Comprehensive Capacity Ensured Distributed Binary Power Allocation in Dense Cognitive Networks

Considering the capacity gain of the secondary system and the capacity loss of the primary system caused by the newly accessing user, a distributed binary power allocation (admittance criterion) is proposed in dense cognitive networks including plentiful secondary nodes. The case that the secondary nodes can detect both transmitter and receiver of the primary system is analyzed first; considering that it is hard for the secondary system to detect the primary receiver without assuming the cooperation with primary system, the case that the secondary nodes only have the information about the primary transmitter is analyzed thereafter. In particular, we propose a simple estimation strategy to transform the problem of detecting primary receiver to the problem of detecting primary transmitter for the latter case. And a general power allocation scheme which is suitable for both of two cases is proposed afterward. By simulations, the restriction on the distance between secondary transmitter and primary receiver, and the restriction on the distance between secondary and primary transmitters are respectively achieved for the two cases. These two restrictions reflect that the capacities of both primary system and secondary system can be ensured to the predefined extents if these two restrictions on the distances are respectively satisfied in two cases.