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CA2495414A1 - Frequency tracking for communications signals using m-ary orthogonal walsh modulation - Google Patents

Frequency tracking for communications signals using m-ary orthogonal walsh modulation Download PDF

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Publication number
CA2495414A1
CA2495414A1 CA002495414A CA2495414A CA2495414A1 CA 2495414 A1 CA2495414 A1 CA 2495414A1 CA 002495414 A CA002495414 A CA 002495414A CA 2495414 A CA2495414 A CA 2495414A CA 2495414 A1 CA2495414 A1 CA 2495414A1
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Canada
Prior art keywords
correlator
frequency
frequency tracking
error signal
output
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
CA002495414A
Other languages
French (fr)
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CA2495414C (en
Inventor
Avneesh Agrawal
Rajiv Vijayan
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Qualcomm Inc
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Individual
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Filing date
Publication date
Priority claimed from US08/625,481 external-priority patent/US6330291B1/en
Application filed by Individual filed Critical Individual
Publication of CA2495414A1 publication Critical patent/CA2495414A1/en
Application granted granted Critical
Publication of CA2495414C publication Critical patent/CA2495414C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Compression, Expansion, Code Conversion, And Decoders (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

A frequency tracking loop for a communication system using orthogonal Walsh modulation is provided. The frequency tracking loop includes a correlator (120) such as a fast Hadamard transformation device, and a discriminator (130). The correlator (120) produces correlation vector (122) representing the result of correlating the input signal with each of a set of Walsh functions, with corresponding index values. The discriminator (130) produces a frequency error signal (ê) based on the correlator (120) output with the highest energy level and other correlator outputs whose indices are related to the index of highest energy correlator output by powers of two.
The frequency error signal (ê) is generated by producing a cross product between the highest energy output and one or more of the other related correlator outputs. In further aspects, a filter (140) can be used to further shape the resulting error signal (ê) and form a frequency offset estimate signal (~).
CA002495414A 1996-03-29 1997-03-26 Frequency tracking for communications signals using m-ary orthogonal walsh modulation Expired - Fee Related CA2495414C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US08/625,481 US6330291B1 (en) 1996-03-29 1996-03-29 Frequency tracking for communication signals using M-ary orthogonal walsh modulation
US625,481 1996-03-29
CA002222644A CA2222644C (en) 1996-03-29 1997-03-26 Frequency tracking for communication signals using m-ary orthogonal walsh modulation

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
CA002222644A Division CA2222644C (en) 1996-03-29 1997-03-26 Frequency tracking for communication signals using m-ary orthogonal walsh modulation

Publications (2)

Publication Number Publication Date
CA2495414A1 true CA2495414A1 (en) 1997-10-09
CA2495414C CA2495414C (en) 2006-12-05

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Family Applications (1)

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CA002495414A Expired - Fee Related CA2495414C (en) 1996-03-29 1997-03-26 Frequency tracking for communications signals using m-ary orthogonal walsh modulation

Country Status (1)

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CA (1) CA2495414C (en)

Also Published As

Publication number Publication date
CA2495414C (en) 2006-12-05

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