DOCSLIB.ORG

LTE Trials in the Return Channel Over Satellite

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
LTE Trials in the Return Channel Over Satellite 2012 6th Advanced Satellite Multimedia Systems Conference (ASMS) and 12th Signal Processing for Space Communications Workshop (SPSC) LTE Trials in the Return Channel Over Satellite Volker Jungnickel, Holger Gaebler, Udo Krueger, Konstantinos Manolakis, Thomas Haustein Fraunhofer Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin, Germany Abstract—Integrating terrestrial and satellite communications promises several advantages, whereas the most evident one is multiplexing of spatial multiplex that modern satellite networks achieve global coverage using a multiple spot using multiple multiple spot beam architecture. In order to increase the spectral signals spots efficiency, orthogonal waveforms like single-carrier frequency- division multiple access (SC-FDMA) are investigated recently. In this paper, we verify experimentally that SC-FDMA waveforms taken from the 3GPP Long Term Evolution (LTE) standard can be transmitted reliably in the return channel over satellite using low-cost equipment. Mainly, we introduce an additional timing advance offset depending on satellite elevation and geographical location. And we ensure that precise information about the frequency offset measured in the forward channel is reused for compensation in the return channel at each terminal. We demon- strate in real-time transmission experiments over a geostationary Ku-band satellite that all modulation formats defined for the up-link in the LTE Release 8 standard can be decoded error- time or frequency free. Using 16-QAM, we have realized a spectral efficiency of 3.2 bits/s/Hz. Figure 1. Modern satellite networks are based on a multi-spot configuration. Index Terms—Long-Term Evolution, SC-FDMA, Satellite On the feeder link, user signals of all spots are multiplexed. Note the overlap Communications, Realtime Implementation, Field Trials between adjacent spots, causing interference similar to cellular networks. I. INTRODUCTION Satellites are convenient for connecting users to the Internet as inter-cell interference coordination (ICIC) [4], frequency- in areas with limited infrastructure. Satellites provide high selective scheduling with interference rejection combining speed data in the forward channel widely used for broadcast- (IRC) [5] and coordinated multi-point (CoMP) [6, 7]. ICIC ing. Efficient techniques for the return channel are recently combines fractional frequency reuse (FFR) with fractional discussed. The digital video broadcasting return channel over power control (FPC). Scheduling and IRC exploit interference satellite (DVB-RCS) standard relies on multi-frequency time- awareness at the transmitter and receiver, respectively. CoMP division multiple access (MF-TDMA) where one out of several uses joint scheduling and spatial processing for multiple cells. carrier frequencies and one or more time slots can be assigned Broadband spatial signal processing is the key for such new flexibly to each terminal [1]. techniques. Using orthogonal frequency-division multiplexing However, some overhead is spent at the physical layer (OFDM) [8], transmission is robust against multi-path and to minimize the cross-talk between the non-orthogonal MF- asynchronous timing. Equalization is simple in the frequency TDMA waveforms. Orthogonal waveforms, such as single- domain. But precise recursive synchronization techniques [9, carrier frequency-division multiple access (SC-FDMA) [2, 3] 10] become mandatory. have the potential to reduce such overhead. Furthermore, they In the multiuser return channel, the timing advance (TA) allow a higher flexibility of the radio resource management protocol measures the individual propagation delay of each (RRM) and enable more sophisticated transmission techniques terminal. Signals are then individually delayed in advance of increasing the spectral efficiency. On the other hand, the the transmission so that they arrive simultaneously. synchronization effort is increased. Using the proprietary frequency advance technique, termi- Modern telecommunication satellites form multiple spot nals measure their frequency offset in the forward channel and beams to serve the desired coverage area consistently with use this information to compensate it in the return channel. higher data rates. Due to the overlap between the spots, Multiple terminals get almost the same carrier frequency in however, there is significant interference similar to terrestrial this way [11]. cellular networks, as depicted in Fig. 1. Nowadays, interfer- SC-OFDM as a special case of SC-FDMA is considered ence is reduced by classical frequency reuse schemes, at the for the satellite component of DVB-NGH [12]. It has been cost of spectral efficiency. Full frequency reuse would increase proposed recently to use SC-FDMA for the DVB-RCS2 [13]. spectral efficiency if the interference could be mitigated. No trials are reported yet proving the feasibility of this In terrestrial mobile networks, complex interference miti- approach in the field of satellite communications. Our in- gation schemes are increasingly used. They can be classified tention in this paper is to close this gap by using SC- 978-1-4673-2676-6/12/$31.00 ©2012 IEEE 238 PSS , SSS t1 ble ream n p CH o A l i R t a a n i t s t2 P m r e DC s C H e t a b curvature of ion miss the earth surface rans ink t up-l Figure 2. SC-FDMA is realized in LTE using DFT spreading in the frequency Figure 3. Left: The timing advance (TA) protocol is used in LTE to equalize domain based on an inner OFDM link. Note that M ≤ N is equivalent to the arrival times of multiple terminals. Right: Depending on satellite elevation a rectangular filter in the frequency domain. Accordingly, there are residual and geographical location, a different TA offset is needed in addition at each envelope fluctuations in the time-domain. In the wireless channel, we have terminal when using LTE. considered the presence of phase noise. With subsequent IDFT despreading, the SC-FDMA receiver FDMA waveforms available in the 3GPP LTE standard. We has low complexity but it realizes the same diversity in multi- mention some changes needed to use LTE over geostationary path fading channels as the optimal linear RAKE receiver with satellites (refer also to [14]) and consider the use of low-cost complex multiuser detection [17]. satellite equipment at the terminal side. We have modified our LTE trial system [15] and demonstrate error-free SC-FDMA B. Timing Advance transmission over satellite for the first time. An intuitive requirement for using OFDM based schemes The paper is organized as follows. In Section II, we describe in the return channel is that the signals of active users are essential implementation steps of SC-FDMA in LTE and time-aligned. Timing advance is a built-in mechanism in the highlight necessary changes for using the common timing LTE air interface. A base station (BS) transmits primary and frequency advance techniques over satellite. Moreover, and secondary synchronization sequences (PSS, SSS) from we investigate the impact of phase noise in low-cost terminal which the terminal identifies the best serving base station equipments. In Section III, we describe the changes made in and derives a corresponding trigger signal. Triggered by this our LTE prototype to enable SC-FDMA transmission in the signal, each terminal transmits individually a so-called ran- return channel over satellite. In Section IV, we report perfor- dom access channel (RACH) preamble to the BS. There are mance measurements over a geostationary Ku-band satellite. up to 64 different sequences per BS enabling simultaneous measurements of the round trip times for multiple terminals. II. USING LTE OVER SATELLITE Finally, each terminal receives from the serving BS the so- In the following, we consider the use of the SC-FDMA called timing advance parameter and sets a constant delay of air interface from the Long Term Evolution (LTE) in the it’s individual waveform so that the waveforms of multiple return channel over satellite and derive essential physical layer terminals are received virtually simultaneous. Of course, there requirements therefore. are measurement inaccuracies, but they can be handled as long as they are within the cyclic prefix (CP) length of 4.7 µs. A. SC-FDMA in LTE This mechanism can in principle be reused in the return SC-FDMA is also denoted as DFT-spread OFDM and channel over satellite as well. In case of satellite, however, widely used in the 3GPP LTE up-link due to lower peak to distance variations among all terminals in one spot beam can average power ratio (PAPR) compared to orthogonal frequency be larger than allowed by the LTE specifications, as illustrated division multiple access (OFDMA). This allows a higher in Fig. 3. Reliable timing measurements using LTE are limited efficiency of the amplifier at the terminal side [16]. SC-FDMA to roughly 100 µs due to the particularly long CP in the RACH can be realized using an outer DFT spreading followed by a preamble. In this way, up to 30 km distance variations among flexible carrier mapping in the frequency domain [2] using an the terminals can be handled. However, satellite spot beams inner OFDM transmitter, as shown in Fig. 2, top. The PAPR may cover an area of several hundred kilometers in diameter. can be further reduced by root raised cosine (RRC) filtering Depending on the satellite elevation and user location, distance in front of the carrier mapping at the cost of more bandwidth. variations may be longer than 30 km. Therefore, we have This scheme emulates classical single-carrier waveforms by introduced a constant offset in the timing advance parameter using OFDM [3]. depending on the geographical location by which the up-link Waveforms of multiple users are transmitted in parallel sub- signals are shifted with respect to the down-link. bands, multiplexed over the air and received with a common OFDM receiver, as depicted in Fig. 2, bottom. The received C. Frequency Advance signals are jointly equalized in the frequency domain with the A second essential requirement of multiuser detection based individual set of channel coefficients of each terminal.
Load more

Recommended publications
  • Ka-Band Satellite Consumer Triple-Play and Professional Video Services
    Ka-Band Satellite Consumer Triple-Play and Professional Video Services Guillaume Benoit, Hector Fenech, Stefano Pezzana, and Alessia Tomatis Eutelsat, 70 rue Balard, 75015 Paris, France +33 1 53 98 47 47 {gbenoit,hfenech,spezzana,atomatis}@eutelsat.fr Abstract. This article presents Eutelsat European Ka-band implementation of the broadband ToowayTM service and its evolution through a dedicated Ka-band exclusive satellite (KA-SAT). It also explains Eutelsat’s choice in se- lecting the Ka-band for interactive services, broadcast video and IPTV ser- vices, demonstrating the optimal consumer service synergy between existing Ku-band and new Ka-band services. KA-SAT satellite is not focusing only on consumer triple-play services. In- deed, Eutelsat strategy consists in offering also professional video and data services in Ka-band (video distribution, video contribution, e-cinema, file transport) sharing the same transparent satellite bandwidth and the same ground segment infrastructure. For those professional video applications the last content processing (SVC) and satellite transport (DVB-S2 ACM) techniques are under deployment and this paper will present simulation results and link budgets estimations for a large number of future commercial applications. 1 Introduction Eutelsat operates 25 satellites in the geostationary arc from 15°W to 70.5°E offering a variety of services from corporate networks to broadcasting. The HOT BIRD™ con- stellation at 13°E constitutes the prime position for DTH (Direct to Home) and cable broadcasting, utilizing the full Ku-band spectrum from 10.70 GHz to 12.75 GHz. There are 102 transponders delivering about 1400 TV channels. The HOT BIRD™ service area reaches some 120 million satellite and cable households.
    [Show full text]
  • Cisco Broadband Data Book
    Broadband Data Book © 2020 Cisco and/or its affiliates. All rights reserved. THE BROADBAND DATABOOK Cable Access Business Unit Systems Engineering Revision 21 August 2019 © 2020 Cisco and/or its affiliates. All rights reserved. 1 Table of Contents Section 1: INTRODUCTION ................................................................................................. 4 Section 2: FREQUENCY CHARTS ........................................................................................ 6 Section 3: RF CHARACTERISTICS OF BROADCAST TV SIGNALS ..................................... 28 Section 4: AMPLIFIER OUTPUT TILT ................................................................................. 37 Section 5: RF TAPS and PASSIVES CHARACTERISTICS ................................................... 42 Section 6: COAXIAL CABLE CHARACTERISTICS .............................................................. 64 Section 7: STANDARD HFC GRAPHIC SYMBOLS ............................................................. 72 Section 8: DTV STANDARDS WORLDWIDE ....................................................................... 80 Section 9: DIGITAL SIGNALS ............................................................................................ 90 Section 10: STANDARD DIGITAL INTERFACES ............................................................... 100 Section 11: DOCSIS SIGNAL CHARACTERISTICS ........................................................... 108 Section 12: FIBER CABLE CHARACTERISTICS ...............................................................
    [Show full text]
  • Digital Satellite Broadcasting System with Flexible Configuration (Television, Sound and Data)
    Recommendation ITU-R BO. 1784-1 (12/2016) Digital satellite broadcasting system with flexible configuration (television, sound and data) BO Series Satellite delivery ii Rec. ITU-R BO.1784-1 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 Annex 1 of 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.
    [Show full text]
  • Laboratory Evaluations of DVB-S2 State-Of-The-Art Equipment
    DIGITAL VIDEO BROADCASTING Laboratory evaluation of DVB-S2 state-of-the-art equipment A. Bertella, V. Mignone, B. Sacco, M. Tabone RAI-CRIT This article describes the results of laboratory tests carried out by RAI-CRIT in June 2006 on DVB-S2 state-of-the-art equipment. AWGN (Additive White Gaussian Noise) performance, non-linear-channel and phase-noise degradation were measured, and the results show that the equipment is in line with the simulation results reported in the DVB-S2 standard. Single-carrier and multi-carrier configurations were implemented and compared to the equivalent DVB-S configurations. The results show that DVB-S2 can offer excellent gains over DVB-S – in terms of not only capacity and/or performance, but also flexibility. DVB-S2 [1][2] is the second-generation DVB system for satellite broadband services, designed for various different types of applications, such as: Broadcasting of standard-definition (SD) and high-definition (HD) TV; Interactive services, including Internet access, for consumer applications running on Integrated Receiver-Decoders (IRDs) and personal computers; Professional applications such as Digital TV contribution and newsgathering; Data content distribution and Internet trunking. The DVB-S2 standard has been specified around three key concepts: best transmission perform- ance, total flexibility and reasonable receiver complexity [3][4]. To achieve the best performance- complexity trade-off – quantifiable in a capacity gain of around 30% over DVB-S [7] – DVB-S2 bene- Abbreviations ACM Adaptive
    [Show full text]
  • Development of Ku-Band Mobile Satellite Internet Access System
    Development of Ku-band Mobile Satellite Internet Access System Byoung-Hak Kim(1), Deock-Gil Oh(1), Yun-Jeong Song(1), Hokyom Kim(1), Ho-Jin Lee(1) (1) Electronics and Telecommunications Research Institute (ETRI) 161 Gajeong-dong, Yuseong-gu, Daejeon, 305-350, Korea Email:byounghak,dgoh,yjsong,hokykim,[email protected] ABSTRACT This paper describes the main characteristics and architecture of a satellite mobile internet access (MSIA) system developed by ETRI. MSIA system provides Internet service, broadcasting, and digital A/V service in both fixed and mobile environments using Ku-band geostationary earth orbit (GEO) satellite. A Ku -band two-way active phased array antenna installed on top of the transportation vehicles can enable the transmission of signals to satellite as well as signal tracking and reception. The forward link and return link are a high speed Time Division Multiplex (TDM) and CDMA transmission media, respectively, both of which carry signaling and user traffic. 1. INTRODUCTION Today, it is increasingly required the mobile multimedia service including Internet service by satellite communications channel or broadcasting channel. Mobile satellite service networks have been designed to provide data to ships, trains, buses, and aircrafts (access to Internet, e-mail, internal corporate networks on vehicles). We have been keeping track of the trend in satellite services calling for broadband & mobility and undertaking the development of the technologies of high-speed IP backbone networks, broadband two-way access platforms, satellite mobile two-way Internet platform, and high efficient transmission [8]. We developed the low-cost DVB-RCS (Digital Video Broadcasting-Return Channel Satellite) VSAT equipment, called BSAN (Broadband Satellite Access Network) system for interactive multimedia service.
    [Show full text]
  • Digital Video Broadcasting (DVB) Implementation Guidelines for the Second Generation System Fo
    ! ! ! ! ! ! ! ! ! ! ! ! ! ! Digital Video Broadcasting (DVB) Implementation guidelines for the second generation system for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications; Part I (DVB-S2) ! Digital Video Broadcasting (DVB); DVB Document A171-1 March 2015 3 Contents Intellectual Property Rights ................................................................................................................................ 5 Foreword............................................................................................................................................................. 5 1 Scope ........................................................................................................................................................ 6 2 References ................................................................................................................................................ 6 3 Symbols and abbreviations ....................................................................................................................... 8 3.1 Symbols ............................................................................................................................................................. 8 3.2 Abbreviations ..................................................................................................................................................... 9 4 General description of the technical characteristics of the DVB-S2 system .........................................
    [Show full text]
  • ETSI EN 302 307 V1.2.1 (2009-08) European Standard (Telecommunications Series)
    ETSI EN 302 307 V1.2.1 (2009-08) European Standard (Telecommunications series) Digital Video Broadcasting (DVB); Second generation framing structure, channel coding and modulation systems for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications (DVB-S2) 2 ETSI EN 302 307 V1.2.1 (2009-08) Reference REN/JTC-DVB-238 Keywords BSS, digital, DVB, modulation, satellite, TV 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 Individual copies of the present document can be downloaded from: http://www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the 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: http://portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permission.
    [Show full text]
  • Interactivity in Terrestrial DTV Systems: the DVB-RCT Standard ♦♦♦
    Interactivity in Terrestrial DTV Systems: the DVB-RCT Standard ♦♦♦ Ângelo Pinelli Martins Samia, Dayan Adionel Guimarães National Institute of Telecommunications – Inatel P.O. Box 05 – 37540-000 Santa Rita do Sapucaí – MG – Brazil Abstract — The use of terrestrial broadcast channel , a higher degree of interactivity is possible digital TV platform to increase the percentage of and the user is able to participate in polls, to purchase the population with access to the Internet is products using the remote control, to buy pay-per-view conditioned to the implementation of a bi- events or to surf the internet. directional link between the user and the Currently, the main focus of discussion about broadcaster. One of the alternatives for the return digital TV in Brazil is the transmission standard for channel is the DVB-RCT (Digital Video terrestrial broadcasting, and the Government has been Broadcasting Return Channel – Terrestrial) supporting the idea of developing its own standard. standard, which suggests the use of a wireless Decree number 4,901 was issued in November, 2003 return path in the VHF/UHF bands. This standard and instituted the SBTVD (acronym for Brazilian has been designed to operate with a DVB-T Digital Television System), whose objectives, among broadcast channel. This work is a tutorial about others, are to promote social inclusion, to stimulate in- the DVB-RCT standard, incorporating the main features of the physical layer and issues like country research and development (R&D), and to capacity and suitability for implementation in motivate the production of interactive content by Brazil. current analog TV broadcasters [1].
    [Show full text]
  • ETSI TS 102 402 V1.1.1 (2005-05) Technical Specification
    ETSI TS 102 402 V1.1.1 (2005-05) Technical Specification Satellite Earth Station and systems (SES); Broadband Satellite Multimedia; Transparent Satellite Star - A (TSS-A); DVB-S and DVB-RCS for transparent satellites; Sub-family 1 (TSS-A1) 2 ETSI TS 102 402 V1.1.1 (2005-05) Reference DTS/SES-00273 Keywords air interface, DVB, architecture, broadband 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 Individual copies of the present document can be downloaded from: http://www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the 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: http://portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permission.
    [Show full text]
  • JUPITER™ System Bandwidth Efficiency
    White Paper JUPITER™ System Bandwidth Efficiency It is well understood by satellite network operators that “bandwidth efficiency” for a VSAT system is a critical element in achieving profitability, as higher efficiency will increase the amount of traffic supported over a given amount of satellite capacity. Not always understood, on the other hand, is that spectral efficiency alone, measured in bits per hertz, is only one factor in determining overall IP network efficiency or net data throughput for a given satellite bandwidth. As illustrated in Figure 1, each of the seven layers of the entire OSI model for networking offers the potential to implement efficiency gains, beyond just the spectral efficiency techniques applied at the physical layer. With this in mind, Hughes has implemented efficiencies across all layers of the OSI model to yield the highest possible overall IP network efficiency. In addition, the JUPITER™ System implements various Figure 1. OSI Seven-Layer Network Model compression schemes to reduce the amount of data that is transmitted across the space segment. Redundant data streams always exist and are intelligently removed before transmission over the satellite. If a stream of data has been transmitted in the past, a much smaller representative set of data is sent along with a lookup location of past packet streams. Leveraging these techniques results in a reduction factor from a given number of “router bits” (those packets delivered to router) to the least “satellite bits” (those transmitted through satellite). Physical Layer Optimization The Hughes JUPITER System utilizes the DVB-S2X wideband forward channel standard with Adaptive Coding Modulation (ACM), supporting rates from 1 Msps to 225 Msps.
    [Show full text]
  • DVB-S2 — Ready for Lift Off
    DIGITAL VIDEO BROADCASTING DVB-S2 — ready for lift off Alberto Morello and Vittoria Mignone RAI, Radiotelevisione Italiana DVB-S2 is the second-generation specification for satellite broadcasting – developed by the DVB (Digital Video Broadcasting) Project in 2003. It benefits from more recent developments in channel coding (LDPC codes) combined with a variety of modulation formats (QPSK, 8PSK, 16APSK and 32APSK). When used for interactive applications, such as Internet navigation, it may implement Adaptive Coding & Modulation (ACM), thus optimizing the transmission parameters for each individual user, dependant on path conditions. Backwards-compatible modes are available, allowing existing DVB-S set-top-boxes to continue working during any transitional period. This article, based on a presentation given at IBC-2004, gives a variety of examples of DVB-S2 – focusing on television applications including broadcasting, contribution TV links and DSNG, and DTT signal distribution to transmitters – which illustrate the advantages of the new system over DVB-S and, indeed, DVB-DSNG. The DVB-S2 system has been designed for several satellite broadband applications: broadcast services for standard definition TV and HDTV; interactive services, including Internet access, for consumer applications; professional applications, such as Digital TV contribution and News Gathering, TV distribution to terrestrial VHF/UHF transmitters; data content distribution and Internet trunking. It is based on a “tool-kit” approach which allows us to cover all the application areas while still keeping the single-chip decoder at reasonable complexity levels, thus enabling the use of mass market products also for professional applications. The DVB-S2 standard has been specified around three key concepts: (i) best transmission perform- ance, (ii) total flexibility and (iii) reasonable receiver complexity.
    [Show full text]
  • Bandwidth Estimation and Optimisation in Rain Faded Dvb-Rcs Networks
    BANDWIDTH ESTIMATION AND OPTIMISATION IN RAIN FADED DVB-RCS NETWORKS Mohamed A. Al-Mosawi This thesis is submitted in partial fulfilment of the requirements for the award of the degree of Doctor of Philosophy of the University of Portsmouth. September 2014 Abstract Broadband satellite communication networks operating at Ka band (20-30 GHz) play a very important role in today’s worldwide telecommunication infrastructure. The problem, however, is that rain can be the most dominant impairment factor for radio propagation in these frequency bands. Allocating frequency bandwidth based on the worst-case rain fading leads to the waste of the frequency spectrum due to over reservation, as actual rain levels may vary. Therefore, it is essential that satellite systems include adaptive radio resource allocation combined with fade mitigation techniques to efficiently counteract rain impairments in real-time. This thesis studies radio resource management problem for rain faded Digital Video Broadcast-Return Channel via Satellite (DVB-RCS) networks. This research stems from taking into account two aspects in the bandwidth estimation and allocation process: the consideration of multiple rain fading levels; and the geographical area size where users are distributed. The thesis investigates how using multiple rain fading levels in time slot allocation can improve bandwidth utilisation in DVB-RCS return links. The thesis presents a mathematical model to calculate the bandwidth on demand. The radio resource allocation is formulated as an optimisation problem, and a novel algorithm for dynamic carrier bandwidth and time slots allocation is proposed, which works with constant bit rate type of traffic. The research provides theoretical analysis for the time slot allocation problem and shows that the proposed algorithm achieves optimal results.
    [Show full text]