Time-frequency synchronization joint estimation method based on multi-carrier receiver of digital television media broadcast (DTMB) system

Abstract

The invention relates to a time-frequency synchronization joint estimation method based on a multi-carrier receiver of a digital television media broadcast (DTMB) system. The method is characterized by comprising the following steps: step 1, carrying out frame header mode recognition and frame header position coarse estimation; step 2, generating a pseudorandom noise (PN) sequence A of a zero phase matched with the frame header mode by a local PN generator, and carrying out carrier frequency offset estimation by utilizing a step-variable frequency sweeping method; step 3, correlating received data with the PN sequence A after compensation carrier is subjected to large frequency offset, so as to estimate a serial number of a frame; generating a PN sequence B of a matched phase matched with the frame header mode, and then correlating the PN sequence B with the received data so as to obtain a frame header position fine estimation value; and step 4, carrying out self-correlation on the frame header position according to the frame header position fine estimation value so as to obtain a carrier frequency offset fine estimation value, and summarizing a carrier frequency large offset estimation value and the carrier frequency offset fine estimation value so as to obtain a final carrier frequency offset estimation value. In the invention, the time-frequency synchronization joint estimation method based on the multi-carrier receiver of the DTMB system is used, thereby facilitating the realization of share of operation data and parameters and reducing the arithmetic labor.

Description

technical field [0001] The invention relates to the technical field of multimedia broadcasting, in particular to a time-frequency synchronization joint estimation method based on a DTMB system multi-carrier receiver. Background technique [0002] On August 30, 2006, the National Standards Committee of China released the digital TV terrestrial broadcast transmission system standard DMB-TH. The basic feature of this standard is the combination of OFDM modulation and spread spectrum communication, and the use of single and multi-carrier modulation methods. Among them, the multi-carrier modulation uses the core technology of time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM). It is different from ordinary OFDM technology in frame structure, replaces the traditional cyclic prefix guard interval with pseudo-random (PN) code frame header, and uses PN frame synchronization header for time domain synchronization, including frame synchronization, frequency s...

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Problems solved by technology

[0005] (1) The traditional mode detection and coarse symbol timing synchronization are based on multi-mode PN sequences, that is, the received data is correlated with the local PN sequence for pattern detection and coarse symbol timing synchronization. The local PN sequence can have multiple construction forms, such The method occupies a lot of resources, takes a long time, and is only applicable to the environment of small frequency offset, and the error of the estimated symbol position is relatively large;

[0006] (2) In some carrier frequency offset estimation methods, either the frequency capture range is limited, or they cannot resist multipath; when there is a large carrier offset or the multipath channel is bad, the performance of the traditional symbol synchronization method will be seriously degraded;

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