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\"A practical review of state-of-the-art non-contiguous multicarrier technologies that are revolutionizing how data is transmitted, received, and processed This book addresses the advantages and the limitations of modern multicarrier technologies and how to meet the challenges they pose using non-contiguous multicarrier technologies and novel algorithms that enhance spectral efficiency, interference robustness, and reception performance. It explores techniques using non-contiguous subcarriers which allow for flexible spectrum aggregation while achieving high spectral efficiency and flexible transmission and reception at lower OSI layers. These include non-contiguous orthogonal frequency division multiplexing (NC-OFDM), its enhanced version, non-contiguous filter-bank-based multicarrier (NC-FBMC), and generalized multicarrier. Following an overview of current multicarrier technologies for radio communication, the authors examine particular properties of these technologies that allow for more efficient usage within key directions of 5G. They examine the principles of NC-OFDM and discuss efficient transmitter and receiver design. They present the principles of FBMC modulation and discuss key challenges for FBMC communications while comparing performance results with traditional OFDM. They move on from there to a fascinating discussion of GMC modulation within which they clearly demonstrate how that technology encompasses all of the advantages of previously discussed techniques, as well as all imaginable multi- and single-carrier waveforms.; Addresses the problems and limitations of current multicarrier technologies (OFDM) Describes innovative techniques using non-contiguous multicarrier waveforms as well as filter-band based and generalized multicarrier waveforms Provides a thorough review of the practical limitations and solutions for evolving and breakthrough 5G communication technologies Explores the future outlook for non-contiguous multicarrier technologies as regards their greater industrial realization, hardware practicality, and other challenges Advanced Multicarrier Technologies for Future Radio Communication: 5G and Beyondis an indispensable working resource fortelecommunication engineers, researchers and academics, as well as graduate and post-graduate students of telecommunications. At the same time, it provides a fascinating look at the shape of things to come for telecommunication industry executives, telecom operators, regulators, policy makers, and economists. \"-- Provided by publisher.

An effective solution to enhance the capacity of an optical‐interconnect link is utilizing advanced multiplexing technologies, like wavelength‐division‐multiplexing (WDM), polarization‐division multiplexing (PDM), spatial‐division multiplexing (SDM), bi‐directional multiplexing, etc. On‐chip (de)multiplexers are necessary as key components for realizing these multiplexing systems and they are desired to have small footprints due to the limited physical space for on‐chip optical interconnects. As silicon photonics has provided a very attractive platform to build ultrasmall photonic integrated devices with CMOS‐compatible processes, in this paper we focus on the discussion of silicon‐based (de)multiplexers, including WDM filters, PDM devices, and SDM devices. The demand of devices to realize a hybrid multiplexing technology (combining WDM, PDM and SDM) as well as a bidirectional multiplexing technologies are also discussed to achieve Peta‐bit optical interconnects.

The phase-sensitive optical time domain reflectometry (Φ-OTDR) has been widely applied in various fields. However, due to fading noise, false alarms often occur; this limits its engineering applications. In this paper, a fading suppression method for Φ-OTDR systems based on multi-domain multiplexing (MDM) is proposed. The principles and limitations of existing suppression methods such as spatial-domain multiplexing (SDM), polarization-domain multiplexing (PDM), and frequency-domain multiplexing (FDM) are analyzed. The principle of MDM is explained in detail, and an experimental system is established to test the fading noise suppression capabilities of different parameter combinations of the PDM, FDM, and SDM methods. Experimental results show that it is difficult to comprehensively suppress fading noise with single-domain multiplexing. Through optimizations of different parameter combinations, MDM can comprehensively suppress fading noise by appropriately selecting the number of FDM frequencies, the spatial weighting intervals, and using PDM, thus obtaining the optimal anti-fading solution between performance and hardware complexity. Through MDM, the fade-free measurement is achieved, providing a promising technical solution for the practical application of the Φ-OTDR technology.

Software implementations of brain-inspired computing underlie many important computational tasks, from image processing to speech recognition, artificial intelligence and deep learning applications. Yet, unlike real neural tissue, traditional computing architectures physically separate the core computing functions of memory and processing, making fast, efficient and low-energy computing difficult to achieve. To overcome such limitations, an attractive alternative is to design hardware that mimics neurons and synapses. Such hardware, when connected in networks or neuromorphic systems, processes information in a way more analogous to brains. Here we present an all-optical version of such a neurosynaptic system, capable of supervised and unsupervised learning. We exploit wavelength division multiplexing techniques to implement a scalable circuit architecture for photonic neural networks, successfully demonstrating pattern recognition directly in the optical domain. Such photonic neurosynaptic networks promise access to the high speed and high bandwidth inherent to optical systems, thus enabling the direct processing of optical telecommunication and visual data. An optical version of a brain-inspired neurosynaptic system, using wavelength division multiplexing techniques, is presented that is capable of supervised and unsupervised learning.

A novel ultra-high capacity free space optics (FSO) link has been developed by incorporating hybrid wavelength divison multiplexing (WDM)-polarization division multiplexing (PDM)-orthogonal frequency division multiplexing (OFDM) techniques with 16-level quadrature amplitude modulation (16-QAM) signals. Coherent detection is employed to enhance the receiver sensitivity in the presence of channel effects. The proposed link is analyzed under the impact of dynamic weather conditions viz. haze, rain, dust and fog using bit error rate, optical signal to noise ratio, error vector magnitude and maximum transmission range performance metrics. Sixteen independent DWDM channels with 0.8 nm channel spacing each carrying 100 Gbps data are successfully tranported using the proposed FSO link realizing a net data rate of 1.6 Tbps. Furthermore, we demonstrated a performance comparison of the link with contemporary works. The proposed FSO link provides a feasible and viable solution to implement ultra-high-capacity wireless transmission networks for last-mile access.

We demonstrate experimentally the feasibility of continuous variable quantum key distribution (CV-QKD) in dense-wavelength-division multiplexing networks (DWDM), where QKD will typically have to coexist with several co-propagating (forward or backward) C-band classical channels whose launch power is around 0 dBm. We have conducted experimental tests of the coexistence of CV-QKD multiplexed with an intense classical channel, for different input powers and different DWDM wavelengths. Over a 25 km fiber, a CV-QKD operated over the 1530.12 nm channel can tolerate the noise arising from up to 11.5 dBm classical channel at 1550.12 nm in the forward direction (9.7 dBm in backward). A positive key rate (0.49 kbits s−1) can be obtained at 75 km with classical channel power of respectively −3 and −9 dBm in forward and backward. Based on these measurements, we have also simulated the excess noise and optimized channel allocation for the integration of CV-QKD in some access networks. We have, for example, shown that CV-QKD could coexist with five pairs of channels (with nominal input powers: 2 dBm forward and 1 dBm backward) over a 25 km WDM-PON network. The obtained results demonstrate the outstanding capacity of CV-QKD to coexist with classical signals of realistic intensity in optical networks.

Data rates in fiber optic communication (FOC) technology are highly increased and optical communication technology has been mostly advancing highly. There are different multiplexing techniques like frequency-division multiplexing (FDM), time-division multiplexing (TDM), wavelength division multiplexing (WDM), dense wavelength division multiplexing (DWDM), code division multiplexing (CDM), and digital coherent technology by using single mode fiber (SMF)/single core fiber (SCF), and using these multiplexing did not produce over 100 Tbps/fiber because of many factors like linearity and nonlinearities of fiber optic. To transmit a high capacity over 100 Tbps/fiber and long-haul transmission, the multiplexing techniques that are needed to break this bottleneck/capacity limit are termed space-division multiplexing, which uses single mode fiber (SMF) and multicore fiber (MCF). The target of this paper is to enhance the capacity of FOC systems using space-division multiplexing (SDM). The result produced during this paperwork is that the capacity enhanced is around 14.75 pb/s/fiber, after it is decreasing and thus the haul of transmission is 250 km with usable wavelength C + L band. The signal/noise ratio is 35 dB in FOC using single mode fiber (SMF) and multicore fiber (MCF). Finally, the SDM includes a great role in fiber optic just in case of effective information transmission by enhancing capacity, reduction of loss, distortion, cross talk, and power consumption reduction during information transmission; SDM in fiber optic is incredibly essential for effective communication systems with extremely high capacity and long haul transmission.

As the Internet of Things (IoT) and communication technologies continue to evolve, the value of multi-service multiplexing in visible light communication (VLC) systems has been increasingly recognized, particularly in addressing the scarcity of wireless spectrum resources. This study reconstructed the stereo transmission protocol through methods such as dynamic level control, designed a timer interrupt service routine with a double buffer, and reassigned channel status bits in the frame processing function. Consequently, a multi-service multiplexing system based on VLC was designed and implemented. The system enables hybrid transmission of audio signals (1–21.6 kHz) and character data (300–1200 bps) via a single channel, accurately reproducing both voice and text input over a 3.2 m communication range. The system, benefiting from the directional nature of visible light communication, exhibits inherent robustness to multipath-induced interference in dominant line-of-sight (LoS) scenarios and can be easily integrated into existing lighting networks. Featuring a simple architecture and cost-effective design, this solution shows promise for deployment in RF-sensitive areas requiring multi-service communication.

This article reports on the interrogation of fiber Bragg grating (FBG)-based sensors that have been multiplexed in a ladder topology. In each line of this topology, FBGs with different wavelengths are connected. In addition, delay fibers have been inserted between each line to enable reflections from different lines to be distinguished. Seven FBGs are interrogated simultaneously by applying time- and wavelength-division multiplexing techniques. To improve the signal-to-noise ratio of the weak reflected signals, the heterodyne detection technique is applied. Through the simulation of three different failure cases, we evaluate the fault detection capability of our method.