Hai Tian

Bio: Hai Tian is an academic researcher. The author has contributed to research in topics: Electric power transmission & Orthogonal frequency-division multiplexing. The author has an hindex of 2, co-authored 2 publications receiving 8 citations.

Data communications over aircraft power lines

Abstract: : This paper introduces a study of the feasibility and initial hardware design for transmitting data over aircraft power lines. The intent of this design is to significantly reduce the wiring in the aircraft instrumentation system. The potential usages of this technology include Common Airborne Instrumentation System (CAIS) or clock distribution. Aircraft power lines channel characteristics are presented and Orthogonal Frequency Division Multiplexing (OFDM) is introduced as an attractive modulation scheme for high-speed power line transmission. A design of a full-duplex transceiver with accurate frequency planning is then discussed. A general discussion of what communications protocols are appropriate for this technology is also provided.

Communications over aircraft power lines: a practical implementation

Abstract: This paper presents a practical implementation of a hardware design for transmission of data over aircraft power lines. The intent of such hardware is to significantly reduce the wiring in the aircraft instrumentation system. The potential usages of this technology include pulse code modulation (PCM), Ethernet and other forms data communications. Details of the fieldprogrammable gate array (FPGA) and printed circuit board (PCB) designs of the digital and analog front end will be discussed. The power line is not designed for data transmission. It contains considerable noise, multipath effects, and time varying impedance. Spectral analysis data of an aircraft is presented to indicate the difficulty of the problem at hand. A robust modulation is required to overcome the harsh environment and to provide reliable transmission. Orthogonal frequency division multiplexing (OFDM) has been used in power line communication industry with a great deal of success. OFDM has been deemed the most appropriate technology for high-speed data transmission on aircraft power lines. Additionally, forward error correction (FEC) techniques are discussed.

Performance analysis of FSK power line communications systems over the time-varying channels: measurements and modeling

Abstract: Power line communication (PLC) is a communications method where signals are carried across already existing power lines, rather than through other mediums such as optical fibers or radio waves. PLC has been a very important interdiscipline topic for power, communications, industrial, and automation engineers and researchers since the 1980s. Designing and planning optimized or standard PLC systems require information and data regarding signal attenuations, load variations, and communication performance for various locations of the world which have different power networks. In this study, PLC system is modeled by ABCD matrix and simulated via electronics workbench. In order to obtain data from Turkey's power lines, signal measurements at the frequencies of 50-200 kHz are carried out. The effects of load, frequency, line length, and the distribution transformers are examined. The properties of home appliances used in an average Turkish household are experimentally determined. System performance in terms of the bit error probability are calculated for FSK modulation.

Theoretical Approach to the Feasibility of Power-Line Communication in Aircrafts

Abstract: In the domain of aeronautics, the future more electric aircraft will have to face a difficult issue related to the increasing number of wires and connectors, impacting on the weight and system reliability. A possible solution for solving at least part of this problem is to introduce power-line communication for specific applications. In this paper, the cabin lighting and communication system has been chosen as an initial scenario. Indeed, the tree-shaped architecture of the cabling is complicated enough to be representative of many other aircraft harness configurations. Channel characteristics are first determined from a propagation model based on the multiwire transmission-line theory. A software tool simulating PLC communication has been developed. By introducing the predicted channel transfer functions of different links into this software, the throughputs that can be reached, taking into account the electromagnetic constraints related to aeronautic standards, are discussed.

Performance analysis of FSK power line communications systems over time-varying channels: measurements and modeling

Abstract: Power line communication (PLC) is a communications method where signals are carried across already existing power lines, rather than through other mediums such as optical fibres or radio waves. PLC has been a very important interdiscipline topic for power, communications, industrial and automation engineers and researchers since 1980s. Designing and planning optimized or standard PLC systems require information and data regarding signal attenuations, load variations and communication performance for various locations of the world which have different power networks. In this study, PLC system is modeled by ABCD matrix and simulated via electronics workbench. In order to obtain data from Turkey's power lines, signal measurements at the frequencies of 50-200 KHz are carried out. The effects of load, frequency, line length, and the distribution transformers are examined. The properties of home appliances used in an average Turkish household are experimentally determined. System performance in terms of the bit error probability is calculated for FSK modulation.

Optimal Frequency Value to Detect Low Current Faults Superposing Voltage Tones

Abstract: Single phase to ground low current faults (LCF) are difficult to be detected with common fault detection techniques. Therefore, several specific methodologies have been developed to identify LCF in an easier way. Among these methodologies, a method based on superposing voltage tones has been proposed. This method requires defining the frequency of the tones that have to be superimposed.

Feasibility of broadband power line communication aboard an aircraft

Abstract: The broadband power line communication (BPLC) technology is proposed aboard an aircraft for the use of mobile communication and Internet access systems during the flight. The possibility of re-using the power distribution network to transmit digital signals in the frequency range between 1 MHz and 30 MHz is investigated. The analysis is performed considering the real installation configuration of the carrier channel on a power line of the C-27J transport aircraft of Alenia Aeronautica. The accurate simulation of the wire-to-wire communication channel, which includes apparatus and bulkhead connectors, allows computing the transfer function between the sending and receiving devices. The crosstalk coupling with a victim power line is also predicted. The multicarrier modulation technique is applied for the computation of the optimal bit loading of the power line carrier channel by modelling the power spectral density of the channel noise and considering the constraint represented by the maximum power available of the sending device. The preliminary results of the study prove the feasibility of the BPLC technology aboard the C-27J transport aircraft.