Browsing by Author "Liang, Wan-Ling"

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100-GHz DD-OFDM-RoF system over 150-km fiber transmission employing pilot-aided phase noise suppression and bit-loading algorithm
(2014-02-24)
Huang, Hou-Tzu
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Liang, Wan-Ling
;
Lin, Chun-Ting
;
Wei, Chia-Chien
;
Chi, Sien
This study extended the transmission distance of a 100-GHz DD-OFDM-RoF system through the reduction of chromatic dispersion-induced phase noise. The implementation of a pilot-aided phase noise suppression (PPNS) scheme enabled the transmission of distance-insensitive 16.97-Gbps QPSK OFDM over 0 similar to 150-km fiber and 2-m air transmission via a DFB laser with linewidth of 1 similar to 10-MHz. We applied a bit-loading algorithm in conjunction with PPNS to maximize spectral efficiency, resulting in a 93% improvement in the data rate from 11.53 to 22.27 Gbps at a fiber transmission of 150 km. (C) 2014 Optical Society of America
150-km 103-GHz Direct-Detection OFDM-RoF System Employing Pilot-aided Phase Noise Suppression
(2014-01-01)
Huang, Hou-Tzu
;
Liang, Wan-Ling
;
Wei, Chia-Chien
;
Lin, Chun-Ting
;
Chi, Sien
Pilot-aided phase noise suppression (PPNS) is employed to demonstrate distance-and linewidth-insensitive 103-GHz DD-OFDM-RoF systems. With 10.3-MHz linewidth, PPNS lowers BER of -6-dBm signal from >10(-2) to <10(-3) over 150-km fiber and 2-m wireless transmission.
2 x 2 MIMO OFDM-RoF System Employing LMS-Based Equalizer With I/Q Imbalance Compensation at 60 GHz
(2014-06-01)
Huang, Hou-Tzu
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Shih, Po-Tsung
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Lin, Chun-Ting
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Cheng, Yu-Hsuan
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Liang, Wan-Ling
Multiple-input-multiple-output (MIMO) technology is a promising method to increase spectral efficiency in wireless communications. In this paper, a 60-GHz orthogonal frequency-division multiplexing radio over fiber (OFDM-RoF) system employing 2 x 2 MIMO wireless technology is demonstrated. With the proposed equalizer employing least mean squares (LMS) algorithm, MIMO channel mixing and I/Q-mismatch can be compensated simultaneously. 16-QAM and 32-QAM OFDM signal transmissions under forward error correction (FEC) threshold (1 x 10(-3)) are demonstrated. A data rate of 76.3 Gb/s can be achieved with a bit-loading algorithm over 25-km fiber transmission and 3.5-m wireless transmission.
Estimation and Suppression of Dispersion-Induced Phase Noise in W-band Direct-Detection OFDM Radio-Over-Fiber Systems
(2014-10-15)
Wei, Chia-Chien
;
Lin, Chun-Ting
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Huang, Hou-Tzu
;
Liang, Wan-Ling
;
Chi, Sien
This study experimentally investigated the impact of dispersion-induced phase noise (DPN) on the transmission performance of a 100-GHz DD OFDM-RoF system. We sought to extend the transmission distance through the reduction of DPN using two digital phase noise suppression (PNS) schemes, based on the assumption that all subcarriers suffer from common DPN. The decision-aided PNS (DA-PNS) scheme treats the OFDM signal as feedback to aid in the calculation of DPN without incurring additional overhead. Pilot-aided PNS (PA-PNS) estimates the common DPN by inserting an additional optical pilot tone with guard band. Although both schemes are able to extend fiber transmission distance to beyond 150 km, the PA-PNS scheme tends to be outperformed by the DA-PNS scheme due to additional power required for the pilot tone. Nonetheless, in the DA-PNS scheme, the bandwidth of the estimated DPN must be truncated to avoid error propagation, which can result in the relatively faster increment in the transmission penalty. In contrast, the PA-PNS scheme maintains the variation in penalty to <1 dB, thereby achieving the performance that is insensitive to transmission distance.
High spectral efficient W-band OFDM-RoF system with direct-detection by two cascaded single-drive MZMs
(2013-07-15)
Huang, Hou-Tzu
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Lin, Chun-Ting
;
Ho, Chun-Hung
;
Liang, Wan-Ling
;
Wei, Chia-Chien
W-band wireless transmission has attracted a lot of interest due to its wider available bandwidth (i.e. 75-110 GHz). In this article, we propose a direct-detection orthogonal frequency division multiplexing radio over fiber (OFDM-RoF) system via two cascaded single-drive MZMs at center frequency of 103 GHz. We discuss maximum bandwidth of different modulation formats under forward error correction (FEC) threshold (3.8x10(-3)). Up to 40-Gbps 16-QAM OFDM signals is achieved over 25-km fiber and 2-m wireless transmission. To overcome the penalty from uneven frequency response, bit-loading algorithm is applied to discuss data rate and spectral efficiency with signal bandwidth from 5 to 10 GHz. With 10-GHz bandwidth, 46.4-Gb/s data rate and 4.64-bit/s/Hz spectral efficiency was achieved. To achieve 40-Gbps data rate, the required bandwidth of OFDM signal with bit-loading is 2 GHz less than that without bit-loading. (C) 2013 Optical Society of America