Free Space Optic Receiver with Strongly Overlapped Photodetectors’ Field of View

Applied Sciences

Jan Nedoma¹  Karel Witas¹ 

[1] Department of Telecommunications, Faculty of Electrical Engineering and Computer Science, VSB–Technical University of Ostrava, 708 33 Ostrava, Czech Republic;

关键词: free space optic;    optical receiver;    omnidirectional;    truncated pyramid;    equal gain combining;    parallel amplifier;    low noise;    noise suppression;   

DOI  :  10.3390/app9020343

来源: DOAJ

【 摘 要 】

In this study, we designed a mobile free space optic receiver that uses several photodetectors to provide omnidirectional receiving capability. Assuming only one transmitter, it is a receiver which builds a single input multiple output optical channel. The photodetectors are fixed to truncated pyramid walls. Electrical signals from the photodetectors are processed using an equal gain combining technique. This architecture allows simple circuits and enables additive noise suppression. The minimum angle between the pyramid base and the direction of falling rays was calculated to determine the threshold for additive noise suppression. Two areas of interest presented themselves: the processing of very weak electrical signals often drowned in noise, and optimization of the number of photodetectors whose fields of view overlapped strongly. We outline the design of the optical receiver circuitry and provide some practical hints concerning its assembly. The receiver was evaluated using bit error rate measurements and comparing signal-to-noise ratio parameters for various photodetector numbers. The measured data confirm the theoretical assumptions.

【 授权许可】

Unknown