Wu Di, Li Dezhi and Wang Zhenyong, Harbin Institute of Technology, China

Sphere Decoding (SD) algorithm is an implement decoding algorithm based on Zero Forcing (ZF) algorithm in the real number field. The classical SD algorithm is famous for its outstanding Bit Error Rate (BER) performance and decoding strategy. The algorithm gets its maximum likelihood solution by recursive shrinking the searching radius gradually. However, it is too complicated to use the method of shrinking the searching radius in ground communication system. This paper proposed a Variable Radius Sphere Decoding (VR-SD) algorithm based on ZF algorithm in order to simplify the complex searching steps. We prove the advantages of VR-SD algorithm by analyzing from the derivation of mathematical formulas and the simulation of the BER performance between SD and VR-SD algorithm.

MIMO, Signal Detecting, Maximum Likelihood Solution, Sphere Decoding, Variable Radius