Carrier phase initialization with sub-LSB accuracy

• US 6,647,080 B1
• Filed: 03/10/2000
• Issued: 11/11/2003
• Est. Priority Date: 03/10/2000
• Status: Expired due to Fees

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Strus, Joseph M., Tuohino, Jeffrey L.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): ODOM, CURTIS B
• Application Number:
  US09/522,556
• Time in Patent Office: 1,341 Days
• Field of Search: 375/371, 375/224, 375/226, 375/373, 701/214, 331/1, 331/17, 331/45
• US Class Current: 375/371
• CPC Class Codes: G06F 1/022 Waveform generators, i.e. devices for generating periodical functions of time, e.g. direct digital synthesizers G06F1/025, G06F1/03 take precedence
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation
• CPC Class Codes: H04L 2027/0016 Stabilisation of local oscillators

Abstract

A method of and computer readable medium for obtaining sub least significant bit phase accuracy in a digitally controlled oscillator by choosing a phase angle, θ; solving the base equation Ap+Bq=1 for A, wherein values of p and q are relatively prime components of a least significant bit; and computing a command value, k, from the command equation k=A*nint(qθ)mod(q).

Claims

1. A method of obtaining sub least significant bit phase accuracy in simulating a carrier phase signal with a digitally controlled oscillator comprising the steps of:

choosing a phase angle, θ

;

solving the base equation

2. The method of claim 1 further comprises the step of entering the appropriate command indicated by said command value, k, into said digitally controlled oscillator.

3. The method of claim 1 wherein said base equation solution uses an Euclidean algorithm.

4. The method of claim 3 wherein said value of p represents a numerator of said least significant bit and said value of q represents a corresponding denominator of said least significant bit.

5. A system for simulating a carrier phase signal comprising:

a computer readable medium having computer executable instructions for causing a computer to perform the step of;

solving the base equation

6. The medium of claim 5 wherein said base equation solution uses an Euclidean algorithm.

7. The medium of claim 6 wherein said value of p represents a numerator of said least significant bit and said value of q represents a corresponding denominator of said least significant bit.

8. The medium of claim 5 wherein said θ

is a desired phase angle.