Comments on 'Orthogonal convolutional coding for the PPM optical channel' by G.E. Atkin and H.P. Corrales

In a recent paper by G.E. Atkin and H.P. Corrales (ibid., vol.7, no.4, p.731-4, 1989) Viterbi's orthogonal convolutional coding scheme is suggested for efficient communication on Pierce's noiseless PPM optical channel. It is pointed out that the performance curves presented there erroneously correspond to a code rate of unity. If the correct code rate of 1/k is used (assuming 2/sup k/-array PPM), the orthogonal convolutional codes are seen to be inferior for the proposed application. A reply by the authors of the original paper is given in the form of a correction (ibid., vo.8, no.6, p.1007-8).<
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