Design of Low Complex Linear Precoding Scheme for MU-MIMO Systems

The block diagonalization (BD) is a linear precoding technique for multiuser interference elimination in multi-user multiple-input multiple-output (MU-MIMO) systems. Though various methods of block diagonalization have been identified, they are convoluted regarding the computations involved. In this paper we have modeled a new paradigm for the performance improvement and complexity reduction in BD based precoding algorithms. This is consummated using principal component analysis (PCA). The traditional highly complex singular value decomposition is replaced by QR decomposition in PCA (QR-PCA) for complexity reduction. The PCA along with QR decomposition and minimum mean squared error (MMSE) channel inversion technique parallelize the MU-MIMO channel into independent and proportionate single user MIMO channel. The simulation result shows that the proposed QR-PCA based precoding algorithm in comparison with the existing algorithm achieves comparatively better sum-rate, lower BER, and lower computational complexity. The PCA along with MMSE channel inversion avoids the decoder structure, which makes the receiver system simple.