TABLE OF CONTENTS In this section, we study the performance of the orthogonal STBCs. First, we provide an analysis of the received SNR to compare the case of multiple transmit antennas with the case of multiple receive antennas. Then, we provide exact formulas for pairwise error probability of orthogonal STBCs.
Let us consider two systems with different arrangements of multiple antennas. The first case consists of N transmit antennas and one receive antenna using OSTBCs for transmission. The channel in Case 1 can be considered as a multiple-input single-output (MISO) channel with path gains ? 1, ? 2, , ? N. The second case contains one transmit antenna and M = N receive antennas with the same set of path gains ? 1, ? 2, , ? N. For this single-input multiple-output (SIMO) channel, we use MRC for ML decoding as discussed in Section 4.3. We have chosen the same set of path gains to have a fair comparison between the two cases. Also, let us assume an equal energy constellation like PSK for the sake of simplicity. Considering the same noise variance N 0/2 per dimension and the same average power of the transmitted symbols, E s, the average receive SNR is the same for both cases. Note that assuming the same power for transmitted symbols in these two cases, the total transmitted power of the first case is N times that of the second...
