| Recently, the use of space-frequency block coding (SFBC) for OFDM has emerged as an effective means of improving transmission reliability in frequency-selective fading environments with applications ranging from high data rate wireless local area networks to broadband mobile wireless systems. However, conventional SFBC decoding proves to be inapt for OFDM since its application results in poor system performance under non-quasi static channel gain variations, a key characteristic of highly frequency-selective environments. This thesis proposes a square-root and division free recursive QR (SDRQR) decomposition based signal detector for SFBC-OFDM systems, The proposed detection scheme is applied to both orthogonal and quasi-orthogonal SFBC-OFDM schemes. Performance of the proposed detector is evaluated under various constraints. Our analyses show an excellent, performance gain attained by SDRQR over previously proposed solutions. It is also shown that the relative computational complexity of SDRQR is justified by the performance gain it attains over the previous solutions. |
