Multi-dynamic multi-envelope receiver

• US 7,885,355 B2
• Filed: 10/15/2007
• Issued: 02/08/2011
• Est. Priority Date: 10/15/2007
• Status: Active Grant

• Current Assignee: CAES Systems LLC
• Original Assignee: Cobham Defense Electronic Corporation
• Inventors: Egri, Robert Gyorgy, Perraud, Laurent Claude
• Primary Examiner(s): Ahn; Sam K
• Application Number:
  US11/872,262
• Publication Number:
  US 20090097601A1
• Time in Patent Office: 1,212 Days
• Field of Search: 375/142, 375/143, 375/144, 375/148, 375/150, 375/152, 375/316, 375/343, 375/346, 455/63.1, 455/114.2, 455/278.1, 455/296
• US Class Current: 375/316
• CPC Class Codes: H04B 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H

Abstract

The present invention is a system and a method of filtering a signal at a receiver, the signal having at least a desired channel and blockers. A first converter converts a first copy of the signal resulting in a relatively narrow band, high-resolution first signal. A second converter converts a second copy of the signal resulting in a relatively wide band, low-resolution second signal. Once each copy of the signal is converted, the copies are passed to a combiner. At the combiner, the two copies of the signal are analyzed and the desired channel is extracted from the first copy of the signal by removing any inter-modulation product caused by any interference detected in the second copy from the blockers (not detected in the first copy).

Claims

1. A method of improving the effective linearity of a receiver that is processing a signal comprising at least a payload component and an interference component, said payload component being within a frequency band, at least a first part of said interference component being outside said frequency band, the method comprising the steps of:

(a) converting a first portion of said signal inside said frequency band to form a relatively narrow band, high-resolution first converted signal;

(b) converting a second portion of said signal including said noise component outside said frequency band to form a relatively wide band, low-resolution second converted signal; and

(c) extracting said payload component from said first converted signal using said interference component derived from said second converted signal to form a filtered signal.

2. The method of claim 1 wherein a frequency band ratio of said first converted signal and said second converted signal is in the range of 1:

25 to 1;

50.

3. The method of claim 2 wherein a resolution ratio of said first converted signal and said second converted signal is in the range of 1.5:

1 to 2.5;

1.

4. The method of claim 1, wherein said first converted signal is a 20 MHz band at 14 bits resolution.

5. The method of claim 4, wherein said second converted signal is a 1 GHz signal at 6 bits resolution.

6. The method of claim 1, wherein step (a) is performed using a first converter comprising a narrow band/low sampling rate, high-resolution analog to digital converter, and step (b) is performed using a second converter comprising a wide band/high sampling rate, low-resolution analog to digital converter.

7. The method of claim 1, wherein said interference component comprises a second part inside said frequency band, said second part being converted by said first converter.

8. The method of claim 7, wherein said extracting comprises at least extracting said second part of said interference component from said first converted signal.

9. The method of claim 8, wherein said extracting comprises subtracting said second part of said interference component detected in said second converted signal from said first converted signal to leave said payload component in said filtered signal.

10. The method of claim 1, wherein said receiver is in a wireless communication device.

11. A system for improving linearity of the receiver, whose received signal comprises at least a payload component and an interference component, said payload component being within a frequency band, at least a first part of said interference component being outside said frequency band, the system comprising:

(a) a first converter for converting a first portion of said signal inside said frequency band to form a relatively narrow band, high-resolution first converted signal;

(b) a second converter for converting a second portion of said signal including said interference component outside said frequency band to form a relatively wide band, low-resolution second converted signal; and

(c) a combiner connected to both said first converter and said second converter, said combiner for extracting said payload component from said first converted signal using said interference component derived from said second converted signal to form a filtered signal.

12. The system of claim 11 wherein a frequency band ratio of said first converted signal and said second converted signal is in the range of 1:

25 to 1;

50.

13. The system of claim 12 wherein a resolution ratio of said first converted signal and said second converted signal is in the range of 1.5:

1 to 2.5;

1.

14. The system of claim 11, wherein said first converted signal is a 20 MHz band at 14 bits resolution.

15. The system of claim 14, wherein said second converted signal is a 1 GHz signal at 6 bits resolution.

16. The system of claim 11, wherein said first converter comprises a narrow band, high-resolution analog to digital converter and said second converter comprises a wide band, low-resolution analog to digital converter.

17. The system of claim 11, wherein said interference component comprises a second part inside said frequency band, said second part being converted by said first converter.

18. The system of claim 17, wherein said extracting comprises at least extracting said second part of said interference component from said first converted signal.

19. The system of claim 18, wherein said extracting comprises subtracting said interference component detected in said second converted signal from said first converted signal to produce said payload component.

20. The system of claim 11, wherein said receiver is in a wireless communication device.