Optimum Linear Filter of PPM Receiver.

This paper considers the problem of an optimum linear filter on the receiving side of the PPM transmission system in which both the additive noise and the signal-dependent noise exist. The optimum filter for the PPM transmission derived in this paper is the one in which the mean-square value (MSE) of the timing error is minimized at the location of the pulse detection. In contrast to the optimum filter in the PAM transmission which maximizes the signal-to-noise ratio in the amplitude direction, the present optimum filter is of a different type which maximizes this ratio in the time-axis direction. In this paper, the general equation which the optimum filter must satisfy is derived as an equation containing the previous research results. Subsequently, the timing error, optimum pulse detection level and the configurations of the filter on the receiving side and of the pulse location detector are presented. It is pointed out that, by the use of the optimum filter derived in this paper, baseband multiplexed transmission systems using pulses can be realized easily by combining the PAM and PPM systems. The method for multiplexing and the receiver configuration are shown. [ABSTRACT FROM AUTHOR]