Opportunism in Dynamic Spectrum Access for 5G: A Concept and Its Application to Duplexing

TL;DR

This paper introduces an opportunity probability (OP) framework for spectrum sharing in 5G, proposing a random MAC algorithm and a hybrid duplexing mode to enhance spectrum utilization and system throughput.

Contribution

It presents a novel OP-based random MAC algorithm and a hybrid duplexing scheme for spectrum sharing in 5G, validated through numerical analysis and FPGA prototype testing.

Findings

Achieves up to 4 times higher throughput than LTE-TDD

Validates the OP framework through real-time FPGA implementation

Demonstrates flexible duplexing mode based on spectrum usage levels

Abstract

With the envisioned massive Internet-of-Things (IoT) era, one of the challenges for 5G wireless systems will be handling the unprecedented spectrum crunch. A potential solution has emerged in the form of spectrum sharing, which deviates from a monopolistic spectrum usage system. This article investigates the medium access control (MAC) as a means of increasing the viability of the spectrum sharing technique. We first quantify the opportunity of spectrum access in a probabilistic manner, a method referred to as opportunity probability (OP). Based on the OP framework, we propose a random MAC algorithm in which the access of a node is randomly determined with its own OP value. As a possible application of our OP based random MAC, we propose a hybrid half duplex (HD)/full duplex (FD) communication where each pair decides the duplexing mode according to the OP values of the two pair nodes. This approach fits well with the spectrum sharing system since it enables a flexible operation for the spectrum access according to the spectrum usage level. From the numerical analysis, we validate the feasibility and verify the performance enhancements by implementing an FPGA based real-time prototype. Measurements and numerical results confirm that the proposed architecture can achieve up to 4 times higher system throughput than conventional LTE-TDD (time division duplex) systems.