scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Combining RF energy harvesting and cooperative communications for low-power wide-area systems

TL;DR: By mathematical analysis, the exact closed-form expressions of outage probabilities, throughput, and symbol error probabilities of the EH-LPWA system over Nakagami- m fading channel are derived and the accuracy of the obtained expressions is demonstrated via Monte-Carlo simulations.
Abstract: This paper presents the combination of energy harvesting (EH) at the wireless sensor and cooperative communications for low-power wide-area (LPWA) systems. Firstly, the Internet of Things sensor harvests the energy from the power beacon with multiple transmit antennas via radio frequency signals and then uses the harvested energy to transmit signals to multiple gateways with multiple receive antennas. Then, the cooperative communications is applied at the server based on the gateway outputs. By mathematical analysis, we derive the exact closed-form expressions of outage probabilities (OPs), throughput, and symbol error probabilities (SEPs) of the EH-LPWA system over Nakagami- m fading channel in the cases without and with cooperative communications. Our expressions can be considered as the first results applying EH for LPWA systems with mathematical analysis. Then, we obtain the optimal value of the time switching ratio that minimizes the OPs and SEPs and maximizes the throughput of the considered EH-LPWA system. Numerical results have clarified that, the distances, path loss exponent, and data transmission rate have a strong impact on the OPs, throughput, and SEPs. Particularly, using a half of transmission blocks for EH can maximize the system performance. Moreover, when the number of transmit antennas at power beacon is equal to the number of receive antennas at gateways, the system performance can be improved significantly. Finally, the accuracy of the obtained expressions is demonstrated via Monte-Carlo simulations.
Citations
More filters
01 Jan 2016
TL;DR: The table of integrals series and products is universally compatible with any devices to read and is available in the book collection an online access to it is set as public so you can get it instantly.
Abstract: Thank you very much for downloading table of integrals series and products. Maybe you have knowledge that, people have look hundreds times for their chosen books like this table of integrals series and products, but end up in harmful downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some harmful virus inside their laptop. table of integrals series and products is available in our book collection an online access to it is set as public so you can get it instantly. Our book servers saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the table of integrals series and products is universally compatible with any devices to read.

4,085 citations

Journal ArticleDOI
TL;DR: It is observed that the RIS-HI system significantly outperforms the P2P- HI system at low transmit power regime, while the performance of the RIS -ID system is always better than that of P1P-ID system.
Abstract: In this paper, the performance of a wireless system, which is beneficial from utilization of multiple reconfigurable intelligent surfaces (RISs) and the direct link between the source node and the mobile user, is analyzed. Especially, the effect of transceiver hardware impairments (HIs) are taken into consideration. We successfully derive the outage probability (OP), throughput, achievable data rate (ADR), and symbol error probability (SEP) expressions of this multiple-RIS assisted wireless systems with and without HIs (referred as RIS-HI and RIS-ID system, respectively) over Nakagami- $m$ fading channels. The above performance factors are also benchmarked with the case that only a point-to-point (P2P) link without RIS is considered (denotes as as P2P-HI and P2P-ID systems for HI and ideal hardware conditions, respectively). All obtained formulas are verified by Monte-Carlo simulations. It is observed that the RIS-HI system significantly outperforms the P2P-HI system at low transmit power regime, while the performance of the RIS-ID system is always better than that of P2P-ID system. On the other hand, HIs show more severe effect for higher data transmission rates or high modulation orders.

7 citations

Posted Content
TL;DR: In this article, the authors consider a receiver which harvests energy from ambient sources and the transmitter, where the received signal is used for both EH and information decoding, and find that the optimal solution is a tradeoff of the two.
Abstract: The difficulty of modeling energy consumption in communication systems leads to challenges in energy harvesting (EH) systems, in which nodes scavenge energy from their environment. An EH receiver must harvest enough energy for demodulating and decoding. The energy required depends upon factors, like code rate and signal-to-noise ratio, which can be adjusted dynamically. We consider a receiver which harvests energy from ambient sources and the transmitter, meaning the received signal is used for both EH and information decoding. Assuming a generalized function for energy consumption, we maximize the total number of information bits decoded, under both average and peak power constraints at the transmitter, by carefully optimizing the power used for EH, power used for information transmission, fraction of time for EH, and code rate. For transmission over a single block, we find there exist problem parameters for which either maximizing power for information transmission or maximizing power for EH is optimal. In the general case, the optimal solution is a tradeoff of the two. For transmission over multiple blocks, we give an upper bound on performance and give sufficient and necessary conditions to achieve this bound. Finally, we give some numerical results to illustrate our results and analysis.

3 citations

Journal ArticleDOI
01 Sep 2022
TL;DR: In this article , the authors proposed a wireless system where multiple advanced reconfigurable intelligent surfaces (RISs) are combined with a traditional relay for significantly enhancing the system performance.
Abstract: In this paper, we propose a wireless system where multiple advanced reconfigurable intelligent surfaces (RISs) are combined with a traditional relay for significantly enhancement the system performance. Unlike previous works where perfect transceiver hardware (PTH) was often assumed in the RISs-aided-wireless systems, imperfect transceiver hardware (ITH) is taken into consideration in this work. Applying mathematical analysis, we obtain the closed-form expressions of outage probability (OP) and throughput of the proposed hybrid RISs and relay aided wireless system with ITH (the hybrid RISs-relay-aided-ITH system). Based on these expressions, it is easy to derive the OP and throughput expressions of hybrid RISs-relay-aided-wireless system with PTH (the hybrid RISs-relay-aided-PTH system), RISs-aided-wireless systems with ITH and PTH (the RISs-aided-ITH/PTH systems), and relay-aided-wireless systems with ITH and PTH (the relay-aided-ITH/PTH systems). We confirm the accuracy of the derived formulas via Monte-Carlo simulations. Numerical illustrations clarify a significant impact of distortion noises due to the ITH on the OP and throughput of the hybrid RISs-relay-aided-ITH system, especially in high threshold and high transmission rate. Moreover, a great benefit of the RISs is confirmed because the OP and throughput performances of the hybrid RISs-relay-aided-ITH/PTH systems are dramatically higher than those of the relay-aided-ITH/PTH systems. On the other hand, the performance loss caused by high carrier frequency of WiFi systems are significant. Additionally, the specific effects of the positions of the RISs and relay, the threshold and transmission rate, and the numbers of reflecting elements (REs) on the OP and throughput of the hybrid RISs-relay-aided-ITH system are detailedly analyzed.

1 citations

References
More filters
Book ChapterDOI

[...]

01 Jan 2012

139,059 citations


"Combining RF energy harvesting and ..." refers background in this paper

  • ...In particular, the wireless devices can harvest the energy from base stations [7]–[9] or from power beacons [10]....

    [...]

01 Jan 2015

12,972 citations


"Combining RF energy harvesting and ..." refers background or methods in this paper

  • ...Furthermore, EH technique is now combined with various new techniques such as fullduplex (FD), cognitive radio (CR), spatial modulation (SM), and non-orthogonal multiple access (NOMA) for enhancements in both energy and spectral efficiencies [7], [10]–[13]....

    [...]

  • ...In particular, the wireless devices can harvest the energy from base stations [7]–[9] or from power beacons [10]....

    [...]

  • ...The mathematical analysis was used to derive the expressions in terms of outage probability (OP), throughput, and symbol error probability (SEP) of the EH communication systems [7], [10]....

    [...]

01 Jan 1917
TL;DR: Basic Forms x n dx = 1 n + 1 x n+1 (1) 1 x dx = ln |x| (2) udv = uv − vdu (3) 1 ax + bdx = 1 a ln|ax + b| (4) Integrals of Rational Functions
Abstract: Basic Forms x n dx = 1 n + 1 x n+1 (1) 1 x dx = ln |x| (2) udv = uv − vdu (3) 1 ax + b dx = 1 a ln |ax + b| (4) Integrals of Rational Functions 1 (x + a) 2 dx = −

11,190 citations


"Combining RF energy harvesting and ..." refers background in this paper

  • ...) are the N −m and KN −m order modified Bessel functions of the second kind [27], respectively....

    [...]

Book
01 Jan 2005

9,038 citations