  This paper investigates a multi-hop cognitive radio network in terms of
end-to-end bit delivery. The network exploits backscatter communication
(BackCom) and harvest-then-transmit (HTT) mode in a hybrid manner. Such a
network can be used in internet of things (IoT) applications in which IoT users
coexist with a primary network (PN) and use the primary spectrum to transmit
data in both BackCom and HTT modes. Besides, such users can harvest energy from
the primary signals. A novel hybrid backscatter and conventional transmission
(HBCT) algorithm is proposed in order to maximize end-to-end bit delivery by
jointly optimizing time and power allocations. For this goal, we formulate a
non-convex optimization problem. Next, we transform the problem into a convex
one and develop a new analytical formulation by which we calculate the optimal
power and time allocation in closed-form equations. The numerical results
demonstrate the superiority of HBCT compared with current schemes.
