Bandwidth (signal processing)

About: Bandwidth (signal processing) is a research topic. Over the lifetime, 48550 publications have been published within this topic receiving 600741 citations. The topic is also known as: Bandwidth (signal processing) & bandwidth.

Cellular telephone service using spread spectrum transmission

Abstract: A spread spectrum processing system that employs wide bandwidth spread spectrum radio transmissions overlaid over the existing cellular voice signals to simultaneously provide additional cellular services without causing objectionable interference to current users of the cellular voice channel. The spread spectrum radio transmissions also support a large number of low rate digital messages. Both vehicle location and messaging functions are obtained without sacrificing any of the existing voice channel capacity. The cell site processor is designed to share the existing cellular frequencies, real estate, antenna towers, antennas, and low noise amplifiers used in the cell site radio frequency receiver chain. The only additional cell site equipment is the spread spectrum signal processor. The processing system provides a means for achieving vehicle location accuracies that are improved by greater than two orders of magnitude over that which is possible by the current transmissions in that band. It provides a means of achieving transmit power control of the vehicle transmitter to combat the extremely large variation (dynamic range) of radio signal path loss to the receiving sites. It also provides a means of excising at the receiver the excessively strong conventional voice cellular signals that are not under power control which ordinarily might interfere with the successful reception of the new broadband signals.

Bandwidth and Latency Requirements for Smart Transmission Grid Applications

Abstract: The rapid increase of phasor measurements on the high voltage power system has opened opportunities for new applications to enhance the operation of the grid. To take advantage of the high sampling rates of these measurement data, these applications will require a high-bandwidth, networked communication system. The specifications for this next generation communication system that will overlay the continental power grids are under intense discussion at this time by organizations like the North-American Synchro-Phasor Initiative (NASPI). In this paper we present a method to simulate, design and test the adequacy of a communication system for a particular transmission grid. The main difference from typical communication system studies is that we formulate the communication requirements from the power grid application requirements, that is, the communication design, simulation and testing is from the viewpoint of the anticipated power applications. The method is demonstrated on a WECC 225 bus and a Polish 2383 bus transmission system models.

Dirty RF: a new paradigm

Abstract: The implementation challenge for new low-cost low-power wireless modem transceivers has continuously been growing with increased modem performance, bandwidth, and carrier frequency. Up to now we have been designing transceivers in a way that we are able to keep the analog (RF) problem domain widely separated from the digital signal processing design. However, with today's deep sub-micron technology, analog impairments-dirt effects-are reaching a new problem level which requires a paradigm shift in the design of transceivers. Examples of these impairments are phase noise, non-linearities, IQ imbalance, ADC impairments, etc. In the world of dirty RF we assume to design digital signal processing such that we can cope with a new level of impairments, allowing lee-way in the requirements set on future RF sub-systems. This paper gives an overview of the topic and presents analytical evaluations of the performance losses due to RF impairments as well as algorithms that allow to live with imperfect RF by compensating the resulting error effects using digital baseband processing

Filter bank modulation techniques for very high speed digital subscriber lines

Abstract: Multicarrier basis functions and related issues are overviewed in this article with an emphasis on filtered multitone (FMT) modulation for VDSL. The combination of filtering, small amounts of excess bandwidth, multicarrier channel partitioning, and some equalization are shown to allow a good match for spectrum management and performance challenges in VDSL transmission. The FMT basic functions are overviewed in the context of filter banks, with appropriate changes for nonzero excess bandwidth.

Detection of Generalized-Roughness Bearing Fault by Spectral-Kurtosis Energy of Vibration or Current Signals

Abstract: Generalized roughness is the most common damage occurring to rolling bearings. It produces a frequency spreading of the characteristic fault frequencies, thus making it difficult to detect with spectral or envelope analysis. A statistical analysis of typical bearing faults is proposed here in order to identify the spreading bandwidth related to specific conditions, relying on current or vibration measurements only. Then, a diagnostic index based on the computation of the energy in the previously defined bandwidth is used to diagnose bearing faults. The proposed method was validated experimentally with vibration signals, with robust and reliable results. The same procedure can be extended to current signals.