Continuous phase modulation receivers based on frequency domain processing

This paper proposes a scheme of continuous phase modulation (CPM) receivers using frequency domain equalization and conventional parallel and serial CPM receiver structures. Frequency domain equalizers for CPM block transmissions provide spectral and power efficient wireless communications with less complexity than conventional time-domain processing receivers over frequency selective fading channels. Adopting a modified zero-padding method of CPM block transmissions to realize cyclic convolution and frequency domain processing at the receiver preserves phase continuity without additional phase control data and enables decision feedback equalizers to be initialized without delays. Serial and parallel receiver structures for minimum shift keying-like demodulators can be combined with frequency domain equalizers for CPM block transmissions. The proposed frequency domain equalizers eliminate the complexity overhead of conventional decomposition-based CPM receivers. Numerical results show that proposed frequency domain CPM equalizers can achieve equivalent performance of conventional equalizers based on Laurent or orthogonal decomposition.