Improved power allocation in parallel Poisson channels

The optimum power allocation for parallel Poisson channels which can minimize average power for obtaining maximum capacity is considered. In this paper a new power allocation scheme that outperforms previous schemes for more than enough powers is presented. Since in Poisson channels unbounded channel feeding with input power do not lead to a better utilization of the channel capacity, in the presented scheme extra powers that are more than required power for achieving maximum capacity are not used or if power dissipation is not possible, the extra power can be allocated in a new way which shows an improvement in the channel capacity. This approach is applied to the 2-fold parallel Poisson channels and is generalized to n-fold.