ANALYSIS OF OPTICAL PPM CHANNEL CAPACITY WITHOUT BACKGROUND NOISE
无背景噪声下的光PPM信道容量分析

The capacity of the optical pulse-position modulation (PPM) channel without background noise is examined. It is shown that the channel capacity is limited not only by the available time resolution (bandwidth) but also by the available pulse power. In fact, as the PPM slot width decreases infinitely, the channel capacity will approach to zero in the power limited channel. There exist the PPM slot width that optimizes the channel capacity and the PPM alphabet sizes that maximize the efficiencies of throughput and energy. These results provide the basis for designing optimum PPM system parameters.