Method for generating precursor symbol in physical frame

A leading symbol and physical frame technology, applied in digital transmission systems, electrical components, transmission systems, etc., can solve the problems of reception algorithm detection failure, inability to apply coherent detection, and no cyclic prefix, etc.

Active Publication Date: 2015-10-28
SHANGHAI NAT ENG RES CENT OF DIGITAL TELEVISION
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  • Claims
  • Application Information

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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

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  • Method for generating precursor symbol in physical frame
  • Method for generating precursor symbol in physical frame
  • Method for generating precursor symbol in physical frame

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Embodiment Construction

[0036] The inventors found that in the current DVB_T2 standard and other standards, there is no cyclic prefix in the DVB_T2 time domain structure, and there is a problem of failure probability in the low-complexity reception algorithm detection of the preamble symbols in the frequency selective fading channel.

[0037] In view of the above problems, the inventor provides a method for generating a leading symbol in a physical frame after research. The problem of channel estimation performance degradation in the frequency domain is solved, and the modulated signal is generated by using the part of the OFDM symbols in the time domain, so that the generated preamble symbols have good performance of small frequency offset and timing synchronization. Further, it is ensured that the receiving end can still process the received signal within the range of the carrier frequency deviation from -500kHz to 500kHz.

[0038] In order to make the above objects, features and advantages of the ...

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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 ...

Claims

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Application Information

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IPC IPC(8): H04L5/00H04L27/26
Inventor 张文军邢观斌黄戈徐洪亮何大治管云峰
Owner SHANGHAI NAT ENG RES CENT OF DIGITAL TELEVISION
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