Radio-on-fiber Systems Research Articles

Performance optimization of radio-on-fiber systems employing erbium doped fiber amplifier for optical single sideband signals considering intermodulation distortion

The performances of radio on fiber (RoF) systems with a dual-electrode Mach-Zehnder modulator and an erbium-doped fiber amplifier (EDFA) are optimized by numerical equations including the third order intermodulation (IM3) as well as amplified spontaneous emission (ASE) noise. We investigate a signal-to-noise-and-distortion ratio (SNDR) considering fiber dispersion with respect to an input signal power and an EDFA gain in both noise-dominant and third order intermodulation (IM3)-dominant cases. We also verify that the numerical analysis results are well matched with those of a commercial simulator, VPItransmissionMaker. In the analysis results, the optimum input signal power for the maximum SNDR of a RoF system with EDFA was reduced over 8 dB compared with that without EDFA. The dramatic reduction of IM3 power at a receiver was resulted from this decrement of input signal power. Thus, the maximum SNDR of the system with EDFA was obtained over 17 dB at 40 km fiber compared with that of the system without EDFA. In addition, the results showed that the SNDR was efficiently improved by EDFA in the noise-dominant case, while the SNDR improvement was negligible by EDFA in the IM3 dominant case.

Technical Trends in Millimeter-wave Band Radio-On-Fiber Access System

Radio On Fiber (ROF) is an optical analog technique for transmitting RF signals. With ROF systems, the base station conflguration is simple and independent of the modulation format and protocol. This advantage means that ROF is expected to become a useful way of realizing ∞exible and high capacity access networks. This paper reviews recent technical trends in ROF access systems, focusing especially on the millimeter-wave band. In addition, this paper describes our proposal based on an optical heterodyne technique for a 60GHz band ROF access system, which realizes a su-cient optical link budget with a simple system conflguration.

1.25-Gb/s Wavelength-Division Multiplexed Single-Wavelength Colorless Radio-on-Fiber Systems Using Reflective Semiconductor Optical Amplifier

A wavelength-division multiplexed colorless radio-on-fiber (RoF) system based on a reflective semiconductor optical amplifier (RSOA) is proposed in this paper. This scheme has a colorless and simple base station (BS), because an RSOA playing the role of amplification and modulation is used at the BS, irrespective of the wavelength. The spurious-free dynamic range, gain, and noise figure of both the downlink and uplink are presented to verify the suitability of the scheme for an RoF system. Error-free transmissions for both uplink and downlink wireless signals of 1.25 Gb/s are demonstrated. From the experimental results using an RF subcarrier of 3 GHz as a wireless signal, it is held that the performance of this scheme will change only slightly when using a millimeter-wave signal (> 30 GHz).

Examination of the dual‐band microwave wireless access system using radio on fiber technique

AbstractThe Radio on Fiber (ROF) technique has great potential in wireless communication systems. In this paper, we report on a fundamental examination of microwave wireless access systems based on Radio on Fiber. First, we designed and constructed examination systems by applying dual band (2.4 and 5 GHz) multiservice transmission systems and confirmed that there was sufficient performance through a transmission experiment. Then, application of FP‐LD (Fabry Perot Laser Diode) was considered in order to reduce the system cost, and for the most part degradation of the transmission characteristics was not observed when FP‐LD was used. Finally, a BIDI (bidirectional) module which integrated LD and PD within one package was made to further reduce costs. By measuring the transmission performance, applying the BIDI module to ROF systems was shown to be effective. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(4): 32–40, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20471

A Novel Millimeter-Wave Receiver Using Self-heterodyne Detection for a Digital Broadcasting Radio on Fiber System

Radio on Fiber (ROF) is an effective method for providing multi-channel digital TV services to subscriber's premises where it is difficult to install optical fibers or coaxial cables.In this paper, we propose a novel millimeter-wave receiver for subscribers that uses self-heterodyne detection.The receiver separates the carrier and the sideband and eliminates thermal noise close to the carrier.It can improve sensitivity by 10 dB compared with a conventional self-heterodyne receiver. A wireless transmission experiment proved the practicality of the receiver and the ROF system.

Examination of the Dual-Band Microwave Wireless Access System Using Radio on Fiber Technique

A Radio on Fiber (ROF) technique has a great potential in wireless communication systems. In this paper, we performed fundamental examination of microwave wireless access systems based on Radio on Fiber.First, we designed and constructed examination systems applying dual band (2.4GHz and 5GHz) multi service transmission systems and confirmed to have sufficient performance by transmission experiment.Then, application of FP-LD (Fabry Perot Laser Diode) was considered in order to reduce the system cost, and most degradation of the transmission characteristics was not observed when FP-LD was used.Finally, BIDI (Bi-directional) module which integrated LD and PD within one package was made for further cost reduction. By measuring the transmission performance, applying BIDI module to ROF systems was shown to be effective.

Wavelength-division-multiplexed Millimeter-waveband radio-on-fiber system using a supercontinuum light source

We propose to use a supercontinuum (SC) for a low-phase-noise multiwavelength light source in wavelength-division-multiplexing (WDM) millimeter-waveband (mm-waveband) radio-on-fiber (RoF) systems. We demonstrate the generation of low-phase-noise 60-GHz-band RoF signal. We also demonstrate the generation of two-channel WDM 60-GHz-band RoF signals and the transmission of the signals over a 25-km standard single-mode fiber (SMF) using photonic upconversion. The single multiwavelength light source can be shared with a number of users and simplifies the system configuration, which would allow the realization of high-reliability as well as low-cost RoF systems. Finally, the RoF network capacity with a single SC light source is estimated to be over 10 000 channels when the spectrum of the SC light source is fully utilized.