Enhancement of grouping scheme for dynamic inter-cell interference coordination in massive-terminal 4G system

Along with the fast development of the Internet of Things, the number of wireless communication devices increases rapidly in the near future, leading to very high time complexity for interference coordination, hence traditional schemes do not work properly anymore. To solve this problem, grouping scheme was proposed, which largely decreases the time complexity without obviously degrading the average spectral efficiency of the system. In this paper, we first work on the performance evaluation of grouping scheme and focus on the problem that the number of terminals may not be divided exactly by the number of groups. We find that simply dropping the rest terminals causes serious fluctuation of the simulation curves, which undermines the precision of the simulation. Then, we enhance the grouping scheme by carefully dealing with the rest terminals and find that putting the rest terminals into the outer groups with one terminal per group is the best method for the tradeoff between average spectral efficiency and time cost. In the end, we work on the fairness issue and propose an alternated grouping scheme which improve the fairness of the original scheme without degrading the average spectral efficiency.