Peak-to-average ratio (PAR) reduction by pulse shaping using a new family of generalized raised cosine filters

A new family of generalized raised cosine filters is formulated in an effort to reduce the peak-to-average ratio (PAR) of the baseband signal over that obtained using the conventional raised cosine filter, while maintaining the same excess bandwidth and the zero intersymbol interference condition. The generalized filters contain a new design parameter d, giving an additional degree of freedom to minimize PAR for a given roll-off factor α. It is shown that PAR can be reduced by more than 0.5 dB over most of the α range. Closed form expressions for the frequency and impulse responses of the generalized raised cosine filters are presented, along with the optimum value of d that yields minimum PAR as a function of α.