This paper considered a multi-relay distributed cooperative system in which not only the source communicates with the destination,but also the relays have communication requests with the destination.In order to achiev...This paper considered a multi-relay distributed cooperative system in which not only the source communicates with the destination,but also the relays have communication requests with the destination.In order to achieve the requirements of simultaneous communication for the source and relays,we propose a distributed cooperative system based on orthogonal frequency division multiplexing with index modulation(OFDM-IM).In this system,the relay can communicate with the destination by superimposing its own signal over the inactive subcarriers on the decoded OFDM-IM signal.Upper bounds on the bit error rates of the source and the active relay are both derived in closed form,whose tightness is verified through simulation results.展开更多
Various efficient generalized sphere decoding (GSD) algorithms have been proposed to approach optimal ML performance for underdetermined linear systems, by transforming the original problem into the full-column-rank o...Various efficient generalized sphere decoding (GSD) algorithms have been proposed to approach optimal ML performance for underdetermined linear systems, by transforming the original problem into the full-column-rank one so that standard SD can be fully applied. However, their design parameters are heuristically set based on observation or the possibility of an ill-conditioned transformed matrix can affect their searching efficiency. This paper presents a better transformation to alleviate the ill-conditioned structure and provides a systematic approach to select design parameters for various GSD algorithms in order to high efficiency. Simulation results on the searching performance confirm that the proposed techniques can provide significant improvement.展开更多
The problem of improving the performance of linear programming（LP） decoding of low-density parity-check（LDPC） codes is considered in this paper.A multistep linear programming（MLP） algorithm was developed for dec...The problem of improving the performance of linear programming（LP） decoding of low-density parity-check（LDPC） codes is considered in this paper.A multistep linear programming（MLP） algorithm was developed for decoding LDPC codes that includes a slight increase in computational complexity.The MLP decoder adaptively adds new constraints which are compatible with a selected check node to refine the results when an error is reported by the original LP decoder.The MLP decoder result is shown to have the maximum-likelihood（ML） certificate property.Simulations with moderate block length LDPC codes suggest that the MLP decoder gives better performance than both the original LP decoder and the conventional sum-product（SP） decoder.展开更多
In order to resolve direction finding problems in the impulse noise,a direction of arrival(DOA)estimation method is proposed.The proposed DOA estimation method can restrain the impulse noise by using infinite norm exp...In order to resolve direction finding problems in the impulse noise,a direction of arrival(DOA)estimation method is proposed.The proposed DOA estimation method can restrain the impulse noise by using infinite norm exponential kernel covariance matrix and obtain excellent performance via the maximumlikelihood(ML)algorithm.In order to obtain the global optimal solutions of this method,a quantum electromagnetic field optimization(QEFO)algorithm is designed.In view of the QEFO algorithm,the proposed method can resolve the difficulties of DOA estimation in the impulse noise.Comparing with some traditional DOA estimation methods,the proposed DOA estimation method shows high superiority and robustness for determining the DOA of independent and coherent sources,which has been verified via the Monte-Carlo experiments of different schemes,especially in the case of snapshot deficiency,low generalized signal to noise ratio(GSNR)and strong impulse noise.Beyond that,the Cramer-Rao bound(CRB)of angle estimation in the impulse noise and the proof of the convergence of the QEFO algorithm are provided in this paper.展开更多
基金supported in part by National Natural Science Foundation of China under Grants 61871190,U1809211 and 61771202in part by Key Program of Marine Economy Development(Six Marine Industries)Special Foundation of Department of Natural Resources of Guangdong Province(GDNRC[2020]009)in part by the Fundamental Research Funds for the Central Universities under No.2019SJ02。
文摘This paper considered a multi-relay distributed cooperative system in which not only the source communicates with the destination,but also the relays have communication requests with the destination.In order to achieve the requirements of simultaneous communication for the source and relays,we propose a distributed cooperative system based on orthogonal frequency division multiplexing with index modulation(OFDM-IM).In this system,the relay can communicate with the destination by superimposing its own signal over the inactive subcarriers on the decoded OFDM-IM signal.Upper bounds on the bit error rates of the source and the active relay are both derived in closed form,whose tightness is verified through simulation results.
文摘Various efficient generalized sphere decoding (GSD) algorithms have been proposed to approach optimal ML performance for underdetermined linear systems, by transforming the original problem into the full-column-rank one so that standard SD can be fully applied. However, their design parameters are heuristically set based on observation or the possibility of an ill-conditioned transformed matrix can affect their searching efficiency. This paper presents a better transformation to alleviate the ill-conditioned structure and provides a systematic approach to select design parameters for various GSD algorithms in order to high efficiency. Simulation results on the searching performance confirm that the proposed techniques can provide significant improvement.
基金Supported by the National Key Basic Research and Development (973) Program of China (No.2009CB320300)
文摘The problem of improving the performance of linear programming（LP） decoding of low-density parity-check（LDPC） codes is considered in this paper.A multistep linear programming（MLP） algorithm was developed for decoding LDPC codes that includes a slight increase in computational complexity.The MLP decoder adaptively adds new constraints which are compatible with a selected check node to refine the results when an error is reported by the original LP decoder.The MLP decoder result is shown to have the maximum-likelihood（ML） certificate property.Simulations with moderate block length LDPC codes suggest that the MLP decoder gives better performance than both the original LP decoder and the conventional sum-product（SP） decoder.
基金supported by the National Natural Science Foundation of China(61571149)the Natural Science Foundation of Heilongjiang Province(LH2020F017)+1 种基金the Initiation Fund for Postdoctoral Research in Heilongjiang Province(LBH-Q19098)the Heilongjiang Province Key Laboratory of High Accuracy Satellite Navigation and Marine Application Laboratory(HKL-2020-Y01).
文摘In order to resolve direction finding problems in the impulse noise,a direction of arrival(DOA)estimation method is proposed.The proposed DOA estimation method can restrain the impulse noise by using infinite norm exponential kernel covariance matrix and obtain excellent performance via the maximumlikelihood(ML)algorithm.In order to obtain the global optimal solutions of this method,a quantum electromagnetic field optimization(QEFO)algorithm is designed.In view of the QEFO algorithm,the proposed method can resolve the difficulties of DOA estimation in the impulse noise.Comparing with some traditional DOA estimation methods,the proposed DOA estimation method shows high superiority and robustness for determining the DOA of independent and coherent sources,which has been verified via the Monte-Carlo experiments of different schemes,especially in the case of snapshot deficiency,low generalized signal to noise ratio(GSNR)and strong impulse noise.Beyond that,the Cramer-Rao bound(CRB)of angle estimation in the impulse noise and the proof of the convergence of the QEFO algorithm are provided in this paper.
