Joint access control and resource allocation for machine type communications

Abstract

As one of the most important components in IoT system, machine type communication (MTC) will definitely play an increasingly important role in the academia and industry in the near future for 5G application. Currently, most of the access control work concentrates on avoiding preamble collision without considering SINR requirement. In order to further improve the number of effective access devices (EADs), we propose a joint access control and resource allocation. Due to the fact that the main characteristics of MTC, distinct from the conventional cellular network, are massive access and small amount of data, we formulate an indicator function optimization problem, rather than a continuous rate function considered in cellular network, to maximize the number of EADs. This optimization problem is NP-hard and highly complex to solve, so we decouple the problem into two sub-problems, then we utilize convex optimization tool (CVX) and Hungarian algorithm to perform the joint access control and resource allocation under multi-cell scenario. Moreover, we derive the optimal closed-form power allocation under 2-cell scenario based on Lagrange KKT method. Simulation results demonstrate that the proposed joint access control and resource allocation scheme can achieve a significant improvement performance on EADs with fewer iterations, compared to some classic access methods.