Cognitive Radio Networks
In this chapter, high-speed vehicles are considered for employing the
TV/broadcasting b and via cognitive radio technology to achieve broad band wireless
communications . In a high-speed moving scenario, primary channel occupancy
is mainly depende nt on the secondary user’s position, moving speed, and direction.
Therefore, the relative prim ary channel occupancy m odel, which mainly depends on
the vehicle’s location, velocity, moving directio n, and so on, is considered. Moreover,
a co gnitive r adio-based high-speed vehicle network (CR-HSVN) is introduced and a
framework of the spectrum resource allocation is introduced for effectively utilizing
TV white space.
5.1 A Cognitive Radio-Based High-Speed
5.1.1 System Model
In this chapter, we employ the following terms: (1) primary base station (PBS): the
TV signal transmission tower; (2) primary user (PU): the TV set; (3) cognitive base
station (CBS): the CBSs are deployed in the considered area similar to the base sta-
tions in the cellular network, and are m anaged a nd operated by wireless ope rators;
(4) co gnitive vehicle (CV): high-speed vehicle; and (5) cognitive user (CU): the pas-
senger in the CV that needs to access the cogn itive radio network. The main variables
are listed in Table 5.1.
As shown in Figure 5.1 , we assume that there are L PBSs in a certain area, de-
noted as P
,l = 1,2,··· ,L. N primary chan nels, denoted as C
, n = 1, 2,··· ,N, are
assigned to PBSs to provide services for PUs in the ir coverage ranges. Each PBS
occupies a ﬁxed and known primary channel C
. Note that whe n N 6 L, differ-
ent PBSs may use the same primary channel if they are far away fro m each other.
Locations of these PBSs are known. The coverage radius r
may be differ-
ent for d ifferent PBSs according to the actu al demand. The PBSs with overlap ped
Figure 5.1: The scenario of CR-based high-speed vehicle communication s.