Rejuvenating direct modulation and direct detection for modern optical communications

  • Che D.
  • Chen X.
  • Hu Q.
  • Li A.
  • Shieh W.

High-speed transoceanic optical fiber transmission using direct modulation (DM) and direct detection (DD) was one of the most stirring breakthroughs for telecommunication in 1990s, which drove the internet as a global phenomenon. However, the later evolution of optical coherent communications in 2000s gradually took over the long-haul applications, due to ...

OpenStack installation using Packstack installer

  • Juszczak G.

For several years, cloud computing has been increasingly appearing in the global IT market, both in corporate infrastructure and among private users. In medium and large companies, they replace the current, not very flexible, poorly scalable and often expensive computer infrastructure, and in the case of small businesses, startups and ...

Physical Layer Security on Fiber-Optic MIMO-SDM Systems: an Overview

  • Cho J.
  • Guan K.
  • Winzer P.

Fiber-optic transmission systems provide large capacities over enormous distance but are vulnerable to simple eavesdropping attacks at the physical layer. We classify key-based and keyless encryption and physical layer security techniques and discuss them in the context of optical multiple-input-multiple-output space-division multiplexed (MIMO-SDM) fiber-optic communication systems. We show that MIMO-SDM ...

Learning process for reducing uncertainties on network parameters and design margins

  • Delezoide C.
  • Pesic J.
  • Pointurier Y.
  • Seve E.

Using monitored physical parameters in a learning process, we decrease design margins by reducing uncertainties on the input parameters of a Quality of Transmission (QoT) tool, improving the accuracy of the signal-to-noise ratio prediction.

Linear Programming Bounds for Entanglement-Assisted Quantum Error-Correcting Codes by Split Weight Enumerators

  • Ashikhmin A.
  • Lai C.

Linear programming approaches have been applied to derive upper bounds on the size of classical and quantum codes. In this paper, we derive similar results for general quantum codes with entanglement assistance by considering a type of split weight enumerator. After deriving the MacWilliams identities for these enumerators, we are ...

138 Tbit/s Mode- and Wavelength Multiplexed Transmission over 6-Mode Graded-Index Fiber

  • Alvarado-Zacarias J.
  • Alvarez-Aguirre R.
  • Amezcua Correa R.
  • Chen H.
  • Fontaine N.
  • Gruner-Nielsen L.
  • Jensen R.
  • Koonen T.
  • Lingle R.
  • Okonkwo C.
  • Ryf R.
  • Sun Y.
  • Van Weerdenburg J.

We report on the multiplexing of 12 spatial channels and 120 wavelength channels in the C-band, each carrying 16-QAM symbols at 30 Gbaud over graded-index few-mode fiber. A combination of multiple fiber spools with positive and negative modal dispersion values are exploited to form a 59 km link with 0.35 ...

Kramers-Kronig Receivers for 100-km Datacenter Interconnects

  • Antonelli C.
  • Chen X.
  • Mecozzi A.
  • Raybon G.
  • Sethumadhavan C.
  • Shtaif M.
  • Winzer P.

In this paper, we review in detail experimental demonstrations of Kramers-Kronig (KK) based direct detection systems with high per-carrier interface rates, high spectral efficiencies, and ~100-km reach. Two realizations of KK based receivers are demonstrated, including single-polarization and dual-polarization versions. Critical aspects of the KK receiver such as the carrier-to-signal ...

Directly Reflectivity Modulated Laser

  • Brent R.
  • Chen Y.
  • Dong P.
  • Maho A.
  • Melikyan A.

We report a novel directly reflectivity modulated laser (DRML) whose output is modulated through a Michelson interferometer reflector of the laser cavity. 25/40 Gb/s on-off-keying and 25 Gb/s binary phase-shift keying signals are generated and the wavelength tunability is >20 nm.

Massive MIMO has Unlimited Capacity

  • Bjornson E.
  • Hoydis J.
  • Sanguinetti L.

The spectral efficiency (SE) of cellular networks can be improved by the unprecedented array gain and spatial multiplexing offered by Massive MIMO. Since its inception, the coherent interference caused by pilot contamination has been believed to create a finite SE limit, as the number of antennas goes to infinity. In ...

QoS-aware protection in flexgrid optical networks

Elastic optical networks generally rely on protection and restoration mechanisms to prevent the detrimental effect of fiber cuts. In particular, we investigate optical protection in flexgrid optical networks where the symbol rate is varied as a complementary approach to modulation format. We propose a novel protection scenario, whereby premium traffic ...

Modulation over Nonlinear Fourier Spectrum: Continuous and Discrete Spectrum

Nonlinear Frequency Division Multiplexed (NFDM) systems are considered when data is modulated in both parts of the nonlinear Fourier spectrum: continuous spectrum and discrete spectrum. An efficient algorithm is introduced to generate a time-domain signal from a given nonlinear spectrum. The transmission of such NFDM symbols is experimentally demonstrated over ...

Modulation on Discrete Nonlinear Spectrum: Perturbation Sensitivity and Achievable Rates

Multi-soliton pulses are studied under small perturbations. By means of mutual information (MI), we show that the nonlinear spectrum becomes correlated when a 64-PSK modulated 2-eigenvalues soliton is perturbed by a small additive white Gaussian noise (AWGN). Transmission over two channels are considered: an AWGN channel (back-to-back scenario) and an ...

Finite-Length Analysis of Spatially-Coupled Regular LDPC Ensembles on Burst-Erasure Channels

Regular Spatially-Coupled LDPC (SC-LDPC) ensembles have gained significant interest since they were shown to universally achieve the capacity of binary memoryless channels under low-complexity belief-propagation decoding. In this work, we focus primarily on the performance of these ensembles over binary channels affected by bursts of erasures. We first develop an ...

A Low-Cost Scalable 32-Element 28-GHz Phased Array Transceiver for 5G Communication Links Based on a 2x2 Beamformer Flip-Chip Unit Cell

This paper presents a scalable 28-GHz phased-array architecture suitable for fifth-generation (5G) communication links based on four-channel (2x2) transmit/receive (TRX) quad-core chips in SiGe BiCMOS with flip-chip packaging. Each channel of the quad-core beamformer chip has 4.6-dB noise figure (NF) in the receive (RX) mode and 10.5-dBm output 1-dB compression ...

Low-Complexity Nonlinear Zero-Forcing Precoding Under Per-Line Power Constraints for Improved Downstream Active-User Peak-Rates

We consider nonlinear zero-forcing (ZF) precoding design to improve the downstream peak-rates when only a few users in the cable binder are active. In order to compute the optimal nonlinear ZF precoder under per-line power constraints (PLPCs), we present a novel low-complexity dual decomposition algorithm, in which the key ...

25.4 Tb/s Transmission over Trans-Pacific Distances Using Truncated Probabilistically Shaped PDM-64QAM

Probabilistic constellation shaping (PCS), digital nonlinear compensation, and multi-rate spatially coupled low-density parity check codes are used to achieve 25.4 Tb/s transmission over 10,285km EDFA-only straight-line testbed at 6.1 bits/symbol/Hz. The gain provided by PCS over standard 64QAM is investigated over trans-Atlantic and trans-Pacific distances. Moreover, the potential benefits of ...

Beamforming with Artificial Noise for Secure MISOME Cognitive Radio Transmissions

In this paper, we consider multiple-input singleoutput multi-eavesdropper (MISOME) cognitive radio networks (CRNs), where a secondary user (SU) aims to transmit confidential information to a legitimate SU receiver (SU-RX) in the presence of a primary user (PU) and a multi-antenna passive eavesdropper in fast fading environments. For this system setting, ...

A Multiscale Sparse Array of Spatially-Spread Electromagnetic-Vector-Sensors for Direction Finding and Polarization Estimation

A multiscale sparse array, which is composed of spatially-spread electromagnetic-vectorsensors (SS-EMVSs), is proposed to estimate the direction-of-arrivals (DOA) and polarizations of multiple sources. The SS-EMVS is composed of three orthogonally oriented but spatially noncollocated dipoles to measure the electric field and three orthogonally oriented but spatially noncollocated loops to measure ...

Compact High Isolation Base-Station Duplexer Using Triple-Mode Ceramic Cavities

  • Abbosh A.
  • Hendry D.

A microwave duplexer with high isolation is presented. The device is based on triple mode filters that are built using silver plated ceramic cuboids. To create a six-pole, six-transmission zero filter in the DCS-1800 band, which is utilized in mobile communications, two cuboids are cascaded. To shift spurious harmonics, low ...

How to ensure reliable connectivity for aerial vehicles over cellular networks

  • Amorim Rafhael
  • Kovacs I.
  • Mogensen P.
  • Nguyen H.
  • Sørensen Troels
  • Wigard J.

Widely deployed cellular networks are an attractive solution to provide large scale radio connectivity to unmanned aerial vehicles. One main prerequisite is that coexistence and optimal performance for both aerial and terrestrial users can be provided. Todays cellular networks are, however, not designed for aerial coverage, and deployments are primarily ...