Coding for multiple antenna transmission in fast fading and in OFDM

The multiple antenna channel coding problem in orthogonal frequency-division multiplexing is reconsidered, because with frequency interleaving the effective channel characteristic across tones is rather fast fading and does not comply with the quasi-static channel model widely assumed for space-time codes. We study the fast-fading multiple transmit and receive antenna channel via evaluation of the capacity of the ergodic channel. Capacity comparisons give guidelines on how to adjust coding rate and modulation cardinality jointly. Simulations show that bit-based coding outperforms space-time codes in fast fading and, furthermore, offers greater flexibility in rate adaptation.