Performance of a cooperative downlink multiplexing scheme using dynamic spectrum access principles

In this study, the authors propose a new cooperative multiplexing scheme for downlink transmission using dynamic spectrum access (DSA) principles. In this scheme, the base-station (BS) transmits to its distant user using a selected relay node in two hops. In the second hop, while the relay forwards information to the distant user, the BS transmits information to another selected user in its vicinity using DSA principles. Assuming peak power and peak interference constraints, the authors derive outage and ergodic rate performance of the user served by DSA assuming various user selection schemes. The authors consider gain-based selection, SINR based selection (SS), interference cancellation (IC), as well as a hybrid scheme that employs both SS and IC. The authors demonstrate that apportioning of time between the first and second hop of relaying can improve outage performance of the user served by DSA while ensuring certain guaranteed performance for the distant user. The presented analytical expressions are compared with computer simulation results.