Performance of a two-dimensional product code with soft-decision decoding

The performance of a relatively simple two-dimensional product code is considered. The column code is a high-rate block code, and the row code is a rate-1/2 or -1/3 short constraint length convolutional code. Both the rows and columns are decoded with soft-decision maximum likelihood decoding, and use of the soft output Viterbi algorithm (SOVA) is assumed. It is shown that, depending on the rate of the row code, reliable signaling is achieved within about 1.0 to 1.5 dB of the critical rate of the wideband additive Gaussian noise channel. In one case, the same decoder may be used for the rows and the columns