Frequency domain joint estimation method of OFDM (Orthogonal Frequency Division Multiplexing) integer frequency offset and fine symbol synchronization

Abstract

The invention discloses a frequency domain joint estimation method of integer frequency offset and fine symbol synchronization. The method comprises the following steps of: carrying out circular shifting and differential modulation on a frequency domain training sequence of a transmitting end; then carrying out cross-correlation on the frequency domain training sequence processed by the circular shifting and the differential modulation and a frequency domain training sequence processed through differential modulation of a receiving end; obtaining a corresponding circular shifting bit through detecting the peak value of a cross-correlation result so as to obtain an integer multiple frequency offset estimation value; and meanwhile, solving for a fine symbol synchronization result through taking a phase angle of the cross-correlation result. By utilizing the invention, the integer multiple frequency offset estimation and the fine symbol synchronization can be carried out simultaneously, the problem that the integer multiple frequency offset estimation and the fine symbol synchronization are not accurate and mutually influence in the traditional time frequency joint estimation method is solved, and the accuracy of the integer multiple frequency offset estimation and the fine symbol synchronization is improved.

Description

technical field The present invention relates to the technical field of synchronization in the communication field, and in particular to a frequency domain joint estimation method for integer frequency offset and symbol fine synchronization applicable to an Orthogonal Frequency Division Multiplexing (OFDM) system. Background technique Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used in current broadband wireless communication systems and digital broadcasting communication systems because of its excellent anti-multipath capability and high spectrum utilization: for example, wireless LAN standards WiFi (802.11a / g / n), WiMax (802.16d / e), LTE downlink, digital broadcasting systems DVB, CMMB, etc. all use OFDM technology. One of the main disadvantages of OFDM technology is that it is sensitive to time and frequency offsets. Time offsets will cause inter-symbol interference, and frequency offsets will destroy the orthogonality between sub-carriers, ...

AI Technical Summary

Problems solved by technology

In view of this, the main purpose of the present invention is to provide a frequency-domain joint estimation method of integer multiple frequency offset and symbol fine synchronization, to solve the contradiction between the inaccurate mutual influence of integer multiple frequency offset estimation and symbol fine synchronization in the traditional estimation method , to improve the accuracy of integer frequency offset and symbol fine synchronization estimation results

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