A device and method for estimating and compensating sampling clock deviation of mobile TV terminal

Abstract

The invention provides a device for estimating and compensating the sampling clock deviation of a mobile phone TV terminal, including the following modules: an over-sampling interpolation filter module completes over-sampling interpolation, filtering and down-sampling extraction of input data, and estimates the deviation according to the final sampling clock As a result, the sampling clock deviation is adjusted; the FFT / de-scrambling module performs FFT operation and de-scrambling processing; the continuous pilot extraction module extracts the continuous pilot sub-carrier data from the descrambled data; the sampling clock deviation estimation module completes the sampling clock deviation Estimation: the sampling clock deviation control module uses the estimation results provided above to obtain a final sampling clock deviation estimation result and provides it to the oversampling interpolation filter module. At the same time, the invention provides a method for estimating and compensating the sampling clock deviation of the mobile phone TV terminal. By adopting the invention, the processing can be simplified and the receiving performance can be guaranteed.

Description

technical field [0001] The present invention relates to the field of Orthogonal Frequency Division Multiplex (OFDM) communication, in particular to a device and method for estimating and compensating the sampling clock deviation of China Mobile Multimedia Broadcasting (CMMB) system. Background technique [0002] Orthogonal frequency division multiplexing technology transmits data in parallel through a group of orthogonal subcarriers, which can effectively reduce the impact of wireless multipath propagation environment, and has been more and more widely used in the field of wireless broadband communication. [0003] Orthogonal frequency division multiplexing technology uses the characteristics of orthogonal subcarrier transmission to determine its sensitivity to frequency synchronization errors; in mobile communication systems, there is usually a certain gap between the local oscillator clock of the terminal receiver and the clock of the transmitting tower. Deviation, the dev...

AI Technical Summary

Problems solved by technology

[0004] At present, the China Mobile Multimedia Broadcasting CMMB standard adopts OFDM as the transmission technology of the physical layer. In order to reduce the cost of CMMB terminals and improve product competitiveness, passive crystals with low cost and poor frequency stability are usually required. As a receiving clock source, it will bring a large sampling clock deviation. At this time, it is necessary to estimate and compensate the sampling clock deviation to ensure the receiving performance.

[0005] At present, the commonly used sampling clock deviation estimation and compensation method is to estimate the sampling frequency deviation and then feed back to the sampling clock source to reduce the sampling clock deviation and achieve the purpose of compensation. This method cannot be applied to the case of passive crystal as the sampling clock source;

[0006] There is also a digital method to correct the phase rotation between symbols and subcarriers in the frequency domain by estimating the sampling frequency deviation. Since the phase compensation amounts of different subcarrier indexes are different, this method is more complicated to implement.

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