Tracking of signals with at least one subcarrier

摘要

A system for tracking a received signal with a subcarrier, the received signal representing a carrier signal modulated with a code signal and with a subcarrier signal. The system comprises independent and cooperatively operating loops: a phase lock loop tracking the carrier signal, a subcarrier lock loop tracking the subcarrier signal, and a delay lock loop tracking the code signal. The subcarrier lock loop comprises a first controllable oscillator and a first early-minus-late discriminator generating a control signal for the first controllable oscillator. The delay lock loop comprising a second controllable oscillator and a second arctan discriminator generating a control signal for the second controllable oscillator.

主权项

1. A system for tracking of a received signal with at least one subcarrier, wherein the received signal represents a carrier signal modulated with a code signal and modulated with a subcarrier signal, wherein the system comprises the following independent and cooperatively operating loops:
a phase lock loop for tracking the carrier signal, a subcarrier lock loop for tracking the subcarrier signal, which comprises a first controllable oscillator and a first early-minus-late discriminator or a first arctan discriminator for generating a control signal for the first controllable oscillator, wherein the first early-minus-late discriminator generates the control signal based on a difference between correlation results with a replica of an advanced subcarrier signal and a replica of a delayed subcarrier signal and the first arctan discriminator generates the control signal based on correlation results with a cosine subcarrier replica and a sine subcarrier replica, and a delay lock loop for tracking the code signal, which comprises a second controllable oscillator and a second arctan discriminator for generating a control signal for the second controllable oscillator, wherein the second arctan discriminator generates the control signal based on correlation results with a replica of a prompt subcarrier signal multiplied with a prompt subcarrier signal and the replica of the prompt subcarrier signal multiplied with the difference of the advanced and the delayed code signal or based on correlation results with the cosine subcarrier replica multiplied with a prompt subcarrier signal and a cosine subcarrier replica multiplied with the difference of the advanced and the delayed code signal.