Fast Algorithm for Decision Feedback Equalization in Multiple Input Multiple Output Channel

In this paper, we propose a new algorithm for zero-forcing decision feedback equalization (ZF-DFE) in multiple input multiple output flat Rayleigh fading channel. The basic idea is to separates the layer ordering and the filter construction operations, thus making both operations tractable and efficient. The new layer ordering strategy approximates the optimal ordering rule (VBLAST) from a geometrical perspective, and the filters in proposed ZF-DFE are constructed using a matrix Cholesky decomposition aided QR decomposition. Compared to the conventional ZF-DFE detectors utilizing optimal and suboptimal ordering rules (SQRD), the proposal is complexity efficient. Additionally, the bit error rate performance of the new algorithm significantly approximates that of the optimal ordering ZF-DFE. Thus a practical signal detection scheme for the vector channel is found.