Multi-modulation programmable transceiver system with turbo coding

A flexible and configurable transceiver based on a field programmable gate array (FPGA) has been developed and tested. The system supports a wide range of parameters, all of which can be changed on the fly, including: modulation type (BPSK to 64-QAM, 8PSK, FSK and GFSK), number of bits/symbol, pulse shaping, etc. It also supports symbol detection of an arbitrary constellation, automatic gain control (AGC), carrier and timing tracking. The system provides an integrated bit error rate (BER) tester in the demodulator and additive white Gaussian noise (AWGN) source in the transmitter to allow rapid characterization of the transceiver performance under conditions difficult or impossible to achieve using software simulations. The demodulator provides timing and phase acquisition for arbitrary constellations. The system is tightly integrated with a commercial turbo-encoder/decoder chip. Graphical user interface (GUI) software has been developed to enable "on the fly" reconfiguration of modulation and coding parameters and real-time observation of key system parameters, including the incoming signal, constellation, signal to noise ratio. The RF subsystem supports frequencies from 1.0 to 2.5 GHz. An external high power traveling wave tube amplifier (TWTA) is integrated into the overall system