Electrical and Electronic Engineering - Research Publications
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ItemPerformance Analysis of Repetition-Coding and Space-Time-Block-Coding as Transmitter Diversity Schemes for Indoor Optical Wireless Communications(Institute of Electrical and Electronics Engineers (IEEE), 2019-10-15)The benefits of 2 × 1 multiple-inputs-single-output scheme for transmitter diversity in the infrared indoor optical wireless communication link are theoretically investigated. The performance of repetition-coding (RC) and Alamouti-type real-valued space-time-block-coding (STBC) as effective transmitter diversity schemes is systematically compared under conditions of channel gain variation caused by the degradation in the received optical power due to the blocking of one optical beam of the optical wireless channel. It is shown that the linear addition of channel gains in the RC scheme outperforms the root-sum-square of channel gains in the STBC scheme with regards to the bit-error-rate (BER) performance. Proof-of-concept experiments are carried out with both schemes under emulated scenarios of channel blockage. The RC scheme exhibits better BER performance when observed experimentally, validating the proposed theoretical model for the two spatial diversity schemes. To understand the performance of RC and STBC schemes against the optical delay caused by the two optical channel path difference within one-bit interval, both schemes are experimentally investigated using on-off-keying modulation, and results show that RC still outperforms STBC. Both theoretical and experimental results indicate that RC has better robustness to channel blockage and differential channel paths induced optical delay.
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ItemAn unusual case of implantable cardioverter-defibrillator inhibition(AUSTRALASIAN MED PUBL CO LTD, 2015-04-06)
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ItemCharacterization of highly-sensitive and fast-responding monitoring module for extended-reach passive optical networks(OPTICAL SOC AMER, 2012-04-09)The extended-reach broadband access network is widely acknowledged as a future-proof solution to providing bandwidth-intensive services to an increased number of users spread across a large geographical area. To address fiber failure detection and reliability issues specific to these networks, a simple automatic protection switching and pump laser shutdown scheme that exploits the use of highly-sensitive and fast-responding monitoring modules is proposed and experimentally demonstrated in this work. We also present an analytical model that describes the probability distribution function of the response time, thus allowing the mean response time, jitter, and sensitivity to be evaluated. Our results show a high sensitivity of < -50 dBm can be achieved, thus allowing the module to be applied in topologies with extended reach and/or split ratio beyond that of conventional PONs.
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ItemEnabling Technologies Incorporating Optical Tandem Single Sideband for Optical-Wireless Integrated Access Networks(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2010-05-15)
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ItemFiber-Wireless Networks and Subsystem Technologies(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2010-02-15)