Combining Beamforming and Space-Time Coding Using Noisy Quantized Feedback

The goal of combining beamforming and space-time coding is to obtain full-diversity order and to provide additional received power (array gain) compared to conventional space-time codes. In this work, a class of code constellations is proposed, called generalized partly orthogonal designs (PODs) and both high-rate and low-rate feedback information is incorporated with possible feedback errors. A binary symmetric channel (BSC) model characterizes feedback errors and two cases are studied: first, when the BSC bit error probability is known a priori to the transmission ends and second, when it is not known exactly. Based on a minimum pairwise error probability (PEP) design criterion, we design a channel optimized vector quantizer (COVQ) and a precoder matrix codebook. The attractive property of our combining scheme is that it converges to conventional space-time coding with low-rate and erroneous feedback and to directional beamforming with high-rate and error-free feedback. This scheme ...

• Type: Journal
• Year: 2008
• Where: CORR
• Authors: Siavash Ekbatani, Hamid Jafarkhani
• Keywords: Conventional Space-time, CORR 2008, Education, Feedback, Feedback Errors