A new optical wireless network based on white LED lights in home area is proposed. It is a duplex channel communication system utilizing signal emitters of white LED lights in the downlink and infrared devices in the ...A new optical wireless network based on white LED lights in home area is proposed. It is a duplex channel communication system utilizing signal emitters of white LED lights in the downlink and infrared devices in the uplink. Strategies for the system construction are given. Performance for users＇ mobile access of different kinds of optical concentrators is investigated. Indoor channel band-width is analyzed considering white LED light distribution, wall reflection, and receivers field of view （FOV）. Various modulation methods are discussed. A demo point-to-point system for surfing the net is constructed using a new line code of 4B6B which is developed to stabilize the optical output, and a peak data rate of 1 Mbps is achieved. This system is built into the lighting infrastructure, therefore decreasing the cost and offering a solution for wireless access in places which are sensitive to radio frequency like hospitals.展开更多
An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the de...An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the detector's output signals under OOK modulation is deduced. With the selected LED, detector and other related parameters, the designed communication system is optimized and its performance is analyzed. The optimized communication distance between the LED and the detector is 0.54 m at the communication bit rate of 1 Mbit/s. With the best communication distance, when the signal-to-noise ratio (SNR) is larger than 6.5 dB, the bit error rate (BER) can drop to 10-4. The analytical model and theory presented in this paper can be of certain practical meanings in the design of similar communication systems.展开更多
Considering that the white LED＇s spectral response decreases exponentially with the increase of carrier frequency for the on-off-keying non-return-to-zero （OOK-NRZ） visible light communication （VLC） data links, a...Considering that the white LED＇s spectral response decreases exponentially with the increase of carrier frequency for the on-off-keying non-return-to-zero （OOK-NRZ） visible light communication （VLC） data links, a fast-order RC high-pass filter isdesigned and fabricated as a post-equalizer （PE） to compensate the LED spectral response. Formulation and simu- lation are both available for illustrating the VLC performance with and without PE. Experiments are performed in detail for the fabricated OOK-NRZ VLC system integrated with PE. The data transmission results show that by using PE, the mea- sured carrier bandwidth is enhanced from 0.8 （0.4-1.2） MHz to 1.7 （0-1.7） MHz, and the bit-error-rate （BER） is less than 10^-9. It proves the feasibility of the proposed scheme in OOK-NRZ VLC data links.展开更多
文摘A new optical wireless network based on white LED lights in home area is proposed. It is a duplex channel communication system utilizing signal emitters of white LED lights in the downlink and infrared devices in the uplink. Strategies for the system construction are given. Performance for users＇ mobile access of different kinds of optical concentrators is investigated. Indoor channel band-width is analyzed considering white LED light distribution, wall reflection, and receivers field of view （FOV）. Various modulation methods are discussed. A demo point-to-point system for surfing the net is constructed using a new line code of 4B6B which is developed to stabilize the optical output, and a peak data rate of 1 Mbps is achieved. This system is built into the lighting infrastructure, therefore decreasing the cost and offering a solution for wireless access in places which are sensitive to radio frequency like hospitals.
基金supported by the Innovation Fund For Technology Based Firms of Changchun, China (No.10ZC04)
文摘An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the detector's output signals under OOK modulation is deduced. With the selected LED, detector and other related parameters, the designed communication system is optimized and its performance is analyzed. The optimized communication distance between the LED and the detector is 0.54 m at the communication bit rate of 1 Mbit/s. With the best communication distance, when the signal-to-noise ratio (SNR) is larger than 6.5 dB, the bit error rate (BER) can drop to 10-4. The analytical model and theory presented in this paper can be of certain practical meanings in the design of similar communication systems.
基金supported by the Innovation Fund for Technology Based Firms of Changchun (No. 10ZC04)the Undergraduate Innovative Experiment Program of Jilin University (No. 2011C51174)
文摘Considering that the white LED＇s spectral response decreases exponentially with the increase of carrier frequency for the on-off-keying non-return-to-zero （OOK-NRZ） visible light communication （VLC） data links, a fast-order RC high-pass filter isdesigned and fabricated as a post-equalizer （PE） to compensate the LED spectral response. Formulation and simu- lation are both available for illustrating the VLC performance with and without PE. Experiments are performed in detail for the fabricated OOK-NRZ VLC system integrated with PE. The data transmission results show that by using PE, the mea- sured carrier bandwidth is enhanced from 0.8 （0.4-1.2） MHz to 1.7 （0-1.7） MHz, and the bit-error-rate （BER） is less than 10^-9. It proves the feasibility of the proposed scheme in OOK-NRZ VLC data links.
