OFDM symbol synchronization position search method and synchronization device

Abstract

The invention discloses an OFDM symbol synchronization position search method which comprises the following steps: to begin with, carrying out edge detection on relevant values of a P1 symbol by utilizing relevant results of the P1 symbol, wherein the step is specifically characterized by carrying out difference on relevant value signals and then, carrying out moving average; and then, searching the absolute value of output signals of the moving average, and if the absolute value is larger than a preset threshold value, continuing to search 5760Samples; when searching the maximum peak, giving two synchronization candidate points according to the polarity thereof; and finally, calculating peak value noise ratio according to the given two synchronization candidate points, and selecting the synchronization candidate point, of which the peak value noise ratio is larger, as the final synchronization point position. The invention further discloses an OFDM symbol synchronization device for the method. P1 symbol synchronization error can be reduced under severe multipath interference; P1 symbol detection and decoding and P2 symbol decoding performances are improved; and deterioration of system performance due to large P1 symbol synchronization error can be prevented.

Description

technical field [0001] The invention relates to the field of communication, in particular to a method for searching the synchronous position of OFDM (orthogonal frequency division multiplexing) symbols of the second-generation European terrestrial digital television (DVB-T2). The invention also relates to an OFDM symbol synchronization device used in the method. Background technique [0002] OFDM technology is widely used in modern communication systems. As the second-generation terrestrial digital television standard in Europe, DVB-T2 ("Digital Video Broadcasting (DVB); Frame structure channel coding and modulation for a second generation digital terrestrial television broadcasting system (DVB-T2)," ETSI EN302755), inherits the OFDM technology of the first generation standard DVB-T, the basic unit of data Called T2 frame. like figure 1 Shown is a structure diagram of a T2 frame, and each frame includes a P1 preamble symbol, a P2 preamble symbol, and a data symbol immedia...

AI Technical Summary

Problems solved by technology

[0009] The above correlation peak method of P1 symbol detection can resist all kinds of serious interference and noise, but its disadvantage is that the error of the synchronization position is very large

[0010] 1) The positive correlation peak does not guarantee that the detected diameter is the anterior diameter (similarly, the negative correlation peak cannot guarantee the posterior diameter);

[0011] 2) Unable to handle Pre / PostEcho (that is, two-path channels with D / U not equal to 0dB);

[0012] 3) It is impossible to distinguish whether the correlation peak really contains superposition effects

Images