System and method of companding an input signal of an energy detecting receiver

• US 8,254,595 B2
• Filed: 03/25/2008
• Issued: 08/28/2012
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Fagg, Russell John
• Primary Examiner(s): Lee, Calvin
• Application Number:
  US12/055,077
• Publication Number:
  US 20090243699A1
• Time in Patent Office: 1,617 Days
• Field of Search: 381/71.1, 381/71.14, 381/106, 381/120
• US Class Current: 381/106
• CPC Class Codes: H03D 1/00 Demodulation of amplitude-modulated oscillations H03D5/00, H03D9/00, H03D11/00 take precedence
• CPC Class Codes: H04B 2001/6908 using time hopping

Abstract

An apparatus configured as a compandor to achieve a defined dynamic range for an output signal in response to an input signal. In particular, the apparatus comprises a first circuit adapted to generate a first signal from the input signal, wherein the first signal includes a first dynamic range (e.g., a first sensitivity and first compression point); and a second circuit adapted to generate a second signal from the input signal, wherein the second signal includes a second dynamic range (e.g., a second sensitivity and second compression point) that is different from the first dynamic range of the first signal. The apparatus may further include a third circuit adapted to generate an output signal related to a sum of the first and second signals. By adjusting the first and second dynamic ranges, an overall dynamic range for the output signal of the companding apparatus may be achieved.

Claims

1. A method of processing an input signal, comprising:

generating a first signal from the input signal, wherein the first signal has a first dynamic range; and

generating a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal,

wherein generating the first signal comprises detecting the input signal with a first sensitivity or gain to generate the first signal, and

wherein generating the first signal comprises generating the first signal not substantially beyond a first compression or threshold level.

2. The method of claim 1, further comprising combining the first and second signals to generate a third signal.

3. The method of claim 1, wherein the first signal is non-linearly related to the input signal.

4. The method of claim 1, wherein generating the second signal comprises detecting the input signal with a second sensitivity or gain to generate the second signal, and further wherein the second sensitivity or gain is different than the first sensitivity or gain.

5. The method of claim 1, wherein generating the second signal comprises generating the second signal not substantially beyond a second compression or threshold level, and further wherein the second compression or threshold level is different than the first compression or threshold level.

6. The method of claim 1, further comprising adjusting the first or second dynamic range.

7. The method of claim 6, wherein adjusting the first or second dynamic range comprises generating a reference voltage or current, respectively.

8. The method of claim 7, wherein generating the reference voltage or current comprises activating a programmable reference level device.

9. The method of claim 1, wherein generating the first or second signal comprises envelope detecting or substantially squaring the input signal.

10. The method of claim 1, wherein generating the first signal comprises applying the input signal to a first transistor pair with transistors of a first size, and further wherein generating the second signal comprises applying the input signal to a second transistor pair with transistors of a second size different than the first size of the transistors of the first transistor pair.

11. The method of claim 10, further comprising providing first and second reference currents for the first and second transistor pairs.

12. An apparatus, comprising:

a first means for generating a first signal from an input signal, wherein the first signal has a first dynamic range; and

a second means for generating a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal,

wherein the first generating means is configured to have a first sensitivity or gain in generating the first signal from the input signal; and

wherein the first generating means is configured to have a first compression point or threshold.

13. The apparatus of claim 12, further comprising means for combining the first and second signals to generate a third signal.

14. The apparatus of claim 12, wherein the first signal is non-linearly related to the input signal.

15. The apparatus of claim 12, wherein the second generating means is configured to have a second sensitivity or gain in generating the second signal from the input signal, and further wherein the second sensitivity or gain of the second generating means is different than the first sensitivity or gain of the first generating means.

16. The apparatus of claim 12, wherein the second generating means is configured to have a second compression point or threshold, and further wherein the second compression point of threshold of the second generating means is different than the first compression point or threshold of the first generating means.

17. The apparatus of claim 12, further comprising a means for adjusting the first or second dynamic range.

18. The apparatus of claim 12, wherein the dynamic range adjusting means is adapted to provide a reference voltage or current to the first or second generating means, respectively.

19. The apparatus of claim 18, wherein the dynamic range adjusting means comprises a programmable reference level device adapted to generate the reference voltage or current.

20. The apparatus of claim 12, wherein the first or second generating means comprises an envelope detector, a squaring device, a differential transistor pair, or a differential amplifier.

21. The apparatus of claim 12, wherein the first generating means comprises a first transistor pair with transistors of a first size, and further wherein the second generating means comprises a second transistor pair with transistors of a second size different than the first size of the transistors of the first transistor pair.

22. The apparatus of claim 21, further comprising means for generating first and second reference currents for the first and second transistor pairs.

23. The apparatus of claim 12, wherein the first or second generating means is adapted to have a fractional bandwidth on the order of 20% or more, a bandwidth on the order of 500 MHz or more, or a fractional bandwidth on the order of 20% or more and a bandwidth on the order of 500 MHz or more.

24. An apparatus, comprising:

a first circuit adapted to generate a first signal from an input signal, wherein the first signal has a first dynamic range; and

a second circuit adapted to generate a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal,

wherein the first circuit is configured to have a first sensitivity or gain in generating the first signal from the input signal; and

wherein the first circuit is configured to have a first compression point or threshold.

25. The apparatus of claim 24, further comprising a third circuit adapted to generate a third signal related to a sum of the first and second signals.

26. The apparatus of claim 24, wherein the first signal is non-linearly related to the input signal.

27. The apparatus of claim 24, wherein the second circuit is configured to have a second sensitivity or gain in generating the second signal from the input signal, and further wherein the second sensitivity or gain of the second circuit is different than the first sensitivity or gain of the first circuit.

28. The apparatus of claim 24, wherein the second circuit is configured to have a second compression point or threshold, and further wherein the second compression point or threshold of the second circuit is different than the first compression point or threshold of the first circuit.

29. The apparatus of claim 24, further comprising a third circuit for adjusting the first or second dynamic range.

30. The apparatus of claim 29, wherein the third circuit is adapted to provide a reference voltage or current to the first or second circuit.

31. The apparatus of claim 30, wherein the third circuit comprises a programmable reference level device adapted to generate the reference voltage or current.

32. The apparatus of claim 24, wherein the first or second circuit comprises an envelope detector, a squaring device, a differential transistor pair, or a differential amplifier.

33. The apparatus of claim 24, wherein the first circuit comprises a first transistor pair with transistors having a first size, and further wherein the second circuit comprises a second transistor pair with transistors having a second size different than the first size of the transistors of the first transistor pair.

34. The apparatus of claim 32, further comprising first and second current sources adapted to provide first and second reference currents for the first and second transistor pairs.