Study of Turbo Codes and Extensions

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9415996 Wilson This project investigates a recently described error control coding technique, called Turbo coding, which claims to significantly lower the signal-to-noise ratio required for reliable communication on the Gaussian noise channel, for still reasonable complexity. The research will study the baseline technique to corroborate the initial findings, and explore the sensitivity to such issues as interleaver design and constituent code complexity. Improvements which lessen the delay, memory, and computational requirements are under study, with the aim of making this concept truly practical in contemporary applications such as packetized wireless networks. Also under study is the extension of the basic coding ideas (component coding with iterative, interacting decoding) to lower rate schemes, with an attempt to get beyond the 0 dB barrier on Eb/No. A 'symmetric' form for the basic iterative decoder has been developed and is under study. More importantly, the concept will be extended to bandwidth efficient trellis coded modulation for the Gaussian channel, and to codes for Rayleigh fading channels. ***