Constellation selection for the high speed digital modems

Abstract

We present a procedure to dynamically generate the constellation sets of pulse code modulation (PCM) octets, which represent digital data on the public switched telephone network (PSTN). The underlying mathematical modeling of the digital modem has been exploited in order to develop a novel technique, which allows the lower power constellation points to be spaced as far apart as possible from each other without compromising on the data rate and power limitation. The application of the algorithm lies in the design and development of the V.90, and V.92 high-speed modems.