Performance analysis and design of STBCs for fading ISI channels

Robert Schober , Wolfgang H. Gerstacker , and Lutz H.–J. Lampe Department of Electrical and Computer Engineering, University of Toronto e-mail: rschober @comm.utoronto.ca Lehrstuhl für Nachrichtentechnik II, Universität Erlangen–Nürnberg Abstract — In this paper, space–time block–coded transmission over fading intersymbol interference (ISI) channels is investigated. A lower bound for the pairwise error probability for optimum detection is given. Also an approximation for the bit error rate is derived and compared with simulation results for maximum–likelihood sequence estimation (MLSE) for the GSM/EDGE (Enhanced Data Rates for GSM Evolution) system. Furthermore, a novel design rule for space–time block codes (STBC’s) for fading ISI channels is provided. A corresponding code is designed and shown to yield higher performance than Alamouti’s code. It is demonstrated that for fading channels with independent impulse response coefficients, STBC’s designed for the flat fading channel can achieve at most a diversity order of if transmit antennas and receive antennas are used. On the other hand, the maximum diversity order employing the proposed code design rule is .