PERFORMANCE OF COHERENT DETECTION SYSTEMS USING DECISION DIRECTED CHANNEL MEASUREMENT,

摘要

A receiver which employs coherent,or synchronous,detection must have a priori knowledge of the phase of the received signal. The receiver acquires this knowledge by performing measurements on the channel. The result of the measurement process is a noisy phase reference which is used by the receiver in the detection processing of the incoming signals. In this report,the effect of using baud decisions to direct the phase measurement process is investigated by means of computer simulation of a coherent communication system employing either orthogonal or phase-reversal signaling. Error rates are given for several signal-to-noise ratios. A major conclusion of this study is that phase measurements obtained through such a decision directed technique results in system error rates which are generally less than error rates of corresponding non-decision directed phase measurement schemes at all signal-to-noise ratios;no threshold exists below which a decision directed phase measurement system deteriorates rapidly. (Author)