Exact Pairwise Error Probability for Block-Fading MIMO OFDM Systems

In this letter, we derive a closed-form solution of the exact pairwise error probability (PEP) for Rayleigh fading orthogonal frequency-division multiplexing (OFDM) channels with multiple transmit and receive antennas. We begin with the case of frequency-selective quasi-static fading OFDM channel model. The analysis is then generalized to the frequency-selective block fading OFDM channel model. This is a suitable model for cooperative space-time coded OFDM systems, where, due to the spatial separation between the cooperating users, the signal-to-noise ratio (SNR), the number of antennas, and the number of nonzero channel taps during each user´s transmission (hence, in each block) may be different. We provide numerical examples to illustrate the usefulness of the derived exact PEP expressions.