In an optical camera communication(OCC) system, multi-level modulation is essential for data rate enhancement with the finite frame rate of the receiving camera constraint, where the K-means algorithm is widely used a...In an optical camera communication(OCC) system, multi-level modulation is essential for data rate enhancement with the finite frame rate of the receiving camera constraint, where the K-means algorithm is widely used as a thresholding scheme. The result of K-means clustering is sensitive to initial cluster centers. In this paper, we propose a multi-level modulation scheme utilizing the pilot-aided K-means(PAK) algorithm. PAK algorithm innovates in both obtaining the state of the stripes propagated through the optical channel under different environments and overcoming the susceptibility of K-means. Our scheme could prompt data rate and improve the performance of OCC. Finally, non-orthogonal multiple access(NOMA) pattern is designed based on the proposed scheme to achieve multiplex communications.展开更多
Optical camera communication(OCC) is gaining increasing attention in researches. However, applying it to a real-world scenario may encounter many practical problems, such as the communication device may sway or there ...Optical camera communication(OCC) is gaining increasing attention in researches. However, applying it to a real-world scenario may encounter many practical problems, such as the communication device may sway or there may be a position offset between the camera and the light source, which may distort the stripes and make the message unreceivable. To this end, we propose pilot-based stripe area estimation(P-SAE) decoding algorithm, and design a pixels rearrangement(PR) scheme and stripes separation logic decision method(SSLD) to improve the decoding performance under sway or receiving position offset. Finally, we build a practical OCC system and carry out experiments to verify the effectiveness of the decoding algorithm. Experimental results show that the lightweight decoding algorithm can resist the impact of smartphone sway and receiving position offset on decoding accuracy.展开更多
基金supported in part by the Jilin Scientific and Technological Development Program(No.20200401147GX)。
文摘In an optical camera communication(OCC) system, multi-level modulation is essential for data rate enhancement with the finite frame rate of the receiving camera constraint, where the K-means algorithm is widely used as a thresholding scheme. The result of K-means clustering is sensitive to initial cluster centers. In this paper, we propose a multi-level modulation scheme utilizing the pilot-aided K-means(PAK) algorithm. PAK algorithm innovates in both obtaining the state of the stripes propagated through the optical channel under different environments and overcoming the susceptibility of K-means. Our scheme could prompt data rate and improve the performance of OCC. Finally, non-orthogonal multiple access(NOMA) pattern is designed based on the proposed scheme to achieve multiplex communications.
基金supported by the Natural Science Foundation of the Department of Science and Technology of Jilin Province(No.20180101040JC).
文摘Optical camera communication(OCC) is gaining increasing attention in researches. However, applying it to a real-world scenario may encounter many practical problems, such as the communication device may sway or there may be a position offset between the camera and the light source, which may distort the stripes and make the message unreceivable. To this end, we propose pilot-based stripe area estimation(P-SAE) decoding algorithm, and design a pixels rearrangement(PR) scheme and stripes separation logic decision method(SSLD) to improve the decoding performance under sway or receiving position offset. Finally, we build a practical OCC system and carry out experiments to verify the effectiveness of the decoding algorithm. Experimental results show that the lightweight decoding algorithm can resist the impact of smartphone sway and receiving position offset on decoding accuracy.
