Production method of frequency domain OFDM symbols

A technology of frequency domain and symbol, applied in the field of wireless broadcast communication, can solve the problem of channel estimation performance degradation in frequency domain

Inactive Publication Date: 2017-07-28
SHANGHAI NAT ENG RES CENT OF DIGITAL TELEVISION
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

Moreover, the DVB_T2 standard proposes that the P1 symbol design based on the CAB time domain structure will cause the performance degradation of the frequency domain channel estimation.

Method used

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  • Production method of frequency domain OFDM symbols
  • Production method of frequency domain OFDM symbols
  • Production method of frequency domain OFDM symbols

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Embodiment Construction

[0058] The inventors have found that the peak average power of the signaling sequence generated using the prior art is relatively high, and the signaling sequence is cyclically shifted or cyclically shifted plus phase shifted in the time domain.

[0059] In view of the above problems, the inventor provides a method for generating frequency-domain OFDM symbols and a method for generating preamble symbols in a physical frame after research. It is avoided that the generated signaling sequence has a characteristic of cyclic shift or cyclic shift plus phase shift in the time domain. Moreover, the problem of channel estimation performance degradation in the frequency domain is solved, and the modulation signal is generated by using the OFDM symbol in the time domain, so that the generated preamble symbols have good decimal frequency offset estimation and timing synchronization performance. Further, it is ensured that the receiving end can still process the received signal within the...

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Abstract

The invention discloses a production method of frequency domain OFDM symbols. The production method comprises the following steps: separately generating fixed sequences and signaling sequences in frequency domain, filling the fixed sequences and the signaling sequences into a valid subcarrier, wherein the fixed sequences and the signaling sequences are arranged in an even-odd alternate array; and filling zero sequence subcarriers on both sides of the valid subcarrier to form the frequency domain OFDM symbol of a predetermined length. wherein according to the length and the number of the signaling sequences, root values in a CAZAC sequence generation formula are determined, different q values are selected to generate CAZAC sequences, the CAZAC sequences are subjected to cyclic shift, the signaling sequences are selected from all the CAZAC sequences based on the determined number of the signaling sequences. According to the method, the problem that the generated signaling sequences have the characteristics of cyclic shift or cyclic shift and phase shift in time domain is avoided, and also the problem of descending performance of the frequency domain channel estimation is solved, which further ensures that a receiving end still can receive and process the signal under the condition of carrier frequency deviation in the range of -500 kHz to 500 kHz.

Description

[0001] This application is a divisional application of the original application, the application number of the original application is 201410185112.9, the application date is May 5, 2014, and the invention name is "the generation method of frequency-domain OFDM symbols and the generation method of leading symbols". technical field [0002] The invention relates to the technical field of wireless broadcast communication, in particular to a method for generating OFDM symbols in the frequency domain and a method for generating leading symbols in physical frames. Background technique [0003] 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...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04J13/14H04J13/00
CPCH04J13/0059H04J13/14H04L27/261H04L27/2613H04L27/2662H04L27/2692
Inventor 张文军徐洪亮黄戈
Owner SHANGHAI NAT ENG RES CENT OF DIGITAL TELEVISION
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