Low Complexity Spectrum Sensing System for GFDM Cognitive Radio Signals

Abstract

Cognitive radio is a promising technology that aims to use the transmission spectrum efficiently. Each cognitive transmission process consists typically of two phases. During the first phase, which is called sensing phase, cognitive system attempts to detect an available spectrum hole. While in the second phase, data transmission phase, the secondary user data is transmitted to the destination via detected hole. The throughput of the cognitive radio system is mainly depending on the ratio of the transmission time to the sensing time. To reduce the sensing time, this paper suggests a design of simple spectrum sensing system capable for detecting Generalized Frequency Division Multiplexing (GFDM) signals. The reduction in sensing time is based on using XilinixVirtix-6 Field Programmable Gate Array (FPGA) as a target device for implementation the proposed design, which operates at 600 MHz clock frequency. This work includes a discussion of more than one approach to reduce the arithmetic operations needed to implement a sensing system with 250 subcarriers. The simulation results show that the power consumption represents the main challenge of such implementation.