An experimental TDMA traffic terminal

Basic concepts, critical design issues, and implementation criteria for an experimental 120-Mbit/s TDMA traffic terminal are presented. The terminal consists of a TDMA controller, modem, digital speech interpolation (DSI) module, and special test equipment. The special test equipment consists of a reference burst generator and a bit error rate/error-free interval measurement unit. The reference burst generator makes it possible to perform tests in a satellite loop configuration. Speed of operation, especially in regard to the unique word detector and the forward error correction unit, was a critical item in the terminal design. Other critical items were the interfacing of 32 DSI modules to the TDMA controller, and the design of a receive-side retiming unit with a demodulator interface which required no clocks after the last symbol of data.