Carrier tracking loop and receiver

Abstract

The embodiment of the invention discloses a carrier tracking loop and a receiver. The carrier tracking loop comprises a first feedback loop module and a second feedback loop module; the first feedback loop module is used for conducting frequency eliminating processing on first data by adopting received first frequency estimation values sent by the second feedback loop module; the second feedback loop module is used for conducting frequency adjustment on third data by adopting second frequency estimation values and demodulating the data subjected to frequency adjustment to obtain bit data. According to the carrier tracking loop, a double-feedback loop mechanism is adopted, the first feedback loop module conducts coarse frequency offset eliminating by adopting the first frequency estimation values and pulls signal Doppler frequency offset to be within the bandwidth range of a matched filter, and signal distortion caused by filtering is reduced; the second feedback loop module conducts precise carrier tracking by adopting the second frequency estimation values, so that a signal frequency spectrum can be stabilized within the main lobe range of the matched filter at every moment.

Description

technical field [0001] The invention relates to the technical field of satellite communication and satellite navigation, in particular to a carrier tracking loop and a receiver. Background technique [0002] The receiver is a device for receiving satellite signals. Its main function is to receive satellite signals to obtain necessary navigation and positioning information and observations, and realize real-time navigation and positioning through simple data processing. After the receiver captures the signal transmitted by the satellite, it obtains the carrier frequency and spread spectrum code of the satellite, and then can demodulate the navigation data message to complete the user's positioning. However, the receiver can only obtain the approximate value of the carrier frequency and the code phase of the spreading code during the acquisition process, so after the acquisition is completed, it must enter the tracking loop to further determine the carrier frequency and the co...

AI Technical Summary

Problems solved by technology

In the process of signal tracking, the Doppler frequency shift fluctuates, causing the center frequency point of the signal spectrum to fluctuate continuously. After the received signal passes through the matched filter, different attenuation will occur at different times, causing bit errors; Especially when tracking continuous wave satellite signals, excessive integral Doppler frequency shift may even cause the carrier loop to lose lock

Images