Extensions of the LAT Protocol

Abstract

The basic LAT protocol considers only one PU and one pair of SUs, which is quite limited. In this chapter, we consider the scenarios with multiple FD users that adopt the LAT protocol as their basic PHY sensing protocol. Firstly, we study the cooperative spectrum sensing under the LAT protocol, in which the interference among cooperative users makes the cooperation different from conventional cooperative schemes [1]. We provide a feasible cooperation scheme that is suitable for FD SUs in Sect. 3.1. Then, we consider both distributed [2] and centralized network [3] scenarios that require design of MAC layer protocols for harmonious multiple access and resource allocation. In distributed scenarios, multiple FD SUs contend for the same spectrum resources without any central controller. Thus, an effective multiple access scheme that can not only mitigate collision among SUs, but also fully explore the benefits of FD is needed. In centralized network, a FD cognitive AP, which can be regarded as a central controller over all SUs beneath, needs to sense the spectrum opportunities and allocate the temporal, frequency and power resources to the SUs properly, so that SUs can enjoy high data rate and the sensing performance of the AP can be guaranteed.