Fast Pairing of Device-to-Device Link Underlay for Spectrum Sharing With Cellular Users

Device-to-device (D2D) communications has attracted substantial research attention recently owing to its simplicity and its potential to improve spectrum and energy efficiency within the existing cellular infrastructure. This work presents a low complexity method for matching D2D links with cellular user equipments (CUEs) to form partners for spectrum sharing. The overall objective is to maximize well defined performance metrics of all D2D links and CUEs after successful pairing under power and QoS constraints. We begin by identifying a set of D2D link candidates for each CUE uplink for a requisite SINR level to reduce the number of potential pairing searches. More importantly, we present a simple pairing algorithm to reduce the computational cost well below the well known Hungarian (Kuhn-Munkres) algorithm used in the literature for the pairing problem. Our new algorithm exhibits low complexity and is effective in improving the sum rate of all spectrum sharing CUEs and D2D links with modest performance loss.