| 摘要 |
A forward error correction scheme (FEC) outputs Galois/finite field (GF) symbols (GFS) 10 with an order greater than two. The GFS are formed into binary images 12, mapped on to symbol constellations (eg. QAM, QPSK) 14 and thence mapped on to MIMO codewords 16. The mapping is subject to rules to optimise maximum likelihood (ML) detection at the receiver. GFS, constellation and MIMO codeword sizes (N, M, P) are selected to accommodate the rules. An I or Q constellation component should relate to a single GFS to reduce correlated errors in FEC codewords. The GFS should be concentrated in as few MIMO codewords as possible, minimising the amount of MIMO codewords that the ML detector must operate on. The GFS should be mapped to MIMO components that experience uncorrelated fading. The MIMO components can be distinguished by frequency, polarisation, space or time. GFS components within one MIMO codeword may be ML decoded together to reduce the number of Euclidean distances that must be calculated.
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