Wen-Jeng Lin

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Synchronization for both time and frequency is a well-known issue in OFDM systems. In order to avoid signal distortion, synchronization is the major job to be completed generally in the receiver end. Especially, the timing error compensation is the first task to be done. This paper proposes two modified preamble patterns with insertion of zero padding for(More)
With equipping multiple antennas at both transmitter and receiver ends, the desired signals in the OFDM wireless communications could be transmitted and received through multiple uncorrelated channels for achieving twofold benefits and high flexibility. For this kind of MIMO-OFDM systems, if the assistance of channel estimation is under consideration, the(More)
In OFDM systems, channel estimation is a crucial consideration for improving system performance. The channel fading effects are eliminated by the equalization of received signal, and the equalizer coefficients are determined according to the results of channel estimation. In this paper, the channel estimation of OFDM systems in time domain for fast fading(More)
It is well-known that in order to enhance system performance, channel estimation in coherent OFDM systems is necessary and crucial. In practice, lots of coherent OFDM systems transmit pilot symbols over some of the subcarriers for the purpose of estimating channel attenuation, and also insert cyclic prefixto avoid inter-carrier and inter-symbol(More)
A new class of wideband ring-type microstrip bandpass filter is proposed under smaller size of three quarters waveguide length section. One via hole is placed at perpendicular positions of a squared ring, whereas two short-circuited sections are formed in the ring-type microstrip bandpass filter similar to a dual-mode ring filter in shape, thereby making up(More)
A novel method for spurious suppression in bandpass filter using Split-Mode Excitations (SME) is proposed. Distinct from traditional ways for spurious suppression, the proposed method uses the different excitations for six-order quarter-wavelength resonators to obtain good out-of-band performance. According to the split-mode, the proposed bandpass filter(More)
Orthogonal frequency division multiplexing (OFDM) technique is effective and powerful in high data rate digital transmission due to its spectral efficiency, robustness in multipath propagation environments and ability to cope with intersymbol interference. Channel estimation is a crucial problem in coherent OFDM systems, and the various estimation(More)
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