Reliable data transfer aims to guarantee that the destination node can successfully receive what have been sent to it, and the basic mechanisms extensively for this purpose in radio frequency (RF) ...networks include redundancy and retransmission. However, this issue becomes much more challenging in underwater acoustic (UWA) networks in comparison with RF networks due to the following peculiar features of UWA channels: poor quality and high dynamics of UWA channels, much smaller channel capacity and much larger propagation delay, as well as asymmetric connectivity of UWA links. These features either limit extensive application of redundancy mechanisms or influence the performance of retransmission mechanisms. Therefore, many research results have been reported in the literature, with several different design strategies and various proposals available. This paper conducts a survey on many schemes proposed from the data link layer to the transport layer, and discusses challenging issues necessary for further research.
This paper explores the merits for high-order data transfer circuits for a simultaneous wireless power and data transfer system, which adopts high-frequency data carrier injection. In order to ...improve the communication quality and low required injection current, the data transfer gain, cross-talk suppression, and input impedance of data channel are derived in a general manner when various networks are used. The limitation of one-element network is discussed, which further guides the design the two-element network. A three-element LCC network is proposed and shown to achieve a better multi-objective design. In the experiment, various data transfer circuits are compared in a 1-kW system. When a 20 kb/s signal is transferred with a carrier frequency at 1 MHz, the proposed LCC network is able to ensure sufficient data transfer gain (-8.4 dB), with high cross-talk suppression ability (-28.2 dB) and high input impedance (136 Ω). The total time delay is 4.5 μs.
This paper presents a wireless power and downlink data transfer system for medical implants operating over a single <inline-formula> <tex-math notation="LaTeX">10~MHz </tex-math></inline-formula> ...inductive link. The system is based on a Carrier Width Modulation (CWM) scheme for high-speed communication and efficient power delivery using a novel modulator circuit design. Unlike conventional modulation techniques, the data rate of the proposed CWM is not limited by the quality factors of the primary and secondary coils. The functionality of the new modulation method is proven using a hybrid implementation comprising a custom-integrated demodulator circuit and board-level discrete components. The proposed Wireless Power and Data Transfer (WPDT) system is also capable of operating under a wide range of data rates. It allows a maximum data rate of <inline-formula> <tex-math notation="LaTeX">3.33~Mb/s </tex-math></inline-formula> for a maximum power delivery of <inline-formula> <tex-math notation="LaTeX">6.1~mW </tex-math></inline-formula> at <inline-formula> <tex-math notation="LaTeX">1~cm </tex-math></inline-formula> coils separation distance. The system can recover more power, reaching <inline-formula> <tex-math notation="LaTeX">55~mW </tex-math></inline-formula> at <inline-formula> <tex-math notation="LaTeX">100~kb/s </tex-math></inline-formula>. Due to the system genericity, an operator can select the best compromise between power and data rates in accordance to application or current need, without reconfiguring the receiver. Another advantage of this modulation technique is the simple implementation and the ultra-low power consumption of the CWM demodulator despite its high-speed demodulation.
This article proposed a novel scheme integrating full-duplex communication into high-power wireless power transfer systems. The power and data are transferred through the same inductive link. A pair ...of coupling coils with taps are employed to omit the trap inductors that are widely employed in former simultaneous wireless power and data transfer (SWPDT) systems. The proposed scheme can reduce the system cost and size and improve the power transfer efficiency. The power and bidirectional data are transmitted using carriers of different frequencies. Frequency division multiplexing technique is utilized for full-duplex communication. The duplexer is carefully designed to separate the transmitted and received data signals. The circuit model of the system is built to analyze the power and data transfer performance. The crosstalk between the power and data transfer is also discussed. To improve the performance of data transfer, the method to determine the optimal coil tap position is proposed. A 300-W SWPDT prototype with a full-duplex data rate of 500 kb/s was built to demonstrate the feasibility of the proposed system.
A new parallel transmission method of power and data is proposed for peer-to-peer wireless power transfer (WPT) systems. Essentially, data are modulated and transferred via high-frequency electric ...field generated by the parasitic capacitances of the coupling coils and the metal shield plates, while power is transferred through relatively low-frequency magnetic field generated by the coupling coils. Coupling structure and operation principle are illustrated and analyzed. Besides, the signal to noisy ratio performance is studied and optimized. With the proposed method, a 40 W prototype is built and the data transmission rate reaches 230 kbps. Experimental results have verified that the proposed method is valid and has the advantages of good flexibility and large spatial position offset redundancy. Because the method does not do any modification on the main circuit of the WPT system, it also has advantages of low cost and easy to implement.
This brief presents a pulse phase modulation scheme for simultaneous wireless power and downlink data transfer system through the same inductive link. It is proved that the impact of data transfer on ...power transfer can be minimized when using the proposed pulse phase modulation. A prototype is built up with 1-MHz resonant frequency for power transfer. It shows that the data can be successfully transferred while achieving a data rate of 125 kb/s, which is 1/8 of carrier frequency, and a bit error rate (BER) of 4.5×10 -6 . Furthermore, compared with the case without data transfer, the input powers and the output powers are almost unchanged, respectively.
Enhanced by the simultaneous wireless power and data transfer, the radio frequency identification (RFID) techniques create new chances for the Internet of Things (IoT), which is used to integrate ...sensitive elements for different sensing purposes. However, the sensor-augmented RFID tags and chip-less RFIDs suffer from the limited power supply and the impact of ambient environments, respectively. This investigation explores the commercial RFID-based sensing techniques to obtain the physical parameters of the RFID-labeled objects with differential sensing via the backscatter coupling between the reader-tag antennas. The main contributions of this investigation include: 1) analysis of RFID backscatter coupling and the establishment of the relational model of measured parameters, antenna parameters, and RFID received signal strength indicator (RSSI)/phase; 2) simulation studies of the electromagnetic coupling between the RFID tag and material under test (MUT) to reveal the relationship of the MUT parameters with antenna impedance; 3) design of an RFID tags differential sensing scheme to compensate for the environment impact using a shielding layer; and 4) determination of sensitive frequencies with principal component analysis (PCA) and measurand reconstruction method with Levenberg-Marquardt (LM) curve fitting. Finally, the experimental studies are conducted with NaCl solution sensing. The results show that the presented techniques can effectively obtain the change in the solution's concentration, which demonstrates the effectiveness of the proposed techniques.
Wireless motors offer significant advantages in terms of installation flexibility and cable-free features but inevitably require multiple power semiconductors and electronic components at the ...receiver side to achieve wireless movement. Moreover, motor speed information is difficult to capture due to technical impediments in realizing wireless speed-sensorless communication. To address these issues, a novel wireless ultrasonic motor (USM) system with highly integrated wireless power, drive, and data transfer (WPD 2 T) is newly proposed in this article. Innovatively, the proposed WPD 2 T takes advantage of inherent capacitive characteristics of the USM to simultaneously realize wireless power transfer, wireless drive control, and sensorless speed information communication using a highly integrated magnetic coupler (IMC) with series inductors only, thus greatly simplifying the system structure and improving reliability, flexibility and compactness. Promisingly, the proposed WPD 2 T system exhibits great potential for miniaturization and biomedical implantable millirobots due to its minimalist structure and flexible controllability. Both theoretical analysis and experimental results are conducted to verify the feasibility of the proposed WPD 2 T system.
With the capability of generating sustainable energy by exploiting the ambient environment (e.g., light, heat, vibrations, etc.), the energy harvesting (EH) technology is increasingly used on ...low-power smart objects, forming self-powered green Internet of Things (IoTs). Despite targeting different application domains, many of these green IoT systems adopt the distributed network paradigm by forming energy harvesting multi-hop wireless networks (EH-MWNs). While distributed networks have good scalability during the deployment phase, they are often complex, inelastic to change, and costly to manage. To this end, LoRa, a promising long-range wireless technology, has been suggested for centralized single-hop network controls in EH-MWNs. However, the signal propagation of LoRa is severely affected by the surrounding environment (e.g., obstructions, terrains, etc.), which not only creates a significant difference in packet delivery rate (PDR) between nodes but also increases the bandwidth cost for network controls. To address this issue, we propose a Cross-interface Data Transfer (CDT) scheme, which leverages the ZigBee interfaces coexisting in EH-MWNs to transfer LoRa data traffic from the nodes with a lower PDR to the nodes with a higher PDR for bandwidth-efficient transmissions. By jointly determining the pairs of nodes performing data transfer and the data transfer rates between them, CDT can reduce the overall LoRa bandwidth consumption while ensuring continuous operation of the EH-MWN. A prototype system is implemented by integrating commercial off-the-shelf LoRa and ZigBee interfaces into an IoT platform. Extensive real-world experiments show that under a moderate data traffic input, the bandwidth consumption of CDT is 25.8% and 48.8% lower than the standard LoRaWAN and a state-of-the-art data transfer scheme, respectively. The average energy cost per node is kept as low as 2.29 mW at the same time. Moreover, CDT also shows its performance advantages in terms of PDR and sustainability.
In this article, a novel simultaneous wireless power and data transfer (SWPDT) system is proposed for underwater wireless sensor networks (UWSNs). A pair of coils is used to establish forward power ...transfer and bidirectional data transfer links based on coupled magnetic resonance. While transmitting power to the load, the forward power waves are also used as the carrier for data transfer, thereby avoiding the use of an additional carrier source on the power transmitter side. An improved double-LCC double-CLC topology is presented to achieve both impedance matching and wave filtering of the SWPDT system in full-duplex mode, instead of using additional wave trappers, transformers, or tap coils. Compared with previous works, the proposed system can simultaneously achieve high power gains, low mutual interference, and simple circuit structure. Moreover, to deal with the conflicts between the power gains and the bandwidths of the channels, an improved multiobjective optimization method is proposed for the SWPDT system. Using this method, the Pareto optimal solutions of the system parameters can be found, and the comprehensive performance of the SWPDT system can be further improved. Finally, an experimental prototype is established, which achieves full-duplex wireless power and data transfer, with a maximum load power of 23.1 W, a forward data transfer rate of 20 kb/s, and a backward data transfer of 300 kb/s. There is almost no interference between power and data transfer. The experimental results show that the proposed SWPDT system has good application prospects in underwater sensor node charging and full-duplex communication.
