Modeling and analysis on M-RATs cooperation for D2D communications

This paper presents Multiple Radio Access Technologies(M-RATs) cooperative model for Device- to-Device (D2D) communications, which depends on both the licensed and unlicensed spectrum. The notion of cooperation factor is introduced to capture and analyze the threshold constraint in cooperation scenes. This paper also derives the coverage probability and link spectrum efficiency in typical RAT, which takes into consideration of cooperation factor, density of D2D users and pathloss exponent. Moreover, the metric of cooperation gain is proposed to depict the differences between cooperation with M-RATs and aggregation of multiple spectrum, which can be proved for a decreasing function of cooperation factor. Simulation and numerical results indicate that cooperation can bring higher link spectrum efficiency than that of the non-cooperation, according with the theoretical analysis perfectly.