New EO-STBC with more feedback bits in inaccurate channel feedback

摘要

This paper analyzes the performance of phase feedback, quasi-orthogonal space-time block codes (QO-STBC) and Extended OSTBC systems in the presence of feedback delay, feedback error and amount of channel feedback. Space-time code constructed for nT transmit antennas can easily be extended to nTtimesp antennas transmit based on a feedback of only p-1 bits. This paper shows that more feedback bits (more than p-1 bits) in ideal system (EOSTBC system with no feedback delay and no feedback error) cause no more considerable performance in the system. But in the inaccurate feedback information with increasing feedback bits from p-1 bits decrease sensitivity of system and increase performance considerably. This paper obtains an upper bound for phase feedback error respect to number of feedback bits. Moreover it shows that the system can select adaptively one of the three modes, phase only feedback, EO-STBC and QO-STBC with respect to reliability and amount of feedback information.