On the Optimal Amount of Training for Peak-Power-Limited Rayleigh Fading Channels

The authors consider the optimal amount of training for single-antenna Rayleigh flat fading channels with peak-power-limited input. The receiver uses known training symbols to perform Minimum Mean Square Error (MMSE) channel estimation. With a block-fading channel model and a perfect interleaving assumption, they first analyze the characteristics of the optimum input distribution, then numerically compute the training-based capacity, and then find the optimal number of training symbols that maximizes the capacity. Channel estimation based on training (pilot) sequences is a commonly used technique in wireless communication systems.