Power line carrier wave communication method based on OFDM modulation

Abstract

The invention discloses a signal frame generating method of a power line carrier wave communication system based on OFDM, synchronous signal frames and control signal frames in signal frames are all obtained by modulating linear frequency modulation signals with pseudo random sequences or barker codes or truncation codes of the pseudo random sequences and the barker codes as modulation signals. As the pseudo random sequences and the barker codes have good dependency and the linear frequency modulation signals also have good self-correlation and cross-correlation performance, generated synchronous signals and control signals also have good dependency, and the synchronous signals have the function that data symbols of a receiving terminal and data symbols of a sending terminal are accurately synchronized. The control signals also have good dependency, so that the receiving terminal can accurately demodulate the current control type of the corresponding system after receiving the control signals, and the signal frames obtained through the method is high in whole accuracy, has constant envelope amplitude and are strong in anti-noise performance. Meanwhile, the frequency band ranges of the synchronous signals and the control signals can be adjusted conveniently, namely the frequency band range of the signal frames is adjustable.

Description

【Technical field】 [0001] The present invention relates to a power line carrier communication system, in particular to a signal frame generating method of the power line carrier communication system. 【Background technique】 [0002] Power line carrier communication technology, referred to as PLC, refers to a communication method that uses power lines to transmit data. It can make full use of the existing power distribution network infrastructure and provide users with data communication services without any wiring. Using the existing power line to realize data communication can greatly save the construction cost of the communication network. However, due to the influence of many factors, the development of power line carrier communication technology is restricted. The main thing is the complex channels on the power line. [0003] The characteristics of the power line carrier channel environment are: various noises, various clutter interference (clutter irregular, unpredicta...

AI Technical Summary

Problems solved by technology

However, since the correlation of the repeated OFDM data is not strong, the synchronization accuracy of the generated synchronization signal is not high, and the noise resistance is not strong

When generating the control signal frame in the signal frame, based on the orthogonal frequency division multiplexing system (OFDM system), the OFDM symbol is usually used to generate the control signal, but in the harsh power line environment, due to the presence of sudden strong pulse interference, During the transmission process, OFDM symbols are often difficult to resist the harsh channel environment, that is, the control signal is not strong against noise, resulting in errors in the control information received by the receiving end

To sum up, the signal frame obtained by the above method is not accurate, and the noise resistance is not strong, and it cannot adapt to the harsh channel environment.

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