New high-rate convolutional codes for concatenated schemes

This paper considers the use of the best high-rate k/(k+1) convolutional codes obtained using the new construction technique described by Graell i Amat, Montorsi and Benedetto (see IEEE Communications Letters, vol.5, no.11, p.453-55, 2001) in a concatenated scheme. Simulation results for an AWGN channel and for a realistic magnetic recording channel are reported. It is shown that these codes, endowed with a decoding algorithm working on the dual code, yield performance improvements over the best known high-rate punctured codes with the same rate and memory in terms of both bit error probability and computational decoding complexity. For both the AWGN channel and the magnetic recording channel the new codes significantly lower the error floor with respect to known turbo-like code structures.