Method, device and system for forming TDD multi-input multi-output descending beam

Abstract

The embodiment of the invention discloses a beam forming method of a time duplex division (TDD) multi-input multi-output (MIMO) system. The method comprises the following steps: generating the transmitted beam of a first data stream based on the maximum-ratio transmission (MRT) principle; and generating the transmitted beam of another data stream other than the first data stream, and allowing the transmitted beam of the another data stream to be restricted in the null space of the first data stream. The embodiment of the invention also discloses a base station, a receiver and a communication system. Under the condition of no feedback information, the beam forming method utilizes the reciprocity-induced imperfect channel information as much as possible, reduces the complexity, and increases the velocity of the data stream.

Description

technical field [0001] The present invention relates to the technical field of time division duplex (TDD, Time Duplex Division), and more specifically, to a downlink beamforming method, device and system of time division duplex multiple-input multiple-output. Background technique [0002] In recent years, information theory research has shown that multiple antenna technology (MIMO, Multiple Input Multiple Output) can significantly improve the multiplexing gain and diversity gain of a communication system. If BLAST technology is used, different transmitting antennas will transmit different data streams, and the capacity of the system will increase in proportion to the rank of the MIMO channel; if space-time coding and single beamforming technology are used, all antennas will transmit the same data stream To improve transmission reliability, the maximum diversity gain can be equal to the product of the number of transmitting antennas and the number of receiving antennas. Of c...

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Problems solved by technology

[0006] However, this method requires the feedback of long-term statistics from the mobile terminal, and the base station and the mobile terminal must simultaneously perform SVD decomposition to select the transmission mode. At the same time, the base station also maintains a random statistic. implementation, so the implementation complexity is relatively high

In addition, this pseudo-eigen beamforming technique does not determine the optimal weight, and only empirical weights can be used in actual use.

Obviously, this pseudo-eigenbeamforming technique does not make full use of accurate PCSI, and the rate of its corresponding data flow cannot be guaranteed

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