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Social and Behavioral Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Science and Technology Studies

University of Wollongong

2009

Low

Articles 1 - 3 of 3

Full-Text Articles in Social and Behavioral Sciences

Low-Complexity Ldpc Coded Bicm-Id With Orthogonal Modulations, S Che, S Tong Jan 2009

Low-Complexity Ldpc Coded Bicm-Id With Orthogonal Modulations, S Che, S Tong

Faculty of Engineering and Information Sciences - Papers: Part A

A low-complexity low density parity check (LDPC) coded bit-interleaved coded modulation with iterative decoding (BICM-ID) scheme with orthogonal modulations is proposed. With a novel mapping strategy of coded bits to symbols, the proposed scheme is equivalent to a generalised LDPC code with Hadamard constraints and thus orthogonal demodulation can be merged into the iterative LDPC decoding process, resulting in a simpler implementation and a lower computational complexity.


Low Temperature Graphene Growth, Shailesh Kumar, N Mcevoy, T. Lutz, G. Keeley, Nicholas Whiteside, Werner Blau, G. Duesberg Jan 2009

Low Temperature Graphene Growth, Shailesh Kumar, N Mcevoy, T. Lutz, G. Keeley, Nicholas Whiteside, Werner Blau, G. Duesberg

Faculty of Engineering and Information Sciences - Papers: Part A

We demonstrate the growth of graphene films on nickel substrates by chemical vapour deposition using acetylene at temperatures as low as 750 degrees celsius, opening a viable route for its scalable production. Raman spectroscopy was used to confirm defect-free mono and multilayer graphene at and above this temperature, and of defective graphene at lower temperatures. Atomic force microscopy and scanning electron microscopy performed directly on the films give an indication of graphene flake size, morphology and also the topography on substrate. An unexpected dependence of graphene thickness on precursor dwell time is reported. This together with low temperature growth suggests …


A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping, Defeng (David) Huang Jan 2009

A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping, Defeng (David) Huang

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we propose a low-complexity iterative joint channel estimation, detection and decoding technique for doubly selective channels. The key to the proposed technique is a segment-by-segment processing strategy under the assumption that the channel is approximately static within a short segment of a data block. Through a virtual zero-padding technique, the proposed segment-by-segment equalization approach inherits the low-complexity advantage of the conventional frequency domain equalization (FDE), but does not need the assistance of guard interval (for cyclic-prefixing or zero-padding), thereby avoiding the spectral and power overheads. Furthermore, we develop a low-complexity bidirectional channel estimator, where the Gaussian message …