Sliding Window Spectrum Sensing for Full-Duplex Cognitive Radios with Low Access-Latency

TL;DR

This paper proposes a sliding-window full-duplex spectrum sensing method for cognitive radios, significantly reducing access-latency and improving resilience to self-interference compared to existing schemes.

Contribution

It introduces a novel sample-by-sample decision scheme in full-duplex cognitive radios, reducing latency and enhancing interference resilience.

Findings

Access-latency reduced by 2.6 times compared to slotted schemes

Latency decreased by approximately 16 times relative to half-duplex systems

Proposed scheme shows higher resilience to residual self-interference

Abstract

In a cognitive radio system the failure of secondary user (SU) transceivers to promptly vacate the channel can introduce significant access-latency for primary or high-priority users (PU). In conventional cognitive radio systems, the backoff latency is exacerbated by frame structures that only allow sensing at periodic intervals. Concurrent transmission and sensing using self-interference suppression has been suggested to improve the performance of cognitive radio systems, allowing decisions to be taken at multiple points within the frame. In this paper, we extend this approach by proposing a sliding-window full-duplex model allowing decisions to be taken on a sample-by-sample basis. We also derive the access-latency for both the existing and the proposed schemes. Our results show that the access-latency of the sliding scheme is decreased by a factor of 2.6 compared to the existing slotted full-duplex scheme and by a factor of approximately 16 compared to a half-duplex cognitive radio system. Moreover, the proposed scheme is significantly more resilient to the destructive effects of residual self-interference compared to previous approaches.