Analysis of decision-aided DPSK in the presence of multipath fading

A decision-aided DPSK receiver scheme is proposed, which can achieve channel equalization using data symbols alone (i.e. no additive reference information is required). It makes use of the fact that for a typical irreducible error rate of 1%, 99% of the received symbols are correctly demodulated. Using this information to remove the modulation from the incoming radio signal effectively results in the recovery of unmodulated carrier component subject to the multiplicative channel distortion. Filtering this regenerated carrier signal to extract the channel information and minimizing noise results in a signal representative of system distortion (assuming flat fading), which can be used to effectively cancel most of the fading distortion on the incoming signal and thereby reduce the irreducible error floor significantly. >