Noncoherent turbo decoding

Noncoherent sequence detection schemes for any coded modulation format have been previously proposed by the authors, which deliver hard decisions by means of a Viterbi algorithm. The current trend in digital transmission towards iterative decoding algorithms motivates an extension of these schemes. In this paper, we propose a soft-output noncoherent sequence detection scheme based on a soft-output Viterbi algorithm and apply it to noncoherent iterative decoding