Coding Capacity and Error Exponent of the Poisson Channel with Time Varying Parameters.

Abstract : The coding capacity of the Poisson channel with nonrandom periodic noise intensity is obtained for an average constraint and a periodic peak constraint on the encoder intensity. The case of almost periodic channel parameters is also treated. For these Poisson channels, the coding capacity equals the information capacity. Also, the coding capacity is the same with and without causal feedback. A random coding lower bound on the optimum error exponent is given for these classes of Poisson channels. These results are derived using work of Wyner for the Poisson channel with nontime-varying channel parameters.