Method for estimating and correcting deviation and error of chip clock frequency of spread spectrum system

Abstract

The invention provides a method for estimating and correcting deviation and error of a chip clock frequency of a spread spectrum system. After receiving a radio-frequency signal, a receiving antenna firstly converts the radio-frequency signal into a digital baseband signal, then a practical zero crossing point value is obtained sequentially through primary synchronization, frequency domain interpolation, secondary synchronization, de-frequency offset and de-phase offset, and calculation of a zero crossing point serial number, and finally a practical chip clock frequency is obtained through the number of the chip corresponding to the zero crossing point and a first-order linear relationship at the moment of the zero crossing point, so that the error of the chip clock frequency is obtained, therefore, compensation and correction of the clock frequency are realized, the chip clock frequency of a transmitter and the chip clock frequency of a receiving end are guaranteed to be consistent, the demodulation performance of a receiver is improved, and the data received by the receiver can be well recovered.

Description

technical field [0001] The invention relates to a chip clock frequency error estimation and correction method of a spread spectrum system, in particular to a WiFi system chip clock frequency error estimation and correction method. Background technique [0002] Spread spectrum technology is the process of extending the spectrum of the baseband signal to a much larger bandwidth than the baseband signal. Spread spectrum communication has the characteristics of strong anti-interference, anti-multipath performance, high spectrum utilization rate, and support for multiple access communication. [0003] WiFi is a technology that connects terminals such as computer network cards and mobile phones to each other by using radio. Now it has been widely used in business districts, universities, airports, and other public areas. The standard used by WiFi is the 802.11 series of standards defined by IEEE. [0004] 802.11b is a protocol that uses direct sequence spread spectrum technolog...

AI Technical Summary

Problems solved by technology

[0005] Due to the possible deviation between the chip clock frequency of the transmitter and the chip clock frequency of the receiving end, at the receiving end, this deviation may cause the receiver to be unable to completely recover the data transmitted by the transmitter

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