• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12A
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• pp.1251-1260
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• 2008

Diffuse wireless optical communication offers more robust optical links in terms of coverage and shadowing than line-of-sight links. However, traditional diffuse wireless infrared (IR) transceiver systems are more susceptible to multi-path distortion and great power decrease, which results in limiting high-speed performance. Multi-beam is an effective technique to compensate for multi-path distortion in a wireless infrared environment. The goal of this paper is to analyze the transmission characteristics by replacing traditional diffuse system (TDS) which contains single wide angle transmitter and single element receiver by system consisting of three-beam transmitter and non-imaging receiver (TNS) attached with compound parabolic concentrator (CPC). In the simulation, we use the recursive model developed by Barry and Kahn and build the scenario based on 10 different cases which have been listed in Table 1. Moreover, we also check the reliability of the TNS diffuse link channel by BER test on the basis of different receiver positions and room sizes. The simulation results not only show the basic transmission characteristics of TNS diffuse link, but also are references to design more efficient and reliable indoor infrared transmission systems.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.309-312
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• 2001

In this paper, we proposed a system for bit stream wireless communication using audio/video infrared transceiver and implemented a circuit. The proposed transmitter system converted bit stream into analog signal format that is similar to NTSC. Then the analog signal can be transmitted by infrared spatial coupler for A/V signals. And the receiver system recover the bit stream by inverse process of transmitter.

• Smart Media Journal
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• v.7 no.3
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• pp.29-34
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• 2018

This paper presents a study on adapting optical communication technology using infrared ray for the enhancement of hearing aids in noisy environment. The transmitter module containing microphone and infrared ray-emitting diode converts audio signal to infrared optical signal and sends it out in the air. The receiver module located in a distance receives the infrared signal, converts it to electrical signal, and transfers it to an input of a digital hearing aid. Especially, the receiver module needs to be small, low voltage, and consume low power since it will be attached to hearing aids. Experiments with applying infrared communication technology of digital modulation method and analog non-modulation method show that the analog non-modulation method is adequate for infrared communication of approximately 5m distance indoor. Prototypes of transmitter module and receiver module were manufactured, and internal parameters of the digital hearing aid were adjusted to confirm normal transmit-receive operation of audio signals.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.331-335
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• 2012

A miniaturized laser beam transmitter, in which a visible laser module at ${\lambda}$=650 nm is precisely stacked upon an infrared (IR) module at ${\lambda}$=905 nm, has been proposed and constructed to provide an IR collimated beam in conjunction with a collinear monitoring visible beam. In particular, the IR beam is selectively dispersed through a perforated sheet diffuser, so as to create a rapidly diverging close-range beam in addition to a highly defined long-range beam simultaneously. The complementary close-range beam plays a role in mitigating the blind region in the vicinity of the transmitter, which is inevitably missed by the main long-range beam, thereby uniformly extending the transmitter's effective trajectory that is sensed by a receiver. The proposed transmitter was designed through numerical simulations and then fabricated by incorporating a diffuser sheet, perforated with an aperture of 2 mm. For the manufactured transmitter, the IR long-range beam was observed to have divergences of ~2.3 and 1.6 mrad in the fast and slow axes, respectively, while the short-range beam yielded a divergence of ~24 mrad. The angular alignment between the long-range IR and visible beams was as accurate as ~0.5 mrad. According to an outdoor feasibility test involving a receiver, the combination of the IR long- and short-range beams was proven to achieve a nearly uniform trajectory over a distance ranging up to ~600 m, with an average detectable cross-section of ${\sim}60{\times}80cm^2$.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.8
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• pp.743-750
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• 2016

The conventional track to train communication is commonly using radio based equipment such as transponder or balise to transmit the data. However, there are some drawbacks of the conventional equipment, for example multipath fading, source of bandwidth limitation, and interference from other users. Moreover, the radio based equipment is very expensive when installed in large numbers. To address these problems, we propose infrared system for trackside to train communication system. Infrared system offers a transmission of data to train and it can be processed to obtain at least a train location. Infrared communication protocol provides practical wireless data communication for direct dedication configuration. Furthermore, on the pole configuration the infrared system provides an abundant bandwidth, an economically sensible, minimalized installation of equipment on the trackside and reliability for heavy rain environment. This paper concentrates on the communication function and measurement performance evaluation. The proposed trackside to train communication system covers about 6 meters between infrared receiver and infrared transmitter, whereas the half angle of the transmitter is set to $19.65^{\circ}$ and the receiver angle is $15^{\circ}$.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.889-895
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• 2003

In this paper, we develop a PC adapter board and application software that do not use mouse or keyboard but the infrared communication, which can control the operation remotely. The infrared communication adapter is made up of the infrared receiver part and the serial communication interface part. The infrared receiver part creates a suitable scan-code using the received signal from the infrared transmitter (remote-controller). The serial communication interface part transmits the scan-code to PC by a serial communication. We implement its application softwares to listen to music and see movies. We can control their operations such as play, stop, pause and volume control remotely.

• Journal of Biosystems Engineering
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• v.25 no.2
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• pp.131-140
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• 2000

Spraying operation is one of the most essential in an orchard management and it is also hazardous to human body. for automatic and unmanned spraying , an autonomous travelling vehicle is demanded. In this study, a telemeter was developed using infrared beam which could detect trunks and obstacles measure distance and direction from the vehicle travelling in the orchard. The telemeter system was composed of two infrared LED transmitters and receivers, a beam scanning device for continuous object detection , two rotary encoders for angle detector, and a beam level controller for uneven soil surface. The detected distance and direction signal s were sent to personal computer which made for the system display the angular and distance measurements through I/O board. According to a field test in an apple farm, the system detected up to 10m distance under 12 V of transmitted beam intensity, however, it was recommended that the proper beam transmit intensity be 7 v at the 10 m distance, because of the negative effect to human body at 12 V. The error rate of this system was 0.92 % when the actual distance was compared to measured one. The system was feasible at the small error rate. The developed telemeter system was an important part for autonomous travelling vehicle provided the real time object recognition . A direction control system could be constructed suing the system. It is expected that the system could greatly contribute to the development of autonomous farm vehicle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2A
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• pp.198-203
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• 2008

In this paper, we consider the diffuse type of indoor wireless optical communication (WOC) system. To find the channel characteristics of indoor wireless infrared communication system, we investigate the simulation process to get the impulse response of diffuse type and analyze the scenario of the indoor structure which we have built. The simulation results of the impulse response include power ratio and time delay due to bounce times. We get and discuss the receiving power distribution according to six configurations which have different transmitter and receiver positions and reflection coefficients of the indoor structure assumed. The results of this paper are useful to design the indoor wireless optical communication systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1513-1518
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• 2012

This paper is implemented media transmission system of VLC transmitter and receiver module using LED of White lighting that is based on PC module and to transmission technology for performance analysis. To realize LED visible light communication receiver is used 1~12 LED light-emitting device and transmitter is used a variable sensor. Developed initial distance of the tranceiver is more than 0~1m for LED VLC and the overall system transmission speed is achieved on variable having Visible light media transmission system. Composition to PC module with LED module and infrared sensor for performance analysis, predict and analyze the communication distance, check about the possibility of application methods. Measure each performance when the lens wearing and not wearing in order to increase the overall efficiency of the LED module, can know that increase efficiency of approximately 20%.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.3
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• pp.265-268
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• 2011

In this paper, we designed and fabricated that fog alarm equipment detected to crew in maritime fog. Developed fog alarm equipment was combined sensor and a transmitter-receiver module using emitting device unit and receiver photoelectric element infrared LED using only the receive sensitivity was low, miniaturization. Experiment of the fabricated device had a standard that was humidity 70%, the fabricated one generating artificial-fog within visibility 1km. When humidity is over 70%, the fabricated one generates alarming sounds for a warning. When developed device apply to vessel will be able to respond quickly, according to dense fog in the accident.