Granted Patent B2

US 6,947,507 · App. 09/989,337 · Granted Sep 20, 2005

Assignee: Calamp Corp.

Abstract

Claims (115)

1. A method of processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the method comprising the steps of:

receiving said transmit signals S tr with a plurality of spatially separated antennas to form respective receive signals S rcv ; and

spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the step of correcting said receive signals S rcv to form respective corrected signals S crct that reduce errors in said signal parameter and further including the steps of:

comparing said signal parameter of at least one of said corrected signals S crct to a known corresponding signal parameter to detect a difference; and

altering phase and gain of said corrected signal S crct to reduce said difference below a predetermined threshold and thereby reduce the contribution of an interference signal to said combined corrected signal S crctcmb .

2. The method of claim 1 , further including the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

3. A method of processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the method comprising the steps of:

receiving said transmit signals S tr with a plurality of spatially separated antennas to form respective receive signals S rcv ; and

spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the step of correcting said received signals S rcv to form respective corrected signals S crct that reduce errors in said signal parameter and further including the steps of:

comparing said signal parameter of at least one of said corrected signals S crct to a known corresponding signal parameter to detect a difference; and

inserting a canceling signal into said corrected signals S crct to reduce said difference below a predetermined threshold and thereby reduce the contribution of an interference signal to said combined corrected signal S crctcmb .

4. The method of claim 3 , further including the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

5. A method of processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the method comprising the steps of:

receiving said transmit signals S tr with a plurality of spatially separated antennas to form respective received signals S rcv ; and

spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

correcting said receive signals S rcv to form respective corrected signals Scrct that reduce temporal errors in said signal parameter; and

combining said corrected signals S crct to reduce spatial errors of said signal parameter in said combined corrected signal S crctcmb .

6. The method of claim 5 , wherein said correcting step includes the step of equalizing said receive channel C rcv .

7. The method of claim 6 , wherein, for each of said receive signals S rcv , said equalizing step includes the steps of:

summing versions of that received signal S rcvd that are modified with respective weights and time delays to form a corrected signal S crct ;

comparing said signal parameter of said corrected signal S crct and a known corresponding signal parameter to detect a difference; and

updating said weights and time delays to reduce said difference.

8. The method of claim 7 , wherein said equalizing step further includes the step of convolving one of said receive signals S rcv with a known version of said signal parameter to determine said time delays.

9. The method of claim 5 , wherein said combining step includes the steps of:

providing said corrected signals S crct with respective weights to form said combined corrected signal S crctcmb ;

comparing said signal parameter of said combined corrected signal S crctcmb and a known corresponding signal parameter to detect a difference; and

updating said weights to reduce said difference.

10. The method of claim 5 , wherein said combining step includes the steps of:

comparing a spectrum of at least one of said corrected signals S crct to a spectrum of a known corresponding signal parameter to detect a difference; and

altering phase and gain of said corrected signals S crct to reduce said difference below a predetermined threshold and thereby reduce the contribution of an interference signal to said combined corrected signal S crctcmb .

11. The method of claim 5 , further including the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

12. A method of processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the method comprising the steps of:

receiving said transmit signals S tr with a plurality of spatially separated antennas to form respective receive signals S rcv ; and

spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

estimating said receive channel C rcv to determine time delays that correspond to said receive paths;

for each determined time delay, summing corresponding receive signals S rcv which are modified by respective weights to provide a respective corrected signal S crct that reduces spatial errors in said signal parameter; and

with their respective time delays, combining all corrected signals S crct derived in said summing step to realize said combined corrected signal Scrctcmb.

13. The method of claim 17 , further including the step of combining the results of said estimating step on at least two of said receive signals S rcv .

14. The method of claim 12 , wherein said estimating step includes the step of convolving one said receive signals S rcv with a known signal parameter that corresponds to said signal parameter of receive signals S rcv to determine delays.

15. The method of claim 12 , wherein said estimating step includes the steps of:

summing versions of one of said receive signal S rcv that have respective weights and time delays to form a test signal S tst ;

comparing said signal parameter of said test signal S tst and a known corresponding signal parameter to detect a difference; and

updating said weights and time delays to reduce said difference.

16. The method of claim 12 , further including the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

17. A method of processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the method comprising the steps of:

receiving said transmit signals S tr with a plurality of spatially separated antennas to form respective receive signals S rcv ; and

spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

for each of said receive signals S rcv , providing signal versions of that receive signal S rcv that have respective weights and time delays;

summing said signal versions of all of said received signals S rcv to form said combined corrected signal S crctcmb ;

comparing said signal parameter of said combined corrected signal S crctcmb and a known corresponding signal parameter to detect a difference; and

updating said weights and time delays to reduce said difference.

18. The method of claim 17 , wherein said comparing step includes the step of convolving one of said receive signals S rcv with a known version of said signal parameter to determine said time delays.

19. The method of claim 18 , wherein said weights are complex coefficients.

20. The method of claim 17 , further including the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

21. A method of processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the method comprising the steps of:

receiving said transmit signals S tr with a plurality of spatially separated antennas to form respective receive signals S rcv ; and

spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

estimating said receive channel C rcv to determine time delays and respective weights for reduction of temporal errors in said signal parameter;

applying complex corrections based on of said weights to said signal portions to obtain corrected signals S crct ; and

summing said corrected signals S crct to obtain said combined corrected signal S crctcmb .

22. The method of claim 21 , further including the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

23. A receiver system for processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the system comprising:

a plurality of spatially separated antennas that convert said transmit signals S tr to receive signals S rcv ;

a downconverter system that coherently downconverts said receive signals S rcv ;

analog-to-digital converters that coherently digitize said receive signals S rcv ; and

at least one data processor that is programmed to execute the step of spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said downconverter system includes:

downconverters that coherently downconvert and multiplex said receive signals S rcv to different first intermediate signals;

tuners that coherently downconvert said first intermediate signals to second intermediate signals; and

a cable that couples said first intermediate signals to said tuners.

24. A receiver system for processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the system comprising:

a plurality of spatially separated antennas that convert said transmit signals S tr to receive signals S rcv ;

a downconverter system that coherently downconverts said receive signals S rcv ;

analog-to-digital converters that coherently digitize said receive signals S rcv ; and

at least one data processor that is programmed to execute the step of spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

correcting said receive signals S rcv to form respective corrected signals S crct that reduce temporal errors in said signal parameter; and

combining said corrected signals S crct to reduce spatial errors of said signal parameter in said combined corrected signal S crctcmb .

25. The system of claim 24 , wherein said processing step further includes the step of selecting said signal parameter from parameters that include signal preamble, signal code, reading code and signal modulation.

26. A receiver system for processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the system comprising:

a plurality of spatially separated antennas that convert said transmit signals S tr to receive signals S rcv ;

a downconverter system that coherently downconverts said receive signals S rcv ;

analog-to-digital converters that coherently digitize said receive signals S rcv ; and

at least one data processor that is programmed to execute the step of spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

estimating said receive channel C rcv to determine time delays that correspond to said receive paths;

for each determined time delay, summing corresponding received signals S rcv which are modified by respective weights to provide a respective corrected signal S crct that reduces spatial errors in said signal parameter; and

with their respective time delays, combining all corrected signals S crct derived in said summing step to realize said combined corrected signal S crctcmb .

27. The system of claim 26 , wherein said processing step further includes the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

28. A receiver system for processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the system comprising:

a plurality of spatially separated antennas that convert said transmit signals S tr to receive signals S rcv ;

a downconverter system that coherently downconverts said receive signals S rcv ;

analog-to-digital converters that coherently digitize said receive signals S rcv ; and

at least one data processor that is programmed to execute the step of spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

for each of said receive signals S rcv , providing signal versions of that receive signals S rcv that have respective weights and time delays;

summing said signal versions of all of said receive signals S rcv to form said combined corrected signal S crctcmb ;

comparing said signal parameter of said combined corrected signal S crctcmb and a known corresponding signal parameter to detect a difference; and

updating said weights and time delays to reduce said difference.

29. The system of claim 28 , wherein said processing step further includes the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

30. A receiver system for processing transmit signals S tr that are received over a receive channel C rcv which is formed by a plurality of receive paths, the system comprising:

a plurality of spatially separated antennas that convert said transmit signals S tr to receive signals S rcv ;

a downconverter system that coherently downconverts said receive signals S rcv ;

analog-to-digital converters that coherently digitize said receive signals S rcv ; and

at least one data processor that is programmed to execute the step of spatially and temporally processing said receive signals S rcv to form a combined corrected signal S crctcmb that reduces errors in at least one signal parameter;

wherein said processing step includes the steps of:

estimating said receive channel C rcv to determine time delays and respective weights for reduction of temporal errors in said signal parameter;

applying complex conjugates of said weights to said signal portions to obtain corrected signals S crct ; and

summing said corrected signals S crct to obtain said combined corrected signal S crctcmb .

31. The system of claim 30 , wherein said processing step further includes the step of selecting said signal parameter from parameters that include signal preamble, signal code, spreading code and signal modulation.

Assignments (9)

Continuity (2)