System and method for improved noise immunity in impulse and radar communications systems

• US 20070189425A1
• Filed: 02/13/2006
• Published: 08/16/2007
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Becker, Robert
• Granted Patent: US 7,835,474 B2
• Time in Patent Office: Days
• US Class Current: 375/343
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04B 14/02 characterised by the use of pulse modulation in radio transmission relays H04B7/17

Abstract

A method of improving noise immunity in a signal is provided. The method comprises receiving a multi-bit symbol comprised of pulses and absences of pulses, incrementing a correlation count if a pulse is present when a pulse is expected, and decrementing the correlation count if a pulse is present when a pulse is not expected.

Claims

1. A method of improving noise immunity in a signal, the method comprising:

receiving a multi-bit symbol comprised of pulses and absences of pulses;

incrementing a correlation count if a pulse is present when a pulse is expected; and

decrementing the correlation count if a pulse is present when a pulse is not expected.

2. The method of claim 1, further comprising:

comparing the correlation count to a threshold value;

accepting the symbol if the correlation count is greater than the threshold value; and

rejecting the symbol if the correlation count is less than the threshold value.

3. The method of claim 1, further comprising:

incrementing the correlation count if a pulse is not present when a pulse is not expected.

4. The method of claim 1, further comprising:

decrementing a counter if a pulse is not present when a pulse is expected.

5. The method of claim 1, further comprising:

balancing the multi-bit symbol such that there are a substantially equal number of pulses as absences of a pulse in the multi-bit symbol.

6. The method of claim 1, wherein receiving a multi-bit symbol further comprises receiving one of a pulse-position modulated symbol, a pulse-code modulated symbol, a pulse-width modulated symbol, a pulse-amplitude modulated symbol, and a pulse-density modulated symbol.

7. A computer program product, comprising:

a computer-usable medium having computer-readable instructions embodied therein for configuring a computer processor, the computer program product comprising;

first instructions configured to cause a computer processor to compare a received multi-bit symbol comprised of pulses and absences of pulses to an expected pattern of pulses and absences of pulses;

second instructions configured to cause a computer processor to increment a correlation count when the received multi-bit symbol matches the expected pattern;

third instructions configured to cause a computer processor to decrement the correlation count when the received multi-bit symbol does not match the expected pattern; and

fourth instructions configured to cause a computer processor to compare the correlation count to a threshold value.

8. The computer program product of claim 7, wherein instructions configured to cause a computer processor to increment a correlation count further comprises:

instructions configured to cause a computer processor to increment the correlation count if a pulse is detected when a pulse is expected.

9. The computer program product of claim 7, wherein instructions configured to cause a computer processor to increment a correlation count further comprises:

instructions configured to cause a computer processor to increment the correlation count if a pulse is not detected when a pulse is not expected.

10. The computer program product of claim 7, wherein instructions configured to cause a computer processor to decrement a correlation count further comprises:

instructions configured to cause a computer processor to decrement the correlation count if a pulse is not detected when a pulse is expected.

11. The computer program product of claim 7, wherein instructions configured to cause a computer processor to decrement a correlation count further comprises:

instructions configured to cause a computer processor to decrement the correlation count if a pulse is detected when a pulse is not expected.

12. The computer program product of claim 7, wherein instructions configured to cause a computer processor to compare the correlation count to a threshold value further comprises:

instructions configured to cause a computer processor to output a signal when the correlation count is less than the threshold value indicating that the received multi-bit symbol is rejected; and

instructions configured to cause a computer processor to output a signal when the correlation count is greater than the threshold value indicating that the received multi-bit symbol is accepted.

13. A communications system, comprising:

a transmit device adapted to transmit a multi-bit symbol, the transmit device being adapted to modulate the multi-bit symbols using a pulse-based modulation scheme; and

a receiving device adapted to accept the received multi-bit symbol when a correlation count exceeds a threshold value and reject the received multi-bit symbol when the correlation count does not exceed the threshold value, wherein the receiving device increments the correlation count if a pulse is present when expected and decrements the correlation count if a pulse is present when a pulse is not expected.

14. The communications system of claim 13, wherein the receiving device comprises:

a processing unit adapted to compare the received multi-bit symbol to an expected pattern of pulses and absences of pulses, wherein the processing unit is further adapted to increment the correlation count for each occurrence of a pulse in the received multi-bit symbol when a pulse is expected in the expected pattern and to decrement the correlation count for each occurrence of a pulse in the received multi-bit symbol when a pulse is not expected.

15. The communications system of claim 13, wherein the receiving device is further adapted to increment the correlation count when a pulse is not detected when not expected.

16. The communications system of claim 13, wherein the receiving device is further adapted to decrement the correlation count when a pulse is not detected when expected.

17. The communications system of claim 13, wherein the transmit device is adapted to balance the multi-bit symbol such that there are a substantially equal number of pulses and absences of pulses in the multi-bit symbol.

18. The communications system of claim 13, wherein the transmit device is adapted to modulate the multi-bit symbol using one of a pulse-position modulation scheme, a pulse-code modulation scheme, a pulse-width modulation scheme, a pulse-amplitude modulation scheme, and a pulse-density modulation scheme.

19. A communications system, comprising:

means for transmitting a multi-bit symbol comprised of pulses and absences of pulses; and

means for receiving the multi-bit symbol, wherein the means for receiving the multi-bit symbol increments a correlation count when a pulse is present when a pulse is expected and decrements the correlation count when a pulse is present when a pulse is not expected.

20. The communications system of claim 19, wherein the means for transmitting the multi-bit symbol is adapted to modulate the multi-bit symbol using one of a pulse-position modulation scheme, a pulse-code modulation scheme, a pulse-width modulation scheme, a pulse-amplitude modulation scheme, and a pulse-density modulation scheme.

21. The communications system of claim 19 wherein the means for receiving the multi-bit symbol is adapted to increment the correlation count when a pulse is not detected when not expected.

22. The communications system of claim 19, wherein the means for receiving the multi-bit symbol is adapted to decrement the correlation count when a pulse is not detected when expected.