Iterative Decoding with M-ary Orthogonal Walsh Modulation in OFDM-CDMA Systems

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Kurzfassung:

Iterative decoding of a serial concatenated coding scheme consisting of an outer convolutional code and M-ary orthogonal Walsh modulation as inner Walsh-Hadamard block code in an OFDM-CDMA system is applied. New aspects arise because OFDM enables the iterative decoding structure to exploit time as well as frequency diversity of a mobile channel. Moreover, the paper points out the low complex symbol-by-symbol maximum a posteriori (SS-MAP) decoding of Walsh-Hadamard block codes. Besides the derivation of the log-likelihood-ratio used for SS-MAP Walsh-Hadamard decoding, simulation results are shown for a differently interleaved indoor channel. They confirm the iterative decoding property to benefit from selectivity in time as well as frequency direction.

Dokumenttyp:

Konferenzbeitrag

Veröffentlichung:

Hamburg, Deutschland, 21. - 22. September 1999

Konferenz:

4th International OFDM-Workshop (InOWo 99)

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