Performance Analysis of Spatial Modulation in Overlay Cognitive Radio Communications

Dynamic interference‐limited relay sharing in cognitive radio networks by using hierarchical modulation

“…Fig. 8 compares the simulation results and high-SNR approximation of (24) and (25) in order to verify our analytical results that were obtained in the previous sections. As it can be realised, the provided approximations are quite accurate in this case.…”

“…Typically in a CR system, transmission happens in one of the underlay or overlay sharing methods or a combination of which that is called the hybrid underlay/overlay spectrum sharing [22,24,25]. In the underlay method, the SU utilises the licensed spectrum with a proper level of power, in order to keep the level of interference imposed to the PU under a given threshold that is tolerable by it.…”

Dynamic Spectrum Sharing in 5G Wireless Networks With Full-Duplex Technology: Recent Advances and Research Challenges

“…Interweave paradigm allows the opportunistic secondary transmission in the frequency channels in which the primary transmission is absent [97] while the underlay paradigm enables the concurrent operation of primary and secondary systems while guaranteeing sufficient protection to the PUs [98,99]. On the contrary, the overlay paradigm utilizes advanced coding and transmission strategies and requires a very high degree of coordination between spectrum sharing systems, which might be complex in practice [100,101]. Out of these three paradigms, this paper discusses the application of FD in interweave and underlay systems.…”

Dual-Hop Spatial Modulation With a Relay Transmitting its Own Information

“…When the relays have their own information to be transmitted, it is inevitable to occupy extra resource such as time slot and frequency band, which degrades the system throughput and increases the network latency. In [28] and [29], the two information-bearing units of SM are exploited in cognitive radio by two different sources, such that the information from the primary and secondary transmitters can be transmitted at the same time. The study of [30] introduces the scheme of distributed SM (DSM) with the aid of multiple single-antenna DF relays, in which the data from the source is encoded into the index of one active relay and the signal domain is exploited to convey the data of the relay.…”

“…(74)It can be shown that in (74), |g m s − gmŝ| 2 and |g m | 2 are two correlated exponentially distributed random variables with correlation coefficient 1/2, and |h l | 2 is an independent exponential random variable. The CDF of λ 3 can be derived as[28]…”