Power Transceiver Research Articles

A Review of Agricultural IoT: Challenges, Applications & Future Research Direction

The field of wireless communication has had significant boom in wireless communication, mostly driven by increasing demand for connectivity and technological advancements in low power transceiver development. An Agriculture IoT (AIoT) refers to the technology to enhance agricultural sustainability, productivity, and efficiency. The agricultural IoT uses artificial intelligence to build a network of interconnected systems by fusing digital sensors, IoT devices, advanced analytics, and cloud computing. Agricultural products will be in high demand by 2030 because of the 40% raise in global population. IoT technology is currently utilized in various industries, including agricultural for automation processes. Therefore time is saved, total productivity is increased and decisions are made more effectively and resulting in higher crop yields. AIoT is also being utilized more to keep updated on the sustainability of agricultural supply chains, environment and water usage. Several IoT applications and problems have been covered in this paper. There is also an outline of potential future agricultural research directions.

A 27 W Wireless Power Transceiver With Compact Single-Stage Regulated Class-E Architecture and Adaptive ZVS Control

A 27 W Wireless Power Transceiver With Compact Single-Stage Regulated Class-E Architecture and Adaptive ZVS Control

Optimizing elastic optical networks quality of transmission with an empirical optical amplifier gain saturation model

In this paper, we revisit the problem of adjusting transceiver power, amplifier gain, and nodal gain in optical-bypass-enabled networks, taking into account an empirical model of erbium-doped fiber amplifier (EDFA) gain saturation. We assume that network demands have been routed via the shortest possible paths. A heuristic algorithm, which estimates the degradation of the signal-to-noise ratio (SNR) for each demand, is used to assign the modulation level and spectrum slots to the routed demands. Our optimization process aims to maximize the minimum SNR margins of demands, by adjusting EDFA small-signal gain, variable optical attenuator (VOA) attenuation, and transceiver power. Constraints and impairments imposed by the physical-layer include EDFA and VOA gain limits, transceiver power limits, receiver sensitivity, insertion loss of optical switch input ports, EDFA gain saturation, EDFA noise, and fiber non-linear interference. These are modeled using the Gaussian noise model. The proposed optimization problem is formulated as a geometric programming problem and then converted into an equivalent convex problem.Numerical results suggest that in the optimal solution of our optimization, all demands are served with typically low bit error rates (BER) (<10−4). We calculate the operational gains of the EDFA to set the spans to full compensation whenever possible. Pre-amplifiers and line amplifiers do not experience gain saturation due to relatively small input powers, while approximately 10% of boosters undergo more than a 1 dB gain reduction due to high input powers. We observe that overlooking the effect of EDFA gain saturation and physical-layer-imposed constraints such as nodal gain limits or transceiver power limits during network optimization leads to a considerable number of blocked demands due to SNR degradation or high BER (>10−3).

Towards Ultra-Low Power Transceivers for Pico-IoT

Towards Ultra-Low Power Transceivers for Pico-IoT

Time-domain low-complexity clock recovery for non-integer oversampled Nyquist signals with a small roll-off factor.

A clock recovery algorithm (CRA) suitable for non-integer oversampled Nyquist signals with a small roll-off factor (ROF) is appealing to short-reach high-speed inter-datacenter transmission systems which need to cut down the transceiver power consumption and cost by reducing the oversampling factor (OSF) and using cheap low-bandwidth components. However, due to the lack of a suitable timing phase error detector (TPED), CRAs proposed now fail for non-integer OSFs below two and small ROFs close to zero and are not hardware-efficient. To solve these problems, we propose a low-complexity TPED by modifying the time-domain quadratic signal and reselecting the synchronization spectral component. We demonstrate that the proposed TPED, in combination with a piece-wise parabolic (PWP) interpolator, can significantly improve the performance of feedback CRAs for non-integer oversampled Nyquist signals with a small ROF. Numerical simulations and experiments show that, based on the improved CRA, the receiver sensitivity penalty can keep below 0.5 dB when the OSF is reduced from 2 to 1.25 and the ROF is varied from 0.1 to 0.001 for 45 GBaud dual-polarization Nyquist 16QAM signals.

Design of high‐speed data transfer turbo code for body channel communication transceivers

SummaryIn this work, a digital differential transmitter based on low‐power wireless compensation transceiver for body channel communication (BCC) is proposed. Further, the proposed transceiver is composed of Touch Status Detection Unit (TSDU), Wireless Status Compensation Unit (WSCU), and a reconfigurable preamplifier. Initially, the human body channel environment for wireless communication is investigated based on properties from 1 to 100 MHz. Further, the turbo code‐based encoding scheme is used to encode the data before transferring the data on the transmitter side. Also, the proposed error‐correcting parallel turbo decoder using a modified step‐by‐step algorithm is presented. The turbo code‐based decoding scheme is used to recover the error‐free transmitted data at the receiver side. Results demonstrate that the proposed BCC transceiver is designed using 90 nm CMOS technology and it is observed that the proposed BCC transceiver has utilized an area of 600mm2. Also, the maximum data rate achieved by a proposed BCC transceiver was 100 Mbps, and the overall transceiver power consumption is 0.42 mW, and energy for communication is 0.02 nj/b.

Multiple Tb/s Coherent Optical Transceivers for Short Reach Interconnect

This paper investigates coherent optical transceivers for short-reach interconnect, where a local oscillator laser is used to boost received optical signals for high receiver sensitivity. We review the state-of-the-art technologies and propose a miniature Mach-Zehnder modulator (mMZM) array with 3D silicon photonic-electronic integration to enable high-density, low-power multiple Tb/s coherent transceivers. For design optimization at transceiver level performances, we develop methodology and models to simulate PN junction and mMZM for high-efficiency high-speed modulation, which can be linked to system performances, including high-speed performances, receiver sensitivity, optical link budget, and coherent optical transceiver power consumption. With the optimized design and state-of-the-art technologies, we achieve highly integrated multiple Tb/s coherent transceivers with high density, high speed, and low power. Our simulation results show 3 pJ/bit for integrated driver/mMZM, 5 pJ/bit for integrated PIC/IC and 6.5 pJ/bit with transceiver optics for 6.4 Tb/s with 60 Gbaud 16QAM. Compared with conventional long phase shifter (PS) MZM (4 mm), mMZM with short PS (2.4 mm) only have an extra loss of ∼2 dB under 60 Gbaud 16QAM modulation with optimized designs. We study the scalability from 6.4 Tb/s to 12.8 Tb/s using 120 Gbaud 16QAM for intra-DC interconnect. The results show that further improvement for modulation efficiency, frequency response and laser output power are needed to enable the 12.8 Tb/s.

A LoRa-Cloud Based Water pH and Air Temperature Sensor Hub

Water pollution has become one of the important issues in Malaysia which occurs frequently especially in the rivers of Selangor. One of the indicators of pollution is the pH of the water. Thus, the main purpose of this study was to design a LoRa-Cloud-based water pollution sensor hub to monitor the real-time water quality. Sensor devices for pH (SEN0161-V2), and temperature and humidity (DHT11) were used to accurately detect water pH, and air temperature and humidity, respectively. REYAX RYLR896 Long Range Low Power (LoRa) transceiver module enabled the transmission of sensor data from the sensor node to the gateway node, while NodeMCU ESP8266 enabled transmission of sensor data to the Cloud. Ubidots IoT platform was used to monitor the real-time sensor data. A 3 W power supply was continuously supplied to the prototype and autonomy was guaranteed with the addition of monocrystalline solar cells. The performance of the prototype device was tested based on the monitoring function, and the overall pH level of Taman Metropolitan Batu Park Lake was slightly alkaline as the pH of the lake water ranged from 7.32 to 9.08 with data updating every 5 minutes on the Ubidots dashboards. The LoRa-Cloud-based water pollution sensor hub was successfully developed to monitor the real-time water quality through the Ubidots IoT platform.

Design of an Integrated Micro-Viscometer for Monitoring Engine Oil.

This paper proposes a novel integrated micro-viscometer for engine-oil monitoring. The final solution consists of a capacitive micromachined ultrasonic transducer (CMUT) and an application-specific integrated circuit (ASIC). The CMUT is used to generate and capture acoustic waves while immersed in engine oil. The low power transceiver ASIC is interfaced with the CMUT structure for actuation and reception. An integrated charge pump boosts the supply voltage from 3.3 to 22 V to generate the DC polarization voltage of the CMUT. The receiver has a power consumption of 72 µW with an input-referred noise current of 3.2 and a bandwidth of 7 MHz. The CMUT array occupies an area of 3.5 × 1 mm, whereas the ASIC has a chip area of 1 × 1 mm. The system was tested using engine oils of different types and ages at different temperatures. Measurement results show a significant frequency shift due to the dynamic viscosity change that occurs as oil ages. A shift of −1.9 kHz/cP was measured, which corresponds to a shift of 33 Hz/mile. This work paves the way for high accuracy-integrated solutions for oil condition monitoring and is expected to play a significant role in a more economic and environmentally friendly usage of oil.

Mesh Networking for Intermittently Powered Devices: Architecture and Challenges

Recent advances in low-power computing enable energy harvesting-powered devices, even in energy scarce conditions. This reduces the reliance on batteries in Internet of Things devices, reducing the cost and enabling new application domains. However, energy scarcity requires devices to operate intermittently, with minimal stored energy and where high-cost radio frequency (RF) communication dominates the power consumption, so transceivers are disabled most of the time. For deployment in challenging environments without high capability neighboring devices, a peer-to-peer topology for intermittently powered devices is required. To remove the requirement for high capability devices, we categorize four receiver types harnessing RF power transfer for a wake-up from other intermittently powered devices. This mesh networking of homogeneous nodes could enable applications where high power coordinators are undesirable or impossible. In this article, we identify the cross-layer challenges of mesh networking with intermittently powered devices and we describe the node receiver hardware required for peer-to-peer networking with intermittently powered devices. We conclude with a case study of transceiver power consumption in this context.

Relay based thermal aware and mobility support routing protocol for wireless body sensor networks

The evolvement of wireless technologies has enabled revolutionizing the health-care industry by monitor patient health condition requiring early diagnosis and interfering when a chronic situation is taking place. In this regard, miniaturized biosensors have been manufactured to cover various medical applications forming therefore a Wireless Body Sensor Network (WBSN). A WBSN is comprised of several small and low power devices capable of sensing vital signs such as heart rate, blood glucose, body temperature etc.. Although WBSN main purpose is to provide the most convenient wireless setting for the networking of human body sensors, there are still a great number of technical challenges to resolve such as: power source miniaturization, low power transceivers, biocompatibility, secure data transfer, minimum transmission delay and high quality of service. These challenges have to be taken into consideration when creating a new routing protocol for WBSNs. This paper proposes a new Relay based Thermal aware and Mobile Routing Protocol (RTM-RP) for Wireless Body Sensor Networks tackling the problem of high energy consumption and high temperature increase where the mobility is a crucial constraint to handle.

Rate-Splitting for Multicarrier Multigroup Multicast: Precoder Design and Error Performance

Employing multi-antenna rate-splitting (RS) at the transmitter and successive interference cancellation (SIC) at the receivers, has emerged as a powerful transceiver strategy for multi-antenna networks. In this paper, we design RS precoders for an overloaded multicarrier multigroup multicast downlink system, and analyse the error performance. RS splits each group message into degraded and designated parts. The degraded parts are combined and encoded into a degraded stream, while the designated parts are encoded in designated streams. All streams are precoded and superimposed in a non-orthogonal fashion before being transmitted over the same time-frequency resource. We first derive the optimized RS-based precoder, where the design philosophy is to achieve a fair user group rate for the considered scenario by solving a joint max-min fairness and sum subcarrier rate optimization problem. Comparing with other precoding schemes including the state-of-the-art multicast transmission scheme, we show that the RS precoder outperforms its counterparts in terms of the fairness rate, with Gaussian signalling, i.e., idealistic assumptions. Then we integrate the optimized RS precoder into a practical transceiver design for link-level simulations (LLS), with realistic assumptions such as finite alphabet inputs and finite code block length. The performance metric becomes the coded bit error rate (BER). In the system under study, low-density parity-check (LDPC) encoding is applied at the transmitter, and iterative soft-input soft-output detection and decoding are employed at the successive interference cancellation based receiver, which completes the LLS processing chain and helps to generate the coded error performance results which validate the effectiveness of the proposed RS precoding scheme compared with benchmark schemes, in terms of the error performance. More importantly, we unveil the corresponding relations between the achievable rate in the idealistic case and coded BER in the realistic case, e.g., with finite alphabet input, for the RS precoded multicarrier multigroup multicast scenario.

Design and implementation of a 3D printed RF power transceiver clamp to measure the water level in PVC water pipes

There is very few ways to detect the amount of water inside polyvinyl chloride (PVC) pipes without physical intervention. In this study, using additive manufacturing technology, it has been tried to determine the filling rate of water in PVC water pipes with a 3D printed clamp. The fact that the dielectric of distilled water is approximately 80 times that of air has been decisive in the transmission of power from the inner medium of the PVC pipe. In this way, when the amount of water increases in the PVC pipe, the RF power transmission will be decrease depending on level of water inner side of the pipe. The clamp was designed in the f0 = 2.45 GHz ISM band. LC impedance matching was applied to the two ports of the clamp. Thus, higher transmission coefficient was obtained. Used as a near field probe, the clamp was designed to be used horizontally anywhere on the pipe, pluggable. Input power from first port of the clamp is sent to the spectrum analyzer through its second port. The measurement and simulation results show that the transmission coefficient between the ports varies between −9 dB and −15 dB according to the selected fill percentages of the pipe.

Cooperative beamforming in cognitive radio systems without feedback of receiver beamforming vectors to transmitter

In this paper, we investigate the problem of transceiver beamforming and power allocation in the downlink of a multiple input multiple output Cognitive radio system. In this system, a base station (BS) services multiple primary users (PU) and multiple secondary users (SU). In order to perform transceiver beamforming and power allocation, three new algorithms are proposed. The first one is an iterative single-objective constrained algorithm, in which the signal to interference plus noise (SINR) of SUs are improved at each iteration subject to constraints on quality of services of PUs (PUs SINR should be above a predefined threshold) and total transmit power of BS. The second and third algorithms, are based on a multi-objective constraint optimization problem, in which the goal is to improve both PUs and SUs SINR at each iteration subject to previous constraints of the first algorithm. The difference between the second and third algorithms is that in the joint maximization of the second algorithm, the cross-influence of each user on the others is ignored, but in the third algorithm, the cross effect of each users SINR on the others is considered. The novelty of these algorithms is the independency of the transmit precoding vectors from the receive beamforming vectors. Therefore, the feedback of receive beamforming to the BS is not needed. The performances of three proposed algorithms are evaluated in simulations vis bit error rate of PUs and SUs, SINR of PUs and SUs and the percent of BS power allocation to SUs.

Development of a YAMUGAG-20 Wireless Exploder for Safe Disposal of Military and Civil Explosives

YAMUGAG-20 Exploder is a Radio Frequency (RF)-based wireless exploder system designed and constructed specially for the Nigerian Air Force (NAF) to overcome the challenges associated with the existing wired exploders used for the disposal of unserviceable ordnances. The Exploder system has three main parts namely, the master transmitter unit, the master receiver/slave transmitter unit, and the slave receiver unit. Each of these units is made up of transceiver module, microcomputer and power source. The microcomputers were programmed using C and C++ programming language of the Integrated Development Environment (IDE) software. The exploder is portable and easy to operate. For a typical demolition exercise, the operation of the exploder is such that signals are relayed from the master transmitter unit to the master receiver/slave transmitter unit onto the slave receiver unit to initiate an electric detonator leading to the detonation of the unserviceable ordnances. Functionality, range, power consumption, and system reliability tests were conducted on the exploder to establish its performance and efficiency. The results obtained from the tests indicated that the exploder transmitting at a frequency of 2.4GHz performed satisfactorily up to a range of 1000 meters. Therefore, the exploder has the potential of not only meeting the demolition demands of the NAF but can also be applied for other nonmilitary purposes like mining and related activities.

Design Considerations for a Sub-mW Receiver Front-End for Internet-of-Things

Internet-of-Things (IoT) and Wireless sensor networks (WSNs) require very low power transceivers. This paper presents techniques for minimizing power consumption of receiver (RX) frontends for short range wireless links. Two key approaches, i.e., current reuse and supply voltage reduction are compared. Different RX architectures such as direct-conversion, low-IF, sliding IF as well as phase-tracking RX, are compared, emphasizing their potential and limitations when targeting sub-mW RX power dissipation. Low-power design techniques for LNA, frequency generation blocks and baseband amplifiers are presented. As a case study, an efficient low-IF RX front-end for IoT is described in detail. In 28 nm CMOS, such a receiver occupies an active area of 0.1 mm2 and consumes only $350~{\mu }\text{W}$ from a 0.9 V supply while showing a minimum in band NF of 6.2 dB. The achieved performance is very competitive with state-of-the-art ultra-low-power receivers, while consuming the lowest power.

Radio-frequency chain selection for energy and spectral efficiency maximization in hybrid beamforming under hardware imperfections

The next-generation wireless communications require reduced energy consumption, increased data rates and better signal coverage. The millimetre-wave frequency spectrum above 30 GHz can help fulfil the performance requirements of the next-generation mobile broadband systems. Multiple-input multiple-output technology can provide performance gains to help mitigate the increased path loss experienced at millimetre-wave frequencies compared with microwave bands. Emerging hybrid beamforming architectures can reduce the energy consumption and hardware complexity with the use of fewer radio-frequency (RF) chains. Energy efficiency is identified as a key fifth-generation metric and will have a major impact on the hybrid beamforming system design. In terms of transceiver power consumption, deactivating parts of the beamformer structure to reduce power typically leads to significant loss of spectral efficiency. Our aim is to achieve the highest energy efficiency for the millimetre-wave communications system while mitigating the resulting loss in spectral efficiency. To achieve this, we propose an optimal selection framework which activates specific RF chains that amplify the digitally beamformed signals with the analogue beamforming network. Practical precoding is considered by including the effects of user interference, noise and hardware impairments in the system modelling.

A hybrid energy-efficient routing protocol for wireless body area networks using ultra-low-power transceivers for eHealth care systems

One of the major applications of Wireless Body Area Networks (WBANs), and the Internet of Things is the Electronic Health-Care systems. The progress in WBANs, and implanted health monitoring technologies have strong potential to alter the future of healthcare services by enabling ubiquitous monitoring of patients. An energy-efficient protocol is an important factor in the operation of eHealth care systems. A hybrid energy-efficient routing protocol is proposed in this paper for the distributed wireless body area network. In which a hybrid communication method and a new synchronization scheme are discussed. The hybrid communication enhances the network lifetime, and the synchronization scheme will consume less energy by avoiding collisions. The performance of the proposed protocol is analyzed, and it is compared with three baseline routing protocols at the 2.4 GHz ISM band with two ultra-low power transceivers.

A Novel AEB-AODV Based AADITHYA Cross Layer Design Hibernation Algorithm for Energy Optimization in WSN

Wireless Sensor Networks (WSN) has gained significant importance in current scenario because of its ability to monitor as well as understand the physical environment in terms of different parameters like temperature, humidity, pressure etc. There is a plethora of applications in WSN is finding importance ranking from military tracking, surveillance to environmental exploration and wildlife monitoring. The main challenge in WSN is energy efficiency especially when the capacity of battery and availability of energy source is a constraint. To address some of key WSN challenges, a novel routing protocol, a hibernation algorithm (cross layer design) along with the low power hardware design for achieving energy efficiency are proposed here.Because of the fact that WSN has requirement to adapt itself according to the needs of the dynamically changing environment, the quantity of sensor nodes which are part of routing tree cannot be the same and need to adapt itself so that it can precisely observe and forecast the physical surroundings. Initially the routing protocols being used popularly for WSN network layer i.e. AODV, AOMDV, and DSR are compared. The next stage is a proposal for adaptive model for AODV routing protocol for sensor node selection based on residual energy (AEB-AODV) towards improving the efficiency of energy and Quality of Service depending on the mentioned targets of performance. Here, the scheme utilizes fewer sensor nodes at a time along the route to the destination from the source of the event, and place remaining sensor nodes’ transceivers in the sleep mode but microcontroller, sensors and low power transceivers of the nodes are ON. The last module is a combined model capable of achieving improvements in efficiency of energy–adaptive routing model (AEB-AODV) and Hibernation of the sensor nodesi.e. AADITHYA algorithm, which reduces energy consumption, duty cycle to great extent and improved the latency, implemented with low power ARM CORTEX microcontroller and two sets of transceivers, one active power (AP) for data transmission and another very low power (LP) for sending wake up signals and control signals to the hibernating neighbors. Simulation results of AEB-AODV routing protocol and actual test readings of the developed hardware have shown that this method is effective in optimizing the energy usage in the nodes and hence improves the life expectancy of the WSN used for any general application.

System Level Simulation of Energy-Detection Based UWB Receivers

The performance of a non-coherent UWB receiver with Binary pulse position modulation is simulated with MATLAB; taking into account the effect of non-linearity, noise, pulse shape and channel effects. This simulation examines the minimum requirements for LNA, AGC, squarer, and operational transconductance amplifier in analog front-end for sensor network application with 100Kb/s data rate and 10-3 BER. The linearity requirement in OTA is achieved using Gilbert cell OTA with the technique of multiple gated transistors. For sensor network applications, analog front-end modules must have 4dB NF (Noise figure), -12dBm IIP3, 50dB gain and -75dBm sensitivity for 100Kb/s data rates. The transceiver power consumption is assumed to be below 50mW. The performance of energy detection non-coherent receiver is simulated in Simulink of MATLAB, it shows that BER of Gaussian pulse is lower than doublet and 4th Gaussian pulse. By increasing the number of transmitted pulse per bit and IIP3, the performance of receiver is improved.