Combining beamforming and space-time coding using noisy quantized feedback

  • Authors:
  • Siavash Ekbatani;Hamid Jafarkhani

  • Affiliations:
  • Department of Electrical Engineering and Computer Science, University of California, Irvine, CA;Department of Electrical Engineering and Computer Science, University of California, Irvine, CA

  • Venue:
  • IEEE Transactions on Communications
  • Year:
  • 2009

Quantified Score

Hi-index 0.06

Visualization

Abstract

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. 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) for feedback information and a precoder matrix codebook to adjust the transmission codewords. 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 also shows desirable robustness against feedback channel modeling mismatch.