Written in English
A numerical method for the analysis of a non-uniform multi-conductor transmission-line structure consisting of a bundle of twisted-wire pairs (TWPs) excited by a plane-wave electromagnetic field is presented. The intended use of such numerical method is to evaluate the susceptibility of TWP bundles to radio frequency interference (RFI) in digital subscriber line (DSL) communication systems. In the past, crosstalk noise in TWP bundles has been successfully characterized by modeling TWPs as a cascade of short uniform transmission-line sections rotated continuously. The presented model is an extension of this approach capable of including the effects of RFI. Computed and measured results for a variety of TWP configurations of interest to DSL systems are presented. Furthermore, the presented numerical method is used to analyze the role that twisting non-uniformities play in the susceptibility analysis of TWPs.
|The Physical Object|
|Number of Pages||90|
Radio frequency interference (RFI) greatly increases the difficulty of channel equalization in a single-carrier based very-high-speed digital subscriber line (VDSL) system. In recent years, Digital subscriber line (DSL) technology has been gaining popularity as a high speed network access technology, capable of the delivery of multimedia services. A major impairment for DSL is impulse noise in the telephone line. However, evaluating the data errors caused by this noise is. Very-high-speed digital subscriber loop modems operate in frequency bands which coincide with many significant radio-frequency interference sources, particularly commercial AM radio. Generally, radio interference of DC transmission lines on rainy days is about 3 dB (μV/m) lower than that in fine weather. Radio interference varies with seasons. More specifically, it is relatively low in late fall and early winter, reaches its peak in summer, and stays at an average level in winter and early fall.
Radio Frequency Spectrum is a key distinguishing factor used to compare alternative mobile radio systems. Radio spectrum for communications ranges from approximately 30 Hz (termed Extremely Low Frequency [ELF]) to above GHz (termed Extremely High Frequency [EHF]). Because of its capability to provide very wide area coverage and pene-. c r,May27,,(studentversion) Motivation: complex exponentials are eigenfunctions Why frequency analysis? Complex exponential signals, which are described by a frequency value, are eigenfunctions or eigensignals of LTI systems. Period signals, which are important in signal processing, are sums of complex exponential Size: KB. common-mode filter should be tried first on TVs or VCRs connected to a cable system. An AC-line interference filter may help with electrical or radio interference. These items can be purchased locally or by mail order. Some interference cures must be applied to the internal circuitry of File Size: 57KB. The issue of radio frequency interference in Digital Subscriber Line (DSL) networks is of particular concern in urban areas with many strong radio sources nearby. This paper investigates in detail the mechanisms underlying the capacity reduction due to the presence of radio frequency signals from Amplitude Modulated (AM).
But it has taken on a special urgency as more wireless services, especially broadband digital ones, come on line; new digital services, such as WiFi and WiMax, are far less tolerant of interference than analog transmission modes (like AM and FM radio)/5(2). In this paper, a digital RFI (radio frequency interference) canceller for DMT (discrete multitone modulation)-based VDSL (very high-speed digital subscribe VLSI design of a digital RFI cancellation scheme for VDSL transceivers - IEEE Conference Publication. Clifford R. Merz, Robert H. Weisberg, in Coastal Ocean Observing Systems, Abstract. This chapter discusses the effects of spatial/temporal radio frequency interference (RFI) variations of two nearby WERA high-frequency (HF) radar sites deployed along the West Florida coast, initially observed via their uneven data storage fill rates. RFI variations impact site operational frequency. The book describes how interference can be managed so that radio systems co-exist, without harmful mutual effects, within a finite amount of spectrum. This is timely in view of the increasing proliferation of wireless systems. It covers both the processes, such as regional or international coordination, as well as the engineering principles/5(5).