The Coexistence of LTE-U and WLAN: Absolute Channel Allocation for Device-to-Device Communication (AD2D)

Device-to-Device (D2D) communication is a recent technology enabled to perform direct communication between devices. The significance of D2D are minimized power consumption, delay and enhanced spectral efficiency and data rates. The use of unlicensed spectrum is extended towards Long Term Evolution (LTE), while creating coexistence with Wireless Local Area Network (WLAN) that is supported for D2D communication. The challenges on utilization of spectrum and also to solve the spectrum scarcity problem, unlicensed bands are made use of LTE. This paper addresses the channel allocation for D2D communication in coexistence of LTE and WLAN over unlicensed band. Both Real Time (RT) and Non-Real Time (NRT) packets are taken in account, two different data packets are allocated with a single channel for two D2D pairs and improve spectrum efficiency. A special sensing entity called Spectrum Agent is deployed to make final decisions on idle sub-frames based on rules and also rank the idle sub-frames using Analytical Hierarchical Process. To enhance the decision making, rules are applied over neural network. Type-2 fuzzy model to identify the users with higher probability followed security validation. This work is implemented in Network Simulator 3 and results show better performances in terms of throughput, spectral efficiency, average delay, secrecy throughput and secrecy rate.