Visible light communication system and channel estimation method based on mimo-ofdm modulation

Abstract

The invention discloses a visible light communication system and a channel estimation method based on MIMO-OFDM modulation, and relates to the field of optical communication. The training sequence is converted into an optical signal through digital-to-analog conversion and electro-optical conversion, and sent together by M light sources at the sending end; M receiving detectors at the receiving end respectively receive the training sequence sent by M light sources to obtain an optical signal; the receiving detector pairs The optical signal undergoes photoelectric conversion and analog-to-digital conversion to obtain a digital electrical signal, and performs frame synchronization and discrete Fourier transform to obtain a frequency domain signal; according to the received frequency domain signal and training symbols, the channel matrix is ​​calculated to obtain the channel frequency domain response. The present invention can solve the channel estimation problem of the visible light communication system based on MIMO-OFDM modulation, ensures effective work when the receiver moves, and is simple to implement.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a visible light communication system and channel estimation method based on MIMO-OFDM modulation. Background technique [0002] For high-speed visible light communication, a multi-carrier modulation method, such as OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing), is generally used. In order to further improve the channel capacity, L. Zeng proposed to introduce MIMO (Multiple-Input Multiple-Output) technology into visible light communication, and analyzed the performance of non-imaging optical MIMO and imaging optical MIMO communication systems, but Lack of a reasonable and effective channel estimation algorithm. The channel estimation algorithm used in L. Zeng needs to accurately know the distance between the receiver and each transmitter, the transmission angle and the reception angle, so it is not suitable for the case where the...

AI Technical Summary

Problems solved by technology

In order to further improve the channel capacity, L. Zeng proposed to introduce MIMO (Multiple-Input Multiple-Output) technology into visible light communication, and analyzed the performance of non-imaging optical MIMO and imaging optical MIMO communication systems, but Lack of a reasonable and effective channel estimation algorithm. The channel estimation algorithm used in L. Zeng needs to accurately know the distance between the receiver and each transmitter, the transmission angle and the reception angle, so it is not suitable for the case where the receiver is mobile indoors

However, the traditional channel equalization technology such as the minimum mean square error algorithm is not suitable for the simplification requirements of the visible light communication system, so the practicability is not high.

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