Robust space-time codes for broadband OFDM systems

A bit-interleaved space-time coded OFDM system is considered in this paper for frequency-selective fading channels. As OFDM divides a frequency-selective fading channel into a set of parallel flat fading channels, space-time block codes for flat fading are transmitted from each subcarrier by multiple transmit antennas to guarantee space diversity, and code bits are bit-wise interleaved across the subcarriers before being grouped and mapped to space-time block code to obtain frequency diversity. Performance bounds and simulation results show that the bit-interleaved space-time coded OFDM system can effectively exploit both space and frequency diversity to improve performance.