Orthogonal Phase-Coded Signals with Additional Differential Phase Shift Keying

The paper examines the version of a equal-energy orthogonal phase-coded signals with additional differential phase modulation of codewords. Adding differential phase modulation of codewords to the phase-coded signal made it possible to reduce the probability of bit error while maintaining the possibility of incoherent detection. A single differential quadrature phase modulation of codewords provides the lowest probability of bit error among the signals under consideration, but in the absence of a frequency offset. At small frequency offsets, the single differential binary phase modulation of codewords has the smallest bit error probability. However, two-fold differential binary phase modulation with a slight loss relative to a single differential modulation in the AWGN channel has the lowest sensitivity to the frequency offset. Additional differential phase modulation it possible to reduces the number of orthogonal signals while preserving the probability of a bit error, or reduces the probability of a bit error while maintaining the occupied bandwidth.