Outage Analysis for SWIPT-Enabled Two-Way Cognitive Cooperative Communications

In this paper, we study a cooperative cognitive radio network (CCRN) where the secondary user-transmitter (SU-Tx) assists bi-directional communication between a pair of primary users (PUs) following the principle of two-way relaying. In return, it gets access to the spectrum of the PUs to enable its own transmission to SU-receiver (SU-Rx). Further, in order to support sustainable operation of the network, SU-Tx is assumed to harvest energy from the RF signals received from the PUs, using the technique of simultaneous wireless information and power transfer (SWIPT). Assuming a decode-and-forward behaviour and power-splitting based relaying protocol at SU-Tx, closed form expressions for outage probability of PU and SU are obtained. Simulation results validate our analytical results and illustrate spectrum-efficiency and energy-efficiency advantages of the proposed system over one-way relaying.Comment: 15 pages, 5 figures, Submitted to IEEE Transactions on Vehicular Technolog

Outage Analysis for SWIPT-Enabled Two-Way Cognitive Cooperative Communications

In this paper, we study a cooperative cognitive radio network (CCRN) where the secondary user-transmitter (SU-Tx) assists bi-directional communication between a pair of primary users (PUs) following the principle of two-way relaying. In return, it gets access to the spectrum of the PUs to enable its own transmission to SU-receiver (SU-Rx). Further, in order to support sustainable operation of the network, SU-Tx is assumed to harvest energy from the RF signals received from the PUs, using the technique of simultaneous wireless information and power transfer (SWIPT). Assuming a decode-and-forward behaviour and power-splitting based relaying protocol at SU-Tx, closed form expressions for outage probability of PU and SU are obtained. Simulation results validate our analytical results and illustrate spectrum-efficiency and energy-efficiency advantages of the proposed system over one-way relaying.Comment: 15 pages, 5 figures, Submitted to IEEE Transactions on Vehicular Technolog

Multisource power splitting energy harvesting relaying network in half-duplex system over block Rayleigh fading channel: System performance analysis

Energy harvesting and information transferring simultaneously by radio frequency (RF) is considered as the novel solution for green-energy wireless communications. From that point of view, the system performance (SP) analysis of multisource power splitting (PS) energy harvesting (EH) relaying network (RN) over block Rayleigh-fading channels is presented and investigated. We investigate the system in both delay-tolerant transmission (DTT), and delay-limited transmission (DLT) modes and devices work in the half-duplex (HD) system. In this model system, the closed-form (CF) expressions for the outage probability (OP), system throughput (ST) in DLT mode and for ergodic capacity (EC) for DTT mode are analyzed and derived, respectively. Furthermore, CF expression for the symbol errors ratio (SER) is demonstrated. Then, the optimal PS factor is investigated. Finally, a Monte Carlo simulation is used for validating the analytical expressions concerning with all system parameters (SP).Web of Science81art. no. 6

Energy Harvesting in Cooperative Communications

Ühiskommunikatsioon on võimalik meetod lahendamaks informatsiooni levimist juhtmeta võrgus mitmikteekonna korral. See võimaldab laiendada võrgu katvust ning pakkuda võimendust kasutades olemasolevat taristut. Praktikas tehakse seda kasutades sõlmpunkte vahereleedena. Nii mitmese ligipääsuga releede süsteem kui paralleelsete releede süsteem on võimalikud kandidaadid tulevastes juhtmeta ühisvõrkudes nende ülekandekiiruse efektiivsuse ning parema energiatarbe tõttu.\n\r\n\rVõimenda-ja-edasta (AF) ning dekodeeri-ja-edasta (DF) on peamised ühisreleede protokollid, mida kasutatakse üle releekanalite. Me uurime käesolevas magistritöös paralleelseid releesid AF ühiskommunikatsiooni võrkudes kasutades QPSK signaliseerimist üle Rayleigh’ kiirelt hajuva kanali koos valge aditiivse Gaussi müraga. Sihtkohas vastuvõetud signaali detekteerimiseks kasutades võrgus olevaid tegevuseta kasutatakse maksimaalse suhte ühendamise (MRC) meetodit. Mõõtes sihtkohast vastu võetud ühendsignaali sümbolite veasuhet (SER) arvutusliku simulatsiooni abil, uurime me suhet releede arvu ning kommunikatsiooni kvaliteedi vahel.\n\r\n\rSüsteemi energeetiline efektiivsus määrab selle operatsioonilise jätkusuutlikkuse. Energiakogumise (EH) meetod on hädavajalik tehnoloogia juhtmeta süsteemides, kus on piiratud ligipääs usaldusväärsele elektritoitele ja laadimisvõimalustele. Käesolevas magistritöös uurime me mitmese ligipääsuga releede süsteeme kasutades EHtehnoloogiat. Me eeldame, et lähte- ja releesõlmedel pole ühendatud energiaallikat, kuid on taaslaetav energiatalletus. Seega, iga sõlme käivitatakse ligipääsupunkti (AP) edastatud raadiosignaalidelt kogutud energiast ning iga sõlm toimib salvesta-siis- koostööta (STC) režiimis. Me simuleerime arvutuslikult ühendusetaseme jõudlust kasutades füüsilise ühenduse võrgukodeerimist EHja DF protokolli olemasolul. Käesolev magistritöö esitab erinevaid energiakogumise meetodeid (EH ja STC) ning nende katkemistõenäosusi. Esitatud skeemid saavutavad SER jõudluse, mis läheneb püsiva toiteallikaga jõudlusele ning laiendab oluliselt süsteemi energiapüsivust, samas säilitades pidevat läbilaskejõudlust.Cooperative communications is a promising technique used to combat the multipath propagation in wireless networks. It can also extend the network coverage and provide the diversity gain by using the existing infrastructure. In practice, this is often achieved by using idle nodes in the network as relays. The multiple access relay system and parallel relay system are appealing candidates for emerging wireless cooperative networks due to bandwidth efficiency and improved power consumption.\n\r\n\rThe amplify and forward (AF) and decode and forwards (DF) protocols are basic cooperative relay protocols used over the relay channels. In this thesis, we study parallel relays in AF cooperative communication networks using QPSK signalling over the Rayleigh fast fading with additive Gaussian noise channels. The maximum ratio combining (MRC) method is employed to detect the received signals at the destination. By simulating the symbol error rate (SER) of the combined received signal at the destination, we study a trade-off between the number of relays and the quality of the communications. \n\r\n\rThe energy efficiency of a system determines its operational sustainability. Energy harvesting (EH) is a crucial technology for a variety of wireless systems that have limited access to a reliable electricity supply or recharging sources. In this thesis, the design of a multiple access relay system (MARS) using EH is considered. We assume that the sources and the relay have no embedded power supply but rechargeable energy storage devices. Thus, each node is powered by harvesting the energy from the RF signals broadcasted by an access point (AP), and it operates in store-then-cooperate (STC) mode. We simulate the link level performance by using the physical layer network coding in the presence of EH with DF protocol. The thesis presents energy harvesting schemes (EH and STC) and outage probability analysis. The schemes presented in this thesis achieve SER performance approaching that of a fixed power supply and contribute significantly to sustaining the energy in the system while maintaining a constant throughput

Energy harvesting over Rician fading channel: A performance analysis for half-duplex bidirectional sensor networks under hardware impairments

In this paper, a rigorous analysis of the performance of time-switching energy harvesting strategy that is applied for a half-duplex bidirectional wireless sensor network with intermediate relay over a Rician fading channel is presented to provide the exact-form expressions of the outage probability, achievable throughput and the symbol-error-rate (SER) of the system under the hardware impairment condition. Using the proposed probabilistic models for wireless channels between mobile nodes as well as for the hardware noises, we derive the outage probability of the system, and then the throughput and SER can be obtained as a result. Both exact analysis and asymptotic analysis at high signal-power-to-noise-ratio regime are provided. Monte Carlo simulation is also conducted to verify the analysis. This work confirms the effectiveness of energy harvesting applied in wireless sensor networks over a Rician fading channel, and can provide an insightful understanding about the effect of various parameters on the system performance.Web of Science186art. no. 1781

Modeling induction and routing to monitor hospitalized patients in multi-hop mobility-aware body area sensor networks

In wireless body area sensor networks (WBASNs), energy efficiency is an area of extreme significance. At first, we present a mathematical model for a non-invasive inductive link which is used to recharge the battery of an implanted biomedical device (pacemaker). Afterwards, we propose a distance-aware relaying energy-efficient (DARE) and mutual information-based DARE (MI-DARE) routing protocols for multihop mobility-aware body area sensor networks (MM-BASNs). Both the routing protocols and the non-invasive inductive link model are tested with the consideration of eight patients in a hospital unit under different topologies, where the vital signs of each patient are monitored through seven on-body sensors and an implanted pacemaker. To reduce energy consumption of the network, the sensors communicate with a sink via an on-body relay which is fixed on the chest of each patient. The behavior (static/mobile) and position of the sink are changed in each topology, and the impact of mobility due to postural changes of the patient(s) arms, legs, and head is also investigated. The MI-DARE protocol further prolongs the network lifetime by minimizing the number of transmissions. Simulation results show that the proposed techniques outperform contemporary schemes in terms of the selected performance metrics. © 2016, Javaid et al