Semi-blind equalization for space time block codes and its ambiguity analysis

The key difference between space time block codes (STBCs) and a general multiple-input multiple-output system is that the transmitted signals of STBC systems are not mutually independent. In this paper we develop an algorithm that exploits the implicit structure of STBCs to achieve direct equalization without knowledge of the channel impulse responses. We analyze the identifiability of the equalizers, and develop explicit conditions for the existence of semi-blind equalizers. The performance of the algorithm is demonstrated through simulation results and compared with an existing scheme.