Timing synchronization method and system for power line carrier communication

Abstract

The invention provides a timing synchronization method and a timing synchronization system for power line carrier communication. The system comprises an analog-to-digital converter, an I / O (Input / Output) demodulator, a narrowband interference detector, an adaptive filter, a normalization module, an auto-correlation calculation module, a comparator and a postprocessor, wherein an OFDM (Orthogonal Frequency Division Multiplexing) carrier signal is converted into an OFDM carrier frequency domain signal by the analog-to-digital converter, the I / O demodulator and the narrowband interference detector. The method comprises the following steps: 1, acquiring average power P of each OFDM subcarrier f; 2, performing narrowband interference detection on the OFDM subcarrier f; 3, filtering the OFDM signal and then performing normalization processing; 4, acquiring start time of the OFDM carrier signal and outputting an OFDM carrier synchronization signal. Compared with the prior art, the timing synchronization method and the timing synchronization system for power line carrier communication have the advantage of higher robustness under various different channel environments of narrowband interference, pulse noise, multi-path propagation and violent change or nonlinear input signal amplitude.

Description

technical field [0001] The invention relates to a communication timing synchronization method and system, in particular to a timing synchronization method and system for power line carrier communication. Background technique [0002] The timing synchronization method is a very important module in the power communication system, and it has a great influence on the performance of the whole system. The timing synchronization technology of the wireless communication system in the electric power communication system mainly uses the repeated structure of several identical parts in the preamble to perform two-step synchronization operations, that is, coarse synchronization (autocorrelation) and fine synchronization (cross-correlation); coarse synchronization is for fast Capture a rough data packet start information; based on the start information, fine synchronization performs cross-correlation operations to obtain a more accurate data packet start position. [0003] At present, m...

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Problems solved by technology

[0004] ①: "2013 International Symposium on Power Line Communication and Its Application" disclosed that the scrambling operation was performed on the cyclic suffix of the preamble sequence to reduce the impact of narrowband interference; but after applying the scrambling operation, the out-of-band energy of the preamble sequence will increase; moreover, the synchronization algorithm performance is not improved in multipath channel or impulsive noise environment

However, if there is narrowband interference or impulse noise in the channel, the performance of the synchronization scheme will drop sharply

[0006] ③: "2011 International Conference on Signal Processing, Communication and Computing (ICSPCC)" disclosed the same synchronization measurement method as recorded in "2007 International Symposium on Power Line Communication and Its Applications", so that the synchronization scheme can be used in multipath attenuation channels It works well in the environment of narrowband interference and impulsive noise, but its performance in the environment of narrowband interference and impulsive noise cannot be guaranteed

However, if an impulsive signal with high energy happens to appear in the preamble, the performance of the synchronization scheme using the traditional normalization method will deteriorate sharply; In a variety of different channel environments such as drastic changes in signal amplitude or nonlinearity, timing synchronization methods and systems with high robustness are particularly important

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