LTE-U sum-rate maximization considering QoS and co-existence issue

Wireless communication industry is facing storm of exponential mobile traffic increase due to richer contents sharing over the network through smart devices. A innocent resolution for envisaging this contravention is to employ more licensed spectrum. But this is a scare resource and sufficient additional spectrum will be unavailable in the upcoming days. So, both academia and industry are engaging different new technologies to deal with this traffic cyclone in cellular networks. Long Term Evaluation-Advanced (LTE-A) is such a recent technology that serves heavy mobile traffic. But with insufficient licensed spectrum, LTE-A also cannot meet the quality of service (QoS) requirements of all it's users. So, by augmenting the benefits of LTE-A into unlicensed spectrum known as LTE-U with the help of carrier aggregation (CA) technique, we can boost the performance of 4G/5G cellular network. The process will degrade the performance of other technologies which are already using same unlicensed band. Moreover, if multiple cellular network operators (CNOs) use the same unlicensed band then they will diminish the benefits of each others. In this paper, we explore the CA of licensed and unlicensed spectrum when QoS of user cannot be met with licensed spectrum by deploying dual mode small cell base station (SBS) and considering minimum requirement of unlicensed WiFi access points (WAP). Here, we formulate the resource allocation as an optimization problem which wants to maximize the sum-rate of LTE-U system. Then we solve this problem with the help of Nash bargaining game (NBG) between LTE-U and WAP by cooperative approach. Simulation results show the effectiveness and efficiency of the proposed approach considering QoS requirement of LTE-U users and coexistence issue with WAPs.