Multiplexing In Terms Research Articles

Beam-Space Multiplexing: Practice, Theory, and Trends, From 4G TD-LTE, 5G, to 6G and Beyond

In this article, the new term, namely beam-space multiplexing, is proposed for the former multi-layer beamforming for 4G TD-LTE in 3GPP releases. We provide a systematic overview of beam-space multiplexing from engineering and theoretical perspectives. First, we clarify the fundamental theory of beam-space multiplexing. Specifically, we provide a comprehensive comparison with antenna-space multiplexing in terms of theoretical analysis, channel state information acquisition, and engineering implementation constraints. Then, we summarize the key technologies and 3GPP standardization of beam-space multiplexing in 4G TD-LTE and 5G new radio (NR) in terms of multi-layer beamforming and massive beamforming, respectively. We also provide system-level performance evaluation of beam-space multiplexing schemes and field results from current commercial TD-LTE networks and field trial of 5G. The practical deployments of 4G TD-LTE and 5G cellular networks demonstrate the superiority of beam-space multiplexing within the limitations of implementation complexity and practical deployment scenarios. Finally, the future trends of beam-space multiplexing in 6G and beyond are discussed, including massive beamforming for extremely large-scale MIMO (XL-MIMO), low earth orbit (LEO) satellite communication, data-driven intelligent massive beamforming, and multi-target spatial signal processing, that is, joint communication and sensing, positioning, and so on.

Design and Implementation of Ternary Logic Circuits for VLSI Applications

This paper mainly concentrates on the design and implementation of ternary logic circuits. The ternary numeral system has its base as 3. Ternary logic will use three symbols, which are, 0,1 and 2. The ternary logic has significant merits over binary logic in designing digital circuits. In this paper, it is proposed to implement a half adder circuit using ternary 3 to 1 multiplexer. The main objective of the work is, to design and implement ternary logic circuits and to analyse the function of the ternary combinational circuits using mentor graphics tool in 90nm technology. This paper also compares the ternary half adder design using k-map method with the proposed ternary half adder using multiplexer in terms of power dissipation, propagation delay and transistor count.

Physical-layer security in fractional orbital angular momentum multiplexing under atmospheric turbulence channel.

In this paper, the physical layer security (PLS) of fractional orbital angular momentum (OAM) multiplexing under atmospheric turbulence channels is studied. Based on the PLS theory, the secrecy capacities and the probabilities of positive secrecy capacities of fractional OAM (FrOAM) multiplexing systems with different topological charge intervals are analyzed. The influence of the eavesdropping ratio and the power allocation on secrecy capacities are compared. The simulation results show that, under the finite aperture limitation, the FrOAM multiplexing technique provides higher security over the integer OAM multiplexing in terms of the total secrecy capacities under weak and medium turbulence.

An optimal design of QCA based 2n:1/1:2n multiplexer/demultiplexer and its efficient digital logic realization

Quantum-Dot Cellular Automata (QCA) is a radical nanotechnology, which works at Nanoscale. In this paper, an optimal design of 2n:1 Multiplexer (MUX) and 1:2n Demultiplexer (DeMUX) is presented. A new approach has been devised to implement efficient digital logic gates using the proposed 2n:1 multiplexer. To verify the functionality of the proposed structures some Boolean proofs are performed. A detailed comparison, structural evaluation and power analysis of the proposed multiplexer with recently robust designs are analyzed. This evaluates the performance of the proposed multiplexer in terms of cell count, area clock delays and energy dissipation as compared to traditional approaches. At temperature T = 2k, the energy dissipation is evaluated under the three separate tunneling energy levels (γ=0.5Ek,γ=1.0,Ek andγ=1.5Ek). New implementation and simulation results of the proposed 4n:1MUX and 1:4n DeMUX are developed using the proposed 2:1 MUX and 1:2 DeMux respectively. In addition, a novel concept of QCA based Multiplexing/Demultiplexing is presented. This paves way sharing a single communication link among the number of devices at nano-regime.

Capacity of Wavelength and Time Division Multiplexing for Quasi-Distributed Measurement Using Fiber Bragg Gratings

In this paper, an analysis of the use of wavelength and time division multiplexing techniques for quasi-distributed measurement in uniform fiber Bragg gratings is presented. To date, publications have concentrated on the determination of the maximum number of fiber Bragg gratings on one optical fiber using wavelength and time division multiplexing. In this paper, these techniques will be extended to determine the spectral width of wavelength division multiplexing in terms of the spectral width of the light emitting diode, the spectral width of the Bragg gratings, the measurement ranges of the individual sensors, and the guard band between two adjacent Bragg gratings. For time division multiplexing, a description of the time and power conditions are given. In particular the reflected power, first order crosstalk and chromatic dispersion have been considered. Finally, these relationships were applied to verify a design in a simulation using OptiSystem software.

When Virtual Meets Physical at the Edge

The wide deployment of virtualization in datacenters catalyzes the emergence of virtual traffic that delivers the network demands between the physical network and the virtual machines hosting clients' services. Virtual traffic presents new opportunities for reducing physical network demands, as well as challenges of increasing management complexity. Given the plethora of prior art on virtualization technologies in datacenters, surprisingly little is still known about such virtual traffic, and its dependence on the physical network and virtual machines. This paper provides a multi-faceted analysis of the patterns and impacts of multiplexing the virtual traffic onto the physical network, particularly from the perspective of the network edge. We use a large collection of field data from production datacenters hosting a large number of diversified services from multiple enterprise tenants. Our first focus is on uncovering the temporal and spatial characteristics of the virtual and physical traffic, i.e., network demand growth and communication patterns, with special attention paid to the traffic of migrating virtual machines. The second focus is on characterizing the effect of network multiplexing in terms of communication locality, traffic load heterogeneity, and the dependency on CPU processing power at the edges of the network. Last but not least, we conduct a mirroring analysis on service QoS, defined by the service unavailability induced by network related issues, e.g., loads. We qualitatively and quantitatively discuss the implications and opportunities that virtual traffic presents for network capacity planning of virtualized networks and datacenters.

Determination of Binding Specificities in Highly Multiplexed Bead-based Assays for Antibody Proteomics

One of the major challenges of antibody-based proteomics is the quality assurance of the generated antibodies to ensure specificity to the target protein. Here we describe a single tube multiplex approach to simultaneously analyze the binding of antibodies to a large number of different antigens. This bead-based assay utilizes the full multiplexing capacity theoretically offered by the Luminex suspension array technology. A protocol for an increased coupling throughput for the immobilization of antigens was developed and used to set up complex and stabile 100-plex bead mixtures. The possibility of using a two-dimensional multiplexing, in terms of high numbers of both analytes and samples or as in this case antigens and antibodies, enables the specificity of 96 antibodies versus 100 different antigens to be determined in 2 h. This high throughput analysis will potentially have great impact on the possibility for the utilization of different antibody proteomics approaches where the quality assessment of antibodies is of the utmost importance.

Analysis and compensation of the bitline multiplexer in SRAM current sense amplifiers

Current sensing in SRAMs is very promising to achieve high-speed operation in low-voltage applications. However, so far, a main limitation of the practical use of current sense amplifiers is the finite resistance of the bitline multiplexer (MUX). In this paper, the MUX itself and its influence on two types of current sense amplifiers is analyzed. It is shown that the MUX causes a significant performance degradation. A principle is presented to compensate for the bitline multiplexer by means of a current sense amplifier with improved feedback structure. The proposed solution is implemented in a 512/spl times/24 bit SRAM macro in 0.18-/spl mu/m 1.8-V CMOS. It is shown by theory and measurements that, using the proposed circuit, it is possible to fully compensate for the MUX in terms of speed and signal amplitude with only little layout area penalty. A speed improvement due to the compensation of typically 0.5 ns is measured.

Performance Analysis of an ATM Multiplexer with Multiple QoS VBR Traffic

In this paper, we propose a new queuing model, MMDP/MMDP/1/K, for an asynchronous transfer mode (ATM) multiplexer with multiple quality of service (QoS) variable bit rate (VBR) traffic in broadband-integrated services digital network (B-ISDN). We use the Markov Modulated Deterministic Process (MMDP) to approximate the actual arrival process and another MMDP for service process. Using queuing analysis, we derive a formula for the cell loss probability of the ATM multiplexer in terms of the limiting probabilities of a Markov chain. The cell loss probability can be used for connection admission control in ATM multiplexer and the calculation of equivalent bandwidth for arrival traffic. The major advantages of this approach are simplicity in analysis, accuracy of analysis by comparison of simulation, and numerical stability.

Time division multiplexing using optical switches

Design considerations are considered for optical time-division multiplexing in terms of bandwidth requirements for the modulators and switches for a particular multiplexing scheme and the corresponding drive signals are derived using a time-domain approach. It is shown that these requirements are stricter than expected from simple considerations. Different types of multiplexing schemes are analyzed and are shown to behave differently due to varying chirping properties; this chirping is also calculated. A comparison to nonmultiplexed systems is made.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>