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Cross-layer rateless coding over wireless relay channel
, Article 2010 5th International Symposium on Telecommunications, IST 2010 ; 2010 , Pages 351-355 ; 9781424481835 (ISBN) ; Hossein Khalaj, B ; Sharif University of Technology
Abstract
This paper focuses on cross-layer transmission based on rateless coding for relay channels. In the proposed method, rateless coding is used at packet level and a separate physical layer coding is used at the physical layer. As rateless codes are originally designed and optimized for erasure channels, using these codes at the physical layer can lead to significant performance degradation. The proposed scheme has the advantage of a cross-layer design which uses a rateless code at the packet level modeled by an erasure channel. Based on the analysis and simulation results provided in this paper, there is an exact tradeoff between physical layer code rate and rateless code depth, and the optimum...
Cross-layer rateless coding over wireless relay networks
, Article IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference, 4 July 2011 through 8 July 2011 ; July , 2011 , Pages 1545-1549 ; 9781424495399 (ISBN) ; Khalaj, B. H ; Pasandshanjani, E ; Sharif University of Technology
2011
Abstract
The focus of the paper is on cross-layer transmission based on rateless coding for relay networks. In the proposed method, rateless coding is used at the packet level and a separate physical layer coding is used at the physical layer. As rateless codes are originally designed and optimized for erasure channels, using these codes at the physical layer can lead to significant performance degradation. The proposed scheme has the advantage of a cross-layer design which uses a rateless code at the packet level modeled by an erasure channel. Based on the analysis and simulation results provided in this paper, the cross-layer scheme results in earlier successful decoding at the destination
Throughput analysis of multiple-access-relay channel based on rateless coding
, Article 2010 5th International Symposium on Telecommunications, IST 2010, 4 December 2010 through 6 December 2010 ; 2010 , Pages 292-296 ; 9781424481835 (ISBN) ; Nasiri Kenari, M ; Sharif University of Technology
Abstract
In this paper, we consider a new scheme based on jointly network and rateless coding for a multiple-access relay channel. In the scheme, whenever the relay can decode multiple messages of the users, it jointly encodes them using a larger rateless code. This scheme is compared with direct transmission and the conventional relaying scheme in which the relay helps each user independently at orthogonal channels. The comparison is made by evaluating the throughput of different schemes. The analytical and the simulation results show that the proposed scheme outperforms the other ones at the cases considered
Cooperative Communications in Free-Space Optical Networks
, Ph.D. Dissertation Sharif University of Technology ; Nasiri Kenari, Masoumeh (Supervisor)
Abstract
With recent successes in laboratory tests, and in atmosphere and space demonstrations, there is no doubt that the free-space optical (FSO) communications is ready for operational deployment. Large bandwidth, unlicensed spectrum, excellent security, and quick and inexpensive setup are among its most attractive features. Despite their attractive features, FSO communications suffer from several challenges in practical deployment; the major of them is fading or scintillation and path loss. To overcome such limitations, Channel Coding along with MIMO and Cooperative techniques have been proposed. Although the promising effects of cooperative transmissions in RF communications have greatly been...
Evaluation of Rateless Coding on Relay Networks
, M.Sc. Thesis Sharif University of Technology ; Hossein Khalaj, Babak (Supervisor)
Abstract
Fountain codes enable wireless networks to adapt their transmission rates to the state of the channels, without the need for channel state information (CSI) at the transmitters. According to the following properties of rateless codes, ever increasing parity generation, mutual information receiver, single bit feedback, and information combining receiver, they are good choice for relay networks. In this research, the design of rateless codes for wireless relay networks has been studied. Cross layer issues should be seriously considered when using rateless codes in the packet level. One cross-layer scheme has been developed in this thesis and analysis show that the performance of the proposed...
Cooperative Communications Based on Jointly Network Coding and Rateless Coding Approach and Their Analysis
, M.Sc. Thesis Sharif University of Technology ; Nasiri Kenari, Masoumeh (Supervisor)
Abstract
In recent years, coded cooperation has been considered as one of the best methods to cope with fading and at the same time to achieve channel coding gain. On the other hand, the idea of network coding has been introduced for increasing the efficiency of cooperative networks. In addition, it has been shown that only by jointly designing of network coding and channel coding, the capacity will be achievable. Also, to adjust the rate to the channel capacity without requiring the channel state information at the transmitter, Rateless coding has been proposed. In this thesis above techniques are combined to gain their advantages and to improve system performance. To this end, first we consider a...
Transmission of Analog Signals in Fading Channels using HARQ
,
M.Sc. Thesis
Sharif University of Technology
;
Hossein Khalaj, Babak
(Supervisor)
Abstract
In this dissertation we will study the problem of transmitting the information of continuous source over fading channel, especially when the transmitter does not have complete information about the channel status. In this situation we will have a tradeoff between the Quality of received packets and the Reliability in transmissions. To increase the quality of packets, for example, we should increase the quantization, and therefore, the transmission rates at the transmitter. But this will also increase the Error Probability at the receiver. It means that if the receiver gets the transmitted packet, it will have a better estimation of information source, but it is likely that error happens and...