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Full-Text Articles in Computer Engineering
Complex Orthogonal Sequences From Amicable Hadamard Matrices, L. C. Tran, J. Seberry, B. J. Wysocki, Tadeusz Wysocki, T. Xia, Ying Zhao
Complex Orthogonal Sequences From Amicable Hadamard Matrices, L. C. Tran, J. Seberry, B. J. Wysocki, Tadeusz Wysocki, T. Xia, Ying Zhao
Professor Jennifer Seberry
The paper deals with the novel technique of designing complex spreading sequences with only four phases (0.25π, 0.75π, 1.25π, 1.75π). The interesting feature of those new sequences is the fact that not only the complex sequences are orthogonal but the real parts and imaginary parts are independently orthogonal. This can be utilized for spreading of complex constellation signals where the independent spreading using bipolar sequences (real part for in-phase component and imaginary part for quadrature component) can be applied. The paper introduces the theoretical background, and some example constructions of the amicable Hadamard matrices and the corresponding complex spreading sequences. …
Modeling Dual Polarization Wireless Fading Channels Using Quaternions, B. J. Wysocki, Tadeusz Wysocki, J. Seberry
Modeling Dual Polarization Wireless Fading Channels Using Quaternions, B. J. Wysocki, Tadeusz Wysocki, J. Seberry
Professor Jennifer Seberry
In the letter we describe signal transmitted between two dual-polarized antennas using a quaternion notation. The channel can then be modeled by a single quaternion gain, instead of a matrix of four complex gains as it is done in a classical approach. The model is very useful as it allows for a simple accommodation of any polarization twist between the transmit and receive antennas, as well as, modeling random fading in both polarizations with or without cross-polar scattering.