ITERATIVE DETECTION AND DECODING FOR A MIMO-OFDM SYSTEM

摘要

Techniques to iteratively detect and decode data transmitted in a wireless MIMO-OFDM communication system. The iterative detection and decoding is performed by iteratively passing soft "a priori" information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. "Extrinsic information" in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprisesthe a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios. Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and "dual-maxima" approximation.