CA2267170A1 - Determination of frequency offsets in communication systems - Google Patents

Determination of frequency offsets in communication systems

Info

Publication number
CA2267170A1
CA2267170A1 CA002267170A CA2267170A CA2267170A1 CA 2267170 A1 CA2267170 A1 CA 2267170A1 CA 002267170 A CA002267170 A CA 002267170A CA 2267170 A CA2267170 A CA 2267170A CA 2267170 A1 CA2267170 A1 CA 2267170A1
Authority
CA
Canada
Prior art keywords
user terminal
error
frequency
doppler
gateway
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
CA002267170A
Other languages
French (fr)
Other versions
CA2267170C (en
Inventor
Steven A. Kremm
Gordon S. Skinner (Deceased)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Qualcomm Inc
Original Assignee
Qualcomm Incorporated
Steven A. Kremm
Gordon S. Skinner (Deceased)
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
Application filed by Qualcomm Incorporated, Steven A. Kremm, Gordon S. Skinner (Deceased) filed Critical Qualcomm Incorporated
Publication of CA2267170A1 publication Critical patent/CA2267170A1/en
Application granted granted Critical
Publication of CA2267170C publication Critical patent/CA2267170C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
    • H04B7/18545—Arrangements for managing station mobility, i.e. for station registration or localisation
    • H04B7/18547—Arrangements for managing station mobility, i.e. for station registration or localisation for geolocalisation of a station
    • H04B7/1855—Arrangements for managing station mobility, i.e. for station registration or localisation for geolocalisation of a station using a telephonic control signal, e.g. propagation delay variation, Doppler frequency variation, power variation, beam identification
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/01—Reducing phase shift

Abstract

A method and apparatus for determining frequency offsets caused by oscillator error or Doppler effects in a user terminal in a communication system. The system (100) includes at least one user terminal (124, 126) and a base station (112), or gateway (120, 122) for communicat-ing through a satellite (116, 118) with predetermined or-bital positions or patterns. A communication signal (500) is precorrected (512) for known Doppler effects, such as between a gateway and a transferring satellite, when used, and transmitted to a user terminal. The user terminal deter-mines the signal frequency relative to a reference oscillator (516, 518), and treats any detected difference as resulting completely from Doppler. The frequency difference is ei-ther transferred as data in reverse link transmissions (524, 526), or used as a pre-correction factor for such transmissions (522, 526). The frequency of the reverse link user terminal signals is measured at the gateway (528), again compensating for knowm Doppler effects, to pro-vide a nominal error measurement (530). Measured fre-quency error or offsets are then divided in half to arrive at a Doppler shift error, or divided in half and scaled to the appropriate frequency to arrive at a user terminal oscilla-tor error (532). The detected error can be transmitted to the user terminal (534) for use in correcting the oscillator output frequency, or for adjusting the timing of, or time tracking for, the user terminal. Alternatively, the detected error can be included as data in subsequent signals for use by gateways or base stations (538, 540).
CA002267170A 1996-09-30 1997-09-26 Determination of frequency offsets in communication systems Expired - Fee Related CA2267170C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US08/723,724 1996-09-30
US08/723,724 US5943606A (en) 1996-09-30 1996-09-30 Determination of frequency offsets in communication systems
PCT/US1997/017323 WO1998015070A1 (en) 1996-09-30 1997-09-26 Determination of frequency offsets in communication systems

Publications (2)

Publication Number Publication Date
CA2267170A1 true CA2267170A1 (en) 1998-04-09
CA2267170C CA2267170C (en) 2009-09-08

Family

ID=24907399

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002267170A Expired - Fee Related CA2267170C (en) 1996-09-30 1997-09-26 Determination of frequency offsets in communication systems

Country Status (15)

Country Link
US (1) US5943606A (en)
EP (1) EP0934633B1 (en)
JP (1) JP4422213B2 (en)
KR (1) KR100506579B1 (en)
CN (1) CN1123990C (en)
AT (1) ATE376723T1 (en)
AU (1) AU723341B2 (en)
CA (1) CA2267170C (en)
DE (1) DE69738236T2 (en)
ES (1) ES2296315T3 (en)
HK (1) HK1022221A1 (en)
RU (1) RU2195772C2 (en)
TW (1) TW405303B (en)
WO (1) WO1998015070A1 (en)
ZA (1) ZA978520B (en)

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Also Published As

Publication number Publication date
DE69738236D1 (en) 2007-12-06
ZA978520B (en) 1999-04-22
EP0934633B1 (en) 2007-10-24
HK1022221A1 (en) 2000-07-28
AU4597597A (en) 1998-04-24
WO1998015070A1 (en) 1998-04-09
ATE376723T1 (en) 2007-11-15
RU2195772C2 (en) 2002-12-27
JP2001509324A (en) 2001-07-10
DE69738236T2 (en) 2008-08-07
CN1123990C (en) 2003-10-08
JP4422213B2 (en) 2010-02-24
KR100506579B1 (en) 2005-08-08
EP0934633A1 (en) 1999-08-11
US5943606A (en) 1999-08-24
AU723341B2 (en) 2000-08-24
TW405303B (en) 2000-09-11
CA2267170C (en) 2009-09-08
KR20000049035A (en) 2000-07-25
CN1239612A (en) 1999-12-22
ES2296315T3 (en) 2008-04-16

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