Patent ID: 6516021
Filing Date: 2003-02-04
Classification: G01S

Abstract:
A method for carrier and code tracking of a received signal in a receiver, the received signal comprising a received carrier signal and a received code signal, the method comprising the steps of,demodulating the received signal with a carrier replica signal for generating a carrier demodulated received signal, correlating the carrier demodulated received signal with a code replica signal for providing output samples, residual prefiltering the output samples for estimating residual errors between the received and code replica signals and for providing residual error data, the residual prefiltering using a prefilter measurement model relating the output samples to residual state variables and a residual process model relating the residual state variables to the residual error data, integration filtering the residual error data for estimating an integration error vector, the integration filtering for estimating the integration error vector using an integration measurement model relating the residual error data to integration state variables and an integration process model relating the integration state variables to the integration error vector, carrier adjusting the replica carrier signal by the integration error vector for providing an adjusted replica carrier signal for demodulating the received signal, and code adjusting the replica code signal by the integration error vector for providing an adjusted replica code signal for correlating the received signal with the adjusted replica code signal for reducing the residual error data during residual prefiltering and for reducing the integration error vector during integration filtering.