[Show abstract][Hide abstract] ABSTRACT: Using a colorless weak-resonant-cavity (WRC) FPLD injected by a centralized light source, we have experimentally demonstrated a superior performance of 20-Gbps uplink transmission in a WDM-PON. Even though the typical modulation bandwidth of a WRC-FPLD is only ~1.25 GHz, using spectrally-efficient 32-QAM OFDM or SC-FDE modulation, 20-Gbps uplink signals can achieve the FEC limit after 25-km dispersion-uncompensated single-mode fiber transmission. Because of the advantage of lower PAPR, the SC-FDE signals outperform the OFDM signals with the fixed 32-QAM format in the proposed system; moreover, SC-FDE scheme can be another promising candidate for uplinks in WDM-PONs, for its simplification to ONUs. The signal at the mode of 1560.7 nm shows similar quality with the signal at the modes of 1545.3 nm and 1574.7 nm, the WRC-FPLD, accordingly, has wide injection wavelength range from at least 1545.3 nm to 1574.7 nm. With the mode spacing of 0.55 nm, consequently, we have demonstrated the applicability of the colorless WRC-FPLD on supporting up to 36 channels in the WDM-PON.
[Show abstract][Hide abstract] ABSTRACT: Multiple-input-multiple-output (MIMO) technique for wireless communications is extensively used these days, especially to increase the spectral efficiency of new wireless communication systems like LTE, WiMAX, etc. MIMO in combination with robust modulation techniques like orthogonal frequency division multiplexing (OFDM) provides a good solution for high data rate wireless links. In this paper, the performance of MIMO for a 60 GHz OFDM radio over fiber link is analyzed. System performance of the MIMO system for different antenna spacing is also studied. Using the optimum system parameters, a MIMO OFDM wireless link of up to 51 Gb/s was successfully demonstrated at 60 GHz in a bandwidth of <7 GHz, with a wireless transmission distance of up to 4 m and optical fiber transmission of \>1 km. To our knowledge this is the highest data rate demonstrated in the 7 GHz band of 60 GHz.
IEEE Journal on Selected Areas in Communications 01/2013; 31(12):780-787. · 3.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We demonstrate a 40-Gb/s OFDM radio-over-fiber system with 10-m wireless distance at 60-GHz by employing simple IM-DD modulation with DSP-based bit-loading and I/Q imbalance compensation. Spectral efficiency of 6-bit/s/Hz was achieved with BER of 9x10−4.
[Show abstract][Hide abstract] ABSTRACT: Record 50-Gb/s wireless signal transmission over 4 m is experimentally demonstrated using a 2x2 MIMO Radio-over-Fiber system at 60 GHz. MIMO spatial multiplexing and 16-QAM OFDM modulation were used to achieve a high combined spectral efficiency of up-to 8 b/s/Hz.
[Show abstract][Hide abstract] ABSTRACT: This work experimentally demonstrates the efficacy of the 2 × 2 multiple-input multiple-output (MIMO) technique for capacity improvement of a 60-GHz radio-over-fiber (RoF) system employing single-carrier modulation format. We employ frequency domain equalization (FDE) to estimate the channel response, including frequency response of the 60 GHz RoF system and the MIMO wireless channel. Using FDE and MIMO techniques, we experimentally demonstrate the doubling the of wireless data capacity of a 60 GHz RoF system to 27.15 Gb/s using 16-QAM modulation format, with transmission over 25 km of standard single-mode fiber and 3 m wireless distance.
[Show abstract][Hide abstract] ABSTRACT: We experimentally demonstrated the transmission performance of orthogonal frequency-division-multiplexing (OFDM) signals in a 60-GHz radio-over-fiber system over up to 100-km standard single-mode fiber employing an adaptive bit-loading algorithm. Considering dispersion-induced phase noise, the maximum capacities after different fiber distances are investigated with and without a phase noise suppression (PNS) algorithm for the first time. When a distributed-feedback (DFB) laser with the linewidth of 1.3~4.1 MHz is modulated to carry the radio signals, the PN will result in more than 21.5% capacity decrease after 100-km fiber and 3-m wireless link, and the PNS algorithm which needs no bandwidth-consuming pilot tones can accomplish more than 15.3% capacity increase.
[Show abstract][Hide abstract] ABSTRACT: Record wireless data transmission of 31.4 Gbps within 7 GHz license-free band at 60 GHz is experimentally demonstrated using adaptive bit-loading OFDM modulation. Adaptive bit-loading OFDM also enables extended fiber transmission distances beyond 5km.
Optical Fiber Communication Conference and Exposition (OFC/NFOEC), 2011 and the National Fiber Optic Engineers Conference; 04/2011
[Show abstract][Hide abstract] ABSTRACT: This paper reviews 60-GHz radio-over-fiber systems employing optical frequency multiplication and adaptive OFDM signals with multi-level modulation formats to achieve an ultra-high data rate of up to 32.65 Gbps within the 7-GHz license-free band. OCIS codes: (060.4510) Optical Communications; (060.4080) Modulation
[Show abstract][Hide abstract] ABSTRACT: Record 35-Gb/s wireless signal transmission is experimentally demonstrated using a Radio-over-Fiber system employing the single-carrier modulation format and 32-quadrature amplitude modulation (QAM). The total occupied spectrum of the transmitted 60 GHz signal was 7-GHz, representing a spectral efficiency of 5 b/s/Hz. A decision feedback equalizer (DFE) was utilized to compensate for the signal distortion caused by fiber dispersion and self-inter-symbol interference. After transmission over 25-km single-mode fiber and 3 m wireless distance, the power penalty was less than 1dB.
[Show abstract][Hide abstract] ABSTRACT: Generation and transmission of a 4-Gb/s electrical single-sideband single carrier QPSK signal within 2-GHz bandwidth in a 60-GHz Radio-over-Fiber system are experimentally demonstrated. After transmission over 50-km single-mode fiber, a negligible power penalty is observed.
[Show abstract][Hide abstract] ABSTRACT: We employ 2×2 MIMO spatial multiplexing to double the spectral efficiency of a 60GHz RoF system. A 27.15-Gbps 16-QAM MIMO signal with 3m wireless transmission is experimentally demonstrated within 7-GHz license-free spectrum at 60 GHz.
Optical Communication (ECOC), 2011 37th European Conference and Exhibition on; 01/2011
[Show abstract][Hide abstract] ABSTRACT: This work demonstrates the feasibility of the generation of an RF direct-detection vector signal using optical in-phase/quadrature-phase (I/Q) upconversion. The advantage of the proposed transmitter is that no electrical mixer is needed to generate the RF signal. Therefore, I/Q data of RF signals are processed at baseband at the transmitter, which is independent of the carrier frequency of the generated RF signal. A 10 Gb/s 16 quadrature amplitude modulation signal is experimentally demonstrated. Following transmission over a 50 km single-mode fiber, the power penalty is negligible. Moreover, I/Q imbalance of the proposed transmitter is studied and compensated by digital signal processing, which is both numerically and experimentally verified.
[Show abstract][Hide abstract] ABSTRACT: We experimentally demonstrated an adaptive I/Q imbalance correction scheme to compensate I/Q-imbalance. With I/Q correction, a 32.65-Gbps OFDM signal at 60 GHz within 7-GHz license-free band is successfully generated and, following 25km SMF transmission, negligible power penalty is observed.
Optical Communication (ECOC), 2010 36th European Conference and Exhibition on; 10/2010
[Show abstract][Hide abstract] ABSTRACT: This paper demonstrates the feasibility of a simple multigigabit-per-second (Gbps) radio-over-fiber (RoF) system employing multilevel orthogonal frequency-division-multiplexing (OFDM) signal modulation at 60 GHz and a single-electrode Mach-Zehnder modulator (MZM). In this paper, the impact of fiber chromatic dispersion and OFDM beat noise on the performance of the RoF system are investigated by theoretical analysis, VPI WDM-TransmissionMaker simulation and experimental demonstration. A 13.875-Gb/s QPSK OFDM signal occupying the full 7-GHz license-free band at 60 GHz with frequency multiplication for the RoF link is demonstrated. After 3 km of standard single-mode fiber transmission with no dispersion compensation, the power penalty is less than 3 dB.
Journal of Lightwave Technology 09/2010; · 2.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study presents a novel hybrid access network for 60-GHz wireless and wireline applications using a frequency quadrupling technique. Both 1.2-Gb/s eight phase-shift keying and 1.25-Gb/s quadruple phase-shift keying radio-frequency (RF) signals for radio-over-fiber (RoF) links are demonstrated. A 1.25-Gb/s baseband (BB) on-off keying (OOK) signal for fiber-to-the- x services is simultaneously generated and transmitted using the same modulator. The proposed system does not suffer from RF fading and needs no narrowband optical filter at the remote node to separate the RF and BB signals. A frequency quadrupling method for RoF link is realized to reduce the bandwidth requirement of the transmitter. Following 25-km single-mode fiber transmission, the observed receiving power penalty is negligible for both RF and BB signals. Wavelength reuse for a 1.25-Gb/s OOK signal via a reflective semiconductor optical amplifier for uplink transmission is also demonstrated.
[Show abstract][Hide abstract] ABSTRACT: The increasing demand for wireless video-based interactive and multimedia data services explains why 60-GHz millimeter-wave wireless system is a promising candidate to provide multi-gigabit-per-second wireless services. While attempting to generate and transmit 60 GHz signals in a wireless system cost effectively and increase the spectral efficiency to facilitate multi-gigabit-per-second services, this work reviews three radio-over-fiber (RoF) systems based on optical frequency multiplication (up to 6 times) to reduce the bandwidth requirement of optical transmitters. Additionally, orthogonal frequency division multiplexing (OFDM) signals with multi-level modulation formats (16 QAM) are utilized to achieve an ultrahigh data rate of 28 Gbps within the 7-GHz license-free band and compensate for an uneven frequency response of 60-GHz RoF systems. Negligible power penalty following 25-km standard single mode fiber (SSMF) transmission is observed, capable of significantly extending the service range to various applications within a building or campus.
Journal of Lightwave Technology 09/2010; · 2.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This work describes a proposed 60-GHz radio-over-fiber (RoF) system employing a frequency sextupling optical up-conversion scheme. Based on the modified single sideband modulation scheme, spectrally efficient vector signals were transmitted with no performance degradation due to dispersion-induced fading. Wavelength-division- multiplexed optical up-conversion can be realized using the proposed system. Since the required transmitter bandwidth is significantly reduced, radio-frequency components with lower bandwidth and higher reliability can be utilized. Both 13.75-Gb/s QPSK-OFDM and 20.625-Gb/s 8QAM-OFDM signals were experimentally demonstrated. After transmission over 25-km of standard single mode fiber, no significant received power penalty was observed.
[Show abstract][Hide abstract] ABSTRACT: This letter presents a novel modulation approach for simultaneous generation and transmission of optical radio-frequency (RF) wireless vector signal and baseband (BB) wireline signal using a single-electrode Mach-Zehnder modulator. Based on a double sideband with carrier suppression scheme and properly predistorted driving vector signal, a 2.5-Gb/s quadrature phase-shift keying (QPSK) signal at 60 GHz is generated with a 1.25-Gb/s BB ON-OFF-keying (OOK) signal. The proposed system can carry higher spectral efficiency vector signals and needs no optical filter to separate the BB and RF signals at remote nodes. Moreover, optical RF signal generation with frequency doubling is also achieved to reduce the bandwidth requirement of the transmitter. After transmission over 25-km single-mode fiber, the power penalties of the generated QPSK and OOK signals are about 4 and 0.1 dB, respectively.
[Show abstract][Hide abstract] ABSTRACT: A simple double-sideband IMDD RoF system is successfully employed to directly transport a 21 Gbps OFDM signal at 60 GHz over 500 m of standard single-mode fiber and 10 m wireless distance.