _{1 The} above method includes: Setting the coding matrix: S-

Weight 1 weight 2

Frequency / time 1

Frequency / Time 2 A S ₂ S ₁

Wherein, Si and S ₂ are symbols before encoding, and rows of the coding matrix represent adjacent time or adjacent frequency i or, and the column represents a weight vector, wherein the weight 1 and the weight 2 are preset by the base station a weight that is determined or adaptively generated; encoded according to the coding matrix to obtain a score y ₂₂

The set processed symbols are Y= where Y=W*S and W is the beamforming weight matrix.

w= value vector, dimension 1x8, W ₂ is the weight of the second beam

The value vector has a dimension of 8x1. According to another aspect of the present invention, an antenna diversity device is provided. The antenna diversity apparatus according to the present invention is applied to a long-term evolution advanced system including 8 antennas, weight 1 weight 2 frequency / time 1 - s frequency / time 2

The device comprises: a setting module for setting the coding matrix: S-

Or weight 1 weight 2

Frequency / time 1 S, S

Frequency / Time 2 -S* S

Wherein, S1 and S2 are symbols before encoding, and rows of the coding matrix represent adjacent time or adjacent frequency i or, and the column represents a weight vector, wherein the weight 1 and the weight 2 are preset or self-determined by the base station Adapt to the generated weight; encoding module, used to set the coding moment according to the setting module The array is encoded to obtain the diversity, where Y=W*S , w

For the beam forming weight matrix, w = weight vector, the dimension is 1x8,

W ₂ is the weight vector of the second beam, and the dimension is 8x1. Through the invention, in the LTE-Advanced system, the 8-antenna downlink diversity still uses the two-antenna Alamouti diversity coding matrix, and then multiplied by different weights, corresponding to different beams for transmission, solving the related art does not provide 8 The problem of diversity mode under the antenna can obtain better diversity gain without adding extra pilot overhead. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flowchart of an antenna diversity method according to an embodiment of the present invention; FIG. 2 is a schematic diagram of an antenna diversity method according to Embodiment 1 of the present invention; FIG. 3 is a flowchart according to the present invention. 2 is a schematic diagram of an antenna diversity method according to Embodiment 3 of the present invention; FIG. 5 is a schematic diagram of an antenna diversity method according to Embodiment 4 of the present invention; A block diagram of a structure of an antenna diversity apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the related art, a multi-antenna processing method combining Beamforming and Alamouti (personal name, Ala Moti) is proposed. Through theoretical analysis and simulation verification, it is proved that the diversity output signals are respectively sent to independent beamforming. Array, which can achieve 6dB gain compared to Alamouti diversity, In the Alamouti diversity, the coding matrix is S=, SI and S2 are pre-encoding symbols.

- s: s:

After Alamouti coding, the row corresponds to an adjacent time or an adjacent frequency, and the column 4 is different from the transmitting antenna. The present invention combines beamforming and transmit diversity to design a diversity method for an LTE-Advanced system under 8 antennas, namely: In an LTE-Advanced system, 8 antennas still use an Alamouti diversity coding matrix of 2 antennas, and multiply by different weights. , corresponding to different beams sent out. Such a diversity method has a gain of 6 dB over conventional beamforming and a performance gain of 9 dB over conventional 2-antenna Alamouti encoding. The invention will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Method Embodiment According to an embodiment of the present invention, an antenna diversity method is provided for a long-term evolution advanced system including 8 antennas, assuming that the transmitted symbol is X = [; FIG. 1 is an embodiment of the present invention. Flowchart of the antenna diversity method, as shown in FIG. 1, the method includes: weight 1 weight 2 frequency / time 1 's ₁ - s frequency / time 2 S ₂ S _l step S102, setting the coding matrix: S- Or weight 1 weight 2

Frequency / time 1

Frequency / time 2 - S ₂ S _l

Where S is generated by X through Alamouti coding, and S ₂ is a symbol before encoding, the row of the coding matrix represents an adjacent time or adjacent frequency domain, the column represents a weight vector, and the weight 1 and the weight 2 are a weight value preset or adaptively generated by the base station;

S104, encoding according to the coding matrix, obtaining the symbol after the diversity processing is y _22, where Y=W*S, W is a beamforming weight matrix, w= , weight w

A fixed value preset for the base station or a weight generated adaptively by the channel information, where is the weight vector of the first beam, the dimension is 1x8, and W ₂ is the weight vector of the second beam, the dimension 8x1; space frequency block coding (SFBC) may be performed according to the coding matrix, or Space Time Block Codes (STBC) may be performed according to the coding matrix; specifically, if the coding is space frequency block coding, then Si and -S ₂ * are transmitted on subcarrier 1; S ₂ and Si* are transmitted on subcarrier 2; Si and S _{2 are} transmitted at time 1 if encoding is empty, and -S ₂ * is transmitted at time 2 with

With this embodiment, a diversity method of 8 antennas is provided. In the LTE-Advanced system, 8 antenna downlink diversity combines beamforming, and different symbols are corresponding to different beams, which solves the problem that the related technology does not provide the diversity mode under 8 antennas. The problem is that a better diversity gain can be obtained without adding extra pilot overhead. The specific implementation process of the present invention will be described in detail below with reference to examples. Embodiment 1 This embodiment provides an antenna diversity method in the case where the weight W is a fixed value preset by the base station and encoded as a space frequency block code, and FIG. 2 is an antenna diversity method according to the first embodiment of the present invention. Schematic diagram, as shown in FIG. 2, the method includes the following steps: Weight 1 Weight 2 Frequency 1 's, - s Frequency 2 ss* As described in step S102, the Alamouti coding matrix is set: S=

Wherein, Si and S ₂ are symbols before encoding, rows of the coding matrix represent adjacent time or adjacent frequency domain, columns represent weight vectors, and weights 1 and 2 are antenna weights preset by the base station; The shape of the beam and the transmitted symbol (ie, the symbol before the encoding) are generated by the weight. As shown in FIG. 2, each cell is sequentially divided into beam 1, beam 2, beam 3, and beam 4 according to the angle of its coverage. Four beams, one for each two beams, beam 1 and beam 3 form the first set of weights, beam 2 and beam 4 form the second set of weights; assuming the coverage area of the base station is 0° ~ 120°, beam 1 Aligned by 15°, beam 2 is aligned with 45°, beam 3 is aligned with 75°, beam 4 is aligned with 105°; as described in step S104, encoding is performed according to the coding matrix, and the symbol obtained by the diversity processing is Y= where Y=W*S , W is the beamforming weight matrix, w= is

^81 ^δΜ

The weight vector of one beam, the dimension is 1x8, W ₂ is the weight vector of the second beam, and the dimension is 8x1. The code is a space frequency block coding. Specifically, Si and -S are transmitted on subcarrier 1. ₂ *, send S ₂ and Si* on subcarrier 2, where 釆 weight 1 sends Si and S ₂ , 权 weight 2 sends - S ₂ * and

In this embodiment, the first set of weights Wi and the second set of weights W ₂ are orthogonal to each other such that the Alamouti-encoded symbols pass through completely independent channels, and the maximum diversity gain is obtained. Embodiment 2 This embodiment provides an antenna diversity method in a case where a weight W is adaptively generated by channel information and encoded as a space frequency block code, and FIG. 3 is a schematic diagram of an antenna diversity method according to Embodiment 2 of the present invention. As shown in FIG. 3, the method includes the following steps: Weight 1 Weight 2 Frequency 1 's ₁ - s: Frequency 2 ss: As described in step S102, the Alamouti coding matrix is set: S=

Wherein, Si and S ₂ are symbols before encoding, rows of the coding matrix represent adjacent time or adjacent frequency domain, columns represent weight vectors, and weights 1 and 2 are adaptively generated by the user according to the uplink channel information. , wherein the weight generates a beam shape and the transmitted symbol is as shown in FIG. 3, each cell is divided into a beam 1 and a beam 2, and the beam 1 and the beam 2 are generated according to the angle of arrival information of the mobile user, where The beam 1 corresponds to the direction of the wave angle of the largest energy, and the beam 2 corresponds to the direction of the wave angle of the second largest energy; as described in step S104, the code is encoded according to the coding matrix, and the symbol obtained by the diversity process is

The weight vector of one beam, the dimension is 1x8, W ₂ is the weight vector of the second beam, and the dimension is 8x1. The code is space frequency block coding, specifically, sending S 1 and on subcarrier 1 - S2*, transmitting S ₂ and Si* on subcarrier 2, where S 1 and S2 are transmitted with weight 1 and sent with weight 2

In this embodiment, the first set of weights Wi and the second set of weights W ₂ are orthogonal to one another, remain unchanged during Alamouti encoded symbols (for Si and S ₂ ), and pass through completely independent channels, The symbol pair of the next Alamouti code can be adaptively adjusted to obtain the maximum diversity gain. Embodiment 3 This embodiment provides an antenna diversity method in a case where a weight W is a fixed value preset by a base station and a coded packet is null, and FIG. 4 is an antenna diversity method according to Embodiment 3 of the present invention. Schematic diagram, as shown in FIG. 4, the method includes the following steps: Weight 1 Weight 2 Time 1 's, - s Time 2 ss: As described in step S102, the Alamouti coding matrix is set: S=

Wherein, Si and S ₂ are symbols before encoding, rows of the coding matrix represent adjacent time or adjacent frequency domain, columns represent weight vectors, and weights 1 and 2 are antenna weights preset by the base station; The shape of the beam generated by the weight and the transmitted symbol (ie, the symbol before the encoding) are as shown in FIG. 4, and each cell is sequentially divided into beam 1, beam 2, beam 3, and beam according to the angle of its coverage. 4 beams, one for each two beams, beam 1 and beam 3 form the first set of weights, beam 2 and beam 4 form the second set of weights; assuming the coverage area of the base station is 0° ~ 120°, the beam 1 is aligned at 15°, beam 2 is aligned at 45°, beam 3 is aligned at 75°, and beam 4 is aligned at 105°; as described in step S104, encoding is performed according to the coding matrix, and the symbol obtained after diversity processing is

Y= is the first

The weight vector of one beam, the dimension is 1x8, W ₂ is the weight vector of the second beam, and the dimension is 8x1. The code is the space frequency block coding. Specifically, the S ^P _ S _{2 is} sent at time 1. *, S ₂ ^ Si* is transmitted at time 2, where S _{2 is} transmitted with weight 1 and _ 8 ₂ * and Si* are transmitted with weight 2. In this embodiment, the first set of weights Wi and the second set of weights W ₂ are orthogonal to each other such that the Alamouti-encoded symbols pass through completely independent channels, and the maximum diversity gain is obtained. Embodiment 4 This embodiment provides an antenna diversity method in the case where the weight W is adaptively generated by the channel information and encoded into space-time block coding, and FIG. 5 is a schematic diagram of the antenna diversity method according to the fourth embodiment of the present invention. As shown in FIG. 5, the method includes the following steps: weight 1 weight 2 time 1 "S! - S _: time 2 S, S; as described in step S102, setting the Alamouti coding matrix: S- where Si and S ₂ are The symbol before coding, the row of the coding matrix represents the adjacent time, the column represents the weight vector, and the diversity process is performed according to Equation 1, and the weight W is adaptively generated by the user according to the uplink channel information, wherein the weight generates a beam. The shape and the transmitted symbols are as shown in FIG. 5, each of which is divided into beam 1 and beam 2, and beam 1 and beam 2 are generated according to the angle of arrival information of the mobile user, wherein beam 1 corresponds to the largest energy. In the direction of the direction of the wave, the beam 2 corresponds to the direction of the angle of arrival of the second largest energy; as described in step S104, the code is encoded according to the coding matrix, and the symbol obtained after the diversity processing is

The weight vector of one beam, the dimension is 1x8, W ₂ is the weight vector of the second beam, and the dimension is 8x1. The code is the space frequency block coding. Specifically, the S ^P _ S _{2 is} sent at time 1. *, send S ₂ at time ₂

In this embodiment, the first set of weights Wi and the second set of weights W ₂ are orthogonal to one another, remain unchanged during Alamouti encoded symbols (for Si and S ₂ ), and pass through completely independent channels, The symbol pair of the next Alamouti code can be adaptively adjusted to obtain the maximum diversity gain. According to an embodiment of the present invention, there is also provided a computer readable medium having stored thereon computer executable instructions for causing a computer or processor to perform, for example, when executed by a computer or processor The processing of step S102 and step S104 shown in FIG. 1 preferably performs one or more of the above-described first to fourth embodiments. Apparatus Embodiment In accordance with an embodiment of the present invention, an antenna diversity apparatus is provided for use in a long term evolution advanced system including 8 antennas. FIG. 6 is a structural block diagram of an antenna diversity apparatus according to an embodiment of the present invention. As shown in FIG. 6, the apparatus includes: a setting module 62 and an encoding module 64. Detailed description of the line. Weight 1 weight 2 frequency / time 1

Frequency/Time 2 S ₂ S _l Setting module 62 for setting the coding matrix: S- ” or weight 1 weight 2

Frequency / time 1 5 S ₂

Frequency / time 2 - S ₂ S _l

Wherein, 8 ₁ and 8 ₂ are symbols before encoding, and rows of the coding matrix represent adjacent time or adjacent frequency i or, and the column represents a weight vector, wherein the weight 1 and the weight 2 are preset by the base station Or adaptively generated weights. The encoding module 64 is connected to the setting module 62 for the encoding moment set according to the setting module 62.

The array is encoded, and the symbol obtained after the diversity processing is Y= , where Y=W*S, w

For the beam forming weight matrix, w = is the weight vector of the first beam, the dimension is 1x8,

W ₂ is a weight vector of the second beam, and the dimension is 8×1 ₍ preferably, the encoding module 64 is used to encode in the following two encoding manners, and the details are as follows:

(1) The encoding module 64 is configured to perform coding in a manner of space frequency block coding, and the encoding module 64 further includes a first sending submodule for performing an encoding and transmitting operation as follows: transmitting 8 ₁ and _ 8 on the subcarrier 1 ₂ *; Send Sz on subcarrier 2

(2) The encoding module 64 is configured to perform encoding by space time block coding, and the encoding module 64 further includes a second sending submodule for performing a code sending operation as follows: transmitting Si and S ₂ at time 1; 2 Transmit - S ₂ * and Si * „ Through the above embodiments of the present invention, in the LTE-Advanced system, 8-antenna downlink diversity combines beamforming, and different symbols correspond to different beams, and the related art does not provide 8 antennas. Under the problem of diversity mode, a better diversity gain can be obtained without adding additional pilot overhead. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or they may be Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

An antenna diversity method is applied to a long-term evolution advanced system including 8 antennas, wherein the method includes: weight 1 weight 2 frequency / time 1

Frequency / time 2

S _l sets the coding matrix S= Ί J or weight 1 weight 2

Frequency / time 1 5 S ₂

Frequency / time 2 L- S ₂ * s;

Wherein, Si and s ₂ are symbols before encoding, and rows of the coding matrix represent adjacent time or adjacent frequency i or, and the column represents a weight vector, wherein the weight 1 and the weight 2 are preset by the base station Fixed or adaptively generated weights;

The code is encoded according to the coding matrix, and the symbols after diversity processing are obtained, where Y=W*S, w is a beamforming weight matrix, w= , Wi

The weight vector of the first beam, the dimension is 1x8, and W ₂ is the weight vector of the second beam, and the dimension is 8x1.

The method according to claim 1, wherein the encoding is a space frequency block coding, and performing space frequency block coding according to the coding matrix comprises:

Sending Sj and -S ₂ * on subcarrier 1;

S ₂ and Si* are transmitted on subcarrier 2.

3. The method according to claim 2, wherein the weight W is a fixed value preset by the base station.

The method according to claim 2, wherein the weight W is adaptively generated by channel information.

The method according to claim 3 or 4, wherein the first set of weights \^ and the second set of weights W ₂ are orthogonal to each other.

The method according to claim 1, wherein the encoding is space-time block coding, and performing space-time block coding according to the coding matrix comprises:

Send 8 and S ₂ at time 1;

At time 2, send -S ₂ * and Si*. An antenna diversity apparatus is applied to a long-term evolution advanced system including 8 antennas, wherein the apparatus comprises: a weight 1 weight 2 frequency/time 1 's, - S frequency/time 2 ss* setting module, Used to set the encoding matrix: S= ” or weight 1 weight 2

Frequency / time 1

Frequency / time 2

An encoding module, configured to encode according to the encoding matrix set by the setting module, y

The symbol obtained after diversity processing is Y= ₂ i yn

Where Y=W*S, w is beam shape

^81 3^ The weighting matrix, , is the weight vector of the first beam, and the dimension is 1x8, W:

The weight vector of the second beam, the dimension is 8x1. The apparatus according to claim 7, wherein the coding module is configured to perform coding in a manner of space frequency group coding, and the coding module further includes:

The first sending submodule is configured to perform a code sending operation as follows: send S ^P _ S ₂ * on subcarrier 1; and send 8 ₂ and 8 ₁ * on subcarrier 2.

The device according to claim 7, wherein the encoding module is configured to perform encoding in a space-time block coding manner, and the encoding module further includes: a second sending sub-module, configured to perform the following manner Code Send Operation: Send at time 1

S ₂ ; _ 8 ₂ * and 8 ₁ * are transmitted at time 2.