scholarly journals Hard-Decision Coded Modulation for High-Throughput Short-Reach Optical Interconnect

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 400
Author(s):  
Bin Chen ◽  
Yi Lei ◽  
Gabriele Liga ◽  
Chigo Okonkwo ◽  
Alex Alvarado
Keyword(s):  
Communication Systems ◽  
Forward Error Correction ◽  
Additive White Gaussian Noise ◽  
Coded Modulation ◽  
Fiber System ◽  
Modulation Formats ◽  
High Data ◽  
Data Rates ◽  
Forward Error ◽  
Hard Decision

Coded modulation (CM), a combination of forward error correction (FEC) and high order modulation formats, has become a key part of modern optical communication systems. Designing CM schemes with strict complexity requirements for optical communications (e.g., data center interconnects) is still challenging mainly because of the expected low latency, low overhead, and the stringent high data rate requirements. In this paper, we propose a CM scheme with bit-wise hard-decision FEC and geometric shaping. In particular, we propose to combine the recently introduced soft-aided bit-marking decoding algorithm for staircase codes (SCCs) with geometrically-shaped constellations. The main goal of this CM scheme is to jointly boost the coding gain and provide shaping gain, while keeping the complexity low. When compared to existing CM systems based on M-ary quadrature-amplitude modulation (MQAM, M = 64 , 128 , 256 ) and conventional decoding of SCCs, the proposed scheme shows improvements of up to 0 . 83 dB at a bit-error rate of 10 - 6 in the additive white Gaussian noise channel. For a nonlinear optical fiber system, simulation results show up to 24 % reach increase. In addition, the proposed CM scheme enables rate adaptivity in single-wavelength systems, offering six different data rates between 450 Gbit/s and 666 Gbit/s.

scholarly journals Performance of combined constellation shaping and bit interleaved coded modulation with iterative decoding (BICM-ID)

2011 ◽  
Vol 9 ◽  
pp. 195-201 ◽  
Author(s):  
T. Arafa ◽  
W. Sauer-Greff ◽  
R. Urbansky
Keyword(s):  
Iterative Decoding ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Coded Modulation ◽  
Bandwidth Utilization ◽  
Signal Constellation ◽  
High Data ◽  
Constellation Shaping ◽  
Forward Error ◽  
Bit Interleaved Coded Modulation

Abstract. The increasing demand of achieving high data rates in modern communication systems requires highly efficient bandwidth utilization. For this purpose, multilevel modulation schemes are used in association with forward error correction (FEC) codes in order to approach the channel capacity. However, there is a gap between the capacity of a uniform signal constellation and the Shannon unconstrained capacity. This gap can be reduced by applying constellation shaping. The task of shaping is to modify a uniform distributed signal constellation towards a Gaussian like distribution. In this paper, we investigate different approaches to combine the constellation shaping with a bit interleaved coded modulation with iterative decoding (BICM-ID) system. Simulation results show that this combination can offer a shaping gain up to 0.6 dB.

Protocol Processing for 100 Gbit/s and Beyond – A Soft Real-Time Approach in Hardware and Software

Frequenz ◽  
2017 ◽  
Vol 71 (9-10) ◽  
pp. 427-438
Author(s):  
Steffen Büchner ◽  
Lukasz Lopacinski ◽  
Rolf Kraemer ◽  
Jörg Nolte
Keyword(s):  
Energy Consumption ◽  
Real Time ◽  
Forward Error Correction ◽  
Communication Protocol ◽  
Ultra Low Power ◽  
High Data ◽  
Wireless Communication Protocol ◽  
Data Rates ◽  
Correction Scheme ◽  
Forward Error

Abstract 100 Gbit/s wireless communication protocol processing stresses all parts of a communication system until the outermost. The efficient use of upcoming 100 Gbit/s and beyond transmission technology requires the rethinking of the way protocols are processed by the communication endpoints. This paper summarizes the achievements of the project End2End100. We will present a comprehensive soft real-time stream processing approach that allows the protocol designer to develop, analyze, and plan scalable protocols for ultra high data rates of 100 Gbit/s and beyond. Furthermore, we will present an ultra-low power, adaptable, and massively parallelized FEC (Forward Error Correction) scheme that detects and corrects bit errors at line rate with an energy consumption between 1 pJ/bit and 13 pJ/bit. The evaluation results discussed in this publication show that our comprehensive approach allows end-to-end communication with a very low protocol processing overhead.

scholarly journals Improving the performance of BICM-ID and MLC systems with different FEC codes

2013 ◽  
Vol 11 ◽  
pp. 87-93 ◽  
Author(s):  
T. Arafa ◽  
W. Sauer-Greff ◽  
R. Urbansky
Keyword(s):  
Turbo Codes ◽  
Channel Coding ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Convolutional Codes ◽  
Coded Modulation ◽  
Modulation Formats ◽  
Coding Schemes ◽  
Multilevel Modulation ◽  
Exit Charts

Abstract. In bandwidth limited communication systems, the high data rate transmission with performance close to capacity limits is achieved by applying multilevel modulation schemes in association with powerful forward error correction (FEC) coding, i.e. coded modulation systems. The most important practical approaches to coded modulation systems are multilevel coding with multistage decoding (MLC/MSD) and bit interleaved coded modulation with iterative demapping and decoding (BICM-ID). Multilevel modulation formats such as M-QAM, which can be used as a part of coded modulation systems, have the capability of multilevel protection. Based on this fact, we investigate the methods to improve the performance of BICM-ID using multiple interleavers with different binary channel coding schemes such as convolutional codes, turbo codes and low-density parity-check (LDPC) codes. Moreover, an MLC system with parallel decoding on levels (PDL) at the receiver is considered. In our contribution, we propose to design the individual coding schemes using the extrinsic information transfer (EXIT) charts for individual bit levels in the constellation. Our simulation results show that the BICM-ID systems, taking into account different bit-level protections, can provide an improvement of 0.65 dB, 1.2 dB and 1.5 dB for 256-QAM with turbo, LDPC and convolutional codes, respectively. On the other hand, MLC systems with PDL designed using EXIT charts for individual bit levels can slightly improve the performance and eliminate the error floor compared to the systems with MSD.

Efficient Discrete Simulation of Coded Wireless Communication Systems

2010 ◽  
pp. 143-177 ◽  
Author(s):  
Pedro J.A. Sebastião ◽  
Francisco A.B. Cercas ◽  
Adolfo V.T. Cartaxo
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Channel Model ◽  
Additive White Gaussian Noise ◽  
Simulation Method ◽  
Potential Range ◽  
Soft Decision ◽  
Bit Error Ratio ◽  
Forward Error

Simulation can be a valuable tool for wireless communication system’s (WCS) designers to assess the performance of its radio interface. It is common to use the Monte Carlo simulation method (MCSM), although this is quite time inefficient, especially when it involves forward error correction (FEC) with very low bit error ratio (BER). New techniques were developed to efficiently evaluate the performance of the new class of TCH (Tomlinson, Cercas, Hughes) codes in an additive white Gaussian noise (AWGN) channel, due to their potential range of applications. These techniques were previously applied using a satellite channel model developed by Lutz with very good results. In this chapter, we present a simulation method, named accelerated simulation method (ASM), that provides a high degree of efficiency and accuracy, namely for lower BER, where the application of methods like the MCSM is prohibitive, due to high computational and time requirements. The present work generalizes the application of the ASM to a WCS modelled as a stochastic discrete channel model, considering a real channel, where there are several random effects that result in random energy fluctuations of the received symbols. The performance of the coded WCS is assessed efficiently, with soft-decision (SD) and hard-decision (HD) decoding. We show that this new method already achieves a time efficiency of two or three orders of magnitude for SD and HD, considering a BER = 1x10-4 , when compared to MCSM. The presented performance results are compared with the MCSM, to check its accuracy.

Light fidelity optical network a comparative performance evaluation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Devendra Kr. Tripathi ◽  
Pallavi Singh
Keyword(s):  
Communication Systems ◽  
Optical Network ◽  
Visible Light Communication ◽  
Data Rate ◽  
Comparative Performance ◽  
Modulation Formats ◽  
High Data ◽  
Modulation Format ◽  
Output Performance ◽  
High Spectral Efficiency

Abstract Light-Fidelity (Li-Fi) is the bidirectional communication technique, tenders almost unlimited bandwidth, exploit unlicensed spectrum of light waves. Accordingly, this manuscript illustrates usage of visible light communication (VLC) applied as Li-Fi, an efficient scheme to broadcast data wirelessly as well safer technique in contrary to the customary Wireless-Fidelity (Wi-Fi) networks. In support numerical simulations have been executed over the proposed Li-Fi model for the parametric variation with the data rate, laser power, modulation format and wavelength, communication length. Investigations have showed good output performance, with hike in data rate BER variation as 10−94–10−23 and testing length. Simulations of network with DPSK and NRZ modulation formats at high data transmission of 10 Gbps have showed good output performance with 10−40 with DPSK format. Li-Fi systems are quality solution for the impending communication systems save cost, provide high spectral efficiency.

scholarly journals Underwater Optical Wireless Communications with Chromatic Dispersion and Time Jitter

Computation ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 35 ◽  
Author(s):  
Roumelas ◽  
Nistazakis ◽  
Stassinakis ◽  
Volos ◽  
Tsigopoulos
Keyword(s):  
Wireless Communications ◽  
Communication Systems ◽  
Chromatic Dispersion ◽  
Mathematical Expression ◽  
Optical Wireless ◽  
Optical Wireless Communications ◽  
Time Jitter ◽  
High Data ◽  
Data Rates ◽  
Very High

The obsolete communication systems used in the underwater environment necessitates the development and use of modern telecommunications technologies. One such technology is the optical wireless communications, which can provide very high data rates, almost infinite bandwidth and very high transmission speed for real time fast and secure underwater links. However, the composition and the optical density of seawater hinder the communication between transmitter and receiver, while many significant effects strongly mitigate the underwater optical wireless communication (UOWC) systems’ performance. In this work, the influences of chromatic dispersion and time jitter are investigated. Chromatic dispersion causes the temporal broadening or narrowing of the pulse, while time jitter complicates the detection process at the receiver. Thus, the broadening of the optical pulse due to chromatic dispersion is studied and the influence of the initial chirp is examined. Moreover, the effect of the time jitter is also taken into consideration and for the first time, to the best of our knowledge, a mathematical expression for the probability of fade is extracted, taking into account the influence of both of the above-mentioned effects for a UOWC system. Finally, the appropriate numerical results are presented.

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