PSK-based constellation expansion for fading multipath channels

Efficient use of bandwidth and the design of efficient modulators remains a primary concern in the design of many emerging communication systems including systems for personal communication services (PCS). The bandwidth required by a communication system depends on a number of factors including the type of source encoders, channel encoders, modulation format, and the access technique. In conventional modulation formats such as PAM, FSK, and PSK, the error rate performance is traded for either bandwidth expansion or larger signal power. The amount of increase of power or bandwidth for the tradeoffs vary from one modulation format to another. Here we develop a modulation technique that improves the performance by creating signal constellations that allow transmission of more information than in a conventional system. We analyze the performance of this new modulation format in fading multipath channels. This method can be used with signal constellations that allow coded modulation formats, such as TCM, as well as uncoded modulation