||Performance Analysis of Multihop Wireless Networks
Nguyen, Dang Khoa
Wireless communication has been considered as the most efficient mean of datatransmission. We have been witnessed the breakthrough of wireless communicationera in many manifolds, such as speech, coverage area, and stability. However,frequency bands, the resource to convey information wirelessly, are limited and expensiveto be granted usage licenses.Attaining the goals of ubiquitous wireless devices will require the future wirelessnetworks stepping forward to overcome the scarcity and expensiveness of wirelessfrequency bands. Thus, the future wireless networks should evolve to utilize wirelessfrequencies more efficiently, such as cognitive relay network where non-licenseusers are able to transmit data in the same frequency band that officially allocated toprimary users. Subsequently, the transmit power of users in a cognitive network islimited and the performance is vulnerable to impairments of transceiver hardware.This dissertation aims to analyze the performance of the cognitive relay networkunder the impact of transceiver hardware impairments. A case study of two-waycognitive relay network is given for further investigate the impact of transceiverhardware impairments on end-to-end outage performance and throughput. Furthermore,we provide a new relaying scheme in order to lessen the impact of transceiverhardware impairment and further boost the system performance. For the purposes,this dissertation is organized into five (5) chapters.Chapter 1: Introduction. In this chapter, multihop wireless networks and the performancemetrics are overviewed. In particular, the relay networks and cognitive relaynetworks are presented. Moreover, the general model of the practical transceiverhardware impairment is detailed for further analysis.Chapter 2: The impact of transceiver hardware impairments on cognitive relay networks.By using the general hardware impairment model for the received signal, theclosed forms of outage probability of the relay network with decode-and-forward(DF) and amplify-and-forward (AF) under the impact of transceiver hardware imperfectionare derived. Based on these results, we provide further discussion ontransceiver hardware selection guideline.Chapter 3: Case study: two-way cognitive relaying in energy harvesting wirelesssensor networks. A two-way relay wireless sensor network equipped withRF energy harvesting node is introduced. This network is aimed to be implementedin hazardous or remote areas where power supply for the relay node isdifficult to maintain. In this chapter, we consider four configurations of the networkwith formed by combining two bidirectional relaying protocols and two wirelesspower transfer policies. The detailed performance analysis of outage probabilityand throughput of the case-study network with four configurations are presented.Based on the analysis, we provide performance comparison between the four andsuggest the network configuration with the best performance.Chapter 4: Soft information relaying protocol. The soft information relaying protocolis proposed and analyzed. The analysis shows that this relaying protocol cangradually reduce the impact of transceiver hardware impairment on cognitive relaynetworks. Hence, soft relaying protocol is considered as a solution for cognitiverelay network with cost-effective wireless transceiver devices.Chapter 5: Overall conclusion. An overall summary of the works presented inthe above is provided in this chapter. Moreover, the future related work is alsodiscussed.The results in this dissertation acknowledge the impact of transceiver hardware impairmentby presenting the reduction of outage probability and throughput of thecognitive relay network. It puts forward the consideration of including the impactof transceiver hardware impairments on wireless network performance analysis, especiallyfor the cognitive networks of which the transmit power is limited.Furthermore, a new relaying protocol, namely soft information relaying protocol,is proposed as a solution to lessen the impact of transceiver hardware impairment.The analysis shows that the impact of transceiver hardware impairment in cognitiverelay network is reduced in compared to conventional relaying schemes.As a final point, we have provided a full picture of performance analysis for thecognitive relay network under the impact of transceiver hardware imperfection andthe solution to reduce the performance loss by applying soft information relayingscheme. This research would contribute to boost the development of cognitive relaynetworks where frequency bands are used more efficiently.
九州工業大学博士学位論文 学位記番号:情工博甲第309号 学位授与年月日:平成28年3月25日
1 Introduction|2 Impact of Transceiver Hardware Impairments on Cognitive Network|3 Case study: Two-Way Cognitive Relay in RF Energy HarvestingWireless Sensor Network|4 Soft Information Relaying Protocol|5 Overall Conclusion and FutureWork