97 research outputs found
Simultaneous Wireless Information and Power Transfer in 5G communication
Green communication technology is expected to be widely adopted in future generation
networks to improve energy efficiency and reliability of wireless communication network.
Among the green communication technologies,simultaneous wireless information and
power transfer (SWIPT) is adopted for its flexible energy harvesting technology through
the radio frequency (RF) signa lthati sused for information transmission. Even though
existing SWIPT techniques are flexible and adoptable for the wireless communication
networks, the power and time resources of the signal need to be shared between infor-
mation transmission and RF energy harvesting, and this compromises the quality of the
signal. Therefore,SWIP Ttechniques need to be designed to allow an efficient resource
allocation for communication and energy harvesting.
The goal oft his thesisis to design SWIP Ttechniques that allow efficient,reliable and
secure joint communications and power transference. A problem associated to SWIPT
techniques combined with multi carrier signals is that the increased power requirements
inherent to energy harvesting purposes can exacerbate nonlinear distortion effects at the
transmitter. Therefore, we evaluate nonlinear distortion and present feasible solutions to
mitigate the impact of nonlinear distortion effects on the performance.Another goal of
the thesisis to take advantage of the energy harvesting signals in SWIP Ttechniques for
channel estimation and security purposes.Theperformance of these SWIPT techniques is
evaluated analytically, and those results are validated by simulations. It is shownthatthe
proposed SWIPT schemes can have excellent performance, out performing conventional
SWIPT schemes.Espera-se que aschamadas tecnologiasde green communications sejam amplamente ado-
tadas em futuras redes de comunicação sem fios para melhorar a sua eficiência energética
a fiabilidade.Entre estas,encontram-se as tecnologias SWIPT (Simultaneous Wireless
Information and Power Transference), nas quais um sinal radio é usado para transferir
simultaneamente potência e informações.Embora as técnicas SWIPT existentes sejam fle-
xÃveis e adequadas para as redes de comunicações sem fios, os recursos de energia e tempo
do sinal precisam ser compartilhados entre a transmissão de informações e de energia, o
que pode comprometer a qualidade do sinal. Deste modo,as técnicas SWIPT precisam ser
projetadas para permitir uma alocação eficiente de recursos para comunicação e recolha
de energia.
O objetivo desta tese é desenvolver técnicas SWIPT que permitam transferência de
energia e comunicações eficientes,fiáveis e seguras.Um problema associado às técnicas
SWIPT combinadas com sinais multi-portadora são as dificuldades de amplificação ine-
rentes à combinação de sinais de transmissão de energia com sinais de transferência de
dados, que podem exacerbar os efeitos de distorção não-linear nos sinais transmitidos.
Deste modo, um dos objectivos desta tese é avaliar o impacto da distorção não-linear em
sinais SWIPT, e apresentar soluções viáveis para mitigar os efeitos da distorção não-linear
no desempenho da transmissão de dados.Outro objetivo da tese é aproveitar as vantagens
dos sinais de transferência de energia em técnicas SWIPT para efeitos de estimação de
canal e segurança na comunicação.Os desempenhos dessas técnicas SWIPT são avaliados
analiticamente,sendo os respectivos resultados validados por simulações.É mostrado que
os esquemas SWIPT propostos podem ter excelente desempenho, superando esquemas
SWIPT convencionais
Regularized Channel Inversion for Simultaneous Confidential Broadcasting and Power Transfer: A Large System Analysis
We propose for the first time new transmission
schemes based on linear precoding to enable simultaneous confidential
broadcasting and power transfer (SCBPT) in a multiuser
multi-input single-output (MISO) network, where a BS with N
antennas simultaneously transmits power and confidential messages
to K single-antenna users. We first design two transmission
schemes based on the rules of regularized channel inversion
(RCI) for both power splitting (PS) and time switching (TS)
receiver architectures, namely, RCI-PS and RCI-TS schemes.
For each scheme, we derive channel-independent expressions to
approximate the secrecy sum rate and the harvested power in
the large-system regime where K, N → ∞ with a fixed ratio
β = K/N. Based on the large-system results, we jointly optimize
the regularization parameter of the RCI and the PS ratio or the
TS ratio such that the secrecy sum rate is maximized subject
to an energy-harvesting constraint. We then present the tradeoff
between the secrecy sum rate and the harvested power achieved
by each scheme, and find that neither scheme always outperforms
the other one. Motivated by this fact, we design an RCI-hybrid
scheme based on the RCI and a newly proposed hybrid receiver
architecture. The hybrid receiver architecture takes advantages
of both the PS and TS receiver architectures. We show that the
RCI-hybrid scheme outperforms both the RCI-PS and RCI-TS
schemes.ARC Discovery Projects Grant DP15010390
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