BANDWIDTH EFFICIENCY FOR DIGITAL COMMUNICATION VIA A HARD LIMITING CHANNEL

Abstract

The achievable burst data rate with typical channel filters is obtained for biphase, quadriphase, and eight-phase modulation. The effect of intersymbol interference in a hard-limiting channel is modeled by a time-domain representation which averages probability of error over all (truncat, ed) equally likely sequences of digits. As measured by the bit rate per unit bandwidth achieved at a given received E(b)/N(o), quadriphase outperforms biphase, but by less than a factor two, in contrast to behavior in a linear channel. Eight phase modulation appears to offer only a marginal improvement over quadriphase, and only for E(b)/N(o) > 15 db.