Analysis of an Iterative Layered Space Time Receiver with Imperfect Feedback

Iterative layered space time (ILST) architectures have been proven to be a promising detection technique for Single-Carrier (SC) MIMO (multiple-input multiple-output) systems. Interference cancellation is applied successively in an ILST receiver by feeding back the detected symbols. In this paper, we analyze the imperfect decision feedback for an ILST receiver. The purpose is to figure out whether the system performance is improved or degrades by unreliable decision feedback. The analytical comparison shows that if the feedback layer and the detecting layer are weighted correlated, the decision feedback always improves the SNIR performance. For the decision feedback from the current layer itself, it improves the performance with probability nearly to 1 in frequency selective channels. This theoretical result coincides with the simulation results.