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Jinhwan KOH Taekon KIM Wonwoo LEE Tapan K. SARKAR
The objective of this paper is to generate a wideband and temporal response from three-dimensional conducting structures. This is accomplished through the use of a hybrid method that involves generation of early time and low frequency information. These two are mutually complementary and contain all the necessary information for a sufficient record length. Utilizing orthogonal polynomials, time domain signal of scattering electromagnetic field could be expressed in an efficient way as well as the corresponding frequency domain responses. The available data is simultaneously extrapolated in both domains. Computational load for electromagnetic analysis, the Method of Moment (MOM), can be significantly reduced.
In this letter, we propose a simple detection ordering which can be applied to successive interference cancellation in low-complexity equalization of OFDM in doubly selective channels. Since the detection ordering can be determined solely on the basis of pilot symbol arrangement, the proposed scheme can lead to a significant performance improvement without additional complexity on the premise that pilot symbols are employed primarily for channel estimation.
Jinhwan KOH Weiwei ZHOU Taekon KIM
We describe an extension of the wideband direction-of-arrival (DOA) estimation method using a frequency-domain frequency-invariant beamformer (FDFIB). The technique uses the Matrix Pencil Method (MPM) instead of conventional methods based on the eigen-structure of the input covariance matrix. MPM offers excellent resolution compared to conventional methods.
Jinhwan KOH Dongmin LIM Tapan K. SARKAR
The objective of this research is to compare the performance of the Matrix Pencil Method (MPM) and well known root-MUSIC algorithm for high resolution DOA estimation. Performance of each technique in terms of the probability of resolution and SNR in the presence of noise is investigated. Simulation results show that the MPM has a superior resolution to the root-MUSIC algorithm.
Fan FAN Tapan K. SARKAR Changwoo PARK Jinhwan KOH
A new approach to reconstructing antenna far-field patterns from the missing part of the pattern is presented in this paper. The antenna far-field pattern can be reconstructed by utilizing the iterative Hilbert transform, which is based on the relationship between the real and imaginary part of the Hilbert transform. A moving average filter is used to reduce the errors in the restored signal as well as the computation load. Under the constraint of the causality of the current source in space, we could successfully reconstruct the data. Several examples dealing with line source antennas and antenna arrays are simulated to illustrate the applicability of this approach.