Method and apparatus for estimating signal noise ratio of frequency-amplifying signal

Abstract

The method comprises: converting the received spread spectrum signals to the digital signals, and dividing the digital signals into the in-phase and quadrature signal components. In the capturing stage, the in-phase and quadrature signal components and the local pseudo random noise code are executed with relevant calculation to get the output of several in-phase and quadrature signal components; making summation for the square of each in-phase and quadrature signal components output to get the signal power and noise power in order to figured out the signal / noise ratio of the spread spectrum signals. In the tracing stage, the in-phase and quadrature signal components and the local pseudo random noise code are executed with relevant calculation; making the summation for the square of output result; based on the in-phase and quadrature signal components, figuring out the average power of noise; based on the signal power and the average power of noise, figuring out the signal / noise ration of spread spectrum signals.

Description

technical field [0001] The present invention relates to a method for processing spread spectrum signals, in particular to a method and device for estimating the signal-to-noise ratio of spread spectrum signals. Background technique [0002] Due to the many advantages of spread spectrum communication technology, it is widely used in various fields such as communication, electronic countermeasures, navigation and positioning. In spread spectrum communication, the information data to be transmitted is modulated by a pseudorandom noise code (PRN) at the transmitting end to achieve spectrum expansion before transmission; the receiving end uses the same code for demodulation and related processing to restore the original information data. [0003] GPS signals are spread spectrum signals transmitted by GPS satellites at L1 or L2 frequencies. Civilian GPS receivers usually use the L1 frequency (1575.42MHZ). Several signals sent on the L1 carrier are: coarse acquisition code (C / A c...

AI Technical Summary

Problems solved by technology

Due to the difference in signal strength, if the tracking loop always uses the same bandwidth and integration time when tracking the GPS signal, when the signal is strong, the loop adjustment speed may be too slow to track the changes of the GPS signal. Cause the loop to lose lock; in addition, when the signal is weak, it will cause the loop filtering effect to be poor, and the weak signal cannot be tracked

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