Enhanced frequency agile radio

• US 6,335,953 B1
• Filed: 11/02/1999
• Issued: 01/01/2002
• Est. Priority Date: 05/08/1992
• Status: Expired due to Fees

• Current Assignee: M&FC Holding, LLC
• Original Assignee: Axonn LLC (Globalstar Incorporated)
• Inventors: Sanderford, H. Britton Jr., Davis, Robert J., Rouquette, Robert E.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Tran, Khai
• Application Number:
  US09/432,258
• Time in Patent Office: 791 Days
• Field of Search: 375/344, 375/130, 455/67.4, 455/71, 455/260, 455/264, 455/161.1, 455/255-257, 455/192.1, 455/192.2, 455/226.1
• US Class Current: 375/344
• CPC Class Codes: H03J 1/0091 provided with means for scanning over a band of frequencies H03J1/0058 takes precedence
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7152 with means for suppressing interference
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal

Abstract

A method utilizing intentionally generated in-band frequency harmonics to compensate for frequency error and frequency drift in a voltage controlled oscillator of a receiver, thereby eliminating the frequency synthesizer and RF divider required in conventional designs. The method includes modulating the intentionally generated frequency in a predetermined manner so that a receiver can identify the intentionally generated frequency and includes the use of plural frequency harmonics for use in a curve fitting technique to correct frequency error in the voltage controlled oscillator.

Claims

1. A method to compensate for frequency error in a receiver, comprising the steps of:

generating, intentionally by the receiver, a frequency in an operating bandwidth of the receiver;

receiving the intentionally generated frequency by the receiver;

correcting frequency error in the receiver by utilizing the intentionally generated frequency received by the receiver; and

performing the generating, receiving, and correcting steps with the receiver,

wherein the step of receiving includes the substep of sweeping an internal local oscillator of the receiver in order to identify said intentionally generated frequency.

2. A method to compensate for frequency error in a receiver, comprising the steps of:

generating, intentionally by the receiver, a frequency in an operating bandwidth of the receiver;

receiving the intentionally generated frequency by the receiver;

correcting frequency error in the receiver by utilizing the intentionally generated frequency received by the receiver;

performing the generating, receiving, and correcting steps with the receiver; and

modulating the intentionally generated frequency in a predetermined manner such that the receiver can uniquely identify the intentionally generated frequency.

4. The method according to claim 2, wherein the step of receiving includes the substep of sweeping an internal local oscillator of the receiver in order to identify said intentionally generated frequency.

3. A method to compensate for frequency error in a receiver, comprising the steps of:

generating, intentionally by the receiver, a frequency in an operating bandwidth of the receiver;

receiving the intentionally generated frequency by the receiver;

correcting frequency error in the receiver by utilizing the intentionally generated frequency received by the receiver; and

performing the generating, receiving, and correcting steps with the receiver,

wherein said step of receiving comprises the substep of utilizing a fast Fourier transform to receive the intentionally generated frequency.

5. The method according to claim 3, wherein the step of receiving includes the substep of sweeping an internal local oscillator of the receiver in order to identify said intentionally generated frequency.

6. A receiver having an operating bandwidth and an internal local oscillator, comprising:

means for intentionally generating a frequency in the operating bandwidth of the receiver;

means for receiving the intentionally generated frequency, including means for sweeping the internal local oscillator in order to identify said intentionally generated frequency; and

means for correcting a frequency error in the receiver by utilizing the received intentionally generated frequency as a reference frequency.

7. A receiver having an operating bandwidth, comprising:

means for intentionally generating a frequency in the operating bandwidth of the receiver;

means for modulating the intentionally generated frequency in a predetermined manner such that the receiver can uniquely identify the intentionally generated frequency;

means for receiving the intentionally generated modulated frequency by the receiver; and

means for correcting a frequency error in the receiver by utilizing the intentionally generated modulated frequency as a reference frequency.

8. The receiver according to claim 7, wherein the means for receiving includes means for sweeping an internal local oscillator of the said receiver in order to identify said intentionally generated frequency.

9. A receiver having an operating bandwidth, comprising:

means for intentionally generating a frequency in the operating bandwidth of the receiver;

means for receiving the intentionally generated frequency including a fast Fourier transform mechanism configured to analyze the intentionally generated frequency; and

means for correcting a frequency error in the receiver by utilizing the received intentionally generated frequency as a reference frequency.

10. The receiver according to claim 9, wherein the means for receiving includes means for sweeping an internal local oscillator of the said receiver in order to identify said intentionally generated frequency.