A Joint Timing and Frequency Synchronization Method Based on Conjugate Structure Preamble

Abstract

The present invention provides a joint timing and frequency synchronization method based on the preamble of the conjugate structure, the steps of the method are as follows: 1. Calculate the correlation signal r0(n,d) of the received signal r(n) and the preamble symbol c(n) ; 2. Calculate the differential correlation signal p(m,d); 3. Perform weighted accumulation on the differential correlation signal p(m,d) to obtain the weighted correlation function P(d); 4. Use the energy of the received signal in the sliding window to The weighted correlation function P(d) is normalized to obtain the normalized timing metric value M(d); 5. Calculate the maximum value of the normalized timing metric M(d) to obtain the timing offset estimator 6. Calculation Carrier frequency offset estimator of the fractional part 7, using the carrier frequency offset estimator of the fractional part to compensate the received signal to obtain the compensated received signal 8, using the received signal after the decimal frequency offset compensation to calculate the frequency offset estimator of the integer part 9, Carrier Frequency Offset Estimator This method only uses a preamble symbol with a conjugate structure to synchronize the joint symbol timing and carrier frequency, and the symbol timing synchronization is not affected by the frequency offset.

Description

technical field [0001] The invention belongs to the technical field of digital wireless communication transmission, and in particular relates to a joint timing and frequency synchronization method based on a conjugate structure preamble. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) can effectively combat the multipath effect of the channel, has a high spectrum utilization rate, and can provide high-speed data transmission under a wireless fading channel. The OFDM system has been applied in the fields of digital video broadcasting (DVB) and the new generation of terrestrial mobile communication and has become an international and industry standard. In the field of satellite communication, OFDM is suitable for high-speed data transmission under broadband satellite communication channels. For example, the European satellite standard DVB-SH has designed a hybrid ground-satellite communication system using OFDM or TDM technology. [0003] Assum...

AI Technical Summary

Problems solved by technology

However, the pseudo-random sequence weighting process on the preamble will deteriorate the power spectrum of the OFDM signal, resulting in serious out-of-band leakage, which will affect adjacent frequency band signals

Therefore, in view of the poor performance of traditional symbol timing and carrier frequency synchronization algorithms in OFDM receivers under multipath fading channels

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