Enhancing Spectrum Sensing Efficiency in Multi-Channel Cognitive Device-to-Device Networks: MAC Layer Strategies and Analysis

The detection and characterization of electromagnetic signals within a specific frequency range, known as spectrum sensing, plays a crucial role in Cognitive Radio Networks (CRNs). The CRNs aim to adapt their communication parameters to the surrounding radio environment, thereby improving the efficiency and utilization of the available radio spectrum. Spectrum sensing is particularly important in device-to-device (D2D) communication when operating independently of the cellular network infrastructure. The Medium Access Control (MAC) protocol coordinates device communication and ensures interference-free operation of the CRN coexisting with the primary cellular network. In this paper, we propose a spectrum sensing strategy at the MAC layer for cognitive D2D communication. Our strategy focuses on reducing the overall sensing period allocated at the MAC layer by having each Cognitive D2D User (cD2DU) sense a smaller subset of available channels while maintaining the same sensing time for cellular user detection at the physical layer. To achieve this, we introduce the concept of concurrent groups of D2D devices in proximity, which are formed by using unique IDs of cD2DUs during the device discovery stage. Each concurrent group senses a specific portion of the cellular user band in a shorter time, resulting in a reduced overall sensing period. In addition to mitigating traffic congestion through data diversion from the cellular network, our proposed strategy facilitates the concurrent sensing of multiple channels by cD2DUs within the underutilized cellular user band. This leads to extended data transmission periods, increased network throughput, and effective offloading of the cellular network. The effectiveness of the proposed work is evaluated by considering factors such as network throughput and transmission time. Simulation results confirm the effectiveness of our approach in improving spectrum utilization and communication efficiency in multi-channel Cognitive D2D Networks (cD2DNs).