Abstract

This paper presents a new method to correct the value range of estimative signals for sphere decoding algorithm (SDA) in Multiple-input Multiple-output (MIMO) system. Proposed algorithm is based on QR decomposition for channel matrix and it takes into account the 2-norm expressions of estimative signal in previous layers (2nE-ES-PL) while estimating transmission signals in current layer (TS-CL). Besides, this paper optimizes conventional SDA in system mathematical model (SMM). As the 2nE-ESPL carries the information of TS-CL, we utilize 2nE-ES-PL in TS-CL derivation to avoid more error accumulation. Thereby, the estimative value of signals is corrected by aid of simplification of SMM. This proposed algorithm can search lattice point more accurate without a significant increase in complexity. Simulation results show that the proposed SDA with new correction scheme can achieve nearly 1dB performance gains contrasting to conventional SDA over Rayleigh fading channels.

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