BD (block diagonalization) pre-coding method and device

Abstract

The invention discloses a BD (block diagonalization) pre-coding method and device, wherein the method comprises the following steps: determining a total user channel matrix Hs according to a downlink channel matrix of each user in a system; carrying out QR factorization on a conjugate transpose matrix of the total user channel matrix Hs to obtain a product of an orthogonal matrix Q and an upper triangular matrix R, and expressing the total user channel matrix Hs as the product of a lower triangular matrix L and a conjugate transpose matrix QH of the orthogonal matrix Q; carrying out inverse calculation on the lower triangular matrix L to obtain L-1; according to the inversed L-1 of the lower triangular matrix L and the orthogonal matrix Q, obtaining a null space orthogonal basis of an interference channel matrix of each user; according to the null space orthogonal basis of the interference channel matrix of each user, constructing a linear pre-coding matrix of each user; and carrying out linear pre-coding on a transmitting signal of each user by utilizing the constructed linear pre-coding matrix. The technical scheme disclosed by the invention can reduce the system complexity and improve the coding efficiency.

Description

technical field [0001] The present invention relates to the field of wireless communication systems, in particular to a block diagonal (BD) precoding method and device. Background technique [0002] To achieve higher data rates, traditional MU-MIMO systems have been extended to Multi-User-MIMO (MU-MIMO) systems. However, since multiple users in the MU-MIMO system share the same time and frequency resources, co-channel interference (CCI) of multiple users will inevitably be introduced, affecting reliable reception of data. [0003] In order to eliminate CCI, the base station needs to first obtain channel state information (CSI) reflecting channel characteristics, for example, obtain channel transmission matrix through channel estimation. Then, according to the channel state information, an appropriate linear precoding matrix is ​​selected to perform linear precoding for eliminating CCI on the transmitted signal, and then send it to the receiving end. [0004] The BD precodi...

AI Technical Summary

Problems solved by technology

[0017] In method 2, although the SVD decomposition is replaced by QR decomposition, the complexity of the algorithm is reduced; but because it needs to perform a QR decomposition for each user's interference channel matrix, the complexity is still very high, making linear precoding still inefficient

[0018] It can be seen that the computational complexity of the BD precoding method in the prior art is relatively high, so that the efficiency of linear precoding when the BD precoding algorithm is used to eliminate CCI is low

Images