A software-defined radio based on the unified SMSE framework

We implemented a software-defined radio based on a recently developed unified framework for constructing various spectrally-modulated, spectrally-encoded (SMSE) signals. Two waveforms, Multi-Carrier Code Division Multiple Access (MC-CDMA) and Transform-Domain Communication System (TDCS) were selected to demonstrate the capabilities of the framework. A transmitter and receiver were each implemented on separate digital signal processor starting kits (DSK). A channel simulator, consisting of additive white Gaussian noise and narrowband BPSK interferers, was implemented on an FPGA. Burst transmissions from transmitter to receiver through the channel simulator were conducted to evaluate the bit-error rate performance of the system. The bit-error results from the hardware implementation closely match theoretical results. Also, TDCS was shown to mitigate effects of narrowband interference compared to MC-CDMA.