453 research outputs found
Revenue Maximization in an Optical Router Node Using Multiple Wavelengths
In this paper, an optical router node with multiple wavelengths is
considered. We introduce revenue for successful transmission and study the
ensuing revenue maximization problem. We present an efficient and accurate
heuristic procedure for solving the NP-hard revenue maximization problem and
investigate the advantage offered by having multiple wavelengths
Demonstration of long-reach PON using 10 Gb/s 3R burst-mode wavelength converter
Long-reach optical access networks promise significant cost savings. To merge existing metro and access networks to a single long-reach network, the long-reach technology has to address not only the power loss and fiber dispersion problems but also mismatch between two merged entities in terms of wavelengths and operational modes, especially during the transition period when support of legacy services is still required. In this letter, we demonstrate a long reach network employing a 10 Gb/s burst-mode O/E/O wavelength converter. The converter can simultaneously address the power loss, dispersion, and mismatch problems by a compact assembly. Two upstream wavelengths located in the 1310 nm and 1550 nm windows in the access section are converted to a DWDM wavelength of 1554.13 nm in the metro section. Error-free performance is achieved with a loud/soft ratio of 10 dB at a sensitivity of −27 dBm and the overhead for the burst-mode operation is as low as 0.512%
Ultrahigh-capacity optical-wireless communication using 2D gratings for steering and decoding of DPSK signals
We demonstrate the use of a 2D-gratings beam-steering device also as a demodulator for multiple differentially-encoded optical-wireless signals. Using this novel concept, ~2bits/sec/Hz spectral-efficiency was achieved without any change in the system compared to on-off-keying
Implementation of a High-Throughput Fast-SSC Polar Decoder with Sequence Repetition Node
Even though polar codes were adopted in the latest 5G cellular standard, they
still have the fundamental problem of high decoding latency. Aiming at solving
this problem, a fast simplified successive cancellation (Fast-SSC) decoder
based on the new class of sequence repetition (SR) nodes has been proposed
recently in \cite{sr2020} and has a lower required number of time steps than
other existing Fast-SSC decoders in theory. This paper focuses on the hardware
implementation of this SR node-based fast-SSC (SRFSC) decoder. The
implementation results for a polar code with length 1024 and code rate 1/2 show
that our implementation has a throughput of Mbps on an Altera Stratix IV
FPGA, which is 17.9% higher with respect to the previous work.Comment: 6 pages, 6 figures. Accepted and to appear in IEEE International
Workshop on Signal Processing Systems, Oct 2020 (SIPS2020). The latest
version. arXiv admin note: text overlap with arXiv:2005.0439
Experimental Demonstration of mm-Wave 5G NR Photonic Beamforming Based on ORRs and Multicore Fiber
[EN] A photonic beamformer system designed for nextgeneration 5G new radio (5G NR) operating in the millimeter waveband is proposed and demonstrated experimentally, including its performance characterization. The photonic beamforming device is based on optical ring resonators (ORRs) implemented on Si3N4 and assisted with multicore fiber (MCF) to feed different antenna elements (AEs). Fast-switching configuration of the ORRs is performed changing the operating wavelength, as tuning the wavelength modifies the coupling coefficient of the rings and, consequently, the induced time delay.
Multibeam operation is evaluated at 17.6- and 26-GHz radio keeping the ORRs¿ configuration. The beamforming performance is evaluated using single-carrier signals with up to 128 quadrature amplitude modulation over up to 4.2-GHz electrical bandwidth. The experimental beamforming system with two AEs provides up to 21 Gb/s per user, while the beamforming system with four AEs provides up to 16.8 Gb/s per user. Wireless transmission confirms that changing the wavelength from 1545.200 to 1545.195 nm modifies the beam steering from 11.3° to 23° with 26-GHz signals (5G NR pioneer band in Europe).This work was supported in part by the Fundacion BBVA Leonardo HYPERCONN Project, in part by the Spain National Plan under Grant MINECO/FEDER UE TEC2015-70858-C2-1-R XCORE and Grant GVA AICO/2018/324 NXTIC, and in part by the Dutch FreeBEAM projects. The work of M. Morant was supported by Spain Juan de la Cierva under Grant IJCI-2016-27578. The work of A. Trinidad was supported by Dutch NWO Zwaartekracht Integrated Nanophotonics.Morant, M.; Trinidad, A.; Tangdiongga, E.; Koonen, T.; Llorente, R. (2019). Experimental Demonstration of mm-Wave 5G NR Photonic Beamforming Based on ORRs and Multicore Fiber. IEEE Transactions on Microwave Theory and Techniques. 67(7):2928-2935. https://doi.org/10.1109/TMTT.2019.28944022928293567
Threshold-Based Fast Successive-Cancellation Decoding of Polar Codes
Fast SC decoding overcomes the latency caused by the serial nature of the SC
decoding by identifying new nodes in the upper levels of the SC decoding tree
and implementing their fast parallel decoders. In this work, we first present a
novel sequence repetition node corresponding to a particular class of bit
sequences. Most existing special node types are special cases of the proposed
sequence repetition node. Then, a fast parallel decoder is proposed for this
class of node. To further speed up the decoding process of general nodes
outside this class, a threshold-based hard-decision-aided scheme is introduced.
The threshold value that guarantees a given error-correction performance in the
proposed scheme is derived theoretically. Analysis and hardware implementation
results on a polar code of length with code rates , , and
show that our proposed algorithm reduces the required clock cycles by up
to , and leads to a improvement in the maximum operating frequency
compared to state-of-the-art decoders without tangibly altering the
error-correction performance. In addition, using the proposed threshold-based
hard-decision-aided scheme, the decoding latency can be further reduced by
at ~dB.Comment: 14 pages, 8 figures, 5 tables, submitted to IEEE Transactions on
Communication
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