Frequency domain OFDM (orthogonal frequency division multiplexing) symbol generation method and preamble symbol generation method

A technology of preamble symbols and symbols, applied in the field of wireless broadcast communication, can solve the problems of frequency domain channel estimation performance degradation, etc., achieve easy decoding and demodulation, good fractional frequency offset estimation performance and timing synchronization performance, and solve the estimation performance degradation. Effect

Active Publication Date: 2015-11-04
SHANGHAI NAT ENG RES CENT OF DIGITAL TELEVISION
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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

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  • Frequency domain OFDM (orthogonal frequency division multiplexing) symbol generation method and preamble symbol generation method
  • Frequency domain OFDM (orthogonal frequency division multiplexing) symbol generation method and preamble symbol generation method
  • Frequency domain OFDM (orthogonal frequency division multiplexing) symbol generation method and preamble symbol generation method

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Embodiment Construction

[0041] 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.

[0042] 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 frequency domain OFDM (orthogonal frequency division multiplexing) symbol generation method and a preamble symbol generation method. The frequency domain OFDM symbol generation method comprises the steps of generating a fixed sequence and a signalling sequence in the frequency domain, wherein the fixed sequence and the signalling sequence are constant modulus sequences, and complex numbers in the fixed sequence and the signalling sequence are equal in modulus; filling the fixed sequence and the signalling sequence to an effective sub-carrier, wherein the fixed sequence and the signalling sequence are in odd-even alternative arrangement; and filling zero-sequence sub-carriers at two sides of the effective sub-carrier respectively so as to form a frequency domain OFDM symbol with predetermined length. The technical scheme disclosed by the invention avoids a characteristic that the generated signalling sequence has cyclic shift or cyclic shaft and phase shift in the time domain, and solves a problem of frequency domain channel estimation performance reduction. Furthermore, a receiving terminal is ensured to still be able to process received signals with the carrier frequency deviation being in a range of -500kHz and 500kHz.

Description

technical field [0001] 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 [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 ...

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Application Information

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IPC IPC(8): H04L25/02H04L27/26H04L25/03
CPCH04L27/2607H04L27/2678H04L27/2691H04L27/2692
Inventor 张文军黄戈徐洪亮邢观斌何大治管云峰
Owner SHANGHAI NAT ENG RES CENT OF DIGITAL TELEVISION
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