Method for assessing integer frequency offset of TD-LTE system

Abstract

The invention discloses a method for assessing an integer frequency offset of a TD-LTE (Long Term Evolution) system. According to the invention, the method comprises the following steps: assessing a timing fine synchropoint and a decimal frequency offset near a coarse synchronous position; performing decimal frequency offset compensation to time-domain signal; confirming an FFT (Fast Fourier Transform) initial window according to the timing fine synchropoint; filtering subcarrier outside a center band frequency of the frequency-domain signal by a filter after switching to the frequency domain; retaining the PSS frequency domain signal; and accessing the integer frequency offset according to the position where the maximal subcarrier data energy is positioned. The method provided by the invention can be effectively resistant to larger timing error, and has the advantages of more accurate calculating and lower calculation complexity.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, in particular to a method for estimating integer frequency offset in the third generation mobile communication long-term evolution system (hereinafter referred to as TD-LTE). Background technique [0002] In order to meet the challenges of emerging broadband access technologies such as WiMAX (Worldwide Interoperability for Microwave Access, WiMAX) and meet the needs of new services, 3GPP (3 rd Generation Partnership Project) launched the Long Term Evolution (LTE, Long Term Evolution) of air technology in March 2005, aiming to increase the data transmission rate, reduce the system delay, and increase the system capacity. [0003] The core technology of the LTE standard downlink is OFDM (Orthogonal Frequency Division Multiplexing) technology, which has the advantages of high spectral efficiency, high peak rate, and good resistance to inter-channel interference, frequency selec...

AI Technical Summary

Problems solved by technology

However, the performance of this algorithm is severely degraded when the timing deviation is large.

The existence of timing deviation causes the phase rotation of the frequency domain data, which reduces the correlation of the training sequence, the peak misjudgment occurs, and the integer multiple frequency deviation cannot be correctly estimated.

Some literature proposes to use the differential correlation algorithm based on the frequency domain sequence to eliminate the phase rotation factor introduced by the timing deviation as much as possible. The performance is not very good in multipath channels with low noise ratio

To sum up, the existing TD-LTE system lacks an efficient multiple anti-timing deviation and low computational complexity integer multiple frequency offset estimation method

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