THE DS SSMA SYSTEMS USING TRELLIS CODING WITH ASYMMETRIC PSK SIGNAL CONSTELLATION/

We analyze the performance of direct-sequence spread spectrum multiple access (DS/SSMA) systems, which use trellis coding with asymmetric ph ase shift keying (PSK) modulation. By designing the signal constellati on to be asymmetric, we obtain a performance gain for the DS/SSMA syst em over the systems using the traditional symmetric signal constellati on. Bit error probability analysis of the proposed system is carried o ut for some cases. Examples are given to show the performance gain due to the asymmetry of the signal constellation. (C) 1998 Elsevier Scien ce B.V. All rights reserved.