OFDM (orthogonal frequency division multiplexing) system symbol timing synchronization realizing method suitable for low-signal-to-noise-ratio channel environments

Abstract

The invention discloses an OFDM (orthogonal frequency division multiplexing) system symbol timing synchronization realizing method suitable for low-signal-to-noise-ratio channel environments. The OFDM system symbol timing synchronization realizing method includes: adopting two conjugated OFDM symbols based on frequency domain PN (pseudo-noise sequence) to serve as a training sequence; subjecting symbol positions of the training sequence and a receiving sequence to sliding conjugation correlation at a receiving end, obtaining a timing offset estimation function via summation and modulus computation; for every moment, taking an estimation function of one timing offset section at every moment to solve a weighted average so as to obtain a dynamic threshold for the corresponding moment; comparing the estimation function with the corresponding dynamic threshold to lock a timing position. Due to the facts that only data symbol position information is required, data are not involved in computation and normalization computation for computation results is not required, the OFDM system symbol timing synchronization realizing method has the advantages that complexity is low and performance cannot be affected by size of received signal power. In addition, the OFDM system symbol timing synchronization realizing method is accurate and stable in timing under a low-signal-to-noise-ratio environment, easy to implement and low in computation complexity.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a method for realizing symbol timing synchronization of an OFDM system suitable for a channel environment with a low signal-to-noise ratio. Background technique [0002] In an OFDM system, if the receiver wants to correctly demodulate the received time domain signal, it must know the correct starting position of a time slot, so that FFT demodulation and frequency offset estimation and correction can be completed accurately. Symbol timing will cause distortion in the amplitude and phase of the received signal and even produce inter-symbol interference (ISI). [0003] Classical symbol timing synchronization algorithms generally work based on the characteristics of the training sequence inserted in the data, which can be roughly divided into the following two categories [0004] (1) Based on the structural characteristics of the training sequence [0005] Schmidl...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the embodiments of the present invention is to provide a method for implementing symbol timing synchronization of an OFDM system suitable for a low SNR channel environment, aiming at solving the problem of unstable timing and high computational complexity of traditional symbol timing algorithms in a low SNR environment , Occupying a lot of hardware resources

Images