Browsing by Author "Huang, Hou-Tzu"

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1.1-Gb/s White-LED-Based Visible Light Communication Employing Carrier-Less Amplitude and Phase Modulation
(2012-10-01)
Wu, Fang-Ming
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Lin, Chun-Ting
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Wei, Chia-Chien
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Chen, Cheng-Wei
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Huang, Hou-Tzu
We demonstrate 1.1-Gb/s visible light communication (VLC) employing carrier-less amplitude and phase modulation (CAP) and a commercially available phosphorescent white light emitting diode (LED). Optical blue filtering, pre-compensation, and decision feedback equalization are used to compensate the frequency response of the phosphor-based white LED. Various modulation orders of CAP signals are investigated to maximize the capacity of the VLC system. The record data rate of 1.1 Gb/s with the bit error rate performance below the FEC limit of 10(-3) is successfully achieved >23-cm air-transmission via a 220-MBaud 32-CAP signal.
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
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Lin, Chun-Ting
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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
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Liang, Wan-Ling
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Wei, Chia-Chien
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Lin, Chun-Ting
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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.
3.22-Gb/s WDM Visible Light Communication of a Single RGB LED Employing Carrier-Less Amplitude and Phase Modulation
(2013)
Wu, Fang-Ming
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Lin, Chun-Ting
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Wei, Chia-Chien
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Chen, Cheng-Wei
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Chen, Zhen-Yu
We experimentally demonstrate WDM-VLC employing CAP modulation and commercially available RGB-type LED. The record aggregate data rate of 3.22 Gb/s with the BER of less than 10(-3) is successfully achieved over >25-cm air-transmission.
5-bit/s/Hz 50-Gbps W-band Optical/Wireless System Employing Single-Sideband Single-Carrier Modulation
(2014-01-01)
Ho, Chun-Hung
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Cheng, Yu-Hsuan
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Huang, Hou-Tzu
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Lin, Chun-Ting
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Wei, Chia-Chien
We experimentally demonstrate W-band radio-over-fiber system employing single-sideband single-carrier modulation with lower PAPR than OFDM. Up to 50-Gbps wireless transmission with the highest spectral efficiency of 5-bit/s/Hz at 103GHz can be achieved over 25-km fiber.
60-GHz optical/wireless MIMO system integrated with optical subcarrier multiplexing and 2x2 wireless communication
(2015-05-04)
Lin, Chi-Hsiang
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Lin, Chun-Ting
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Huang, Hou-Tzu
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Zeng, Wei-Siang
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Chiang, Shou-Chih
This paper proposes a 2x2 MIMO OFDM Radio-over-Fiber scheme based on optical subcarrier multiplexing and 60-GHz MIMO wireless transmission. We also schematically investigated the principle of optical subcarrier multiplexing, which is based on a dual-parallel Mach-Zehnder modulator (DP-MZM). In our simulation result, combining two MIMO OFDM signals to drive DP-MZM gives rise to the PAPR augmentation of less than 0.4 dB, which mitigates nonlinear distortion. Moreover, we applied a Levin-Campello bit-loading algorithm to compensate for the uneven frequency responses in the V-band. The resulting system achieves OFDM signal rates of 61.5-Gbits/s with BER of 10(-3) over 25-km SMF transmission followed by 3-m wireless transmission. (C) 2015 Optical Society of America
84-Gbps 64-QAM 2 x 2 MIMO RoF System at 60 GHz Employing Single-Sideband Single-Carrier Modulation
(2014-01-01)
Lin, Chun-Ting
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Ho, Chun-Hung
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Huang, Hou-Tzu
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Cheng, Yu-Hsuan
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光電系統研究所
2 x 2 MIMO RoF system employing single-sideband single-carrier modulation is experimentally demonstrated. Compared with OFDM, it has lower PAPR. The highest 84-Gbps data rate within 7-GHz unlicensed band at 60 GHz can be achieved.
Direct-Detection PDM-OFDM RoF System for 60-GHz 2 x 2 MIMO Wireless Transmission Without Polarization Tracking
(2018-09-01)
Huang, Hou-Tzu
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Sun, Chung-Shin
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Lin, Chun-Ting
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Wei, Chia-Chien
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Zeng, Wei-Siang
This work experimentally demonstrates a 60-GHz direct-detection polarization division multiplexing and orthogonal frequency division multiplexing (PDM-OFDM) system that does not require polarization tracking. The frequency offset of un-modulated optical carriers and a novel training symbol design enable the estimation of optical polarization mixing and wireless multi-input-multi-output (MIMO) channels for signal demodulation. We also adopted an empty subcarrier to mediate noise enhancement. Simulation and experiment results both demonstrate the feasibility of this approach. With pre-compensation, we achieved a BER of 1 x 10(-3) under all polarization states over 10-km fiber and 3-m wireless MIMO transmission. The maximal allowable transmission data rate of up to 52 Gb at the worst case of states of polarization can he achieved.
Direct-Detection PDM-OFDM RoF System for 60-GHz Wireless VHMO transmission without Polarization Tracking
(2015)
Huang, Hou-Tzu
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Sun, Chung-Shin
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Lin, Chun-Ting
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Wei, Chia-Chien
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Zeng, Wei-Siang
This work experimentally demonstrates a 60-GHz direct-detection PDM-OFDM system without polarization tracking at the receiver. A BER of 3.8x10(-3) was achieved with all states of polarization over 10-km fiber and 3-m wireless MIMO 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
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Lin, Chun-Ting
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Huang, Hou-Tzu
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Liang, Wan-Ling
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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
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Ho, Chun-Hung
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Liang, Wan-Ling
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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
High spectral efficient W-band optical/wireless system employing Single-Sideband Single-Carrier Modulation
(2014-02-24)
Ho, Chun-Hung
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Lin, Chun-Ting
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Cheng, Yu-Hsuan
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Huang, Hou-Tzu
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Wei, Chia-Chien
With broader available bandwidth, W-band wireless transmission has attracted a lot of interests for future Giga-bit communication. In this article, we experimentally demonstrate W-band radio-over-fiber (RoF) system employing single-sideband single-carrier (SSB-SC) modulation with lower peak-to-average-power ratio (PAPR) than orthogonal frequency division multiplex (OFDM). To overcome the inter-symbol interference (ISI) of the penalty from uneven frequency response and SSB-SC modulation, frequency domain equalizer (FDE) and decision feedback equalizer (DFE) are implemented. We discuss the maximum available bandwidth of different modulation formats between SSB-SC and OFDM signals at the BER below forward error correction (FEC) threshold (3.8 x 10(-3)). Up to 50-Gbps 32-QAM SSB-SC signals with spectral efficiency of 5 bit/s/Hz can be achieved. (C) 2014 Optical Society of America
Simple 2 x 2 MIMO 60-GHz Optical/Wireless System With Extending Fiber Transmission Distance
(2014-10-15)
Huang, Hou-Tzu
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Lin, Chun-Ting
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Chiang, Ya-Tang
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Wei, Chia-Chien
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Ho, Chun-Hung
This paper presents a simple 2 x 2 multiple-input multiple-output (MIMO) 60-GHz radio-over-fiber system. Due to the proposed specific frequency arrangement of driving signals, each optical transmitter requires only a single-drive Mach-Zehnder modulator with 3-dB bandwidth of less than 35 GHz. This arrangement of frequencies can increase the tolerance of optical signals to dispersion-induced RF fading, thereby extending fiber transmission distance. Unfortunately, this scheme leads to signal-to-signal beating interference (SSBI), which can deteriorate system performance. Thus, we employed a 2 x 2 MIMO scheme to enhance data capacity by combining two data streams and two corresponding SSBIs prior to signal demodulation. We also developed a novel iterative equalization technique to mitigate SSBI in the MIMO system. The proposed system achieved a maximum capacity of 55.9-Gb/s in the transmission of 7-GHz orthogonal frequency division multiplexing signals over 12-km fiber and 3.5-m air transmission using a bit-loading algorithm.
Simple 2x2 MIMO 60-GHz OFDM RoF System with Single-Electrode MZMs Employing Beating Interference Mitigation and IQ Imbalance Compensation
(2013)
Huang, Hou-Tzu
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Chiang, Ya-Tang
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Lin, Chun-Ting
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Wei, Chia-Chien
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Ho, Chun-Hung
We propose simple 2x2 MIMO 60-GHz RoF systems using single-electrode MZMs. Employing signal-signal beating interference mitigation, IQ imbalance compensation, and bit-loading technique, >40-Gbps OFDM signals over 12-km fiber and 3.5-m wireless transmission are achieved.
Simple 60-GHz Radio-over-Fiber System with Transmission Distance Improvement Employing Signal-to-Signal Beat Noise Compensation
(2013-12-01)
Lin, Chun-Ting
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Chen, Wei-Erh
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Huang, Hou-Tzu
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光電系統研究所
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Institute of Photonic System
We propose a simple 60-GHz RoF system using one single-electrode Mach-Zehnder modulator (MZM). By choosing proper carrier frequencies of two MZM driving signals, fiber transmission distance can be extended up to 12 km. Compared with conventional intensity modulation with direct detection using 60-GHz MZM or electro-absorption modulator (EAM), the proposed RoF system can support longer fiber transmission distance (up to 12 km) and has less bandwidth requirement of optical orthogonal frequency-division multiplexing (OFDM) transmitter (34 GHz vs. 64 GHz). However, the generated 60-GHz OFDM signal will have beat noise after square-law photo-detection. In this paper, the beat noise is analytically analyzed. Hence, the beat noise mitigation algorithm with the beat noise re-construction technique is proposed and utilized to reduce beat-noise-induced interference and improve signal-to-noise ratio (SNR). 60-GHz 13.75-Gbps quadrature phase shift keying (QPSK) and 20.625-Gbps 8-quadrature-amplitude-modulation (QAM) OFDM signals with 3-m wireless transmission are experimentally demonstrated and transmitted over 12-km and 6-km single-mode fiber, respectively.
Simple Receiving Scheme in 100-GHz DD OFDM RoF Systems Employing Low-Sampling-Rate ADCs and Digital Preprocess
(2015)
Liu, Huan-Ching
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Lin, Chi-Hsiang
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Lin, Chun-Ting
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Wei, Chia-Chien
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Huang, Hou-Tzu
A simple low-sampling-rate receiving scheme is proposed for W-hand OFDM-RoF systems, Using the proposed preprocess, aliasing-free suhcarriers can be received, and employing the optimized delays to ADCs can achieve the performance insensitive to sampling rate.
Study of Wireless Channel Characteristics of 2x2 60-GHz MIMO OFDM RoF System Employing Lattice Reduction-aided Detection
(2013)
Huang, Hou-Tzu
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Ho, Chun-Hung
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Lu, Tsung-Hung
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Wang, Chih-Yun
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Lin, Chun-Ting
We experimentally investigate the wireless channel characteristics of 2x2 60-GHz MIMO OFDM RoF system with 3.5-m wireless distance. With lattice-reduction-aided detection, the achievable data rate can be improved from 0.58Gbps to 12.61Gbps for the worst case.
Theoretical and Experimental Investigation of a 2 x 2 MIMO OFDM Radio-Over-Fiber System at 60-GHz With I/Q Imbalance Compensation
(2014-10-15)
Ho, Chun-Hung
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Lin, Chun-Ting
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Lu, Tsung-Hung
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Huang, Hou-Tzu
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Shih, Boris (Po-Tsung)
This paper investigates the efficacy of two methods for compensating I/Q imbalance, which causes serious performance problems in wideband (6.98-GHz spectrum) millimeter-wave systems employing MIMO signal transmission. A 60-GHz orthogonal frequency division multiplexing (OFDM) RoF system employing 2 x 2 MIMO technology is implemented using a commonly used training symbol arrangement and a proposed method. We experimentally demonstrate that the proposed training symbol arrangement performed significantly better than the commonly used approach. By combining the proposed training symbol arrangement with LMS I/Q compensation and bit-loading, we achieve an extremely high wireless data rate transmission of 75.211 Gb/s over both 50 km of standard single-mode fiber and 3.5-m wireless distance. The optical power penalty after 50-km fiber transmission was only similar to 1 dB.
Ultrahigh capacity 2 x 2 MIMO RoF system at 60 GHz employing single-sideband single-carrier modulation
(2014-03-15)
Lin, Chun-Ting
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Ho, Chun-Hung
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Huang, Hou-Tzu
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Cheng, Yu-Hsuan
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光電系統研究所
This article proposes and experimentally demonstrates a radio-over-fiber system employing single-sideband single-carrier (SSB-SC) modulation at 60 GHz. SSB-SC modulation has a lower peak-to-average-power ratio than orthogonal frequency division multiplex (OFDM) modulation; therefore, the SSB-SC signals provide superior nonlinear tolerance, compared to OFDM signals. Moreover, multiple-input multiple-output (MIMO) technology was used extensively to enhance spectral efficiency. A least-mean-square-based equalizer was implemented, including MIMO channel estimation, frequency response equalization, and I/Q imbalance compensation to recover the MIMO signals. Thus, using 2 x 2 MIMO technology and 64-QAM SSB-SC signals, we achieved the highest data rate of 84 Gbps with 12 bit/s/Hz spectral efficiency using the 7-GHz license-free band at 60 GHz. (C) 2014 Optical Society of America