Cognitive Radio Universal Software Hardware

Cognitive radio (CR) allows a pair of wireless communicating devices to intelligently adapt their transmission parameters based on the characteristics of the radio frequency (RF) environment, possibly using vacant portions of licensed frequency bands. A key step in this process is spectrum sensing, where the presence of primary users of the spectrum is detected by sending raw samples from the front-end to the host computer, a process that incurs significant processing delay. In this paper we introduce the Cognitive Radio Universal Software Hardware (CRUSH) platform that revisits the classical software defined radio (SDR) architecture by including a Xilinx ML605 FPGA board, thereby flexibly sharing the processing load with the host computer. CRUSH shifts the spectrum sensing overhead closer to the front-end. Our design results in orders of magnitude speedup and can flexibly connect up to three SDRs together, resulting in a powerful platform suitable for time-sensitive CR functions.