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We propose a novel 60-GHz compact antenna module integrated with photodiode. The module is actually designed and fabricated, and it is successfully demonstrated that the antenna beams of 1×8 and 2×4 arrayed modules can be remotely controlled by tuning wavelength of 60-GHz RoF signals.
We demonstrate 3.5-Gbit/s QPSK signal transmission in radio-over-fiber system with beam forming of a 60 GHz-band integrated photonic array-antenna. The relationship between beam forming operation and signal quality is quantitatively confirmed.
A government-funded R and D program aiming at a resilient optical and millimeter-wave wireless link for a novel span protection scheme in a disaster recovery is presented. We also describe the key enabling technologies of both optical and wireless sub- systems and devices, including MIMO radio-over- fiber system, optical two-tone generation, and the transceiver and power amplifier in W-band.
A novel array-antenna is proposed, where antenna element and photodiode as well as optical fiber for RF power feeding are integrated. 4×2 60GHz arrayed patch antenna is actually fabricated and it is experimentally demonstrated that the two dimensional antenna beam steering is achieved by tuning the wavelength of the optical signal.
We demonstrated the feasibility of seamless optical and radio transmissions with plural W-band wireless sections for the first time. A 5-Gbaud QPSK signal was successfully transmitted over 2×20-km SMF spans and 2×2-m W-band wireless links.
We demonstrate digital signal transmission in RoF system with antenna beam steering capability. Beam steering operation for 40-GHz array-antenna has been experimentally confirmed by quantitatively analyzing the relationship between wavelength tuning range and signal quality.
The performance of a Radio-over-Fiber (RoF) transmission in millimeter-wave (MMW) band with optical signal re-modulation is experimentally studied. By investigating the trade-off between the two typical signal modulation schemes utilizing two-tone and an intermediate frequency, we clarify a chart for the system design and reveal the applicable fields of each modulation scheme in the system. The obtained...
A beam steering scheme of photonic array-antennas for 60 GHz RF signals generated by optical two-tone technique is reported. It is experimentally demonstrated that 60 GHz antenna beam can be remotely steered by tuning wavelengths.
System architecture utilizing photonic technology for beam forming of RF phased array antenna is studied. RSOA solution for uplink signal transmission and multi-core fiber approach for two dimensional phased array antenna are demonstrated.
The impact of data compression on LTE performance is investigated in C-RAN requiring 20-Gbit/s transmission rate. The nonlinear quantization-based compression was found to be indispensable for achieving 20-km transmissions with keeping the required LTE quality.
In order to keep up with the explosive mobile traffic increase, many wireless access points in a millimeter-wave band will be deployed in the future. A beam steering of an array antenna is effective for avoiding interference among plural access points, and a 2-dimensional (2-D) array operation is required for more flexible beam control. The Radio over Fiber (RoF) is one of the promising solutions...
RoF uplink transmission scheme for remotely beam steerable photonic array-antennas utilizing reflective semiconductor optical amplifiers was proposed. Our proposed scheme would be able to realize cost effective photonic antenna systems with a simple structure.
We demonstrated beam steering of array-antenna in millimeter-wave band at 39 GHz by WDM Radio over Fiber. The proposed photonic antenna can realize future ultra-broadband and smart antenna systems by a novel photonic approach.
We studied effects of fiber chromatic dispersions on radio over fiber systems using multi-wavelength tunable laser sources. A beam forming experiment of 2 GHz-band array antennas by controlling wavelengths of four light sources was conducted, where 5 km single-mode fiber and 3 nm wavelength tuning range yielded π phase shift of RF signals. We also studied transmission penalties due to the phase difference...
We propose a novel dynamic ONU registration scheme utilizing a simple circuitry for estimating the number of unregistered ONUs. Through experiments and numerical simulations, we successfully validated our scheme for TDMA-PONs with ultra-high-split.
RF power feeding to array antennas through fiber using multi-wavelength tunable light sources is studied. Effects of chromatic dispersion on beam steering capability and RF throughput penalty are focused.
We propose a hybrid all-optical repeater for 10G/1G-EPON mixed bit-rate upstream link. Through a bidirectional transmission experiments, we successfully achieved a total loss budget of 62.1 dB which corresponds to 80km reach and 1024 split.
We report an ONU tester prototype employing our proposed diagnosis technique for TDMA-PON utilizing MPCP messages in order to solve rogue-ONU and optical multiple-reflection problems. We experimentally confirm that our proposed method can identify such failures without any modification of already installed ONUs.
We propose and demonstrate a failed ONU detecting method by controlling ONUs to periodically transmit with MPCP frames of commercially available EPON. Proposed method can specify failed ONUs even when disturbing lights are higher by 18 dB than normal ONUs.
An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch,...
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