Individual satellite users are restricted in connectivity because the satellites are not capable of processing all available user modulation waveforms. Greatly increased satellite availability and user connectivity would be possible if all new satellites were capable of processing the wide variety of commonly used modulation waveforms. This Phase I effort researches preliminary designs leading toward a Phase II preliminary development of a multi-user, programmable modem. This device, intended for satellite, Space Station and ground sites, will provide for modulation, acquisition, tracking and demodulation of a wide variety of commonly used modulation waveforms including BPSK, QPSK, OQPSK and MSK; as well as analog AM and FM voice. The modem will feature: (1) real-time operator-selectable or ground up-link commandable modem configuration changes; (2) automatic demodulator signal recognition; and (3) simultaneous demodulation of several waveforms. The Phase I effort encompasses: (1) identification of common and unique algorithm among the modulation waveforms; (2) algorithm partitioning into efficient processing functions; (3) identification of processing speed requirements and channel data rates for various technologies suitable for implementation; and (4) associated analytical support and computer simulations for performance verification.