Precoding method, system and apparatus in MIMO system

A technology of precoding and precoding vector, applied in the field of wireless communication, can solve the problem of difficult realization of channel information, and achieve the effect of good bit error rate performance and low decoding complexity

Inactive Publication Date: 2008-07-30
HUAWEI TECH CO LTD
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  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] However, the channel information increases with the product of the number of transmit antennas, the number of receive antennas, and the number of users. For MIMO channel capacity, which increases linearly with the number of transmit antennas or the number of receive antennas, it is difficult to feed back complete channel information (ideal feedback) in practical systems. realized in

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  • Precoding method, system and apparatus in MIMO system
  • Precoding method, system and apparatus in MIMO system
  • Precoding method, system and apparatus in MIMO system

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specific Embodiment approach 1

[0055] The first specific embodiment describes how to use a non-unitary matrix for precoding when orthogonal space-time coding is used in a MIMO-OFDM system. details as follows:

[0056] After receiving the signal, the receiving end performs channel estimation and obtains M r × M f The channel matrix H of . H can be obtained by any known channel estimation method, and will not be repeated here; according to the number of transmitting antennas and the number of feedback bits, the optimal decision can be made on the precoding matrix in the corresponding beamforming codebook set, and the optimal Launch vector v, the judgment is based on the following formula:

[0057] v = arg max v i ∈ ζ | | H v i ...

specific Embodiment approach 2

[0062] In the following, the precoding method involved in the present invention will be specifically described by taking the Alamouti orthogonal space-time block coding of closed-loop 2-transmit and 1-receive as an example. In order to compare the performance of the specific implementation of the present invention with the prior art below, it is assumed that the optimal precoding matrix generated according to the prior art decision is F I , and the optimal precoding matrix generated according to the method judgment according to the specific embodiment of the present invention is F II .

[0063] In the MIMO-OFDM system adopting closed-loop 2-transmit-1-receive Alamouti orthogonal space-time block coding, the number of transmit antennas is 2, because this specific implementation is based on the optimal precoding vector in the beamforming codebook to construct the optimal Precoding matrix, so when the number of feedback bits is 3 bits, select a vector in the (2, 1, 3) codebook s...

specific Embodiment approach 3

[0101] Embodiment 3 of the present invention provides a MIMO system using limited feedback precoding, and the system includes a transmitter 710 and a receiver 720 . The system adopts orthogonal space-time coding and adopts more than two data streams, and the receiver 720 includes:

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Abstract

The invention discloses a pre-coding method, a system and a device in a MIMO system. The method, the system and the device which are related to by the invention can be applied in the orthogonal space-time coding circumstance. The inventive method adopts a non-unitary matrix for pre-coding, and the non-unitary matrix is obtained by judging the obtained optimal pre-coding vector construction. The inventive system includes a transmitter and a receiver, wherein, the transmitter includes a code list, a pre-coding matrix construction unit and a pre-coding unit; the receiver includes a channel estimation unit, the code list and a judgement unit. The simulation and the analysis show that, compared with the prior art, the usage of the inventive proposal can lower the bit error rate and reduce the complexity of decoding simultaneously in the situation of the same signal-to-noise ratio.

Description

technical field [0001] The present invention relates to wireless communication technology, in particular to a precoding technology in MIMO system. Background technique [0002] Research on information theory proves that the communication system using multiple antennas can obtain higher channel capacity. Under the assumption that the channel is independent Rayleigh fading and the receiver knows the channel state information, the multiple-input multiple-output of multiple antennas is used at both the transmitting end and the receiving end. (Multiple Input Multiple Output, MIMO) The theoretical channel capacity of the system increases approximately linearly with the smaller value of the number of transmitting antennas and the number of receiving antennas. The way the MIMO system increases capacity is called space division multiplexing. The MIMO-OFDM system, which combines the MIMO system with Orthogonal Frequency Division Multiplexing (OFDM) technology, can effectively combat m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L1/06H04L25/03H04B7/06
Inventor 文雪李杰王吉滨
Owner HUAWEI TECH CO LTD
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