Performance Results for a Concatenated Code Design on the DPSK Channel

The performance of concatenated codes that employ a short-constraint-length convolutional inner code and a Reed-Solomon outer code is considered on the DPSK channel. It is shown that, as in the coherent case, reliable communications can be provided at signal-to-noise ratios that are close to the SNR corresponding to the critical rate of the channel. High rate Reed-Solomon codes defined on 6-, 7-, 8-, and 9-bit alphabets and k= 5, k= 7, and k = 9 rate-¿ convolutional codes are considered. It is shown that an overall post-decoding bit-error rate of 10^-6 can be provided with 5.6 dB ¿ Eb/N0 ¿ 7.0 dB for concatenated code designs that employ the aforementioned codes.