2013/04/01 by Peter Kairouz, Andrew C. Singer, Kairouz, Peter +1
Engineering · #Advanced Photonic Communication Systems #FOS: Computer and information sciences #Information Theory (cs.IT) #Optical Network Technologies #Power Line Communications and Noise
paper · pdf · doi:10.48550/arxiv.1304.0422
openalex publication_date 2013/04/01 · openalex created_date 2025/10/27 · openalex updated_date 2026/07/28
We consider multi-input multi-output (MIMO) communications over multi-mode\nfibers (MMFs). Current MMF standards, such as OM3 and OM4, use fibers with core\nradii of 50 \μ m, allowing hundreds of modes to propagate. Unfortunately, due\nto physical and computational complexity limitations, we cannot couple and\ndetect hundreds of data streams into and out of the fiber. In order to\ncircumvent this issue, we present input-output coupling schemes that allow the\nuser to couple and extract a reasonable number of signals from a fiber with\nmany modes. This approach is particularly attractive as it is scalable; i.e.,\nthe fibers do not have to be replaced every time the number of transmitters or\nreceivers is increased, a phenomenon that is likely to happen in the near\nfuture.\n We present a statistical channel model that incorporates intermodal\ndispersion, chromatic dispersion, mode dependent losses, mode coupling, and\ninput-output coupling. We show that the statistics of the fiber's frequency\nresponse are independent of frequency. This simplifies the computation of the\naverage Shannon capacity of the fiber. We also provide an input-output coupling\nstrategy that leads to an increase in the overall capacity. This strategy can\nbe used whenever channel state information (CSI) is available at the\ntransmitter. We show that the capacity of an Nt by Nt MIMO system over a fiber\nwith M>>Nt modes can approach the capacity of an Nt-mode fiber with no\nmode-dependent losses. We finally present a statistical input-output coupling\nmodel in order to quantify the loss in capacity when CSI is not available at\nthe transmitter. It turns out that the loss, relative to Nt-mode fibers, is\nminimal (less than 0.5 dB) for a wide range of signal-to-noise ratios (SNRs)\nand a reasonable range of MDLs.\n