Double-codebook multi-user multiple-input multiple-output (MU-MIMO) precoding method based on Schmidt orthonormalization

Abstract

The invention discloses a double-codebook multi-user multiple-input multiple-output (MU-MIMO) precoding method based on Schmidt orthonormalization, and belongs to the communication field. The precoding method includes the following steps: (1) constructing a codebook I according to the Grossmann space packing principle, then constructing a codebook II according to the Schmidt orthonormalization principle and considering the chordal distance between vectors, and storing the two codebooks together in a base station end and a mobile station, (2) carrying out channel estimation according to pilot signals sent by a base station, then going through precoding vectors in the codebook I, selecting out best matching code words, and sending indexes and corresponding signal interference plus noise ratio (SINR) values of the code words to the base station as feedback, (3) the base station ensuring a present precoding matrix in the codebook II according to the collected feedback information, and carrying out user scheduling on the basis. Through adoption of the method, an expanded space of the codebooks are enabled to be larger, moreover orthogonal property of the precoding matrix is guaranteed, and restraining capacity to color contribution index (CCI) is ensured. Meanwhile, the user scheduling scheme of the base station end enables the failure phenomenon of user matching not to exist.

Description

technical field [0001] The invention belongs to the communication field and relates to a codebook-based precoding method in an LTE system. Background technique [0002] The 3GPP LTE project is the largest new technology research and development project launched by 3GPP in recent years. LTE has the advantages of flexible spectrum use, seamless interoperability with existing technologies, and low cost of network deployment and management. It improves and enhances 3G Air access technology can bring enhanced mobile broadband experience with higher speed and simpler technology. [0003] In LTE, MIMO-OFDM is adopted. OFDM technology can resist the inter-symbol interference caused by the multipath delay extension of the wireless channel, and at the same time, it can convert the channel equalization from complex time domain processing to simple frequency domain processing. The MIMO technology provides space diversity and multiplexing through multiple antennas, and can obtain higher...

AI Technical Summary

Problems solved by technology

Among them, the unitary codebook is simple to implement, but the degree of matching to the channel space is low, and the CCI suppression of the Grassmann codebook needs to be improved

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