A low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment

Abstract

The invention discloses a low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment. Different scalar adjustment coefficients are selected according to the time domain peak value of each OFDM symbol, so that symbols with particularly large peak values ​​are compressed to a certain degree. Therefore, the PAPR of the whole frame signal is reduced, thereby improving the transmission performance; at the receiving end, it is only necessary to measure the average power of the received symbol to estimate the scalar coefficient multiplied by the transmitting end, which is simple to implement; the improvement of PAPR reduces the system impact on the power amplifier. And the linearity requirements of LED lamps reduce the nonlinear distortion of the signal in the electrical and optical domains, and improve the system receiving performance; the decrease of PAPR also reduces the DC bias that needs to be increased at the transmitter and reduces the system power consumption.

Description

technical field [0001] The invention relates to a low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment, which belongs to the wireless optical communication technology. 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. In order to achieve high-speed data transmission in wireless optical communication and reduce inter-symbol interference (ISI), OFDM modulation is introduced in wireless optical communication, and high-speed data transmission can be provided by sending modulated symbols on orthogonal subcarriers in parallel. Combat multipath effects. [0003] Intensity modulation / direct detection (IM / DD) is often used in wireless optical communication, so the time-domain transmitted signal after OFDM modulation needs to be ...

AI Technical Summary

Problems solved by technology

This can not only ensure that the time domain signal sent is a positive real signal, but also reduce the transmission power and save resources, but the frequency utilization rate is low, and N subcarriers can only send N / 4 symbols. This method sacrifices the data rate for The trade-off avoids the power loss of adding a DC bias

DCO-OFDM is to add a DC bias to the OFDM modulated signal to make the signal a positive value. This method is simple to implement and has a high frequency utilization rate, but increases the DC power consumption.

[0004] Similar to the OFDM system in radio frequency communication, the OFDM system in wireless optical communication also has the problem of high signal peak-to-average power ratio

A high PAPR will put forward high requirements on the linearity of the power amplifier at the transmitter. In an optical OFDM system, an excessively high PAPR will not only impose higher requirements on the linearity of the LED lamp but also the power amplifier. Because the power amplifier and the LED lamp Non-linear characteristics can cause nonlinear distortion, which can seriously degrade the overall performance of the system

At the same time, in the wireless optical communication DCO-OFDM system, high PAPR will also lead to an increase in the required DC bias, thereby increasing system power consumption

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