Method for processing in dual frequency civilian GPS receiver

A system for estimating phase and magnitude of an L2 GPS signal, the L2 signal having a P code and a W code modulated onto it, the W code being an unknown code, the system comprising:

• a. means for generating an L1 baseband signal using the L1 signal;
• b. means for generating an L2 baseband signal using the L2 signal;
• c. a first accumulator accumulating the L1 baseband signal over one P code bit to generate an L1 second baseband signal;
• d. a second accumulator accumulating the L2 baseband signal over one P code bit to generate an L2 second baseband signal;
• e. a W code generator, the W code generator generating an L2 W code estimate using the L1 second baseband signal and the L2 second baseband signal, the W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L2 signal at that time instant;
• f. a multiplier removing the L2 W code estimate from the L2 second baseband signal to generate an L2 first signal;
• and
• g. a third accumulator accumulating the L2 first signal to generate an L2 accumulated signal which is a measure of the phase and the magnitude of the L2 Y code carrier signal.

A method of estimating the W code for an L2 GPS signal, the L2 signal having a P code and a W code modulated onto it, the W code being an unknown code, the method comprising the steps of:

• a. generating an L1 baseband signal using the L1 signal;
• b. generating an L2 baseband signal using the L2 signal;
• and
• c. generating the W code estimate using the L1 baseband signal and the L2 baseband signal, the W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L2 signal at that time instant.

A system for estimating the W code for an L2 GPS signal, the L2 signal having a P code and a W code modulated onto it, the W code being an unknown code, the system comprising:

• a. means for generating an L1 baseband signal using the L1 signal;
• b. means for generating an L2 baseband signal using the L2 signal;
• and
• c. a W code generator generating the W code estimate using the L1 baseband signal and the L2 baseband signal, the W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L2 signal at that time instant.

A method of estimating the W code for L1 GPS signals and L2 GPS signals, the signals having a P code and a W code modulated onto it, the W code being an unknown code, the method comprising the steps of:

• a. generating an L1 primary signal using the L1 signal;
• b. generating an L2 primary signal using the L2 signal;
• and
• c. generatng the W code estimate using the L1 primary signal and the L2 primary signal, the W code estimate at a time instant being uncorrelated with the errors in the inphase and the quadrature components of the L1 signal and the L2 signal at that time instant.

A method of estimating phase and magnitude of L1 and L2 signals, the signals having a P code and a W code modulated onto it, the W code being an unknown code, the method comprising the steps of:

• a. generating an L1 baseband signal using the L1 signal;
• b. generating an L2 baseband signal using the L2 signal;
• c. generating an L1 W code estimate and an L2 W code estimate using the L1 baseband signal and the L2 baseband signal, the L1 W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L1 signal at that instant, the L2 W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L2 signal at that instant;
• d. removing the L1 W code estimate from the L1 baseband signal to generate an L1 first signal;
• e. removing the L2 W code estimate from the L2 baseband signal to generate an L2 first signal;
• f. accumulating the L1 first signal to generate an L1 accumulated signal, the L1 accumulated signal being a measure of the phase and the magnitude of the L1 Y code carrier signal;
• and
• g. accumulating the L2 first signal to generate an L2 accumulated signal, the L2 accumulated signal being a measure of the phase and the magnitude of the L2 Y code carrier signal.

A system for estimating phase and magnitude of L1 and L2 signals, the signals having a P code and a W code modulated onto it, the W code being an unknown code, the system comprising:

• a. means for generating an L1 baseband signal using the L1 signal;
• b. means for generating an L2 baseband signal using the L2 signal;
• c. a W code generator, the W code generator generating an L1 W code estimate and an L2 W code estimate using the L1 baseband signal and the L2 baseband signal, the L1 W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L1 signal at that time instant, the L2 W code estimate at a time instant being uncorrelated with the error in the inphase and the quadrature components of the L2 signal at that time. instant;
• d. a first multiplier removing the L1 W code estimate from the L1 baseband signal to generate an L1 first signal;
• e. a second multiplier removing the L2 W code estimate from the L2 baseband signal to generate an L2 first signal;
• f. a first accumulator accumulating the L1 first signal to generate an L1 accumulated signal, the L1 accumulated signal being a measure of the phase and the magnitude of the L1 Y code carrier signal;
• and
• g. a second accumulator accumulating the L2 first signal to generate an L2 accumulated signal, the L2 accumulated signal being a measure of the phase and the magnitude of the L2 Y code carrier signal.