Blind-detection assisted sub-band adaptive turbo-coded OFDM schemes

Burst-by-burst adaptive OFDM modems efficiently combat the effects of strong time-variant multipath interference. Their performance is investigated using blind modem mode detection and turbo coding. Virtually error-free modem mode detection is achieved over Gaussian channels for signal-to-noise ratios (SNR) in excess of about 10 dB upon using one of four modem modes, namely 0, 1, 2 and 4 bits/symbol in each of the sub-bands employed. The system can be configured for maintaining arbitrary target BERs, including virtually error-free communications, when adjusting the target number of bits per OFDM symbol transmitted.