An improved scheme of sphere decoding for MIMO system
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.
Author's Name: Qi, J., Li, J., Cai, C.
Volume: Volume 9
Issues: Issue 22
Keywords: 2nE-ES-PL, Correction scheme, MIMO, QR decomposition, SDA