ADO-OFDM visible light communication system based on improved algorithm

Abstract

The invention discloses an ADO-OFDM (asymmetrical-clipping and DC bias orthogonal frequency division multiplexing) visible light communication system based on an improved algorithm. The system comprises a transmitter end and a receiver end. An ACO-OFDM signal of the transmitter end is transmitted on odd subcarriers, while a DCO-OFDM signal is transmitted on even subcarriers; after IFFT (inverse fast Fourier transform), asymmetrically clipping is carried out on the odd subcarriers, while the signal on the even subcarriers is subjected to DC bias to generate a single-polarity signal; and then, the odd subcarriers and the even subcarriers are merged to form an ADO-OFDM signal. By increasing the power of the ACO-OFDM input signal in data mapping, error rate of the system is reduced, and reliability can be improved. At the receiver end, the ACO-OFDM signal is subjected to estimation and optimization based on the newly-recovered DCO-OFDM signal, and furthermore, influence of the clipping noise on the DCO-OFDM signal is eliminated through the optimized and regenerated ACO-OFDM signal, thereby improving the received signal and improving system reliability.

Description

technical field [0001] The present invention relates to visible light communication technology, in particular to a visible light communication system based on the improved algorithm ADO-OFDM. Background technique [0002] The visible light communication system using visible light as the signal carrier, because it works in the unlicensed frequency band, has the advantages of high security, low energy consumption and anti-electromagnetic interference, it has attracted considerable attention in the application of next-generation indoor communication . Compared with traditional fluorescent lamps, white light-emitting diodes (LEDs) can meet the requirements of high efficiency, low voltage and current, and have long life and high reliability. As the future lighting infrastructure, LED can realize the function of communication at the same time, and has a lower cost. If LED lighting equipment installed indoors is used in a communication network, efficient indoor visible light comm...

AI Technical Summary

Problems solved by technology

But ACO-OFDM technology will lead to lower spectral efficiency

In DCO-OFDM, the signal becomes positive by adding a DC bias, but this increases power consumption

Therefore, the visible light communication system based on asymmetric clipping and DC bias optical orthogonal frequency division multiplexing (ADO-OFDM) can be used to transmit unipolar OFDM baseband signals, but the reliability of the traditional ADO-OFDM system needs to be improved. promote

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