An Iterative Detection/Decoding Algorithm of Correlated Sources for the LDPC-Based Relay Systems

An iterative detection/decoding algorithm of correlated sources for the LDPC-based relay systems is presented. The signal from the source-destination(S-D) link is formulated as a highly correlated counterpart from the relay-destination(R-D) link. A special XOR vector is defined using the correlated hard decision information blocks from two decoders and the extrinsic information exchanged between the two decoders is derived by the log-likelihood ratio(LLR) associated with the XOR vector. Such the decoding scheme is different from the traditional turbo-like detection/decoding algorithm, where the extrinsic information is computed by the side information and the soft decoder outputs. Simulations show that the presented algorithm has a slightly better performance than the traditional turbo-like algorithm(Taking the(255,175) EG-LDPC code as an example, it achieves about 0.1 dB performance gains aroundBLER=10^(-4)). Furthermore, the presented algorithm requires fewer computing operations per iteration and has faster convergence rate. For example, the average iteration of the presented algorithm is 33 at SNR=1.8 dB, which is about twice faster than that of the turbo-like algorithm, when decoding the(961,721) QC-LDPC code. Therefore, the presented decoding algorithm of correlated sources provides an alternative decoding solution for the LDPC-based relay systems.

Research on the implementation of West Africa-North Africa grid interconnection using new electricity-water composite transmission technology

Combining the characteristics of the reverse distribution of solar resources and water resources in North Africa,West Africa and the Sahara,this paper proposes the West Africa-North Africa grid interconnection project to realize the optimal configuration of desert solar resources and surrounding water resources,and introduce the water resources of West Africa's Niger River and North Africa's desalinated seawater to improve the living environment and development conditions in the hinterland of the Sahara Desert;build photovoltaic bases along the route to send clean electricity to North Africa and West Africa.This paper studies the transmission channel path,electricity-water composite transmission technology and project scheme,and analyzes the economics of the project and the water supply and demand conditions of the Niger River.The research results show that it is feasible in hydrological characteristics to lead the Niger River water along the power transmission channel that crosses the Sahara Desert,and the new electricity-water composite transmission technology has obvious economic advantages.

Economic dispatch constrained by central multi-period security for Global Energy Interconnection and its application in the Northeast Asia

In recent years, the global energy interconnection(GEI) has more and more profound influence around the world, which is a highly practical way for humans to handle the energy crisis. In the studies of GEI, the economic dispatch(ED) is a basic and important content. In this paper, a model of dynamic economic dispatch(DED) of GEI is presented, which include the renewable energy generation. The objective function of this model is composed of the operating costs and the renewable energy curtailment. A series of case studies for the transnational energy interconnection in Northeast Asia are given to verify the superiority of GEI and for further analysis.