Efficient transmission method of wireless light based on optimal amplitude modulation

Abstract

The invention discloses an efficient transmission method of wireless light based on optimal amplitude modulation. The efficient transmission method is carried out according to the following steps that: a system generates a frequency domain symbol, which needs to be transmitted, on a transmitting end; a frequency domain signal generates a base band time domain transmitting signal in an actual value; optimal amplitude modulation coefficients are figured up, zoom amplitude modulation is carried out on the frequency domain signal on each sub-carrier and DC bias is added into an amplitude limiting time domain transmitting signal to drive a light emitting diode to transmit; a received optical signal is converted to an electric signal by a photoelectric diode, and a time domain receiving signal is obtained after processing, such as filtration and amplification, at a receiving end; fast Fourier transform is carried out on the time domain receiving signal, so that a frequency domain receiving signal is obtained and a conjugate symmetry part is removed; and lastly, a final receiving symbol is obtained through constellation demodulation. The efficient transmission method has the advantages of simple implementation and capabilities of reducing a peak-to-average power ratio of a wireless light communication OFDM (Orthogonal Frequency Division Multiplexing) system, reducing requirements of the transmitting end on linearity of a power amplifier and an LED (Light Emitting Diode) lamp and improving an error rate of an AC signal transmitting power reducing system.

Description

technical field [0001] The invention relates to a wireless optical high-efficiency transmission method based on optimized amplitude modulation, which belongs to the field of wireless optical communication system design. Background technique [0002] Due to its rich spectrum resources, good communication security, high transmission power, and less electromagnetic radiation, wireless optical communication has become a research hotspot in the field of communication in recent years. Wireless optical communication can be realized by simple on-off key modulation (OOK) or pulse modulation (PPM). In order to achieve high-speed data transmission in wireless optical communication and reduce inter-symbol interference (ISI), orthogonal frequency division multiplexing technology is introduced in wireless optical communication. By sending modulated symbols in parallel on orthogonal subcarriers, it can Provides high-speed data transmission and combats multipath effects. [0003] Intensit...

AI Technical Summary

Problems solved by technology

By continuously reducing the clipping threshold, the PAPR of the system can be continuously reduced, but too much clipping will also bring serious clipping noise, resulting in a decline in system receiving performance

On the other hand, wireless optical communication is different from radio frequency communication. The AC power of the radio frequency communication transmission signal is limited, while optical communication needs to realize the two functions of lighting and communication at the same time, so the main emission limitation is the light intensity.

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