Mitigation strategy for transmission impairments in millimeter-wave radio-over-fiber networks [Invited]

Abstract

Hybrid fiber-wireless networks for fixed wireless access operating in the millimeter-wave (mm-wave) frequency region have been actively pursued to provide ultrahigh bandwidth for untethered connectivity. Moving the radio operating frequency into the mm-wave region overcomes the spectral congestion in the lower microwave region and is also capable of providing high-capacity broadband wireless services in a picocellular or microcellular architecture. Optical fiber backhaul provides the broadband interconnectivity between a centralized location and a large number of high-throughput antenna base stations necessary in such an architecture. The transportation of mm-wave wireless signals within the hybrid network is subject to numerous impairments ranging from low conversion efficiency to fiber chromatic dispersion and also to signal degradation due to nonlinearity along the link. One of the major technical challenges in implementing these networks lies in the mitigation of these impairments that the wireless signals experience while traversing the links. In this paper, we present an overview of the different techniques and schemes to overcome some of the impairments for transporting mm-wave signals over optical fibers.

W-band photonic-wireless link with a Schottky diode envelope detector and bend insensitive fiber

“…• fiber installation: the requirements for fiber to be installed directly to the transmitting antenna have not been regarded; previous investigations have focussed on the transmission fiber and associated impairments [19,20] or on capacity enhancements through fiber spatial multiplexing and multiple-input multiple-output (MIMO) RF transmission [21]. The necessity for bend insensitive fiber (BIF) for on-site installation is obvious and similar to the case of fiber-to-the-x [22,23] and the impact of including it in the transmission line is analyzed and discussed in section 4.2.…”

Requirements for bend insensitive fiber in millimeter-wave fronthaul systems

“…The transmission fiber itself has received attention mostly with regard to transmission impairments due to dispersion and fiber nonlinearities [9] or the combination of single-and multi-mode fibers [7] andmore recently-as a means for capacity increase by combining spatial multiplexing in the fiber with the well known concept of multiple-input multiple-output (MIMO) RF transmission [3].…”

Digital coherent detection of multi-gigabit 40 GHz carrier frequency radio-over-fibre signals using photonic downconversion

“…By using photonic downconversion in a coherent receiver, detection of high bit-rate 16-QAM signals, up to 4 Gbit/s, at a 40 GHz carrier frequency using low bandwidth electronics, has been experimentally demonstrated.Introduction: Currently, there is a rapid increase and interest in new radio-over-fibre (RoF) technologies capable of enabling high capacity wireless access links [1,2]. The current trend is moving towards millimetre (mm)-wave frequencies, where complex modulation formats (QPSK, QAM [2, 3]) and multiplexing schemes such as OFDM can be used in order to reach multi-gigabit capacities.…”

“…Introduction: Currently, there is a rapid increase and interest in new radio-over-fibre (RoF) technologies capable of enabling high capacity wireless access links [1,2]. The current trend is moving towards millimetre (mm)-wave frequencies, where complex modulation formats (QPSK, QAM [2,3]) and multiplexing schemes such as OFDM can be used in order to reach multi-gigabit capacities.…”

“…The current trend is moving towards millimetre (mm)-wave frequencies, where complex modulation formats (QPSK, QAM [2,3]) and multiplexing schemes such as OFDM can be used in order to reach multi-gigabit capacities. Most of the reported works so far focus on the photonic generation of multi-gigabit mm-wave signals [1][2][3], i.e downstream channel. However, the demodulation of signals at mm-wave frequencies still posseses many technical challenges since it requires very high-speed and linear radio-frequency (RF) electronics [1 -3].…”