10 research outputs found
A single chip VLSI Reed-Solomon decoder
A new VLSI design of a pipeline Reed-Solomon decoder is presented. The transform decoding technique used in a previous design is replaced by a time domain algorithm. A new architecture that implements such an algorithm permits efficient pipeline processing with minimum circuitry. A systolic array is also developed to perform erasure corrections in the new design. A modified form of Euclid's algorithm is implemented by a new architecture that maintains the throughput rate with less circuitry. Such improvements result in both enhanced capability and a significant reduction in silicon area, therefore making it possible to build a pipeline (31,15)RS decoder on a single VLSI chip
On the VLSI design of a pipeline Reed-Solomon decoder using systolic arrays
A new very large scale integration (VLSI) design of a pipeline Reed-Solomon decoder is presented. The transform decoding technique used in a previous article is replaced by a time domain algorithm through a detailed comparison of their VLSI implementations. A new architecture that implements the time domain algorithm permits efficient pipeline processing with reduced circuitry. Erasure correction capability is also incorporated with little additional complexity. By using a multiplexing technique, a new implementation of Euclid's algorithm maintains the throughput rate with less circuitry. Such improvements result in both enhanced capability and significant reduction in silicon area
A comparison of VLSI architectures for time and transform domain decoding of Reed-Solomon codes
It is well known that the Euclidean algorithm or its equivalent, continued fractions, can be used to find the error locator polynomial needed to decode a Reed-Solomon (RS) code. It is shown that this algorithm can be used for both time and transform domain decoding by replacing its initial conditions with the Forney syndromes and the erasure locator polynomial. By this means both the errata locator polynomial and the errate evaluator polynomial can be obtained with the Euclidean algorithm. With these ideas, both time and transform domain Reed-Solomon decoders for correcting errors and erasures are simplified and compared. As a consequence, the architectures of Reed-Solomon decoders for correcting both errors and erasures can be made more modular, regular, simple, and naturally suitable for VLSI implementation
REED SOLOMON CODES FOR RELIABLE COMMUNICATION IN INTERNET OF THINGS (IOT)
In the networking field, Internet of Things ( IOT, shortly) is the current state
of the art in the nowadays Information of Technology era. The networking may
be defined as external network or internal network. The backbone of the IOT
is the internet connections. The IOT connects various objects together to the
internet so that they can communicate and exchange billions of data and
information among various devices and services. They may be remotely
controlled from distant area. As IOT systems will be open and available
everywhere, a number of security issue may arise. One issue that remains open
in the IOT technology is security and privacy issues. Because of this security
issue, the communications among many different devices powered by IOT
could not be said as a reliable technology.
Because of this, the security of the IOT systems can be enhanced by adding
error correction scheme both in communication channel as well as the data
store. By introducing the error correction scheme, the risks may be reduced to
acceptable level and the security could be enhanced. A Reed-Solomon (RS)
code is one of many error control coding schemes that firstly introduced by
Reed and Solomon in 1960. This code has been used in various applications,
such as CD-ROMs, space communications, DVD technology, digital TV and
much more.
Here, Reed-Solomon code is discussed in detail. It raised the issue of RS
decoding scheme using the Welch Berlekamp algorithm. It presents the
implementation of the Welch Berlekamp algorithm for RS decoder in detail.
The VHDL implementation VHDL for Hard Decision Decoding using the
Welch Berlekamp algorithm is also presented. Without loss of generality, th
Desenvolvimento em linguagem de descrição de hardware de codificador e decodificador Reed-Solomon
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2014.Atualmente, diversos sistemas de comunicação demandam grandes volumes de tráfego de dados para consumo quase instantâneo. Estes dados devem ser entregues aos usuários tal qual foram gerados: sem erros. Por isso, técnicas de controle e correção de erros estão intrinsecamente ligadas aos sistemas que realizam trocas de dados, sejam sistemas de armazenamento, os quais estão sujeitos a falhas durante a leitura, ou sistemas de comunicação, que estão sujeitos às adversidades do meio (radiação, interferência eletromagnética, desvanecimento, entre outros). Neste cenário, os códigos Reed-Solomon representam uma solução viável para inúmeras aplicações, bem como pesquisas acadêmicas, mesmo tanto tempo após sua invenção. Este trabalho realiza um estudo da teoria que embasa os códigos Reed-Solomon, assim como implementa as técnicas do estado-da-arte dos módulos que compõem tanto o codificador quanto o decodificador, as quais são prototipadas em hardware reconfigurável.2014-08-06T18:05:10
Physical layer forward error correcetion in DVB-S2 networks.
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.The rapid growth of wireless systems has shown little sign of ceasing, due to increased
consumer demand for reliable interactive services. A key component of the development has
centered on satellite networks, which allows provision of services in scenarios where terrestrial
systems are not viable. The Digital Video Broadcasting-Satellite Second Generation (DVB-S2)
standard was developed for use in satellite broadcast applications, the foremost being video
broadcasting. Inherent to DVB-S2 is a powerful forward error correction (FEC) module, present
in both the Physical and Data Link Layer. Improving the error correcting capability of the FEC
is a natural advent in improving the quality of service of the protocol. This is more crucial in
real time satellite video broadcast where retransmission of data is not viable, due to high
latency.
The Physical Layer error correcting capability is implemented in the form of a concatenated
BCH-LDPC code. The DVB-S2 standard does not define the decoding structure for the receiver
system however many powerful decoding systems have been presented in the literature; the
Belief Propagation-Chase concatenated decoder being chief amongst them. The decoder utilizes
the concept of soft information transfer between the Chase and Belief Propagation (BP)
decoders to provide improved error correcting capability above that of the component decoders.
The following dissertation is motivated by the physical layer (PL) FEC scheme, focused on the
concatenated Chase-BP decoder. The aim is to generate results based on the BP-Chase decoder
in a satellite channel as well as improve the error correcting capability.
The BP-Chase decoder has shown to be very powerful however the current literature provides
performance results only in AWGN channels. The AWGN channel however is not an accurate
representation of a land-mobile satellite (LMS) channel; it does not consider the effect of
shadowing, which is prevalent in satellite systems. The development of Markov chain models
have allowed for better description of the characteristics of the LMS channel. The outcome
being the selection of a Ku band LMS channel model. The selected LMS channel model is
composed of 3 states, each generating a different degree of shadowing. The PL system has been
simulated using the LMS channel and BP-Chase receiver to provide a more accurate
representation of performance of a DVB-S2 network. The effect of shadowing has shown to
reduce coding performance by approximately 4dB, measured over several code lengths and
decoders, when compared with AWGN performance results.
The second body of work aims to improve the error correcting capability of the BP-Chase
decoder, concentrating on improving the LDPC decoding module performance. The LDPC
system is the basis for the powerful error correcting ability of the concatenated scheme. In
attempting to improve the LDPC decoder a reciprocal improvement is expected in the overall
decoding performance of the concatenated decoder. There have been several schemes presented
which improve BP performance. The BP-Ordered statistics decoder (OSD) was selected
through a process of literary review; a novel decoding structure is presented incorporating the
BP-OSD decoder into the BP-Chase structure. The result of which is the BP-OSD-Chase
decoder. The decoder contains two stages of concatenation; the first stage implements the BPOSD
algorithm which decodes the LDPC code and the second stage decodes the BCH code
using the Chase algorithm. Simulation results of the novel decoder implementation in the DVBS2
PL show a coding gain of 0.45dB and 0.15dB versus the BP and BP-Chase decoders
respectively, across both the AWGN and LMS channel
Optical Communication
Optical communication is very much useful in telecommunication systems, data processing and networking. It consists of a transmitter that encodes a message into an optical signal, a channel that carries the signal to its desired destination, and a receiver that reproduces the message from the received optical signal. It presents up to date results on communication systems, along with the explanations of their relevance, from leading researchers in this field. The chapters cover general concepts of optical communication, components, systems, networks, signal processing and MIMO systems. In recent years, optical components and other enhanced signal processing functions are also considered in depth for optical communications systems. The researcher has also concentrated on optical devices, networking, signal processing, and MIMO systems and other enhanced functions for optical communication. This book is targeted at research, development and design engineers from the teams in manufacturing industry, academia and telecommunication industries
The Telecommunications and Data Acquisition Report
This quarterly publication (July-Sept. 1986) provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio astronomy, it reports on activities of the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, in supporting research and technology, in implementation, and in operations. This work is performed for NASA's Office of Space Tracking and Data Systems (OSTDS). In geodynamics, the publication reports on the application of radio interferometry at microwave frequencies for geodynamic measurements. In the search for extraterrestrial intelligence (SETI), it reports on implementation and operations for searching the microwave spectrum. The latter two programs are performed for NASA's Office of Space Science and Applications (OSSA)