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A novel concept for integrating visible light communications (VLC) with three-dimensional indoor positioning is presented. A VLC link based on transmitter and receiver characteristics using experimental measurements was modelled. Proposed is a three-dimensional positioning algorithm using received signal strength indication, which changes based on the angle and distance of the location based service. To reduce inter-cell interference, the transmitter's location code was sent using different subcarriers. A demonstration shows that the proposed algorithm can obtain a user's position, including height, accurately and without inter-cell interference.

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simulation and the measurement are listed in Table 1. The photos of the experimental circuit are given in Figure 7. CONCLUSIONThis letter presents a quasilumped approach of the MMR SSL BPF design with a source-load coupling structure. The lumped-elements approach is successfully applied to design and analyze the circuit's performance. The source-load-coupling created transmission zeros have effectively enhanced the circuit's signal selectivity. The equivalent LC circuit model is intuitive, accurate, and comprehensive. The demonstrated BPF achieves benefits of very low-insertion losses, compact size, and excellent noise interference immunity. It is believed that the quasilumped approach of the MMR SSL BPF should be very useful in the further filter design.ABSTRACT: In this article, we propose an indoor location estimation algorithm that uses the signal extinction ratio distribution of LED-based visible light communication. To improve the positioning accuracy, we use the received extinction ratio from different LED transmitters. In order to mitigate interference between transmitters, a location code was sent using time division multiplexing (TDM). We verified the feasibility of the proposed position estimation algorithm with an experimental demonstration. The proposed algorithm provided positioning accuracy with a 1.5787-cm mean distance error for a given equilateral triangle cell with three 60-cm sides.ABSTRACT: This article studies the bias and oscillation-amplitude dependent RF tuning property of varactor-switching dual-band voltagecontrolled oscillators (VCOs). The dual-resonance LC-tank n-core and p-core VCOs have been fabricated using 0.18 lm CMOS technology, and they use dual-resonance LC resonator consisted of a parallel-tuned LC resonator and a series resonant resonator. The accumulation-mode MOS varactors are used. The RF circuit parameters such as oscillation frequency, tuning range, and transition frequency between low-band and high band as a function of varactor bias, supply voltage, and oscillation amplitude are examined experimentally.

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Technique to develop active devices by modifying Brillouin gain spectrum, Electron Lett 45 (2009), 637-638.ABSTRACT: We propose the visible light communication (VLC) system based on optical access network using light-emitting diode (LED) and electroabsorption transceiver (EAT). The EAT based on electroabsorption modulator is used as an optical network unit in order to be connected with VLC link based on white LED and photodiode (PD). The proposed architecture is demonstrated experimentally, and its performance is verified through the experimental investigation of quality factor and eye pattern of 5 Mbps baseband data. The variation of performance is shown depending on both the existence of the ambient light and the distance between the LED array and PD. A total of 5 Mbps downlink and uplink transmission is verified through 23.2-km single-mode fiber and wireless channel experimentally.

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Visible light communication (VLC) has many issues, including realizing complex modulations, increasing data rate, addressing the light emitting diode (LED) bandwidth limitation, and achieving multiservice capabilities such as for location‐based service (LBS). Therefore, we investigated frequency optimization for VLC parameters such as offset OFDM frequency location, allocated RF signal frequency location, allocated RF signal input power, operating point, and clipping. We experimentally demonstrated the characteristics of the proposed system. The results show that received offset frequency division multiplexing (OFDM) can achieve a 12‐Mbps data rate with a BER of 8 × 10−4. Additionally, the received allocated RF signal can satisfy a BER requirement of 10−4 after conversion from its EVM. The transmission distance was 1.8 m in an indoor environment when using white LED. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1431–1437, 2014