Cognitive Ad Hoc Network with Limited Feedback

Abstract

In this chapter, we study the opportunistic spectrum sharing in ad hoc networks. Both primary and secondary transmitters are modeled as Poisson point processes. The primary and secondary receivers each sends 1-bit feedback of local channel gain to their corresponding transmitters. The primary transmitters are active if their local primary channel gains are above a certain threshold. In the first scheme, the secondary transmitters transmit if their local channel gains are above the required threshold. In the second scheme, the secondary transmitters transmit if their local channel gains are above the threshold and they are outside the primary exclusive regions of the active primary receivers. Using stochastic geometry theory, the analytical solutions of the optimal secondary node density are derived by maximizing the average secondary throughput per unit area under the reliability constraints of both primary and secondary users.With tight secondary constraint, the scheme without primary exclusive region is more beneficial. With tight primary constraint, the scheme with primary exclusive regions is recommended.