Probabilistic Band-Splitting for a Buffered Cooperative Cognitive Terminal

TL;DR

This paper introduces a probabilistic band-splitting cognitive protocol that enhances cooperative communication between primary and secondary users, improving throughput and delay performance over existing prioritized relaying methods.

Contribution

The paper proposes a novel probabilistic band-splitting protocol for cognitive radios that optimizes bandwidth sharing and relaying, outperforming traditional prioritized relaying schemes.

Findings

The protocol improves throughput compared to PCR.

Bandwidth splitting can be optimized via linear programming.

Numerical results show significant performance gains.

Abstract

In this paper, we propose a cognitive protocol that involves cooperation between the primary and secondary users. In addition to its own queue, the secondary user (SU) has a queue to store, and then relay, the undelivered primary packets. When the primary queue is nonempty, the SU remains idle and attempts to decode the primary packet. When the primary queue is empty, the SU splits the total channel bandwidth into two orthogonal subbands and assigns each to a queue probabilistically. We show the advantage of the proposed protocol over the prioritized cognitive relaying (PCR) protocol in which the SU assigns a priority in transmission to the primary packets over its own packets. We present two problem formulations, one based on throughput and the other on delay. Both optimization problems are shown to be linear programs for a given bandwidth assignment. Numerical results demonstrate the benefits of the proposed protocol.