Method for generating precursor symbol in physical frame

Abstract

The invention discloses a method for generating a precursor symbol in a physical frame. The method comprises the following steps of: performing discrete Fourier inversion of a frequency-domain OFDM symbol with a preset length to obtain a time-domain OFDM symbol; determining a circulation prefix length; intercepting a partial time-domain OFDM symbol with the circulation prefix length from the rear part of the time-domain OFDM symbol, and taking the partial the time-domain OFDM symbol as a circulation prefix; generating a modulating signal according to the partial time-domain OFDM symbol; and generating the precursor symbol based on the circulation prefix, the time-domain OFDM symbol, and the modulating signal. According to the technical scheme of the invention, the problem of decrease of frequency-domain channel estimated performance is solved, and the modulating signal is generated by utilizing the partial time-domain OFDM symbol, so that the generated precursor symbol has small frequency offset and excellent timing synchronism. Furthermore, processing of a received signal by a receiving terminal is guaranteed, with carrier frequency deviation being in a range from -500 kHz to 500 kHz.

Description

technical field [0001] The invention relates to the technical field of wireless broadcast communication, in particular to a method for generating a leading symbol in a physical frame. Background technique [0002] Generally, in order for the receiving end of the OFDM system to correctly demodulate the data sent by the sending end, the OFDM system must realize accurate and reliable time synchronization between the sending end and the receiving end. At the same time, since the OFDM system is very sensitive to the frequency offset of the carrier, the receiving end of the OFDM system also needs to provide an accurate and efficient carrier spectrum estimation method to accurately estimate and correct the carrier frequency offset. [0003] At present, the method for realizing time synchronization between the transmitting end and the receiving end in the OFDM system is basically based on preamble symbols. The preamble symbol is a symbol sequence known to both the transmitting end ...

AI Technical Summary

Problems solved by technology

[0008] The problem solved by the present invention is that in the current DVB_T2 standard and other standards, there is no cyclic prefix in the DVB_T2 time domain structure, which cannot be applied to coherent detection, and the preamble symbol has a low probability of failure in the detection of low-complexity receiving algorithms under complex frequency selective fading channels. question

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