Joint Spatial-Temporal Access Scheme for Multihop Cognitive Relay Networks Over Nakagami-m Fading

Abstract

This paper investigates the cooperative multihop cognitive relay networks (CRNs) under a novel two-dimensional spatial-temporal opportunity model, in which free opportunity and sharing opportunity are defined to enhance the spectrum efficiency. Correspondingly, a joint spatial-temporal access scheme (JSTAS) is proposed to realize successive spectrum access for continuous data transmission. The multihop CRNs with fixed relaying employ decode-and-forward with and without signal-to-noise ratio selection, which are named as SDF and DF, respectively. Then, considering the interference constraints from multiple primary receivers, the interference of one primary transmitter and the maximum transmit powers of cognitive users, we study the outage performance of multihop CRNs with JSTAS over Nakagami-m fading. To comprehensively evaluate JSTAS, we further present the pure spatial access scheme (SAS) and the pure temporal access scheme (TAS) under the spatial-temporal opportunity model, and calculate their average network outage probabilities. Simulation results demonstrate that SDF outperforms DF, while JSTAS outperforms SAS and TAS under all considered scenarios.

Multi-Hop Cognitive Wireless Powered Networks: Outage Analysis and Optimization

“…One practical scenario for such simulation setups is that each PB is one antenna of an AP with multi-antenna. Similar simulation setups are also made for those from PUs to each SU as well as those among SUs, namely d I ,k and d D,k [20], [21]. Then, with full consideration of the large-scale path loss, the rate parameter is calculated as Table 1.…”

“…As PBs locate close to each other, the channels from PBs to each SU follow independent identically distributed (i.i.d.). Similarly, the channels from each SU to PUs and those among SUs are also assumed to be i.i.d., respectively [20], [21]. Note that the channels among PBs, SUs and PUs are independent but not necessarily identically distributed (i.n.i.d.).…”

Energy Efficient Multiband Cooperative Spectrum Sensing for Heterogeneous Cognitive Industrial Wireless Sensor Networks

“…In particular, the high energy cost for spectrum sensing against the inherent energy-constrained nature of IWSNs are the biggest challenge. Existing studies mainly focus on spectrum sensing [7]- [10], spectrum access [11], [12], energy efficient resource allocation [13], [14], etc. In this paper, our attention is paid on the architecture of CIWSN and its energy cost.…”