Adjacent channel interference in partial response continuous phase modulation systems with MSK-type receivers

Partial Response Continuous Phase Modulation (CPM) schemes employing simple sub-optimum receivers have found wide acceptance due to their compact spectra and comparable performance with other traditional modulation schemes. In this paper we study the Adjacent Channel Interference (ACI) in Partial Response CPM schemes employing MSK-type receivers. Signal to mean-square crosstalk ratio is evaluated as a function of channel spacing for various modulation schemes and receiver filters. These results are compared with those of MSK scheme employing optimum receiver to determine the improvement in ACI rejection offered by Partial Response schemes. Results show the importance of receiver filters in addition to the compactness of the transmitted spectra in assuring a low crosstalk.