Analysis on deployment parameters of secondary users in cognitive radio networks

Cognitive radio has emerged as an efficient approach to implement reuse of the licensed spectrums. How to appropriately deploy and construct the secondary network plays a rather important role. In this paper, a novel deployment scheme, which integrates the radio environment map (REM) and primary exclusive zones (PEZ) together, is proposed. We first illustrate secondary users' achievable region around one primary receiver based on protocol interference model. Then we give the close-form of secondary users' density, which provides a standard for controlling number of secondary users in that achievable region. In other words, our analysis result presents how many secondary transmitters can exist around one primary receiver. We also give a density control algorithm to manage the number of secondary transmitters according to our standard. At last, the keep-out region is simulated and some related parameters are calculated. Meanwhile, the simulation result of secondary density well matches with the theoretical result from our analysis.