This PDF file contains the front matter associated with SPIE Proceedings Volume 9007, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Motivated by the looming radio frequency (RF) spectrum crisis, this paper aims at demonstrating that optical wireless communication (OWC) has now reached a state where it can demonstrate that it is a viable and matured solution to this fundamental problem. In particular, for indoor communications where most mobile data traffic is consumed, light fidelity (Li-Fi) which is related to visible light communication (VLC) offers many key advantages, and effective solutions to the issues that have been posed in the last decade. This paper discusses all key component technologies required to realize optical cellular communication systems referred to here as optical attocell networks. Optical attocells are the next step in the progression towards ever smaller cells, a progression which is known to be the most significant contributor to the improvements in network spectral efficiencies in RF wireless networks.

Optical Flow Switching (OFS) is a promising solution for large Internet data transfers. In this paper, we introduce UltraFlow Access, a novel optical access network architecture that offers dual-mode service to its end-users: IP and OFS. With UltraFlow Access, we design and implement a new dual-mode control plane and a new dual-mode network stack to ensure efficient connection setup and reliable and optimal data transmission. We study the impact of the UltraFlow system’s design on the network throughput. Our experimental results show that with an optimized system design, near optimal (around 10 Gb/s) OFS data throughput can be attained when the line rate is 10Gb/s.

The bandwidth of next generation access networks will require beyond that of current optical access, handling the big data to download of huge data, images, and videos, as well as to upload a large number of sensor data, any time and anywhere. The technical convergence with wired and wireless plays an important role to achieve the next generation access networks. In this paper, we show the perspective on next generation access networks considering the resilience against disasters.

We propose and experimentally demonstrate several different approaches for the realization of over 100Gb/s fiberwireless integration system, including optical PDM combined with MIMO reception, advanced multi-level modulation, optical multi-carrier modulation, electrical multi-carrier modulation, antenna polarization multiplexing and multi-band multiplexing. These approaches can effectively reduce the signal baud rate as well as the required bandwidth for optical and electrical devices. We also experimentally investigate the problems, such as multi-path effect due to different wireless transmission distance, existing in the large capacity fiber-wireless integration system. We experimentally demonstrate these problems can be effectively solved by advanced DSP algorithms including classic CMA.

An exhausted capacity of current Passive Optical Networks has been anticipated as bandwidth-hungry applications such as HDTV and 3D video become available to end-users. To enhance their performance, the next generation optical access networks have been proposed, using optical carriers allocated within the E-band (1360-1460 nm). It is partly motivated by the low-water peak fiber being manufactured by Corning. At these wavelengths, choices for low cost optical amplifiers, with compact size, low energy consumption and feasibility for integration with other optoelectronic components are limited, making the semiconductor optical amplifiers (SOA) a realistic solution. An experimental characterization of a broadband and low polarization sensitive asymmetric multi quantum well (MQW) SOA operating in the E-band is reported. The SOA device is composed of nine 6 nm In_1-xGa_xAsyP_1-y 0.2% tensile strained asymmetric MQW layers sandwiched between nine latticed matched 6 nm InGaAsP barrier layers. The active region is grown on an n-doped InP substrate and buried by p-doped InGaAsP layers. The SOA devices have 7-degrees tilt anti-reflected coated facets, with 2 μm ridge width, and a cavity length of 900 μm. For input powers of -10 dBm and -20 dBm, a maximum gain of 20 dB at 1360 nm with a polarization insensitivity under 3 dB for over 90 nm bandwidth is measured. Polarization sensitivity of less than 0.5 dB is observed for some wavelengths. Obtained results indicate a promising SOA with broadband amplification, polarization insensitivity and high gain. These SOAs were designed and characterized at the Photonics Technology Laboratory, University of Ottawa, Canada.

In this paper, a multiband, multi-wavelength, all-fibre source array consisting of an 810nm pump laser diode, thretwo fiber splitters and three segments of Er-, Tm- and Nd-doped fiber is proposed for PON applications. In the set-up, cascaded pairs of standard fiber gratings are used for extracting the required multiple wavelengths within their corresponding bands. A thorough design parameter description, optical array details and full simulation results, such as: full multi-wavelength spectrum, peak and average powers for each generated wavelength, linewidth at FWHM for each generated signal, and individual and overall conversion efficiency, will be included in the manuscript.

The Radio on Fiber (RoF) technologies are unique transmission means of radio analog signals through optical fiber cables. These technologies are currently discussed at international standard organizations such as ITU-T, IEC, APT and IEEE802. This invited paper summarizes RoF standardization activities at those standard organizations.

This paper addresses the wireless channel capacity in small cells provided by RoF-DAS over WDM-PON that can increase the capacity in a small cell with RoF entrance link and MIMO distributed antenna. Considering the SNR of the RF signal transmitted in the RoF entrance network and the interferences among wireless cells, computer simulation results show the optimized cell size to maximize the MIMO channel capacity.

In this paper, we propose a simple and efficient predistortion method using schottky diodes to compensate the nonlinearity of RoF systems. L-I curve in LD is compared with I-V curve in schottky diode and the nonlinear characteristics are analyzed. The predistortion circuit has been designed with two paths. One path is the nonlinearity generation circuit with schottky diode, while the other path has only a time delay. Then, these two paths are recombined to suppress the IMD3 (3^rd inter - modulation distortion) of LD. Experimental results show that the enhancements of about 26 dBc in the IMD3 and about 8.5 dB in the SFDR are achieved at 2.4 GHz.

The availability of high-bandwidth internet connections to home gateways will place increasing demands on the home access network that provides connections to computers and other devices. In this paper the use of infrared optical wireless to provide connections to user appliances and terminals is discussed. The design and implementation of two demonstration systems operating at hundreds of Mbit/s and above are detailed. Future challenges are also discussed.

Passive optical network based on orthogonal frequency division multiplexing (OFDM-PON) exhibits excellent performance in optical access networks due to its greater resistance to fiber dispersion, high spectral efficiency and exibility on both multiple services and dynamic bandwidth allocation. The major elements of conventional OFDM communication system are two-dimensional (2-D) signal mapper and one-dimensional (1-D) inverse fast fourier transform (IFFT). Three dimensional (3-D) OFDM use the concept of 3-D signal mapper and 2-D IFFT. With 3-D OFDM, minimum Euclidean distance (MED) is increased which results in BER performance improvement. As bit error rate (BER) depends on minimum Euclidean distance (MED) which is 15.46 % more in case of 3-D OFDM as compared to 2-D OFDM. Forward error correction (FEC) coding is a technique where redundancy is added to original bit sequence to increase the reliability of communication system. In this paper, we propose and analytically analyze a new PON architecture based on 3-D OFDM with convolutional coding and Viterbi decoding and is compared with conventional 2-D OFDM under various system impairments for coherent optical orthogonal frequency division multiplexing (CO-OFDM) without using any optical dispersion compensation. Analytical result show that at BER of 10^-9, there is 2.7 dB, 3.8 dB and 9.3 dB signal-to-noise ratio (SNR) gain with 3-D OFDM, 3-D OFDM combined with convolutional coding and Viterbi hard decision decoding (CC-HDD) and 3-D OFDM combined with convolutional coding and Viterbi soft decision decoding (CC-SDD) respectively as compared to 2-D OFDM-PON. At BER of 10^-9, 3-D OFDM-PON with CC-HDD gives 2.8 dB improvement in optical budget for both upstream and downstream path and gives 5.7 dB improvement in optical budget using 3-D OFDM-PON combined with CC-SDD as compared to conventional OFDM-PON system.

This paper experimentally investigates power budget extension configurations for WDM NG-PONs. Differential Phase Shift Keying (DPSK), and Differential Quadrature Phase Shift Keying (DQPSK) are considered. The budget enhancement techniques are based on Semiconductor Optical Amplifier (SOA). The paper thoroughly studies power budget enhancement for the two modulation formats and shows that the proposed configurations comply with current standards such as XG-PON1.

As demand for higher bandwidth is drastically increasing, bandwidth efficiency is going to be an issue in Passive Optical Networks (PONs). Moreover, network operators plan to reduce the number of central offices (COs) while extending the reach of the optical links, this enables them to reduce the deployment costs. This paper demonstrates the advantages of advanced modulation formats and a suitable configuration for the power budget enhancement of hybrid Wavelength Division Multiplexing-Time Division Multiplexing-Passive Optical Networks (WDM-TDM-PONs). The proposed technique can offer higher data rate, better bandwidth efficiency, and large number of customers. Differential (Quadrature) Phase Shift Keying (DQPSK) signals and Orthogonal Frequency Division Multiplexing (OFDM) will be considered. Simulations are performed using different modulation formats to evaluate the behavior of the proposed PON extender. Finally, Transmission of 1 Tbps WDM/TDM-OFDMPON over 60 km optical link is presented here. The simulation results, prove that 1600 users can be covered with 40 Gbps peak data rate.

Demands by the communications industry for greater bandwidth push the capability of conventional wireless technology. Part of the Radio Spectrum that is suitable for mobility is very limited. Higher frequency waves above 30 GHz tend to travel only a few miles or less and generally do not penetrate solid materials very well. Unmanned Aerial System applications require electronic scanning antenna capabilities, in challenging environmental conditions, over very large bandwidths. In addition to that, it is desirable to have as much reduction as possible in size, weight, power and cost. Metamaterials are recently being introduced by periodic repetition of some inclusions in a host medium, which may be described as effective media characterized by a set of equivalent constitutive parameters. Self-similarity in creating periodic structures is the basis of building volume or 2D holographic components. The latter does more than periodic repeats. Similar, but more advanced concepts (fractal in nature) are used to model phase screens used in modeling the atmospheric turbulence. Unfortunately, metamaterials (MTMs) are anisotropic (direction-dependent) and this makes their application limited in terms of use as antennas for mobile platforms. However, conceptually, controlled-anisotropy can be applied to make phased-arrays, beam-forming, and beam scanning. This issue then begs the question of cost comparison with conventional materials that can be found in nature, e.g., low-cost optics lenses, or conventional RF scanning antennas. As for lensing and fixed platform imaging, the story is very different, as super-lens is expected to be a byproduct. Nevertheless, even if metamaterials become readily available, the atmosphere around the globe cannot be replaced. Neither, broadband wireless connectivity to a mobile can be achieved via fiber optics. This paper, presents a Hybrid radio-frequency (RF) and Wireless Optical solution to provide adaptive sensing in an opportunistic fashion, with or without metamaterials. A byproduct of the latter will be broadband and reliable global connectivity.

The Polymer Optical Fiber (POF) has certain advantages over alternative data communication media such as glass fibers, copper cables, and wireless systems. It is pliable, durable, and cost effective, has small weight and a short bend radius, allows easy installation and quick troubleshooting, and provides immunity to electromagnetic interference. Due to its advantages, POF is a promising candidate for broadband in-house networks. Among different types of POF, the 1 mm PMMA Step-Index POF (SI-POF) is the best known and by far the most widely used type of POF. Present communication systems over POF use a single channel for data transmission. To increase the capacity of a single POF, multiple bandwidth-efficient channels can be transmitted over the same fiber. The technique is known as wavelength division multiplexing (WDM).

This paper reports on the current development status of a four-channel coarse WDM (CWDM) transmission system for Multi-Gbit/s in-house data communication via SI-POF. The block diagram of the experimental setup and the complete description of established communication system will be given in the full paper. The key photonic component in a CWDM system under development is a demultiplexer (DEMUX). To spatially separate different wavelength channels, a four-channel DEMUX with low insertion loss (<6 dB) and low crosstalk (<-30 dB) is realized in bulk optics technology at the Harz University. The operating principle, the description of the opto-mechanical setup, and the transfer function of the DEMUX will be shown. In addition, an optical link power budget analysis, based on the experimentally obtained data, will be carried out for all four channels. Finally, Multi-Gbit/s data transmission experiments will be performed with violet, blue, green, and red laser diodes via up to 25 m SI-POF links, and the results and their analysis will be presented.

With the fast growing and popularization of smart computing devices, there is a rise in demand for accurate and reliable indoor positioning. Recently, systems using visible light communications (VLC) technology have been considered as candidates for indoor positioning applications. A number of researchers have reported that VLC-based positioning systems could achieve position estimation accuracy in the order of centimeter. This paper proposes an Indoors navigation environment, based on visible light communications (VLC) technology. Light-emitting-diodes (LEDs), which are essentially semiconductor devices, can be easily modulated and used as transmitters within the proposed system. Positioning is realized by collecting received-signal-strength (RSS) information on the receiver side, following which least square estimation is performed to obtain the receiver position. To enable tracking of user’s trajectory and reduce the effect of wild values in raw measurements, different filters are employed. In this paper, by computer simulations we have shown that Gaussian mixture Sigma-point particle filter (GM-SPPF) outperforms other filters such as basic Kalman filter and sequential importance-resampling particle filter (SIR-PF), at a reasonable computational cost.

Novel concept for integrating visible light produced by LEDs with indoor positioning using tilted multiple optical receivers is presented in this paper. Generally, positioning system based on visible light communication (VLC) estimates transmission distance through received signal strength (RSS), which is based on intensity modulation and direct detection (IM/DD) method. In order to estimate position using trilateration through transmission distances, receiver needs to know the positions of three or more reference nodes. Thus, the system has limitation that optical receiver should receive signals from at least three different transmitters without interference. For this reason, a carrier allocation or TDM technique have been utilized and positioning area is limited by overlapped area of different transmitters. Furthermore, additional information on characteristics of transmitter, which have a decisive effect on signal strength, is required even though the inter-cell interference problem is solved because the characteristics of transmitters can be varied for different indoor environments.

We propose an artificially tilted multiple optical receivers structure to control incidence angle gain and positioning algorithm using the received power difference. PDs are densely placed, thus, transmission distances between LED and PDs and radiation angles are the same. Inter-cell interference is fundamentally removed and positioning area is extended when compared with previous researches. In order to estimate the position, the transmitter’s location code from single LED was received using multiple optical receivers. The validity of the proposed scheme was experimentally demonstrated by determining the local position of single transmitter and angle gain profile of receivers.

Optical phase-locked loop (OPLL) is used to improve the linearity of an optical link for transmission of analog signals. The finite loop delay and the presence of a low-pass filter, required for stable loop operation, lead to a nontrivial frequency response. Here, the linearity improvement in OPLL is investigated, and simple relation among the loop delay, the open-loop gain, and the loop-filter bandwidth that must be satisfied for stable operation of the OPLL is found. This relation is used to determine the fundamental limit on spur-free dynamic range (SFDR) improvement that OPLL can offer over a conventional Mach-Zehnder (MZ)-type detector.

We propose a delta-sigma modulation scheme for low- and medium-frequency signal transmission in a digital photonic network system. A 10-Gb/s-class optical transceiver with a delta-sigma modulator utilized as a high-speed analog-to-digital converter (ADC) provides a binary optical signal. On the signal reception side, a low-cost and slow-speed photonic receiver directly converts the binary signal into an analog signal at frequencies from several hundreds of kilohertz several tens of megahertz. Further, by using a clock and data recovery circuit at the receiver to reduce jitters, the single-sideband phase noise of the generated signals can be significantly reduced.

Combined optimization of the source precoder, relay weighting matrices, and destination decoder is proposed in dual-hop amplify-and-forward (AF) multiple-input multiple-output (MIMO) multiple-relay networks with the source-to-destination link in correlated channels. This broadband cooperative transceiver design is studied based on the minimum mean-squared error (MMSE) criterion under correlated fading channels. The optimization problem belongs neither concave nor convex so that an iterative nonlinear matrix conjugate gradient (MCG) search algorithm is applied to explore local optimal solutions. Simulation results show that the broadband cooperative transceiver joint architecture performs better the non-cooperative transceiver design in terms of the bit-error-rate (BER).