Direct Bit Detection Receiver Performance Analyses for 8-DPSK (Differential Phase Shift Keyed) Modulated Signals Operating with Improper Carrier Phase Synchronization

摘要

The application of Direct Bit Detection methods are analyzed and evaluated in digital communication systems employing Differential Phase Shift Keyed (DPSK) modulation. Assuming an additive white Gaussian noise interference model, and direct bit detection methods used in the receiver, 8-DPSK and 16-DPSK communication systems are considered and their performances evaluated in terms of the delivered bit error rate as a function of signal-to-noise ratio. The advantages and disadvantages of Direct Bit Detection Receiver (DBDR) systems used in conjunction with differential phase encoding are determined, with specific application to 8-DPSK and 16-DPSK modulated signals. The effect of improper receiver carrier phase synchronization is considered in detail, and resulting performance degradations are evaluated. Numerical results show that for receiver phase errors of more than a few degrees, severe performance degradations result for both DPSK modulation schemes, unless a complete phase reversal (i.e., 180 deg.) takes place.