Abstract-We investigate a pricing based approach to control interference from a tier-2 base station (BS) to a tier-1 BS in reversed time division duplex (TDD) multi-antenna systems. The tier-2 BS is being charged for causing interference to the tier-1 BS. Also, the tier-2 BS has to satisfy the signal-tointerference-plus-noise ratio (SINR) targets of its downlink users under a maximum transmission power constraint. Analytical and simulation studies are carried out to understand the behavior of the tier-2 BS for different charges and for different power budgets. Observations from the analyses suggest that the tier-1 BS can perform interference control and/or profit maximization without knowing the downlink channels of the tier-2 BS. Heterogeneous networks (HetNets) and massive multipleinput multiple-output (MIMO) have been identified as the enabling technologies for the next generation of cellular networks [1, 2] . To avoid the heavy signalling on training the channels between the tier-1 base stations (BSs) and the tier-2 BSs in conventional time division duplex (TDD) systems, reversed TDD protocol has been proposed in [3] , where the tier-2 BSs perform downlink transmissions while the tier-1 users perform uplink transmissions. On the other hand, it is expensive or even infeasible to establish wired backhaul links from the tier-2 BSs (the smaller BSs) to the tier-1 BSs as cellular networks become more densified, so that wireless backhaul has to be considered in certain scenarios [4] . In order to perform interference control from a tier-2 BS to a tier-1 BS while keeping the signalling across the two tiers low in reversed TDD systems, we consider the downlink beamforming problem for the tier-2 BS, where the tier-1 BS charges the tier-2 BS for causing interference. We perform both theoretical analysis and simulation studies on how the tier-2 BS behaves under different charges and different power budgets. Based on the observations from our studies, we believe that the tier-1 BS can perform interference control by probing through a number of charge values, thus removing the need for the tier-1 BS to know the downlink channels of the tier-2 BS as in centralized designs. The same mechanism can also be used in scenarios where the tier-1 BS is interested in making profit from the tier-2 BS, where the profit comes from charging on the interference.
Building on REF in which we mainly analyze the effect of power budget of the tier-2 BS on the interference leakage towards a single tier-1 BS, in this paper, we conduct detailed analyses on a more general system setting with multiple tier-1 BSs.
Pricing based interference control in reversed time division duplex heterogeneous networks
2016 IEEE International Conference on Communications (ICC)
2016 IEEE International Conference on Communications (ICC)
Computer Science