Chip-Asynchronous Binary Optical CDMA: An Optimum Signaling Scheme for Random Delays

IEEE Photonics Journal

Salman A. Khan¹  Jan Bajcsy¹ 

[1] Department of Electrical and Computer Engineering, McGill University, Montreal, Canada;

关键词: Optical code division multiple access (OCDMA);    nonuniform signaling;    chip asynchronism;    channel capacity;   

DOI  :  10.1109/JPHOT.2013.2255033

来源: DOAJ

【 摘 要 】

Most optical code division multiple access (OCDMA) research literature has focused on chip-synchronous OCDMA. However, practical OCDMA networks are inherently chip-asynchronous since users transmit their signals from different locations without any coordination. This paper focuses on binary chip-asynchronous OCDMA with time spreading, and the main result is that appropriate nonuniform signaling can achieve a data throughput of 2.5 bits per OCDMA chip. This result shows that the presence of chip asynchronism leads to approximately a threefold capacity gain over chip-synchronous OCDMA capacity. Additional results are presented to illustrate that the near capacity multiuser interference has a low variance and a non-Gaussian distribution. Finally, the robustness of the achieved capacity gains is verified in the presence of additive channel noise.

【 授权许可】

Unknown