A low peak-to-average ratio wireless optical transmission method using clipping shift

Abstract

Disclosed is a low peak-to-average ratio wireless optical transmission method by means of clipping migration. The method comprises: using the characteristic that one of paired signals of ACO-OFDM time domain signals must be 0, if a positive signal in the paired signals exceeds a set threshold value, clipping same, and putting the clipped quantity in a position of 0 in the paired signals, thereby achieving the action of reducing a PAPR. The present invention is simple to achieve, and can effectively reduce the peak-to-average power ratio of an ACO-OFDM wireless optical communication system, reduce the power consumption of the system, reduce the requirements for the linearity of a power amplifier and an LED lamp, and reduce the nonlinear distortion of a signal in an electrical domain and an optical domain, thereby improving the receiving performance of the system.

Description

technical field [0001] The invention relates to a low peak-to-average ratio wireless optical transmission method using clipping and shifting, which belongs to the wireless optical communication technology. Background technique [0002] Wireless Optical Communication (OWC) has attracted the attention of researchers in the field of communication due to its rich and unrestricted spectrum resources, high transmission power can improve the acceptance signal-to-noise ratio, low electromagnetic radiation level, and good security, and has gradually become a research hotspot. . In order to improve the transmission rate of the wireless optical communication system and combat multipath interference, the OFDM modulation method was introduced. The researchers found that OFDM is an effective way to improve the performance of the wireless optical communication system from theory and experiments. [0003] Since the current wireless optical communication system generally adopts intensity mo...

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Problems solved by technology

The frequency domain symbols of DCO-OFDM also satisfy conjugate symmetry, but it does not require the value on even subcarriers to be 0, 1 / 2 subcarriers are used to transmit effective symbols, and the spectrum utilization rate is high, but it is used to make the time domain The signal is a positive value, and an additional DC bias needs to be added to the signal output by the IFFT, which reduces the energy utilization rate

[0004] The problem of too high peak-to-average ratio (PAPR) has always been the main shortcoming of the OFDM system. This problem also exists in the OFDM system of wireless optical communication. If the PAPR is too high, the signal will enter the nonlinear region when passing through the power amplifier or LED drive circuit, thus This will cause signal distortion, which will have a great impact on the overall performance of the system, so it is necessary to optimize the wireless optical communication OFDM system to reduce PAPR

These methods can reduce the PAPR of the OFDM system to a certain extent, but they are computationally intensive

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