Power line communication channel estimation method

Abstract

The invention discloses a power line communication channel estimation method. The power line communication channel estimation method comprises the steps of receiving signal conversion; selecting pilot frequency; conducting estimation by using a compressed sensing signal recovery algorithm. Aiming at the disadvantages that the channel estimation performance of the traditional estimation algorithm based on a least square method and a minimum mean square error is reduced with pilot frequency number, the estimation accuracy is reduced, the calculation complexity is high and the like, power line channel estimation is conducted by using the feature that power line channels have sparsity and by adopting a compressed sensing method, unit impulse responses of the channels are obtained through the known pilot frequency information by using a matching tracking algorithm, the pilot frequency number is reduced, the calculation complexity is decreased and the transmission efficiency and communication quality are improved. By adopting irregular pilot frequency distribution and designing pilot frequency distribution according to channel and noise conditions, a typical strategy is to interpose pilot frequency reference information at frequency points with small channel attenuation or larger signal-to-noise ratio to improve the accuracy of channel estimation.

Description

technical field [0001] The invention relates to a power line communication technology, in particular to a power line communication channel estimation method. Background technique [0002] Low-voltage power line communication (Power Line Communication, PLC) refers to the use of low-voltage power distribution lines as the medium to communicate using the power network. The block diagram of the power line communication system based on OFDM modulation technology is as follows: figure 1 shown. The low-voltage distribution network is mainly used for power frequency AC transmission, and it is not considered to transmit data when the network is designed. Therefore, the channel characteristics of low-voltage power lines have a great influence on the reliable transmission of power line communications. [0003] In fact, the channel characteristics of low-voltage power lines are very complex, mainly including: [0004] 1. The distribution network topology of each indoor user is differ...

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Problems solved by technology

[0004] 1. The distribution network topology of each indoor user is different;

[0005] 2. The different transmission environments from the transformer to the user will cause the signal attenuation to change continuously, so that the communication terminal needs to provide different amplification factors for the signal;

[0008] 5. The random start or stop of the low-voltage power distribution network load will generate pulse interference, which will have a serious impact on the carrier signal on the low-voltage power line

[0035] 1. It is necessary to calculate the autocorrelation matrix R HH and inverse operations, so the computational complexity is large;

[0036] 2. The performance of channel estimation is related to the number of pilots. The smaller the number of pilots, the larger the interval between pilots and the lower the accuracy

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