Remote Transceiver Research Articles

Electrical Devices Control System Using Google Assistant

This paper designed to develop an electrical devices control system using Google Assistant which can control the electrical on/off operations with voice via smartphone to increase the comfort, modernity, and safety from electric shock in the case touching switch on/off buttons directly. The design used the speaker Google home mini as the voice command in English from the smartphone via Google Assistant and direct voice commands; The commands were created on the IFTTT web, the NodeMCU ESP8266 board used to connect between hardware and software, as well as the processing and sending logic commands to change the relay status to control the electric devices and also use the Tuya S08 remote transceiver to control the operation of the air conditioner via Google Assistant. The results of the design and experiments showed that the system can control the electrical equipment as according to the goals and objectives set, including lights, fan, and air conditioner. Blynk APP and Google assistant can control the turn on/off the device at anywhere and anytime. in terms of system mobile must be connected to the Internet. For control with the Google home mini speaker only (without a smartphone) can be controlled at a distance of 10 meters and (also dependenting on the level of the sound that we order. In addition, in the case of air conditioning control, the Tuya S08 transmitter can be placed up to 8 meters away from the air conditioner to be controlled. The results showed that designed systems are more likely to be applied to provide comfort, safety and enable people who are unable to help themselves to walk around to turn on/off electrical devices such as the elderly or disabled person.

Frequency-Modulated Continuous-Wave Coherent Lidar With Downlink Communications Capability

A frequency-modulated continuous-wave (FMCW) coherent lidar with downlink communication capability is proposed based on phase-diversity coherent detection, by which laser ranging, laser velocimetry and free-space optical downlink communications can be simultaneously achieved. In the local transceiver, a linear-frequency modulated (LFM) optical signal is generated and used as the lidar signal. The LFM optical signal is received by the remote transceiver and coded with data via amplitude modulation. Then, the light is transmitted back to the local transceiver, in which a phase-diversity coherent optical receiver is used to simultaneously extract the range, velocity, and communication data. The in-phase and quadrature outputs from the phase-diversity coherent optical receiver are simultaneously recorded to reform a complex signal. The data is extracted from the intensity of the complex signal, while the range and velocity are obtained from the argument of it. A demonstration experiment is carried out. Different digital baseband signals are encoded on the reflected signal via an intensity modulator, while the 80-MHz Doppler frequency shift is simulated by an acousto-optic modulator. The impact of the digital signal on lidar detection is removed. Meanwhile, the communication quality is little affected by the varied frequency of the de-chirped signal. Therefore, the lidar detection and the free-space optical communications are simultaneously implemented.

A space division multiplexed free-space-optical communication system that can auto-locate and fully self align with a remote transceiver

Free-Space Optical (FSO) systems offer the ability to distribute high speed digital links into remote and rural communities where terrain, installation cost or infrastructure security pose critical hurdles to deployment. A challenge in any point-to-point FSO system is initiating and maintaining optical alignment from the sender to the receiver. In this paper we propose and demonstrate a low-complexity self-aligning FSO prototype that can completely self-align with no requirement for initial manual positioning and could therefore form the opto-mechanical basis for a mesh network of optical transceivers. The prototype utilises off-the-shelf consumer electrical components and a bespoke alignment algorithm. We demonstrate an eight fibre spatially multiplexed link with a loss of 15 dB over 210 m.

Multi-Objective Optimization of a Wireless Body Area Network for Varying Body Positions.

The purpose of this research was to improve the performance of a wireless body area sensor network, operating on a person in the seated and standing positions. Optimization-focused on both the on-body transmission channel and off-body link performance. The system consists of three nodes. One node (on the user’s head) is fixed, while the positions of the other two (one on the user’s trunk and the other on one leg) with respect to the body (local coordinates) are design variables. The objective function used in the design process is characterized by two components: the first controls the wireless channel for on-body data transmission between the three sensor nodes, while the second controls the off-body transmission between the nodes and a remote transceiver. The optimal design procedure exploits a low-cost Estra, which is an evolutionary strategy optimization algorithm linked with Remcom XFdtd, a full-wave Finite-Difference Time-Domain (FDTD) electromagnetic field analysis package. The Pareto-like approach applied in this study searches for a non-dominated solution that gives the best compromise between on-body and off-body performance.

Remote light source for silicon photonic transceivers in mobile fronthaul applications

The design and experimental characterisation of a depolarised light source for feeding a remote transceiver based on silicon photonics are presented. Since the transceiver only works in TE mode, the source is designed to deliver, over up to 10 km standard single-mode fibre links, a continuous-wave light with almost constant power along this polarisation direction, whatever be the random polarisation rotation because of the fibre link. The depolarised light source is realised by combining the output of two independent distributed feedback lasers, having orthogonal polarisation and controlled frequency difference. The transmission performance and stability of the remote light source are successfully tested.

Distributed MIMO Systems for Nomadic Applications Over a Symmetric Interference Channel

A single source communicates with a single destination via a remote wireless multiple-antenna (multiple-input multiple-output (MIMO)) transceiver. The source has access to each of the transmit antennas through a finite-capacity link, and likewise the destination is connected to the receiving antennas via capacity-constrained channels (e.g., as for wired or time-division multiple access (TDMA) channels). Targeting a nomadic communication scenario, in which the remote MIMO transceiver is designed to serve different standards or services, it is assumed that transmitters and receivers are oblivious to the encoding function shared by source and destination. Assuming a Gaussian symmetric interference network as the channel model (as for regularly placed transmitters and receivers), achievable rates are investigated and compared with an upper bound (that holds also for codebook-dependent operation). Closed-form expressions are derived for large numbers of antennas (and in some cases large signal-to-noise ratios (SNRs)), and asymptotics of the achievable rates are studied with respect to either link capacities or SNR. Overall, the analysis points to effective transmission/reception strategies for the distributed MIMO channel at hand, which are optimal under specified conditions. In particular, it is concluded that in certain asymptotic and nonasymptotic regimes there is no loss of optimality in designing the system for nomadic applications (i.e., assuming oblivious transmitters and receivers). Numerical results validate the analysis.

Towards a Miniature Implantable In Vivo Telemetry Monitoring System Dynamically Configurable as a Potentiostat or Galvanostat for Two- and Three-Electrode Biosensors

A miniature implantable and dynamically configurable potentiostat and galvanostat for two- and three-electrode biosensors with a telemetry electronics package was developed to provide remote monitoring of implantable amperometric and voltametric biosensors such as for glucose. Included are circuitry for sensor biasing, a transimpedance amplifier to produce the sensor proportional output signal, and a transceiver (transmitter and receiver) which can both receive setup parameter values and transmit the biosensor concentration data to a corresponding remote transceiver and computer for monitoring. Remotely configurable features included in the in vivo implanted unit include: sensor excitation changes; filter frequency cutoff values, amplifier gain; and transmission intervals utilizing 303.825-MHz UHF RF telemetry for end-to-end remote data monitoring. The developed mP/Gstat printed circuit board measures about 51/spl times/22/spl times/1mm thick, and is suitable for bench top or encapsulated use. Instrumentation developed in this paper will allow other researchers to develop implantable units. Evaluation in two- and three-electrode mPstat and two electrode mGstat modes with simulated biosensors showed overall average theoretical to actual recorded value differences of only 0.5859% reading (RDG) with a standard deviation (SD) of 0.5376% indicating excellent design performance. System testing in two-electrode mPstat mode with actual glucose sensors showed excellent stability and correlation to standard biosensor calibrations with an average difference of only 7.33% full scale (FS) with 3.65% SD, which is minimal considering two totally independent calibration instrument configurations.

Improved reliability and data rates for AUV acoustic communications

The availability of parallel channels in a point-to-point communication system may be exploited to increase data rate and reliability, without additional power, beyond that possible with a single channel. The severe power and bandwidth constraints imposed on an autonomous underwater vehicle acoustic telemetry link motivate the use of spatial modulation techniques to achieve these benefits, particularly for missions requiring real time sensor data transmission. Theoretical performance improvements for coherent modulation schemes yielding the equivalent of 6 dB or greater signal-to-noise ratio gain are shown. Experimental results from an underwater range near the Bahama Islands are given. Inclusion of a modest horizontal line array on the vehicle and a remote transceiver on the surface are the sole additional requirements beyond a conventional telemetry system.

Analysis, computation, and mitigation of the interference to a remote receiver from two collocated vehicular transceivers

The widespread use of mobile communications makes the installation of two transceivers in the same vehicle commonplace. This paper presents the analysis, computation methods, and mitigation techniques for the mutual interference caused by two collocated transceivers on a remote receiver. It is, in fact, a complement to a paper presented by Gavan (see ibid., vol.43, no.3, p.447, 1994) that analyzed and computed the mutual interference effects between the two collocated transceivers only. The remote transceiver is less affected by desensitization with increasing separation distances. More important become the effects of single-tone spurious and intermodulation distortion interference, which are thoroughly treated. The qualitative analysis is followed by quantitative computations of the mutual interference effects for a typical VHF/FM-FSK vehicular radio system. Deterministic and semiempirical computation methods are applied and effective mitigation techniques are presented. The presented methods are also efficient for different frequency ranges and modulation methods. Application of these methods by simulation from the initial development phase of new radio systems intended for use in collocated operations will optimize the system performance and improve the frequency spectrum utilization and management.