EMF-reduction Uplink Resource Allocation Scheme for Non-Orthogonal Multiple Access Systems

The increasing number of users and the demand for higher data rate due to multimedia services, requires high capacity/bandwidth, low latency and high quality of service (QoS). In turn, some of these requirements have/will lead to the deployment of numerous new access points. Given that wireless communication systems utilize radio frequency (RF) waves to operate, more users and more access points imply more electromagnetic field (EMF) exposure. Meanwhile, the possible health consequences of EMF exposure from these systems are progressively becoming a major concern due to their ever growing ubiquity and increased transmission power. In an endeavor to reduce the EMF exposure due to wireless communication systems, we design an optimization scheme for minimizing the EMF exposure of users in the uplink of non-orthogonal multiple access (NOMA) systems, while satisfying each user with an acceptable QoS. We define EMF minimization strategy as a convex optimization problem and iteratively solve it by assigning bits to each user. Each subcarrier is strategically allocated to a group of users having minimum interference and is found by using the classic binary search algorithm. Simulation results depict that our proposed strategy provides a reduction of at least 1 order of magnitude in terms of EMF exposure, while satisfying QoS constraints, in comparison with the state-of-art techniques in the literature.