Performance Enhancement for Multihop Cognitive DF and AF Relaying Protocols under Joint Impact of Interference and Hardware Noises: NOMA for Primary Network and Best-Path Selection for Secondary Network

In this paper, we propose and evaluate performance of multihop multipath underlay cognitive radio networks. In a primary network, an uplink nonorthogonal multiple access method is employed to allow primary transmitters to simultaneously transmit their data to a primary receiver. Using an underlay spectrum-sharing method, secondary source and secondary relays must adjust their transmit power to guarantee quality of service of the primary network. Under the limited transmit power, cochannel interference from the primary transmitters, and hardware noises caused by impairments, we propose best-path selection methods to improve the end-to-end performance for the secondary network. Moreover, both multihop decode-and-forward and amplify-and-forward relaying protocols are considered in this paper. We derive expressions of outage probability for the primary and secondary networks and propose an efficient method to calculate the transmit power of the secondary transmitters. Then, computer simulations employing the Monte-Carlo approach are realized to validate the derivations.

Relaying Protocols for Wireless Energy Harvesting and Information Processing

Most of the ongoing exploration in wireless relay node networks and data preparing has considered point-to-point correspondence system. In remote helpful or then again sensor organizes, the hand-off or sensor relay node may have restricted battery holds and may need to depend on some outside charging component so as to stay dynamic in the system. Along these lines, vitality reaping in such systems is especially significant as it can empower data handing-off. In this thesis, we are worried about the issue of remote vitality collecting and data preparing in an intensify and-forward (AF) remote agreeable or sensor arrange. We consider the situation that a vitality obliged hand-off relay node harvests vitality from the RF sign communicated by a source node and utilizations that reaped vitality to advance the source signal to a destination node. We consider time switching (TS) and power switch (PS) scheme structures. we propose two transferring conventions: i) TS-based handing-off (TSR) convention and; ii) PS-based handing-off (PSR) convention for discrete data handling and vitality reaping at the vitality compelled wireless relay node. The primary commitments of this thesis are abridged as pursues: • We propose the TSR and the PSR conventions to empower remote vitality reaping and data handling at the vitality obliged transfer in remote AF transferring systems, in light of the TS and PS collector structures. • For the TSR and the PSR conventions, we determine logical articulations for the reachable throughput at the goal. • Comparing the TSR and the PSR conventions, our numerical investigation demonstrates that in postponement restricted transmission mode, the throughput execution of the TSR convention is better than the PSR convention at higher transmission rates, at generally lower signal-to-commotion proportion (SNR), and for lower vitality gathering productivity. • We propose the combination ATPSR system and demonstrate the optimal throughput for that system. • Finally, design and built the hardware circuit and using particle swarm optimization techniques to find the optimal value for the parameters.

Outage Performance Analysis and SWIPT Optimization in Energy-Harvesting Wireless Sensor Network Deploying NOMA

Thanks to the benefits of non-orthogonal multiple access (NOMA) in wireless communications, we evaluate a wireless sensor network deploying NOMA (WSN-NOMA), where the destination can receive two data symbols in a whole transmission process with two time slots. In this work, two relaying protocols, so-called time-switching-based relaying WSN-NOMA (TSR WSN-NOMA) and power-splitting-based relaying WSN-NOMA (PSR WSN-NOMA) are deployed to study energy-harvesting (EH). Regarding the system performance analysis, we obtain the closed-form expressions for the exact and approximate outage probability (OP) in both protocols, and the delay-limited throughput is also evaluated. We then compare the two protocols theoretically, and two optimization problems are formulated to reduce the impact of OP and optimize the data rate. Our numerical and simulation results are provided to prove the theoretical and analytical analysis. Thanks to these results, a great performance gain can be achieved for both TSR WSN-NOMA and PSR WSN-NOMA if optimal values of TS and PS ratios are found. In addition, the optimized TSR WSN-NOMA outperforms that of PSR WSN-NOMA in terms of OP.