Method and apparatus of pulse position demodulation

• US 5,977,822 A
• Filed: 04/04/1998
• Issued: 11/02/1999
• Est. Priority Date: 04/04/1998
• Status: Expired due to Term

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: SigmaTel Incorporated (NXP Semiconductors NV)
• Inventors: Markison, Timothy W., Rybicki, Mathew A., Margules, Michael A., Jackson, H. Spence, Kodra, Gregg S.
• Primary Examiner(s): Grimm, Siegfried H.
• Application Number:
  US09/055,190
• Time in Patent Office: 577 Days
• Field of Search: 329/313, 329/314, 329/311, 375/239, 375/340, 375/342
• US Class Current: 329/313
• CPC Class Codes: H03K 7/04 Position modulation, i.e. PPM
• CPC Class Codes: H03K 9/04 of position-modulated pulses
• CPC Class Codes: H03K 9/10 of pulses having combined modulation
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation

Abstract

A method and apparatus for pulse position demodulation begins by receiving a pulse that is positioned approximately at one of a plurality of time intervals within a time chip, where the pulse has a pulse width that is greater than each of the plurality of time intervals. The decoding process then continues by determining the time interval in which a transition edge of the pulse lies. From the particular time interval, a set of bits is determined.

Claims

1. A method for pulse position demodulation, the method comprising the steps of:

a) receiving a pulse that is positioned approximately at one of a plurality of time intervals within a time chip, wherein the pulse has a pulse width that is greater than any one of the plurality of time intervals;

b) determining the one of the plurality of time intervals based on a transition edge of the pulse; and

c) determining a set of bits based on the one of the plurality of time intervals.

2. The method of claim 1 further comprises:

receiving a second pulse that is positioned approximately at one of the plurality of time intervals of another time chip;

determining the one of the plurality of time intervals of the another time chip; and

determining a second set of bits based on the one of the plurality of time intervals of the another time chip.

3. The method of claim 1 further comprises, within step (b), utilizing a leading or trailing transition edge of the pulse to determine the set of bits.

4. The method of claim 1 further comprises, within step (c), utilizing a look-up table to determine the set of bits from the one of the plurality of time intervals.

5. The method of claim 1 further comprises determining amplitude of the pulse and utilizing the amplitude to further determine the set of bits.

6. The method of claim 1 further comprises determining pulse width of the pulse and utilizing the pulse width to further determine the set of bits.

7. A method for pulse position demodulation, the method comprising the steps of:

a) receiving a plurality of pulses, wherein each pulse of the plurality of pulses is received in a separate time chip and wherein the time chip includes a plurality of time intervals;

b) determining time interval positioning of a pulse of the plurality of pulses, wherein the time interval positioning is based on a transition edge of the pulse being positioned at one of a plurality of time intervals;

c) determining a data value based on the time interval positioning of the pulse; and

d) repeating steps (b) and (c) for other pulses of the plurality of pulses.

8. The method of claim 7 further comprises determining pulse width of the pulse and utilizing the pulse width to further determine the data value.

9. The method of claim 7 further comprises determining an amplitude of the pulse and utilizing the amplitude to further determine the data value.

10. A pulse position demodulator comprising:

a receiver operably coupled to receive a pulse of pulse position modulated data;

pulse position detector operably coupled to the receiver, wherein the pulse position detector detects time interval location of the pulse within a time chip, wherein the time chip includes a plurality of time intervals; and

data recovery circuit operably coupled to the pulse position detector, wherein the data recovery circuit determines a data value based on the time interval location.

11. The pulse position demodulator of claim 10 further comprises the data recovery circuit determines a set of bits as the data value.

12. The pulse position demodulator of claim 10 further comprises an amplitude demodulator that is operably coupled to the receiver, wherein the amplitude demodulator detects an amplitude of the pulse and wherein the data recovery circuit further determines the data value based on the amplitude.

13. The pulse position demodulator of claim 10 further comprises a pulse width detector that is operably coupled to the receiver, wherein the pulse width detector detects a pulse width of the pulse and wherein the data recovery circuit further determines the data value based on the pulse width.

14. A pulse position demodulator comprising:

a receiver operably coupled to receive a pulse modulated signal having a pulse positioned approximately at one of a plurality of time intervals within a time chip, wherein the pulse includes a pulse width that is greater than any one of the plurality of time intervals;

a processing unit; and

memory operably coupled to the processing unit, wherein the memory stores programming instructions that, when read by the processing unit, causes the processing unit to determine the one of the plurality of time intervals based on a transition edge of the pulse, and determine a set of bits based on the one of the plurality of time intervals.

15. The digital demodulator of claim 14 further comprises, within the memory, programming instructions that, when read by the processing unit, causes the processing unit to utilize a look-up table to determine the set of bits.

16. The digital demodulator of claim 14 further comprises, within the memory, programming instructions that, when read by the processing unit, causes the processing unit to determine amplitude of the pulse and utilize the amplitude to further determine the set of bits.

17. The digital demodulator of claim 14 further comprises, within the memory, programming instructions that, when read by the processing unit, causes the processing unit to determine pulse width of the pulse and utilize the pulse width to further determine the set of bits.

18. A pulse position demodulator comprising:

a receiver operably coupled to receive a plurality of pulses, wherein each pulse of the plurality of pulses is received in a separate time chip and wherein the time chip includes a plurality of time intervals, and wherein each of the plurality of pulses has a pulse width that is greater than any one of the plurality of time intervals;

a processing unit; and

memory operably coupled to the processing unit, wherein the memory stores programming instructions that, when read by the processing unit, causes the processing unit to determine time interval positioning for a pulse of the plurality of pulses, wherein the time interval positioning is based on a transition edge of the pulse being positioned at one of the plurality of time intervals;

determine a data value based on the time interval positioning of the pulse; and

repeat the determining of time interval positioning and the determining of a data value for other pulses of the plurality of pulses.

19. The digital demodulator of claim 18 further comprises, within the memory, programming instructions that, when read by the processing unit, causes the processing unit to determine pulse width of the pulse and utilize the pulse width to further determine the data value.

20. The digital demodulator of claim 18 further comprises, within the memory, programming instructions that, when read by the processing unit, causes the processing unit to determine an amplitude of the pulse and utilize the amplitude to further determine the data value.