DOCSLIB.ORG

Data Transmission Using Hierarchical Modulation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Data Transmission Using Hierarchical Modulation Europäisches Patentamt *EP001406421A2* (19) European Patent Office Office européen des brevets (11) EP 1 406 421 A2 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.7: H04L 27/34 07.04.2004 Bulletin 2004/15 (21) Application number: 03256098.9 (22) Date of filing: 29.09.2003 (84) Designated Contracting States: • Hayashi, Takahiro, c/o NTT DoCoMo Inc. AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Tokyo 100-6150 (JP) HU IE IT LI LU MC NL PT RO SE SI SK TR • Futakata, Toshiyuki, c/o NTT DoCoMo Inc. Designated Extension States: Tokyo 100-6150 (JP) AL LT LV MK (74) Representative: (30) Priority: 03.10.2002 JP 2002291571 Luckhurst, Anthony Henry William MARKS & CLERK, (71) Applicant: NTT DoCoMo, Inc. 57-60 Lincoln’s Inn Fields Tokyo 100-6150 (JP) London WC2A 3LS (GB) (72) Inventors: • Moon, Sung Uk, NTT DoCoMo Inc. Tokyo 100-6150 (JP) (54) Data transmission using hierarchical modulation (57) A modulation device comprises a modulation ta having been subjected to hierarchical modulation us- unit (2) that modulates data in a hierarchical manner us- ing multiple types of modulation techniques, and a de- ing multiple types of modulation techniques, and a trans- modulation unit (6) that demodulates the hierarchical mission unit (3) that transmits the hierarchically modu- modulation data using a demodulation technique corre- lated data. A demodulation device comprises a receiv- sponding to a specific hierarchy of the hierarchical mod- ing unit (4) that receives the hierarchical modulation da- ulation data. EP 1 406 421 A2 Printed by Jouve, 75001 PARIS (FR) 1 EP 1 406 421 A2 2 Description with the above-described QPSK under the same trans- mission rate, the occupied band-width of 16-QAM is nar- BACKGROUND OF THE INVENTION rower than that of QPSK. This means that 16-QAM is more effective to realize high-speed digital data trans- [0001] The present invention generally relates to 5 mission. However, 16-QAM is easily influenced by fad- modulation and demodulation in digital data transmis- ing, which is the phenomenon of sharp fluctuation in in- sion, and more particularly to a modulation and demod- tensity level of a radio wave due to environmental ulation technique capable of dealing with multiple types change including time and the distance between the of modulation based on hierarchical modulation. transmitter and the receiver. The 16-QAM is mainly used [0002] In recent radio communications, digital modu- 10 for digital MCA (telecommunications business). lation techniques are employed in, for instance, cellular [0007] Since the above-described two modulation phone networks, BS television broadcast, and other dig- techniques, QPSK and 16-QAM, are used in digital mo- ital communication networks. Known modulation tech- bile telecommunications, hardware capable of dealing niques used in digital mobile communications include with these two modulation techniques is desirable. Such quadrature phase shift keying (QPSK) and quadrature 15 hardware is advantageous for both users and manufac- amplitude modulation (QAM). turers, reducing the cost of components and the space [0003] Quadrature phase shift keying (QPSK) is a for accommodating the hardware, while improving op- modulation technique that uses two carriers out of erability. From this standpoint, JPA 9-27426 proposes a phase by 90 degrees (that is, quarternary signal states), demodulation technique for demodulating both QAM allowing 2 bits/symbol transmission. FIG. 1 is a QPSK 20 modulation signals and QPSK modulation signals in one signal constellation, in which the in-phase component system. and the guadrature component of the QPSK modulation [0008] However, in spite of the existence of multiple signal are expressed in the phase plane defined by the modulation techniques used in digital telecommunica- I-axis (representing the real number) and the Q-axis tions, the transmission ability and the receiving ability (representing the imaginary number). The signal con- 25 are not always consistent with each other. If a receiver stellation is also called "signal diagram". In QPSK mod- is capable of dealing with only QPSK modulation sig- ulation, modulation signals with four different phases nals, 16-QAM modulation signals transmitted from a are arranged at the vertexes of a square. In other words, transmitter cannot be demodulated. To overcome this the transmission signal is represented by one of the four problem, a 16-QAM demodulator has to be furnished in phases. 30 the receiver, in addition to the QPSK demodulator, or [0004] Another type of QPSK modulation is pi/4-shift alternatively, a system proposed in JPA 9-275426 is re- QPSK, which is derived from the above-described quired. The former method causes the circuit scale and QPSK and used in personal digital cellular (PDC) the cost to increase because an extra demodulator has phones based on the second generation mobile com- to be added to the receiver. The latter method provides munications standard. With pi/4-shift QPSK, the phase 35 two independent signal paths, one functioning as a QAM of the carrier rotates by pi/4 per symbol, providing quar- demodulator when receiving a QAM modulation signal, ternary signal states. and the other functioning as a QPSK demodulator when [0005] In W-CDMA in FDD mode, which is one of the receiving a QPSK modulation signal. One of these two radio transmission protocols used in the third generation demodulation types is selected depending on the mod- cellular systems based on the International Mobile Tel- 40 ulation type of the received signal. Accordingly, it is es- ecommunications-2000 (IMT-2000) standard, BPSK sential to furnish the functions of a QAM demodulator (binary phase shift keying) is used for uplink data mod- and a QPSK demodulator in the circuit structure. ulation, while QPSK is used for downlink data modula- tion. In TDD mode, QPSK is employed for data modu- SUMMARY OF THE INVENTION lation on both uplink and downlink. 45 [0006] Another known modulation technique is [0009] The present invention is conceived to over- 16-QAM (quadrature amplitude modulation), which al- come the above-described problems, and it is an object lows 4 bits/symbol data transmission using a combina- of the invention to provide a modulation/demodulation tion of phase and amplitude of the carrier representing technique that allows received data to be demodulated one of sixteen (16) four-bit patterns. FIG. 2 is an exam- 50 according to the demodulation ability of the receiver ple of a 16-QAM signal constellation. With 16-QAM, four even if the demodulation ability on the receiving side is bits (16 patterns) of an input sequence are divided into not totally consistent with the modulation functions of four 2-bit patterns. The two carriers out of phase by 90 the transmission side apparatus. degrees are amplitude-modulated in the respective four [0010] To achieve the object, in one aspect of the in- signal states, and synthesized. The constellation plotted 55 vention, a modulation device is furnished with a hierar- after the amplitude modulation is shown in FIG. 2. The chical modulation function. To be more precise, the divisions on the I-axis and the Q-axis are -0.9487, modulation device comprises a modulation unit that -0.3162, 0.3162, and 0.9487. Comparing the 16-QAM modulates data in a hierarchical manner using multiple 2 3 EP 1 406 421 A2 4 types of modulation techniques, and a transmission unit modulation functions, the optimum demodulation type that transmits the hierarchically modulated data. is selected, taking into account the propagation environ- [0011] The modulation device further comprises a ment and other factors. Consequently, telecommunica- sampling pattern generating unit that generates a sam- tions can be maintained without undesirable disconnec- pling pattern for each of the modulation techniques. The 5 tion even if the propagation environment abruptly sampling pattern defines a sampling space for quantiz- changes. ing said data in accordance with each of said modulation techniques. In this case, the modulation unit modulates BRIEF DESCRIPTION OF THE DRAWINGS said data in the hierarchical manner using a digital signal sampled based on the sampling pattern. 10 [0019] [0012] The sampling pattern defines the sampling space of a carrier used in, for example, multi-phase FIG. 1 is an example of a QPSK signal constellation; phase shift keying or multi-value quadrature amplitude FIG. 2 is an example of a 16-QAM signal constella- modulation. tion; [0013] Preferably, the transmission unit transmits the 15 FIG. 3 illustrates the structure of the modulation and sampling pattern together with the hierarchically modu- demodulation device according to an embodiment lated data. of the invention; [0014] In another aspect of the invention, a demodu- FIG. 4 is a block diagram of the modulator included lation device that receives and demodulates hierarchi- in the modulation and demodulation device shown cal modulation data is provided. The demodulation de- 20 in FIG. 1; vice comprises a receiving unit that receives hierarchi- FIG. 5 is a block diagram of the demodulator includ- cal modulation data having been subjected to hierarchi- ed in the modulation and demodulation device cal modulation using multiple types of modulation tech- shown in FIG. 1; niques, and a demodulation unit that demodulates the FIG. 6 is a graph showing an example of hierarchi- hierarchical modulation data using a demodulation tech- 25 cal modulation carried out by the modulator shown nique corresponding to a specific hierarchy of the hier- in FIG. 4; archical modulation data. FIG. 7 is a table of a set of 16-QAM modulation sig- [0015] Preferably, the demodulation unit is furnished nals; with multiple types of demodulation techniques, and in FIG. 8 is a table of sampled transmission data mod- this case, the demodulation device further comprises a 30 ulated by 16-QAM; demodulation type selection unit that selects one of the FIG.
Load more

Recommended publications
  • CS647: Advanced Topics in Wireless Networks Basics
    CS647: Advanced Topics in Wireless Networks Basics of Wireless Transmission Part II Drs. Baruch Awerbuch & Amitabh Mishra Computer Science Department Johns Hopkins University CS 647 2.1 Antenna Gain For a circular reflector antenna G = η ( π D / λ )2 η = net efficiency (depends on the electric field distribution over the antenna aperture, losses such as ohmic heating , typically 0.55) D = diameter, thus, G = η (π D f /c )2, c = λ f (c is speed of light) Example: Antenna with diameter = 2 m, frequency = 6 GHz, wavelength = 0.05 m G = 39.4 dB Frequency = 14 GHz, same diameter, wavelength = 0.021 m G = 46.9 dB * Higher the frequency, higher the gain for the same size antenna CS 647 2.2 Path Loss (Free-space) Definition of path loss LP : Pt LP = , Pr Path Loss in Free-space: 2 2 Lf =(4π d/λ) = (4π f cd/c ) LPF (dB) = 32.45+ 20log10 fc (MHz) + 20log10 d(km), where fc is the carrier frequency This shows greater the fc, more is the loss. CS 647 2.3 Example of Path Loss (Free-space) Path Loss in Free-space 130 120 fc=150MHz (dB) f f =200MHz 110 c f =400MHz 100 c fc=800MHz 90 fc=1000MHz 80 Path Loss L fc=1500MHz 70 0 5 10 15 20 25 30 Distance d (km) CS 647 2.4 Land Propagation The received signal power: G G P P = t r t r L L is the propagation loss in the channel, i.e., L = LP LS LF Fast fading Slow fading (Shadowing) Path loss CS 647 2.5 Propagation Loss Fast Fading (Short-term fading) Slow Fading (Long-term fading) Signal Strength (dB) Path Loss Distance CS 647 2.6 Path Loss (Land Propagation) Simplest Formula: -α Lp = A d where A and
    [Show full text]
  • Criteria for Choosing Line Codes in Data Communication
    ISTANBUL UNIVERSITY – YEAR : 2003 (843-857) JOURNAL OF ELECTRICAL & ELECTRONICS ENGINEERING VOLUME : 3 NUMBER : 2 CRITERIA FOR CHOOSING LINE CODES IN DATA COMMUNICATION Demir Öner Istanbul University, Engineering Faculty, Electrical and Electronics Engineering Department Avcılar, 34850, İstanbul, Turkey E-mail: [email protected] ABSTRACT In this paper, line codes used in data communication are investigated. The need for the line codes is emphasized, classification of line codes is presented, coding techniques of widely used line codes are explained with their advantages and disadvantages and criteria for chosing a line code are given. Keywords: Line codes, correlative coding, criteria for chosing line codes.. coding is either performed just before the 1. INTRODUCTION modulation or it is combined with the modulation process. The place of line coding in High-voltage-high-power pulse current The transmission systems is shown in Figure 1. purpose of applying line coding to digital signals before transmission is to reduce the undesirable The line coder at the transmitter and the effects of transmission medium such as noise, corresponding decoder at the receiver must attenuation, distortion and interference and to operate at the transmitted symbol rate. For this ensure reliable transmission by putting the signal reason, epecially for high-speed systems, a into a form that is suitable for the properties of reasonably simple design is usually essential. the transmission medium. For example, a sampled and quantized signal is not in a suitable form for transmission. Such a signal can be put 2. ISSUES TO BE CONSIDERED IN into a more suitable form by coding the LINE CODING quantized samples.
    [Show full text]
  • Optimal Multiplexed Hierarchical Modulation for Unequal Error Protection of Progressive Bit Streams
    UC San Diego UC San Diego Previously Published Works Title Optimal Multiplexed Hierarchical Modulation for Unequal Error Protection of Progressive Bit Streams Permalink https://escholarship.org/uc/item/9gc392b0 Authors Chang, S.-H. Rim, M Cosman, P C et al. Publication Date 2009-11-01 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Optimal Multiplexed Hierarchical Modulation for Unequal Error Protection of Progressive Bit Streams Seok-Ho Chang†, Minjoong Rim‡, Pamela C. Cosman† and Laurence B. Milstein† †ECE Dept., University of California at San Diego, La Jolla, CA 92093, USA ‡ICE Dept., Dongguk University, Seoul, Korea Abstract—Progressive image and scalable video have gradual quality. Since these progressive transmissions have gradual differences of importance in their bitstreams, which can benefit differences of importance in their bitstreams, a large number from multiple levels of unequal error protection (UEP). Though of error protection levels are required. However, hierarchical hierarchical modulation has been intensively studied as an UEP approach for digital broadcasting and multimedia transmission, modulation can achieve only a limited number of UEP levels methods of achieving a large number of UEP levels have rarely for a given constellation size. For example, hierarchical 16 been studied. In this paper, we propose a multilevel UEP system QAM provides two levels of UEP, and hierarchical 64 QAM using multiplexed hierarchical quadrature amplitude modulation yields at most three levels [11]. In the DVB-T standard, video (QAM) for progressive transmission over mobile radio channels. data encoded by MPEG-2 consists of two different layers, We suggest a specific way of multiplexing, and prove that multiple levels of UEP are achieved by the suggested method.
    [Show full text]
  • (12) Patent Application Publication (10) Pub. No.: US 2004/0131130A1 Shor Et Al
    US 2004O131130A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2004/0131130A1 Shor et al. (43) Pub. Date: Jul. 8, 2004 (54) SYSTEM AND METHOD FOR MULTI-BAND (60) Provisional application No. 60/404,070, filed on Aug. ULTRA-WIDE BAND SIGNAL GENERATORS 16, 2002. Provisional application No. 60/450,737, filed on Feb. 28, 2003. (76) Inventors: Gadi Shor, Tel-Aviv (IL); David Yaish, Tel-Aviv (IL); Yaron Knobel, Publication Classification Givat-Shmuel (IL); David Meshulam, Hod-Hasharon (IL); Zeev Rubin, (51) Int. Cl. ................................................. H04L 27/20 Alphei-Mcnashe (IL); Benny Blumer, Kfar-Saba (IL) (52) U.S. Cl. .............................................................. 375/308 Correspondence Address: BROWN, RAYSMAN, MILLSTEIN FELDER & STEINER LLP 9 9 (57) ABSTRACT 900 THIRDAVENUE NEW YORK, NY 10022 (US) The present invention provides Systems and methods relat ing to ultra-wide band communications. A method is pro (21) Appl. No.: 10/643,108 Vided for transmitting information using ultra-wide band transmission. The method includes allocating, for Signal (22)22) FileFilled: Aug.ug. 18,185, 2003 transmission, each of a plurality of frequencys Sub-bands. Related U.S. Application Data The method further includes sending an ultra-wide band transmission comprising the information by transmitting a (63) Continuation-in-part of application No. 10/389,789, burst symbol cycle Signal over each of the plurality of filed on Mar. 17, 2003. frequency Sub-bands. 10560Mhz. 1320 MHz 213 Data Y1 2O2 Out 5280,5060Hz Clk Z 211 Ref 210 RF Out MHz 1012OMZ Z Channel IFMHz :253 5280 5060 88O 3960 528O 5060 440 5280 5060 0 4840 5280 5060 5280 5060 5940 5280 5060 1320 6160 5280 5060 1760 6600 Patent Application Publication Jul.
    [Show full text]
  • 192620010 Mobile & Wireless Networking Lecture 2: Wireless
    192620010 Mobile & Wireless Networking Lecture 2: Wireless Transmission (2/2) [Schiller, Section 2.6 & 2.7] [Reader Part 1: OFDM: An architecture for the fourth generation] Geert Heijenk Mobile and Wireless Networking 2013 / 2014 Outline of Lecture 2 q Wireless Transmission (2/2) q Modulation q Spread Spectrum q Orthogonal Frequency Division Multiplexing (OFDM) 2 Mobile and Wireless Networking 2013 / 2014 Modulation Process of encoding information from a message source in a manner suitable for transmission Two major steps: 1. Digital modulation q digital data is translated into an analog signal (baseband) 2. Analog modulation q shifts center frequency of baseband signal up to the radio carrier q Motivation l smaller antennas (e.g., λ/4) l Frequency Division Multiplexing l medium characteristics 3 Mobile and Wireless Networking 2013 / 2014 Modulation and demodulation analog baseband digital signal data digital analog 101101001 modulation modulation radio transmitter radio carrier analog baseband digital signal analog synchronization data demodulation decision 101101001 radio receiver radio carrier 4 Mobile and Wireless Networking 2013 / 2014 Modulation q Carrier s(t) = At sin(2 π ft t + ϕt) q Basic analog modulation schemes schemes q Amplitude Modulation (AM) q Frequency Modulation (FM) q Phase Modulation (PM) q Digital modulation q ASK, FSK, PSK - main focus here q differences in spectral efficiency, power efficiency, robustness 5 Mobile and Wireless Networking 2013 / 2014 Digital modulation Modulation of digital signals known as Shift
    [Show full text]
  • "CPM Signals for Machine to Machine Communications"
    N o d’ordre: 2015telb0367 Sous le sceau de l’Université Européenne de Bretagne Télécom Bretagne En accréditation conjointe avec l’Ecole Doctorale Sicma Application des signaux CPM pour la collecte de données à grande échelle provenant d’émetteurs faible coût Thèse de Doctorat Mention: Sciences et Technologies de l’information et de la Communication (STIC) Présentée par: Malek Messai Département: Signal et Communications Laboratoire: LabSTICC Pôle CACS/COM Directrice de thèse: Karine AMIS Soutenue le 20 Novembre 2015 Jury : Rapporteurs: Mérouane Debbah - Centrale-Supélec/ HUAWEI Philippe Ciblat - Telecom Paris Tech Examinateurs: Giulio Colavolpe - Università degli Studi di Parma (Italy) Gilles Burel - Université de Bretagne Occidentale Jérôme Lebrun - CNRS/ Université de Nice Sophia Antipolis Encadrants: Karine Amis - Telecom Bretagne Frédéric Guilloud - Telecom Bretagne Invité: Alain Dominique Thomas - Zodiac Aerospace Acknowledgments would like to express my sincerest thanks and appreciation to all the members of I the Signal and Communications department for welcoming me in your laboratory. I have met many people inside and outside the work sphere that made the Ph.D an enjoyable adventure. I am deeply grateful to my supervisors, Dr. Karine AMIS and Dr. Frédéric GUILLOUD, for their invaluable advice, kindness, encouragements, patience and support during these three years. Their profound scientific knowledge, invaluable insight and experience have had a great impact on the success of the thesis. There is no doubt in my mind that without their comments, criticisms and guidance, my Phd will not be accomplished. I am also indebted to them for giving me the opportunity to improve my research background and experience. I am very lucky to have had the opportunity to work with them.
    [Show full text]
  • Hierarchical Modulation Performance Analysis: Application to DVB-SH and DVB-S2
    1 Generic Approach for Hierarchical Modulation Performance Analysis: Application to DVB-SH and DVB-S2 Hugo Meric´ ∗y,Jer´ omeˆ Lacany∗, Caroline Amiot-Bazilez, Fabrice Arnalx and Marie-Laure Boucherety∗ ∗TeSA,´ Toulouse, France yUniversite´ de Toulouse, Toulouse, France zCNES, Toulouse, France xThales Alenia Space, Toulouse, France Email: [email protected], [email protected], [email protected], [email protected], [email protected] Abstract Broadcasting systems have to deal with channel variability in order to offer the best rate to the users. Hierarchical modulation is a practical solution to provide different rates to the receivers in function of the channel quality. Unfortunately, the performance evaluation of such modulations requires time consuming simulations. We propose in this paper a novel approach based on the channel capacity to avoid these simulations. The method allows to study the performance of hierarchical and also classical modulations combined with error correcting codes. We will also compare hierarchical modulation with time sharing strategy in terms of achievable rates and indisponibility. Our work will be applied to the DVB-SH and DVB-S2 standards, which both consider hierarchical modulation as an optional feature. arXiv:1103.1742v1 [cs.IT] 9 Mar 2011 Index Terms Hierarchical Modulation, Channel Capacity, Digital Video Broadcasting, System Performance. I. INTRODUCTION In most broadcast applications, all the receivers do not experience the same signal-to-noise ratio (SNR). For instance, in satellite communications the channel quality decreases with the presence of clouds in Ku or Ka band, or with shadowing effects of the environment in lower bands. The material in this paper will be presented in part at WTS 2011, New-York, United States, April 2011.
    [Show full text]
  • Advanced Modulation Formats and Multiplexing Techniques for Optical Telecommunication Systems 13
    Advanced Modulation Formats and Multiplexing Techniques for Optical Telecommunication Systems 13 Advanced Modulation Formats and Multiplexing Techniques for Optical X2 Telecommunication Systems Ghafour Amouzad Mahdiraji and Ahmad Fauzi Abas Advanced Modulation Formats and Multiplexing Techniques for Optical Telecommunication Systems Ghafour Amouzad Mahdiraji1 and Ahmad Fauzi Abas2 1UCSI University & 2Universiti Putra Malaysia Malaysia 1. Introduction Since ancient times, one of the principal needs of people has been to communicate. This need created interest in devising communication systems for sending messages from one place to another. The advent of high performance computer processors brought many advantages for digital communications over that of analog. These benefits include more features, easy storage and faster processing. These caused huge amount of information, which is increasing exponentially every year, to be carried over communication networks. Various types of communication system appeared over the years. Among the basic motivations behind each type are to improve the transmission fidelity, increase the data rate, and increase the transmission distance between stations. All these facilities are achievable utilizing optical fiber communications. Optical fiber offers several advantages over the traditional media (e.g., twisted wire pair and coaxial cable). Its decisive advantages are huge bandwidth and very low attenuation and noise (Arumugam, 2001). The first, results in higher bit rate, and the second, results in longer transmission distance. These potentials can be further pushed by utilizing multiplexing techniques and/or advanced modulation formats. The invention of wavelength division multiplexing (WDM) (G. E. Keiser, 1999) contributes great benefit to the optical fiber communication systems especially after the introduction of Erbium-doped fiber amplifier (EDFA).
    [Show full text]
  • CODING and MODULATION for BANDWIDTH COMPRESSION of TELEVISION and FACSIMILE SIGNALS. a Thesis Submitted for the Degree of Doctor
    CODING AND MODULATION FOR BANDWIDTH COMPRESSION OF TELEVISION AND FACSIMILE SIGNALS. A thesis submitted for the degree of Doctor of Philosophy by PIOTR WLADYSLAW JOZta BYLANSKI Imperial College, University of London. 1966. 2. ABSTRACT Two aspects relevant to the coding of picture signals with a view to compression of signal bandwidth are considered. Firstly: the problem of combining the information associated with the run length representation of the picture signal, for transmission over a practical channel, is studied. A solution is proposed in terms of combined amplitude and phase modulation and an analysis is presented which demonstrates the feasibility of the technique. Secondly, several aspects of the digram representation of the picture signal are studied. The second order redundancy is experimentally determined using a digital technique. The results obtained lead to the design of several simple and efficient digram -based codes for black and white facsimile pictures, result- ing in useful reduction of signal bandwidth. These codes are implemented and assessed experimentally. An adaptive encoding technique is proposed whereby errors produced by a non-uniquely decodable code may be minimised in a controlled way by the use of predictive feedback at the encoder. 3. CONTENTS. Item Page ABSTRACT 2 CONTENTS 3 LIST OF SYMBOLS AND ABBREVIATIONS 6 ACKNOWLEDGEMENTS 9 CHAPTER. 1. INTRODUCTION 10 141 The Trend of Modern Communications. 10 1.2 Visual Redundancy. 11 1.3 Signal Compression. 13 1.4 Television and Facsimile Communication. 16 1,5 The Organisation of the Material of this Work. 18 1.6 Summaries of Individual Chapters. 19 CHAPTER 2. THE PROBLEM OF CHANNEL UTILISATION.
    [Show full text]
  • Method, System and Transceiver Device for Bi-Directionally
    (19) TZZ ¥Z ¥_T (11) EP 2 830 239 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 28.01.2015 Bulletin 2015/05 H04B 10/25 (2013.01) H04J 14/02 (2006.01) H04B 10/516 (2013.01) (21) Application number: 13003679.1 (22) Date of filing: 23.07.2013 (84) Designated Contracting States: • Elbers, Jörg-Peter AL AT BE BG CH CY CZ DE DK EE ES FI FR GB 82256 Fürstenfeldbruck (DE) GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO • Griesser, Helmut PL PT RO RS SE SI SK SM TR 86551 Aichach (DE) Designated Extension States: • Eiselt, Michael BA ME 99334 Kirchheim (DE) (71) Applicant: ADVA AG Optical Networking (74) Representative: Eder, Thomas 98617 Meiningen (DE) Eder & Schieschke Patentanwälte (72) Inventors: Elisabethstrasse 34 • Grobe, Klaus 80796 München (DE) 82152 Planegg (DE) (54) Method, system and transceiver device for bi- directionally transmitting digital optical signals over an optical transmission link (57) The invention relates to a method for bi-direc- (S1TX,CHI) received at the second end of the optical trans- tionally transmitting digital optical signals over an optical mission link, the optical wavelength reuse signal being transmission link, wherein a first optical transmit signal modulated according to a second digital signal in such a (S1TX,CHI) at a predetermined optical wavelength is sup- way that the bit information of the second digital signal plied to a first end of the optical transmission link and is included in second sections of the symbol interval of transmitted in a first transmission direction to a second the first optical transmit signal (S1TX,CHI) received.
    [Show full text]
  • Mobile Communications Chapter 2: Wireless Transmission
    Mobile Communications Chapter 2: Wireless Transmission Frequencies Multiplexing Signals Spread spectrum Antenna Modulation Signal propagation Cellular systems Prof. Dr.-Ing. Jochen Schiller, http://www.jochenschiller.de/ MC SS05 2.1 Frequencies for communication twisted coax cable optical transmission pair 1 Mm 10 km 100 m 1 m 10 mm 100 µm 1 µm 300 Hz 30 kHz 3 MHz 300 MHz 30 GHz 3 THz 300 THz VLF LF MF HF VHF UHF SHF EHF infrared visible light UV VLF = Very Low Frequency UHF = Ultra High Frequency LF = Low Frequency SHF = Super High Frequency MF = Medium Frequency EHF = Extra High Frequency HF = High Frequency UV = Ultraviolet Light VHF = Very High Frequency Frequency and wave length: λ = c/f wave length λ, speed of light c ≅ 3x108m/s, frequency f Prof. Dr.-Ing. Jochen Schiller, http://www.jochenschiller.de/ MC SS05 2.2 Frequencies for mobile communication VHF-/UHF-ranges for mobile radio simple, small antenna for cars deterministic propagation characteristics, reliable connections SHF and higher for directed radio links, satellite communication small antenna, beam forming large bandwidth available Wireless LANs use frequencies in UHF to SHF range some systems planned up to EHF limitations due to absorption by water and oxygen molecules (resonance frequencies) z weather dependent fading, signal loss caused by heavy rainfall etc. Prof. Dr.-Ing. Jochen Schiller, http://www.jochenschiller.de/ MC SS05 2.3 Frequencies and regulations ITU-R holds auctions for new frequencies, manages frequency bands worldwide (WRC, World Radio
    [Show full text]
  • Five Decades of Hierarchical Modulation and Its Benefits in Relay-Aided Networking
    Received November 26, 2015, accepted December 18, 2015, date of publication December 22, 2015, date of current version January 5, 2016. Digital Object Identifier 10.1109/ACCESS.2015.2510702 Five Decades of Hierarchical Modulation and Its Benefits in Relay-Aided Networking HUA SUN1, CHEN DONG2, SOON XIN NG3, (Senior Member, IEEE), AND LAJOS HANZO3, (Fellow, IEEE) 1Research Group of Communications, Signal Processing and Control, School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ, U.K. 2University of Southampton, Southampton SO17 1BJ, U.K. 3School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ, U.K. Corresponding author: L. Hanzo ([email protected]) This work was supported in part by the European Research Council Advanced Fellow Grant and in part by the Engineering and Physical Sciences Research Council U.K. under Grant EP/L018659/1. ABSTRACT Hierarchical modulation (HM), which is also known as layered modulation, has been widely adopted across the telecommunication industry. Its strict backward compatibility with single-layer modems and its low complexity facilitate the seamless upgrading of wireless communication services. The specific features of HM may be conveniently exploited for improving the throughput/information-rate of the system without requiring any extra bandwidth, while its complexity may even be lower than that of the equivalent system relying on conventional modulation schemes. As a recent research trend, the potential employment of HM in the context of cooperative communications has also attracted substantial research interests. Motivated by the lower complexity and higher flexibility of HM, we provide a comprehensive survey and conclude with a range of promising future research directions.
    [Show full text]