Wireless laser communication PPM polarization modulation and demodulation method

A polarization modulation and demodulation method technology, applied in the field of communication, can solve the problems of short communication distance, low speed, easy to be affected by atmospheric random channels, etc., and achieve the effect of overcoming the influence and improving the code rate and transmission distance.
CN101110649AInactive Publication Date: 2008-01-23XIAN UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN ยท China
Current Assignee / Owner
XIAN UNIV OF TECH
Publication Date
2008-01-23
Estimated Expiration
Not applicable ยท inactive patent

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Abstract

The present invention relates to a wireless laser communication PPM polarization modulation- demodulation method, which creates one-to-one correspondence between a PPM signal of an information source and an elliptic polarizing angle. Based on the correspondence, the signal of the information source is modulated into an elliptic polarized light with a corresponding elliptic polarizing angle and emits the light in the form of an optical signal. During demodulation, the polarizing angle of the received elliptic polarized light is calculated to confirm information of the information source corresponding to the polarizing angle according to the correspondence above and then complete information demodulation. The modulation-demodulation method overcomes impact of atmospheric channel on communication and effectively eliminates lower communication code rate and short communication distance of wireless laser communication.
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Description

technical field

[0001] The invention belongs to the technical field of communication, and in particular relates to a PPM polarization modulation and demodulation method for wireless laser communication. Background technique

[0002] Modulation and demodulation is a key technology in wireless laser communication. At present, there are two main modulation and demodulation systems in wireless laser communication, one is intensity modulation / direct detection (IM / DD) system, and the other is coherent Modulation / heterodyne detection system. In the IM / DD system, the transmitting end obtains the modulated signal by directly modulating the intensity of the optical carrier, and the optical signal is directly converted into an electrical signal by using a photodetector at the receiving end. The direct detection system has the advantages of small size, light weight, simple structure, low cost, and easy implementation, but its frequency band utilization rate is low, and the receiving se...

Claims

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