Fractal, Diffraction-encoded Space-Division Multiplexing for FSO with Misalignment-Robust, Roaming Transceivers

With free space optical (FSO) communication systems, information is generally transmitted to minimize diffraction. Here, we demonstrate an alternate paradigm, "diffractal space-division multiplexing" (DSDM), in which the diffraction of fractals enable a wider cone for reception to support roaming transceiver. As a result, DSDM is robust to misalignment over longer-distance links. We examine the consequence of mid-field, non-far-field propagation and the result on kernel bit error rates. The sparse and redundant encoding of information in DSDM may be relevant to other FSO acquisition, pointing, and tracking.

Best selected optical fibers with wavelength multiplexing techniques for minimum bit error rates

In this study, six different types of optical fibers (SMF, HNLF, HNL-DFF, NZDSF, LEAF (step core) and LEAF (ring core)) can be used for different number of channels (16, 32, 64, and 80) at different bit rates to calculate the quality factor for these types of optical fibers at the optimum length for max BER × 10−9 and min BER × 10−12. By using the software Optisystem version 13, the work has been demonstrated and compared with previous study to find the best one under the same operating conditions.

Multiple error correction towards optimisation of energy in sensor network

<span>Hybrid ARQ (HARQ) is among the optimum error controls implemented in Wireless Sensor Network as it reduces the overhead from retransmission and error correcting codes. The advancement in WSN includes the usage of high number of nodes and the increase in traffic with large data transmitted among the nodes had concerned the need for a new approach in error control algorithm. This paper proposed the multiple error correction based on HARQ process to aid the changes in channel with proper error correction assignment towards optimising the performances of WSN in terms of bit error rates, remaining energy, and latency for different types of congestion and channel conditions. In this study, we have developed the channel adaptation algorithm that can adapt to sudden changes and demonstrated the optimal error correcting codes as well as adjustment on the transmit power for the given channel condition and congestion presented. From the result analysed, the optimisation between the remaining energy and Bit Error rates happened on the basis of adapting to these different channel condition and congestion to minimize redundancies appended. From the result obtained, we concluded that by using multiple error correction algorithm with the aid of adjustment on the transmit power, the remaining energy can be optimised together with Bit Error rates and the excessive redundancies can be reduced</span>

Feedforward Equalizers for MDM–WDM in Multimode Fiber Interconnects

In this paper, we present new tap configurations of a feedforward equalizer to mitigate mode coupling in a 60-Gbps 18-channel mode-wavelength division multiplexing system in a 2.5-km-long multimode fiber. The performance of the equalization is measured through analyses on eye diagrams, power coupling coefficients and bit-error rates.