ATE544078T1 - Modulationssignale für ein satellitennavigationssystem - Google Patents

Modulationssignale für ein satellitennavigationssystem

Info

Publication number
ATE544078T1
ATE544078T1 AT07012296T AT07012296T ATE544078T1 AT E544078 T1 ATE544078 T1 AT E544078T1 AT 07012296 T AT07012296 T AT 07012296T AT 07012296 T AT07012296 T AT 07012296T AT E544078 T1 ATE544078 T1 AT E544078T1
Authority
AT
Austria
Prior art keywords
navigation system
satellite navigation
boc
modulation signals
modulation signal
Prior art date
Application number
AT07012296T
Other languages
English (en)
Inventor
Anthony Richard Pratt
John Ivor Rewbridge Owen
Original Assignee
Secr Defence
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=28686629&utm_source=***_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=ATE544078(T1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Secr Defence filed Critical Secr Defence
Application granted granted Critical
Publication of ATE544078T1 publication Critical patent/ATE544078T1/de

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/02—Details of the space or ground control segments
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Radar, Positioning & Navigation (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • Signal Processing (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)
  • Radio Relay Systems (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Transmitters (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Color Television Systems (AREA)
AT07012296T 2003-09-01 2004-09-01 Modulationssignale für ein satellitennavigationssystem ATE544078T1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GBGB0320352.8A GB0320352D0 (en) 2003-09-01 2003-09-01 Digital modulation waveforms for use in ranging systems

Publications (1)

Publication Number Publication Date
ATE544078T1 true ATE544078T1 (de) 2012-02-15

Family

ID=28686629

Family Applications (2)

Application Number Title Priority Date Filing Date
AT04768293T ATE370428T1 (de) 2003-09-01 2004-09-01 Modulationssignale für ein satelliten- navigationssystem
AT07012296T ATE544078T1 (de) 2003-09-01 2004-09-01 Modulationssignale für ein satellitennavigationssystem

Family Applications Before (1)

Application Number Title Priority Date Filing Date
AT04768293T ATE370428T1 (de) 2003-09-01 2004-09-01 Modulationssignale für ein satelliten- navigationssystem

Country Status (15)

Country Link
US (4) US8976891B2 (de)
EP (2) EP1664827B1 (de)
JP (2) JP4850065B2 (de)
CN (4) CN102426366B (de)
AT (2) ATE370428T1 (de)
AU (1) AU2004268254B9 (de)
CA (1) CA2537809C (de)
DE (1) DE602004008306T2 (de)
DK (2) DK1830199T3 (de)
ES (2) ES2289555T3 (de)
GB (1) GB0320352D0 (de)
NZ (2) NZ545527A (de)
PL (1) PL1830199T3 (de)
RU (3) RU2385466C2 (de)
WO (1) WO2005022186A1 (de)

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6816710B2 (en) * 1998-05-06 2004-11-09 Snaptrack, Inc. Method and apparatus for signal processing in a satellite positioning system
EP1681773A1 (de) * 2005-01-13 2006-07-19 Centre National D'etudes Spatiales Spreizspektrumsignal
JP4861428B2 (ja) * 2005-11-18 2012-01-25 ノキア コーポレイション 信号のサンプル・シーケンスの処理
JP4738231B2 (ja) * 2006-03-29 2011-08-03 日本無線株式会社 スペクトラム拡散信号受信装置
GB0612142D0 (en) * 2006-06-20 2006-08-02 Secr Defence Spreading modulation spectrum control
US20080262726A1 (en) * 2007-04-20 2008-10-23 Nigel Sheriden Hoult Method and generator for generating a spread-spectrum signal
US7948929B1 (en) * 2009-05-18 2011-05-24 Itt Manufacturing Enterprises, Inc. System for generating constant envelope simultaneous data and ranging waveform with anti-jam properties
US8774315B2 (en) * 2009-08-25 2014-07-08 The Aerospace Corporation Phase-optimized constant envelope transmission (POCET) method, apparatus and system
JP5614029B2 (ja) * 2009-11-24 2014-10-29 セイコーエプソン株式会社 捕捉周波数決定方法
US8675751B2 (en) * 2010-04-08 2014-03-18 Comtech Ef Data Corp. Meta-carrier embedding technique with improved performance for BPSK, MSK, and O-QPSK modulation
CN102694569B (zh) * 2012-06-07 2014-05-14 清华大学 导航信号的恒包络复用方法、生成装置以及接收方法
US8781039B2 (en) 2012-10-26 2014-07-15 Deere & Company Receiver and method for receiving a composite signal
US8942157B2 (en) 2012-10-26 2015-01-27 Deere & Company Receiver and method for receiving a composite signal
US8942264B2 (en) 2012-10-26 2015-01-27 Deere & Company Receiver and method for receiving a composite signal
US9048964B2 (en) 2012-10-26 2015-06-02 Deere & Company Receiver and method for receiving a composite signal
CN103023598B (zh) * 2012-11-23 2016-03-30 清华大学 双频四分量扩频信号的恒包络复用方法、装置及接收方法
CN104702311B (zh) 2013-12-06 2017-08-11 清华大学 扩频信号的生成方法、生成装置、接收方法和接收装置
GB201401237D0 (en) 2014-01-24 2014-03-12 Qinetiq Ltd Improvements to satellite positioning methods
US9432110B2 (en) * 2014-05-07 2016-08-30 The Boeing Company System and method for code multiplexing
US9945932B2 (en) * 2014-09-30 2018-04-17 Raytheon Company Real-time multi-array sum power spectrum control
CA3065394C (en) * 2015-03-06 2022-05-17 Electronics And Telecommunications Research Institute Broadcast signal frame generating apparatus and broadcast signal frame generating method using bootstrap and preamble
JP2017011682A (ja) * 2015-06-17 2017-01-12 パナソニック インテレクチュアル プロパティ コーポレーション オブ アメリカＰａｎａｓｏｎｉｃ Ｉｎｔｅｌｌｅｃｔｕａｌ Ｐｒｏｐｅｒｔｙ Ｃｏｒｐｏｒａｔｉｏｎ ｏｆ Ａｍｅｒｉｃａ 送信方法、受信方法、送信装置、及び受信装置
CN112491488B (zh) * 2015-06-17 2024-02-27 松下电器（美国）知识产权公司 发送方法、接收方法、发送装置及接收装置
RU2601136C1 (ru) * 2015-10-12 2016-10-27 Акционерное общество "Научно-производственное объединение измерительной техники" Многофункциональное устройство для формирования телеметрических радиосигналов с угловой модуляцией для передачи аналого-цифровой или цифровой информации
CN105656827B (zh) * 2016-01-29 2018-09-18 东南大学 一种时分复用连续相位直接载波调制和解调方法
CN106547004A (zh) * 2016-11-08 2017-03-29 上海海洋大学 卫星导航***信号的可控旁瓣二进制偏移载波调制方法
CN107479075B (zh) * 2017-07-27 2019-10-25 武汉大学 基于Hzb码北斗卫星子测距码相位分配实现方法和***
US10687567B2 (en) * 2017-08-28 2020-06-23 Nico Hawk LaRosa Hand and forearm protector for egg collection
US10432447B2 (en) 2017-11-10 2019-10-01 The Boeing Company System and method for amplitude pre-distortion optimization for GPS signal constant envelope transmission
USD912907S1 (en) 2018-08-28 2021-03-09 Nico Hawk LaRosa Arm and wrist guard
US11294067B2 (en) 2019-12-06 2022-04-05 Samsung Electronics Co., Ltd System and method for providing global navigation satellite system (GNSS) signal processing in multipath environment
US10797920B1 (en) * 2020-03-18 2020-10-06 Rockwell Collins, Inc. High-entropy continuous phase modulation data transmitter
WO2021240536A1 (en) * 2020-05-29 2021-12-02 Indian Space Research Organization Method for generating modulation signals for a satellite navigation system
KR20240037492A (ko) * 2022-09-15 2024-03-22 한국전자통신연구원 무선 통신 시스템에서의 상수포락선 다중화 방법 및 장치

Family Cites Families (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4206462A (en) * 1961-02-08 1980-06-03 International Telephone And Telegraph Corporation Secure communication and ranging system
US3328798A (en) * 1965-05-07 1967-06-27 Wilcox Electric Company Inc Double bridge network for producing signals having a modulation envelope phase difference
US4004237A (en) * 1970-05-01 1977-01-18 Harris Corporation System for communication and navigation
US3737776A (en) * 1971-06-09 1973-06-05 J Fletcher Two carrier communication system with single transmitter
EP0209902B1 (de) * 1985-07-24 1993-12-08 Nec Corporation Mehrpegel-Modulator mit einer kompakten Einheit zur Erzeugung eines Fehlerkorrekturkodes
DE3601576A1 (de) 1986-01-21 1987-07-23 Standard Elektrik Lorenz Ag Empfaenger fuer bandgespreizte signale
US4809006A (en) * 1986-05-30 1989-02-28 General Electric Company Satellite communications using the telemetry tracking and control system
US4816783A (en) * 1988-01-11 1989-03-28 Motorola, Inc. Method and apparatus for quadrature modulation
US5045859A (en) * 1988-09-15 1991-09-03 Aviation Systems Concepts, Inc. Phase reference navigation system and method
US5239670A (en) * 1989-11-30 1993-08-24 Motorola, Inc. Satellite based global paging system
US5053782A (en) * 1989-12-13 1991-10-01 Gilat Communication Systems Ltd. Commercial satellite communications system
US5133083A (en) * 1990-01-12 1992-07-21 Hewlett-Packard Company Adjacent channel selectivity signal generator system
IT1240444B (it) 1990-05-18 1993-12-16 Borsano Corrado Procedimento per l'attuazione della modulazione digitale multilivello mediante un elaboratore di segnali numerici
US5214787A (en) 1990-08-31 1993-05-25 Karkota Jr Frank P Multiple audio channel broadcast system
JPH07177057A (ja) * 1993-12-20 1995-07-14 Victor Co Of Japan Ltd スペクトル拡散変調及び／又は復調装置
US5684833A (en) * 1994-04-21 1997-11-04 Aichidenshi Kabushiki Kaisha Mutual conversion method of binary data and multilevel signal, its communication method, and its receiving device
JP3055085B2 (ja) * 1994-04-22 2000-06-19 株式会社アドバンテスト デジタル変調解析装置
JP3002944B2 (ja) * 1994-07-14 2000-01-24 シャープ株式会社 スペクトル拡散通信システム
JP3577754B2 (ja) * 1994-09-09 2004-10-13 ソニー株式会社 通信方法及び装置
JP3215018B2 (ja) * 1994-09-09 2001-10-02 三菱電機株式会社 移動通信システム
US5717722A (en) * 1994-11-08 1998-02-10 Anritsu Corporation Precision symbol demodulation system for multi-carrier modulation signal
JP3419567B2 (ja) * 1994-11-08 2003-06-23 アンリツ株式会社 デジタル信号のシンボル識別点検出回路
US5729570A (en) * 1994-12-08 1998-03-17 Stanford Telecommunications, Inc. Orthogonal code division multiple access communication system having multicarrier modulation
US6351497B1 (en) * 1995-09-06 2002-02-26 Sony Corporation Communication system
US5673051A (en) 1995-12-21 1997-09-30 Hughes Electronics Discrete phase modulator
US5778307A (en) * 1996-03-29 1998-07-07 Motorola, Inc. Amplifier with adaptive output allocation and method thereof
US5978823A (en) * 1997-01-27 1999-11-02 Hitachi America, Ltd. Methods and apparatus for implementing and controlling a digital modulator
US6178197B1 (en) 1997-06-23 2001-01-23 Cellnet Data Systems, Inc. Frequency discrimination in a spread spectrum signal processing system
US5847680A (en) * 1997-12-05 1998-12-08 Trimble Navigation Limited GPS receiver having fast resolution of carrier phase ambiguity
US6075781A (en) * 1997-12-12 2000-06-13 Stanford Telecommunications, Inc. Flux density reduction in OCDMA satellite communication system
US6324159B1 (en) * 1998-05-06 2001-11-27 Sirius Communications N.V. Method and apparatus for code division multiple access communication with increased capacity through self-noise reduction
EP1021019A1 (de) 1999-01-15 2000-07-19 Sony International (Europe) GmbH Verfahren zur quasi-differentiellen Modulation und Demodulation von multi-amplituden Signalen und OFDM System
IL129270A0 (en) * 1999-03-30 2000-02-17 Dip Digital Power Ltd Class "d" amplifier
US6430213B1 (en) * 1999-05-26 2002-08-06 The Aerospace Corporation Coherent adaptive subcarrier modulation method
US7120198B1 (en) * 1999-05-26 2006-10-10 The Aerospace Corporation Quadrature product subcarrier modulation system
DE10030455B4 (de) 1999-06-21 2010-04-08 Nissan Motor Co., Ltd., Yokohama-shi Vorrichtung zum Erzeugen von Straßeninformationen aus einer gespeicherten digitalen Kartendatenbank
JP2001028556A (ja) * 1999-07-13 2001-01-30 Fujitsu Ten Ltd スペクトラム拡散された信号の復調装置
US6359504B1 (en) 2000-01-28 2002-03-19 Lucent Technologies Inc. Power amplifier using upstream signal information
US6658048B1 (en) 2000-04-07 2003-12-02 Nokia Mobile Phones, Ltd. Global positioning system code phase detector with multipath compensation and method for reducing multipath components associated with a received signal
US6301306B1 (en) * 2000-05-26 2001-10-09 Motorola, Inc. Method and apparatus for generating a short-range wireless data communication link
US7418043B2 (en) * 2000-07-19 2008-08-26 Lot 41 Acquisition Foundation, Llc Software adaptable high performance multicarrier transmission protocol
US7239707B2 (en) * 2000-11-28 2007-07-03 Itt Manufacturing Enterprises, Inc. Staggered pulse acquisition method and apparatus
US7346918B2 (en) 2000-12-27 2008-03-18 Z-Band, Inc. Intelligent device system and method for distribution of digital signals on a wideband signal distribution system
FR2820567B1 (fr) * 2001-02-08 2006-07-14 Cit Alcatel Satellite a liaison de telemesure, suivi et telecommande a modulation double
GB2373417B (en) * 2001-03-13 2004-06-09 Tandberg Television Asa Satellite communication apparatus
CA2704041C (en) * 2001-03-30 2013-09-03 M&Fc Holding, Llc Enhanced wireless packet data communication system, method, and apparatus applicable to both wide area networks and local area networks
JP2002328157A (ja) 2001-04-27 2002-11-15 Pioneer Electronic Corp 測位誤差領域設定装置、測位誤差領域設定方法、測位誤差領域設定処理プログラムおよびナビゲーション装置
GB2375016B (en) * 2001-04-27 2005-03-16 Tandberg Television Asa Satellite up-link fade compensation
US7039126B2 (en) * 2001-06-18 2006-05-02 Northrop Grumman Corp. M-ary signal constellations suitable for non-linear amplification
US6574285B2 (en) * 2001-07-16 2003-06-03 Northrop Grumman Corporation 128-ary signal constellations suitable for non-linear amplification
US6515557B1 (en) 2001-08-13 2003-02-04 Raytheon Company Isolating signal divider/combiner and method of combining signals of first and second frequencies
DE10142102A1 (de) 2001-08-30 2003-03-27 Schleifring Und Appbau Gmbh Vorrichtung zur störarmen Signalübertragung
JP4634672B2 (ja) * 2001-09-25 2011-02-16 三菱電機株式会社 サイトダイバーシチ送受信装置
FR2832806B1 (fr) * 2001-11-23 2006-07-21 Thales Sa Procede et dispositif de calcul de la fonction discriminante de signaux modules avec une ou plusieurs sous-porteuse
JP3649179B2 (ja) * 2001-12-04 2005-05-18 住友電気工業株式会社 移動体通信装置
US20030152387A1 (en) * 2001-12-04 2003-08-14 Duling Irl N. Method for transmitting multi-level signals through dispersive media
US6606010B1 (en) * 2002-01-30 2003-08-12 The Aerospace Corporation Quadrature vestigial sideband digital communications method
DE10219216B4 (de) 2002-04-29 2005-04-07 Eads Astrium Gmbh Verfahren und Endgerät zur Verarbeitung eines Navigationssignals in einem Satelliten-Navigationssystem
US7224721B2 (en) * 2002-10-11 2007-05-29 The Mitre Corporation System for direct acquisition of received signals
FR2848748B1 (fr) 2002-12-13 2005-02-18 Centre Nat Etd Spatiales Procede et dispositif de generation d'un signal de navigation a enveloppe constante a quatre codes independants
FR2848743A1 (fr) * 2002-12-17 2004-06-18 Thales Sa Procede de traitement d'un signal analogique et dispositif de mise en oeuvre du procede
JP2004271322A (ja) * 2003-03-07 2004-09-30 Natl Space Development Agency Of Japan 搬送波駆動擬似雑音符号型測位信号生成方法及びそのシステム
US7286624B2 (en) * 2003-07-03 2007-10-23 Navcom Technology Inc. Two-way RF ranging system and method for local positioning
US6922167B2 (en) * 2003-07-14 2005-07-26 European Space Agency Hardware architecture for processing galileo alternate binary offset carrier (AltBOC) signals
JP4177726B2 (ja) * 2003-07-28 2008-11-05 株式会社東芝 測位システム
KR100651454B1 (ko) * 2004-03-05 2006-11-29 삼성전자주식회사 직교 주파수 분할 다중 접속 셀룰러 통신 시스템에서 부채널 할당 방법
US7321641B2 (en) * 2004-06-03 2008-01-22 The Aerospace Corporation Baseband time-domain communications system
KR100686737B1 (ko) * 2005-08-29 2007-02-26 삼성전자주식회사 채널 등화기와 채널 등화 방법, 및 그에 사용되는 탭 계수갱신 방법
KR101268291B1 (ko) * 2010-09-03 2013-05-28 한국과학기술원 동료 지원을 통한 초고속 ｇｎｓｓ 초기 위치 획득 장치, 방법 및 그 기록매체

Also Published As

Publication number Publication date
CN102426366B (zh) 2016-08-03
AU2004268254B9 (en) 2010-03-04
US8989301B2 (en) 2015-03-24
JP2007504731A (ja) 2007-03-01
US20080063119A1 (en) 2008-03-13
ATE370428T1 (de) 2007-09-15
CN1846146A (zh) 2006-10-11
EP1830199B1 (de) 2012-02-01
DK1664827T3 (da) 2008-01-07
AU2004268254B2 (en) 2009-07-16
RU2441255C2 (ru) 2012-01-27
JP4904227B2 (ja) 2012-03-28
AU2004268254A1 (en) 2005-03-10
EP1830199A2 (de) 2007-09-05
EP1664827A1 (de) 2006-06-07
DE602004008306T2 (de) 2008-05-08
CA2537809A1 (en) 2005-03-10
RU2011141106A (ru) 2013-10-27
ES2289555T3 (es) 2008-02-01
US20120269235A1 (en) 2012-10-25
CA2537809C (en) 2017-08-08
NZ545527A (en) 2008-01-31
WO2005022186A1 (en) 2005-03-10
EP1664827B1 (de) 2007-08-15
US8976891B2 (en) 2015-03-10
ES2379827T3 (es) 2012-05-04
CN101093253B (zh) 2012-02-15
CN102426366A (zh) 2012-04-25
GB0320352D0 (en) 2003-10-01
CN101093253A (zh) 2007-12-26
RU2385466C2 (ru) 2010-03-27
RU2006110570A (ru) 2007-10-20
DK1830199T3 (da) 2012-05-21
NZ560344A (en) 2009-10-30
CN102436001A (zh) 2012-05-02
US20070176676A1 (en) 2007-08-02
EP1830199A3 (de) 2007-09-12
US8995575B2 (en) 2015-03-31
RU2007129147A (ru) 2009-02-10
CN1846146B (zh) 2011-10-05
PL1830199T3 (pl) 2012-07-31
JP4850065B2 (ja) 2012-01-11
JP2008032737A (ja) 2008-02-14
US20110051781A1 (en) 2011-03-03
DE602004008306D1 (de) 2007-09-27

Similar Documents

Publication Publication Date Title
ATE370428T1 (de) Modulationssignale für ein satelliten- navigationssystem
ATE247876T1 (de) Verfahren und gerät zur generierung eines linear- moduliertes signal mittels polarer modulierung
MY139836A (en) Device and method for generating a data stream and for generating a multi-channel representation
DE69942068D1 (de) Erzeugen eines nichtlinearen modells und erzeugen tzung desselben
SE9400767D0 (sv) FM multiplex broadcasting and receiving system
CA2325299A1 (en) Air separation module using a fast start valve for fast warm up of a permeable membrane separation module
WO2007055518A3 (en) Method and apparatus for improving papr in ofdm or ordma communication system
WO1998042106A3 (en) Iq modulator, and associated method
PL1718021T3 (pl) Urządzenie odbiorcze i sposób komunikacji w systemie komunikacyjnym OFDM z nową strukturą preambuły
AU2003243046A1 (en) Modulation apparatus using mixed-radix fast fourier transform
ATE328418T1 (de) Multiplexverfahren in einem mehrträger- sendediversitysystem
TWI348079B (en) Method for generating a clock signal having desired spectral characteristics, system for generating a clock signal having spread spectrum modulation and the modulator circuit therefor
AP2000001940A0 (en) Frame structure and frame synchronization for multicarrier systems.
FI955839A (fi) Merkinantopaketti kommunikaatiojärjestelmälle, jossa on aikaperusteisesti moduloitu referenssi
GB2433325A (en) Superimposing current or previous graphing data for anamoly detection
DE69530865D1 (de) Tonsignalidentifikation unter verwendung digitaler markierungssignale
EP1005188A3 (de) Verfahren und Vorrichtung für Zusatzdaten in einem WDM-System
DK1186126T3 (da) Fremgangsmåde og apparat til bestemmelse af karakteristikker af en kommunikationskanals komponenter
ES2162336T3 (es) Modulo de espectroscopia de correlacion de fluorescencia para un microscopio.
TW200729797A (en) Method for transmitting information in digital radio mondiale (DRM) system
EP1590902A4 (de) Verfahren und vorrichtung zum testen von netzwerkdatensignalen in einem optischen wellenlängenmultiplex-netzwerk
DE60034655D1 (de) Verfahren zur Übertragungskanalschätzung
ATE397822T1 (de) Ofdm kodierung unter verwendung von hermite- polynomen
ATE334542T1 (de) Verfahren und vorrichtung zur umwandlung einer kanalschätzung
GB2429888A (en) Adaptive pre-emphasis filtering in a phase modulator