Receiver Design for Linearly Modulated Signals with Unknown Carrier Frequency and Phase Offset

This paper is concerned with receiver design for digital communications with linearly modulated signals over the additive, white Gaussian noise channel with unknown carrier frequency and phase offset. The modulation techniques examined are phase shift keying with and without differential encoding and M-ary quadrature amplitude modulation. Two types of receiver structures are proposed, namely, the symbol-by-symbol receiver with pilot-symbol assisted-modulation and the simultaneous data detection and carrier frequency/phase offset estimation receiver. Both receivers incorporate the use of the maximum likelihood frequency/phase estimator of a single sinusoid in noise that we recently derived in the work of Fu and Kam (2007 and 2006) to estimate and compensate for the effects of the unknown carrier frequency and phase offset. The error performance of the proposed receivers are examined via computer simulations.