Intermodulation Distortion in RF Connectors
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Loudspeaker FM and AM Distortion an 10
Loudspeaker FM and AM Distortion AN 10 Application Note to the KLIPPEL R&D SYSTEM The amplitude modulation of a high frequency tone f1 (voice tone) and a low frequency tone f2 (bass tone) is measured by using the 3D Distortion Measurement module (DIS) of the KLIPPEL R&D SYSTEM. The maximal variation of the envelope of the voice tone f1 is represented by the top and bottom value referred to the averaged envelope. The amplitude modulation distortion (AMD) is the ratio between the rms value of the variation referred to the averaged value and is comparable to the modulation distortion Ld2 and Ld3 of the IEC standard 60268 provided that the loudspeaker generates pure amplitude modulation of second- or third-order. The measurement of amplitude modulation distortion (AMD) allows assessment of the effects of Bl(x) and Le(x) nonlinearity and radiation distortion due to pure amplitude modulation without Doppler effect. CONTENTS: 1 Method of Measurement ............................................................................................................................... 2 2 Checklist for dominant modulation distortion ............................................................................................... 3 3 Using the 3D distortion measurement (DIS) .................................................................................................. 4 4 Setup parameters for DIS Module .................................................................................................................. 4 5 Example ......................................................................................................................................................... -
Performance Improvement of Papr Reduction for Ofdm Signal in Lte System
International Journal of Wireless & Mobile Networks (IJWMN) Vol. 5, No. 4, August 2013 PERFORMANCE IMPROVEMENT OF PAPR REDUCTION FOR OFDM SIGNAL IN LTE SYSTEM Md. Munjure Mowla1 and S.M. Mahmud Hasan2 1Department of Electrical & Electronic Engineering, Rajshahi University of Engineering & Technology, Rajshahi, Bangladesh [email protected] 2 Department of Electronics & Telecommunication Engineering, Rajshahi University of Engineering & Technology, Rajshahi, Bangladesh [email protected] ABSTRACT Orthogonal frequency division multiplexing (OFDM) is an emerging research field of wireless communication. It is one of the most proficient multi-carrier transmission techniques widely used today as broadband wired & wireless applications having several attributes such as provides greater immunity to multipath fading & impulse noise, eliminating inter symbol interference (ISI), inter carrier interference (ICI) & the need for equalizers. OFDM signals have a general problem of high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. The drawback of high PAPR is that the dynamic range of the power amplifier (PA) and digital-to-analog converter (DAC). In this paper, an improved scheme of amplitude clipping & filtering method is proposed and implemented which shows the significant improvement in case of PAPR reduction while increasing slight BER compare to an existing method. Also, the comparative studies of different parameters will be covered. KEYWORDS Bit Error rate (BER), Complementary Cumulative Distribution Function (CCDF), Long Term Evolution (LTE), Orthogonal Frequency Division Multiplexing (OFDM) and Peak to Average Power Ratio (PAPR). 1. INTRODUCTION Long term evolution (LTE) is the one of the latest steps toward the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile telephone networks. -
Sm.1446-0 (04/2000)
Recommendation ITU-R SM.1446-0 (04/2000) Definition and measurement of intermodulation products in transmitter using frequency, phase, or complex modulation techniques SM Series Spectrum management ii Rec. ITU-R SM.1446-0 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http://www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http://www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. -
Statistical Distortion: Consequences of Data Cleaning
Statistical Distortion: Consequences of Data Cleaning Tamraparni Dasu Ji Meng Loh AT&T Labs Research AT&T Labs Research 180 Park Avenue 180 Park Avenue Florham Park, NJ 07932 Florham Park, NJ 07932 [email protected] [email protected] ABSTRACT There is considerable research in the database community We introduce the notion of statistical distortion as an essen- on varied aspects of data quality, data repair and data clean- tial metric for measuring the effectiveness of data cleaning ing. Recent work includes the use of machine learning for strategies. We use this metric to propose a widely applica- guiding database repair [14]; inferring and imputing miss- ble yet scalable experimental framework for evaluating data ing values in databases [10] ; resolving inconsistencies using cleaning strategies along three dimensions: glitch improve- functional dependencies [6]; and for data fusion [8]. ment, statistical distortion and cost-related criteria. Exist- From an enterprise perspective, data and information qual- ing metrics focus on glitch improvement and cost, but not ity assessment has been an active area of research as well. on the statistical impact of data cleaning strategies. We The paper [12] describes subjective and objective measures illustrate our framework on real world data, with a compre- for assessing the quality of a corporation’s data. An overview hensive suite of experiments and analyses. of well known data quality techniques and their comparative uses and benefits is provided in [2]. A DIMACS/CICCADA 1 workshop on data quality metrics featured a mix of speak- 1. INTRODUCTION ers from database and statistics communities. It covered a Measuring effectiveness of data cleaning strategies is al- wide array of topics from schema mapping, graphs, detailed most as difficult as devising cleaning strategies. -
En 300 720 V2.1.0 (2015-12)
Draft ETSI EN 300 720 V2.1.0 (2015-12) HARMONISED EUROPEAN STANDARD Ultra-High Frequency (UHF) on-board vessels communications systems and equipment; Harmonised Standard covering the essential requirements of article 3.2 of the Directive 2014/53/EU 2 Draft ETSI EN 300 720 V2.1.0 (2015-12) Reference REN/ERM-TG26-136 Keywords Harmonised Standard, maritime, radio, UHF ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N° 348 623 562 00017 - NAF 742 C Association à but non lucratif enregistrée à la Sous-Préfecture de Grasse (06) N° 7803/88 Important notice The present document can be downloaded from: http://www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at http://portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: https://portal.etsi.org/People/CommiteeSupportStaff.aspx Copyright Notification No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm except as authorized by written permission of ETSI. -
DTV Interference Rejection Thresholds Are Shown on the Plot As a Reference
Interference Rejection Thresholds of Consumer Digital Television Receivers Available in 2005 and 2006 March 30, 2007 Technical Research Branch Laboratory Division Office of Engineering and Technology Federal Communications Commission OET Report Prepared by: FCC/OET 07-TR-1003 Stephen R. Martin ACKNOWLEDGEMENTS The author gratefully acknowledges the following contributions to this work. Mark Hryszko of the Digital Television group of Advanced Micro Devices provided the “Muddy Waters” RF vector file (mathematically derived from an MPEG2 transport stream) that was used with the Wavetech WS2100 RF player to provide a “desired signal” for the final few tests performed for this report. John Gabrysch of the Commission’s Media Bureau set up and evaluated the performance of the Rohde and Schwarz SFU DTV signal generator and developed channel assignment files for the instrument. The work of Charles Rhodes on third-order intermodulation inspired the paired-signal tests in this project. Gary Sgrignoli of MSW provided a fast-track DTV education to prepare the author for the prequel to this project. The author thanks the following Commission employees for reviewing drafts of this document: Alan Stillwell, Rashmi Doshi, and William Hurst (Office of Engineering and Technology); Doug Miller, John Raymond, and Steve DeSena (Enforcement Bureau); Richard Engelman and Sankar Persaud (International Bureau). The author also acknowledges the support of wife, Dr. Bonnie Dorr, through many long hours spent completing this work. i TABLE OF CONTENTS EXECUTIVE SUMMARY -
Spatial Characteristics of Distortion Radiated from Antenna Arrays with Transceiver Nonlinearities Christopher Mollen,´ Ulf Gustavsson, Thomas Eriksson, Erik G
1 Spatial Characteristics of Distortion Radiated from Antenna Arrays with Transceiver Nonlinearities Christopher Mollen,´ Ulf Gustavsson, Thomas Eriksson, Erik G. Larsson Abstract—The distortion from massive MIMO (multiple-input– paper is to give a rigorous description of the distortion created multiple-output) base stations with nonlinear amplifiers is studied by nonlinear hardware in multi-antenna transmitters, and to and its radiation pattern is derived. The distortion is analyzed quantify to which degree the distortion combines coherently. both in-band and out-of-band. By using an orthogonal Her- mite representation of the amplified signal, the spatial cross- The contribution of this paper is to give a rigorous correlation matrix of the nonlinear distortion is obtained. It continuous-time system model of a multi-antenna transmitter shows that, if the input signal to the amplifiers has a dominant for both single-carrier and OFDM (orthogonal frequency- beam, the distortion is beamformed in the same way as that beam. division multiplexing) transmission that uses digital precoding When there are multiple beams without any one being dominant, to beamform to multiple users. Orthogonal polynomials are it is shown that the distortion is practically isotropic. The derived theory is useful to predict how the nonlinear distortion will used to partition the amplified transmit signal into a desired behave, to analyze the out-of-band radiation, to do reciprocity signal—the linearly amplified signal—and a distortion term calibration, and to schedule users in the frequency plane to that is uncorrelated from the desired signal in order to analyze minimize the effect of in-band distortion. -
Third Order Intercept Point
Third Order Intercept Point Third order intercept point (IP3) is a term sometimes heard when amateur radio operators are discussing the qualities, or lack thereof, of a receiver. Third order intercept point is just one of several specifications that can be used to judge the quality of a receiver. Some of the other specifications such as signal to noise ratio and selectivity are relatively easy to understand and interpret. It should be pointed out that in many instances complete specifications are not provided in manufacturing literature and must be obtained from independent testing sources or through other means. The term is somewhat involved and many people don’t actually know what it really means. Most who us it do know that the higher the number the better the receiver. Numbers may range from something like –10db to something in the range of +30 to 40 db. In very simple terms IP3 is a way of expressing how well a receiver separates two closely spaced signals. However, there is a second part that creates confusion. This second part will be the basis for our discussion. It is based one the two closely spaced signals just mentioned. Lets be clear that IP3 is a theoretical point that is calculated and is not measured as is specifications such as selectivity. All modern receivers have at least one intermediate frequency (IF) between their antenna input and their audio amplification stages which drive the speaker. Most have at least two and in some models three mixers. When a single signal is received and processed it of course can be easily heard and understood. -
Intermodulation, Phase Noise and Dynamic Range AN156-2 the Radio Receiver Operates in a Non-Benign Environment
Intermodulation, Phase Noise and Dynamic Range AN156-2 The radio receiver operates in a non-benign environment. It needs to pick out a very weak wanted signal from a background of noise at the same time as it rejects a large number to much stronger unwanted signals. These may be present either fortuitously as in the case of the overcrowded radio spectrum, or because of deliberate action, as in the case of Electronic Warfare. In either case, the use of suitable devices may considerably influence the job of the equipment designer. Dynamic range is a 'catch all' term, applied to limitations of intermodulation or phase noise: it has many definitions depending upon the application. Firstly, however, it is advisable to define those terms which limit the dynamic range of a receiver. INTERMODULATION This is described as the 'result of a non linear transfer upon the actual transfer function of the device and thus vary characteristic’. The mathematics have been exhaustively with device type. For example a truly square law device such treated and Ref.1 is recommended to those interested. as a perfect FET, produces no third order products (2f2 - f1, 2f1 The effects of intermodulation are similar to those produced - f2). Intermodulation products are additional to the harmonics by mixing and harmonic production, in so far as the application 2f1, 2f2, 3f1, 3f2 etc. Fig.1 shows intermodulation products of two signals of frequencies f1 and f2 produce outputs of 2f2 - diagrammatically. f1 2f1 - f2, 2f1, 2f2 etc. The levels of these signals are dependent Amplitude 2 2 2 1 1 1 f1 f2 2f1 2 2f2 -f -f Frequency +f 1 2 -3f -2f -2f -3f 1 f 1 1 2 2 2f 2f 4f 3f 3f 4f Fig. -
WAVEFORM TESTING Victor Nicholson CTIC the Urban Institute
WAVEFORM TESTING Victor Nicholson CTIC The Urban Institute Washington, DC have resulted in many complaints by broadcasters, of excessive degradation of their local channels when carried by a cable system. This is especially true of local UHF signals Abstract where interference is often introduced at the Existing subjective and frequency domain head end by the mixing of harmonics of the local testing procedures are shown to have major oscillator from the converter with other UHF. weaknesses in ensuring the delivery of accep Distribution system testing has little value in table television pictures to cable subscribers. resolving these complaints. Recommended, instead, are waveform test techniques using VIT signals as generated by Waveform test procedures have had little the networks. Applications of measurement application in the past to the cable industry as procedures and performance objectives are it was expensive to introduce these test signals discussed for echoes, noise and chrominance I at the head end. In addition, they provided no luminance gain and delay. information as to the quality of incoming tele ·,rision signals. Equipment was necessary to demodulate each channel, insert these diagnostic signals and then remodulate them; all of which added degradation to the desired TV signal. Today, waveform test procedures are applicable to the cable industry as these diagnostic signals are already injected into the Waveform testing of television signals four major network transmissions; ABC, CBS, introduces a valuable concept to the performance NBC, and PBS. This eliminates the need for testing and maintenance of R. F. distribution a cable operator to own expensive equipment to systems; including cable, satellite and fiber introduce these signals. -
Nonlinear Distortion Identification Based on Intra-Wave Frequency
Appl. Math. Inf. Sci. 6, No. 3, 689-695 (2012) 689 Applied Mathematics & Information Sciences An International Journal ⃝c 2012 NSP Natural Sciences Publishing Cor. Nonlinear Distortion Identification based on Intra-wave Frequency Modulation Yutian Wang1, Hui Wang1 and Qin Zhang1 Information Engineering School, Communication University of China, Beijing 100024, China Received: Apr. 8, 2012; Revised May 4, 2012; Accepted May 26, 2012 Published online: 1 September 2012 Abstract: Recently, most of the methods used to measure and analysis signal property are based on the linear transform theory, such as FFT, STFT, wavelet, etc. Unfortunately, these methods usually cause meaningless results when it is used to analysis nonlinear signal. In this paper, we use Hilbert-Huang transform (HHT) to review the nonlinear distortion and define a novel nonlinear parameter named Nonlinear Distortion Degree (NDD) which is based on intra-wave frequency modulation measurement. The loudspeaker model simulations are used to illustrate the intra-wave frequency modulation caused by nonlinear distortion. The results agree that NDD can reveal more accurate and physical meaningful nonlinear distortion characteristic. Keywords: Nonlinear distortion, HHT, intra-wave frequency modulation, loudspeaker. 1. Introduction Huang et. al. raised a novel signal processing method named Hilbert-Huang Transform (HHT) based on EMD (Empirical Mode Decomposition), which is suitable for In the signal analysis field, Fourier based analysis meth- analyzing nonlinear and non-stationary signal [2]. Differ- ods such as FFT and STFT take the dominated position. ent from the traditional signal processing methods, the H- However, there are some crucial restrictions of the Fourier HT is an adaptive decomposition method and can yield spectral analysis: the system must be linear and the data more physical results. -
On Nicam Datacasting
ON NICAM DATACASTING Cristian Ciressan, Lucian Prodan EPFL CH-1015 Ecublens, Suisse Emails: [email protected]fl.ch, prodan@epfl.ch Abstract Data transmission technologies changes rapidly these days due to increased re- quirements in bandwidth and reliability. NICAM standard (which stands for Near Instantaneous Companded Audio Multiplex ) was designed to be a digital audio transmission standard and later it was used by the BBC to convey digital stereo sound for TV. It was obvious that allowing data transmission would be, if not a must, at least a welcome feature and in consequence it was extended to allow raw data or mixed data and sound to be transmitted. NICAM is feasible for terrestrial, cable, microwave links and satellites. This paper introduces some basic notions about NICAM datacasting and presents the results of a project whose aim was to design two PC-cards that allow unidirectional data transmission using the NICAM standard. Keywords: NICAM 728, subcarrier, QPSK 1. Introduction NICAM (or to give it its full name, NICAM 728) was invented during the early 1980’s by the BBC Research Center, Kingswood Warren. It was first applied to the British ”System I” 625 line PAL colour TV broadcasting system, and premiered in 1986 on the ”First Night of the Proms” concert program. Since that time it has been slightly modified by the Nordic broadcasters to work with the more common “System B/G” used over much of continental Europe. It has been demonstrated to work also with “System D/K” used in some countries of eastern Europe , and with “System L” used in France.