Electrical and Electronic Engineering - Research Publications
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ItemNo Preview AvailableApproaches to improve performance of 60 GHz radio-0verFiber fronthaul linksLim, C ; Tian, Y ; Nirmalathas, A ; Lee, KL (OSA Publishing, 2020)In this paper, we review the work we have done to improve the performance of users located at the cell boundary of a 60 GHz radio-over-fibre fronthaul using coordinated-multipoint (CoMP) together with non-orthogonal-multiple-access (NOMA).
ItemDemonstration of High-speed Indoor Optical Wireless Communications using Few-mode Based Uniform Beam ShapingLi, J ; Lim, C ; Nirmalathas, A ; O'Keefe, N ; Lee, KL (IEEE, 2020-10-04)A high-speed indoor optical wireless communications link using few-mode based uniform beam shaping is experimentally demonstrated. Results show that high-quality uniform beam can be realized and the BER performance can be improved significantly by combining the signals from different channels supported by different modes.
ItemPerformance Analysis of Repetition-Coding and Space-Time-Block-Coding as Transmitter Diversity Schemes for Indoor Optical Wireless CommunicationsSong, T ; Nirmalathas, A ; Lim, C ; Wong, E ; Lee, K-L ; Hong, Y ; Alameh, K ; Wang, K (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.
ItemReduction of Third-Order Intermodulation Distortions for Optical Single Sideband Modulated SignalsLim, C ; Nirmalathas, A ; Lee, K ; Novak, D ; Waterhouse, R (IEEE, 2006-09)
ItemSimplified base station configuration for fiber-wireless applicationsWong, E ; Lim, C ; Prasanna, AG ; Lee, KL ; Nirmalathas, A ; Ortsiefer, M ; Neumeyr, C (IEE, 2007-01-01)
ItemOptical interface for IMD reduction in fiber-radio systems with simultaneous baseband transmission for heterogeneous access networksLim, C ; Lee, KL ; Nirmalathas, A ; Novak, D ; Waterhouse, R (IEEE, 2007-12-01)
ItemPolarization and bit-length independent all-optical logic gate based active correlator for bit serial label processingGopalakrishnapillai, BS ; Lee, KL ; Nirmalathas, A ; Lim, C ; Shinada, S ; Wada, N ; Miyazaki, T (IEEE, 2006-01-01)
ItemFiber-Wireless Networks and Subsystem TechnologiesLim, C ; Nirmalathas, A ; Bakaul, M ; Gamage, P ; Lee, K-L ; Yang, Y ; Novak, D ; Waterhouse, R (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2010-02-15)