A Low Complexity Cooperative Spectrum Sensor for Cognitive –Radio Network Based on Approximate Computing

With the rapid growth of new wireless technologies, the issue of spectrum scarcity is becoming more prominent due to the limited availability of radio spectrum. Unutilized spectrum bands designated for primary users are known as spectrum holes or white spaces. Assigning these white spaces to secondary users can enhance spectrum utilization. Dynamic spectrum access is crucial for sharing licensed spectrum with secondary users, as opposed to static allocation policies which impede effective spectrum utilization. Spectrum sensing aims to detect licensed users in the spectrum to prevent interference from secondary users. Approximate computing has emerged as a strategy to enhance efficiency by leveraging the fault resilience of various applications. It introduces trade-offs in design optimizations, allowing for significant reductions in VLSI circuit area and energy consumption. A cooperative spectrum-sensing (CSS) algorithm based on approximate computing for cooperative cognitive-radio networks is proposed to reduce computational complexity for efficient hardware design while maintaining detection performance. The hardware-efficient architecture of the cooperative spectrum sensor (CSR) based on the CSS algorithm, combined with resource-sharing architectural optimization, outperforms existing implementations by occupying less area, achieving shorter sensing times, and displaying superior hardware efficiency.