Performance analysis of a hybrid ARQ system in half duplex transmission at 2400 BPS

Hybrid ARQ/FEC protocols have been proposed to provide high data link integrities whilst keeping at the same time a high mean throughput rate. Nevertheless, hybrid ARQ strategies offer a lot of choices and none of them can be considered the optimum in any case. Three alternative protocol strategies using BCH codes are evaluated and the HF channel models used for the tests are discussed.Peer ReviewedPostprint (published version

Energy-efficient coding for high speed links

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (leaves 76-77).Throughput and energy-efficiency of high-speed chip-to-chip interconnects present critical bottlenecks in a whole range of important applications, from processor-memory interfaces, to network routers. These links currently rely solely on complex equalization techniques to maintain the bit error rate lower than 10-15. While applicable to data rates up to 10 Gb/s on most links, this approach does not scale well to higher data rates or better energy-efficiency. The work described in the thesis shows that it may be possible to use coding techniques to share the burden of combating errors, while increasing the throughput of the link or improving its energy-efficiency. Since codes here attempt to alleviate the impact of partially correlated sources of error (like reflections interference, crosstalk and jitter), an experimental setup was created for characterization of link channel properties and performance gains from different codes. Four codes, specifically Hamming, BCH, Fire, and SEC-DED codes, are implemented and analyzed with various configurations (i.e. different blocksizes, data rates, and detection or correction). Most significantly, it is discovered that detection and retransmission of even the simple codes implemented in this project may be able to maintain a bit error rate of 10-15.by Maxine Lee.M.Eng

Coding Theory and its Applications in Communication systems

Error control coding has been used extensively in digital communication systems because of its cost-effectiveness in achieving efficient, reliable digital transmission. Coding now plays an important role in the design of modern communication systems. This paper reviews the development of basic coding theory and state-of-art coding techniques. The applications of coding to communication systems and future trends are also discussed

Recent Developments in Algebraic Decoding

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / DAAB-07-67-C-0199National Science Foundation / GK-233

Codes on s-periodic errors

In this paper, we study linear codes capable of detecting and correcting s-periodic errors. Lower and upper bounds on the number of parity check digits required for codes detecting such errors are obtained. Another bound on codes correcting such errors is also obtained. An example of a code detecting such errors is provided

Versatile Error-Control Coding Systems

$NC research reported in this thesis is in the field of error-correcting codes, which has evolved as a very important branch of information theory. The main use of error-correcting codes is to increase the reliability of digital data transmitted through a noisy environment. There are, sometimes, alternative ways of increasing the reliability of data transmission, but coding methods are now competitive in cost and complexity in many cases because of recent advances in technology. The first two chapters of this thesis introduce the subject of error-correcting codes, review some of the published literature in this field and discuss the advan­tages of various coding techniques. After presenting linear block codes attention is from then on concentrated on cyclic codes, which is the subject of Chapter 3. The first part of Chapter 3 presents the mathemati­cal background necessary for the study of cyclic codes and examines existing methods of encoding and their practical implementation. In the second part of Chapter 3 various ways of decoding cyclic codes are studied and from these considerations, a general decoder for cyclic codes is devised and is presented in Chapter 4. Also, a review of the principal classes of cyclic codes is presented. Chapter 4 describes an experimental system constructed for measuring the performance of cyclic codes initially RC5GI5SCD by random errors and then by bursts of errors. Simulated channels are used both for random and burst errors. A computer simulation of the whole system was made in order to verify the accuracy of the experimental results obtained. Chapter 5 presents the various results obtained with the experimental system and by computer simulation, which allow a comparison of the efficiency of various cyclic codes to be made. Finally, Chapter 6 summarises and dis­cusses the main results of the research and suggests interesting points for future investigation in the area. The main objective of this research is to contribute towards the solution of a fairly wide range of problems arising in the design of efficient coding schemes for practical applications; i.e. a study of coding from an engineering point of view