一种高速调制解调器，它通过电话线发送和接收一载频集的数字数据。 该调制解调器包括在载波之间可变地分配数据和功率，以便补偿等效噪声和使数据速率最大的系统。 此外，也介绍不需要一个均衡网络、可自适应地分配信道的控制和可跟踪线上参数变化的系统。

Ensemble modem structure for imperfect transmission media

The manufacturing of intelligent and secure visual data transmission over the wireless sensor network is key requirement nowadays to many applications. The two-way transmission of image under a wireless channel needed image must compatible along channel characteristics such as band width, energy-efficient, time consumption and security because the image adopts big space under the device of storage and need a long time that easily undergoes cipher attacks. Moreover, Quizzical the problem for the additional time under compression results that, the secondary process of the compression followed through the acquisition consumes more time.,Hence, for resolving these issues, compressive sensing (CS) has emerged, which compressed the image at the time of sensing emerges as a speedy manner that reduces the time consumption and saves bandwidth utilization but fails under secured transmission. Several kinds of research paved path to resolve the security problems under CS through providing security such as the secondary process.,Thus, concerning the above issues, this paper proposed the Corvus corone module two-way image transmission that provides energy efficiency along CS model, secured transmission through a matrix of security under CS such as inbuilt method, which was named as compressed secured matrix and faultless reconstruction along that of eminent random matrix counting under CS.,Experimental outputs shows intelligent module gives energy efficient, secured transmission along lower computational timing also decreased bit error rate.

Manufacturing intelligent Corvus corone module for a secured two way image transmission under WSN

The design of application-specific integrated circuits (ASIC) is at the core of modern ultra-high-speed transponders employing advanced digital signal processing (DSP) algorithms. This manuscript discusses the motivations for jointly utilizing transmission techniques such as probabilistic shaping and digital sub-carrier multiplexing in digital coherent optical transmissions systems. First, we describe the key-building blocks of modern high-speed DSP-based transponders working at up to 800G per wave. Second, we show the benefits of these transmission methods in terms of system level performance. Finally, we report, to the best of our knowledge, the first long-haul experimental transmission – e.g., over 1000 km – with a real-time 7 nm DSP ASIC and digital coherent optics (DCO) capable of data rates up to 1.6 Tb/s using two waves (2 × 800G).

/pdf/800g-dsp-asic-design-using-probabilistic-shaping-and-digital-2yhfdgnk8t.pdf

800G DSP ASIC Design Using Probabilistic Shaping and Digital Sub-Carrier Multiplexing

LiFi is networked, bidirectional wireless communication with light. It is used to connect fixed and mobile devices at very high data rates by harnessing the visible light and infrared spectrum. Combined, these spectral resources are 2600 times larger than the entire radio frequency (RF) spectrum. This paper provides the motivation behind why LiFi is a very timely technology, especially for 6th generation (6G) cellular communications. It discusses and reviews essential networking technologies, such as interference mitigation and hybrid LiFi/Wi-Fi networking topologies. We also consider the seamless integration of LiFi into existing wireless networks to form heterogeneous networks across the optical and RF domains and discuss implications and solutions in terms of load balancing. Finally, we provide the results of a real-world hybrid LiFi/Wi-Fi network deployment in a software defined networking testbed. In addition, results from a LiFi deployment in a school classroom are provided, which show that Wi-Fi network performance can be improved significantly by offloading traffic to the LiFi.

/pdf/introduction-to-indoor-networking-concepts-and-challenges-in-3898f2kbc4.pdf

Introduction to indoor networking concepts and challenges in LiFi

This tutorial discusses the design and ASIC implementation of coherent optical transceivers. Algorithmic and architectural options and tradeoffs between performance and complexity/power dissipation are presented. Particular emphasis is placed on flexible (or reconfigurable) transceivers because of their importance as building blocks of software-defined optical networks. The paper elaborates on some advanced digital signal processing (DSP) techniques such as iterative decoding, which are likely to be applied in future coherent transceivers based on higher order modulations. Complexity and performance of critical DSP blocks such as the forward error correction decoder and the frequency-domain bulk chromatic dispersion equalizer are analyzed in detail. Other important ASIC implementation aspects including physical design, signal and power integrity, and design for testability, are also discussed.

/pdf/design-tradeoffs-and-challenges-in-practical-coherent-zu2krholke.pdf

Design Tradeoffs and Challenges in Practical Coherent Optical Transceiver Implementations

We present a linear and nonlinear digital pre-distortion (DPD) tailored to the components of an optical transmitter. The DPD concept uses nonlinear models of the transmitter devices, which are obtained from direct component measurements. While the digital-to-analog converter and driver amplifier are modeled jointly by a Volterra series, the modulator is modeled independently as a Wiener system. This allows for a block-wise compensation of the modulator by a Hammerstein system and a pre-distortion of the electrical components by a second Volterra series. In simulations and extensive experiments, the performance of our approach for nonlinear DPD is compared to an equivalent linear solution as well as to a configuration without any DPD. The experiments were performed using M -ary quadrature-amplitude modulation ( M -QAM) formats ranging from 16- to 128-QAM at a symbol rate of 32 GBd. It is shown that the DPD improves the required optical signal-to-noise ratio at a bit error ratio of 2·10 −2 by at least 1.2 dB. Nonlinear DPD outperforms linear DPD by an additional 0.9 and 2.7 dB for higher-order modulation formats such as 64-QAM and 128-QAM, respectively.

Nonlinear Digital Pre-distortion of Transmitter Components

This paper reports on a field trial in a robotic manufacturing cell. Channel measurements and transmission experiments were conducted, assisting the development of a light-emitting diode-based optical wireless communication (OWC) system tailored for the needs of industrial wireless applications. These are moderate data rates, reliability, and low latency. Since dedicated radio spectrum is hardly available, the usage of light is an interesting alternative. Due to its spatial confinement, OWC links provide enhanced security and are difficult to jam from outside a building—a particularly interesting property for industrial applications. We performed broadband distributed $8\times 6$ multiple-input multiple-output (MIMO) channel measurements in a manufacturing cell. Results confirm that the signal-to-noise ratio is sufficient if a line-of-sight (LOS) is available and bandwidth is limited to a few megahertz. However, small movements and rotations may lead to sudden fades of 10–20 dB, when an LOS is blocked. To improve reliability, antenna diversity concepts are applied. Results show that for reliable communication, MIMO diversity schemes are indispensable as it increases the probability of a free LOS significantly. Based on these insights, we suggest an OWC design tailored to industrial wireless applications.

Optical Wireless MIMO Experiments in an Industrial Environment

We briefly introduce a concept for linear an d nonlinear digital pre-distortion (DPD) of high-speed optical transmitters. As an extension to previous results, we investigate the imp act of th e DPD schemes on a wavelength-division multiplexing (WDM) trans mission of 32 GBd polariz ation-division multiplexed (P DM) M –ary quadrature amplitude modulated (M-QAM) signals. The investigated formats range from 32- to 128-QAM.

Nonlinear digital pre-distortion of transmitter components

Based on measurements, we derive a linear and nonlinear pre-distortion tailored to the components of an optical transmitter and investigate their performance in simulations and experiments. Significant performance improvements are demonstrated for higher-order modulation formats such as 64- and 128-QAM.

As the use of optical wireless communication (OWC) in industrial production environments is gaining interest, it is necessary to consider the application's challenging requirements with respect to reliability and low latency. In this paper, we first analyze the factors limiting coverage and reliability in OWC. We discuss increased drive signal powers with an optional nonlinear post-equalizer, which improves the signal-to-noise ratio by an additional 3.5 dB. Further, spanning a multiple-input multiple-output (MIMO) channel and exploiting antenna diversity is shown to significantly increase the reliability of the OWC physical layer. The insights obtained from a series of experiments lead to a real-time demonstration of OWC with intrinsically high coverage and reliability. These first real-time results of OWC in an industrial production environment are discussed and physical layer data rates of up to 150 Mb/s with an average latency of $ 1 ms are shown.

/pdf/real-time-optical-wireless-mobile-communication-with-high-3661681nh2.pdf

Pablo Wilke Berenguer

Papers

Nonlinear Digital Pre-distortion of Transmitter Components

Optical Wireless MIMO Experiments in an Industrial Environment

Nonlinear digital pre-distortion of transmitter components

Nonlinear digital pre-distortion of transmitter components

Real-Time Optical Wireless Mobile Communication With High Physical Layer Reliability