Frequency offset insensitive multiple symbol detection of MPSK

A novel extension of multiple symbol detection (MSD) of non-coherent MPSK is presented in which the presence of an arbitrary and unknown frequency offset is considered. The resulting detector is insensitive to frequency offset present on the received signal. A near maximum-likelihood (ML), frequency insensitive multiple symbol detection (FI-MSD) metric is derived, and its performance in the detection of double differential MPSK (DD-MPSK) is analysed by simulation. It is shown that as the observation length is increased, the performance approaches that of coherent detection. The new detector removes the need for explicit estimation and removal of frequency offset prior to detection, and may be suited to use with random access communication channels that experience large frequency deviations (such as low Earth orbit (LEO) satellite channels)