Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1208879
Byungchuhl Kim, I. Lu
A novel time-frequency processing scheme is developed to exploit Doppler diversity of time varying multipath channel for OFDM mobile communication systems. Extensive simulations show that the proposed time-frequency MMSE processing scheme alters the statistics of the fading to improve BER significantly.
{"title":"Doppler diversity for OFDM wireless mobile communications. Part II: time-frequency processing","authors":"Byungchuhl Kim, I. Lu","doi":"10.1109/VETECS.2003.1208879","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1208879","url":null,"abstract":"A novel time-frequency processing scheme is developed to exploit Doppler diversity of time varying multipath channel for OFDM mobile communication systems. Extensive simulations show that the proposed time-frequency MMSE processing scheme alters the statistics of the fading to improve BER significantly.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130520427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1208853
N. D. Vo, T. Le-Ngoc
A new optimal, efficient filter design synthesis for interpolation filters suitable for software-defined radio receivers is presented. The proposed cost function takes into consideration the desired time and frequency responses as well as the symbol timing error, suitable for practical design objectives. Illustrative filter design examples are given and their performance are compared with that of other similar interpolators with a similar complexity. Simulation results show that the new interpolators outperform others.
{"title":"Optimal interpolators for flexible digital receivers","authors":"N. D. Vo, T. Le-Ngoc","doi":"10.1109/VETECS.2003.1208853","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1208853","url":null,"abstract":"A new optimal, efficient filter design synthesis for interpolation filters suitable for software-defined radio receivers is presented. The proposed cost function takes into consideration the desired time and frequency responses as well as the symbol timing error, suitable for practical design objectives. Illustrative filter design examples are given and their performance are compared with that of other similar interpolators with a similar complexity. Simulation results show that the new interpolators outperform others.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130580577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1207813
Heung-no Lee
We study the performance of coded modulation schemes where the Gallager code is used as the underlying frequency-space code over MIMO fading ISI channels. Two systems are compared: one is the OFDM based system; the other is the single-carrier system, which employs the turbo-iterative decoding, and equalization at the receiver. With simulations over a number of ISI channels, we confirm that in all channel settings detection performance-perhaps already well known. In this paper, a particular attention is given to answer the question: how close is the performance of OFDM system to the performance of the optimal time-domain equalization when the LDPC code is used as the frequency-space code. It is shown that over the ensemble of MIMO fading channels, the performance degradation of OFDM is only about 2 dB, when two transmit and two receive antennas are used.
{"title":"LDPC coded modulation MIMO OFDM transceiver: performance comparison with MAP equalization","authors":"Heung-no Lee","doi":"10.1109/VETECS.2003.1207813","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1207813","url":null,"abstract":"We study the performance of coded modulation schemes where the Gallager code is used as the underlying frequency-space code over MIMO fading ISI channels. Two systems are compared: one is the OFDM based system; the other is the single-carrier system, which employs the turbo-iterative decoding, and equalization at the receiver. With simulations over a number of ISI channels, we confirm that in all channel settings detection performance-perhaps already well known. In this paper, a particular attention is given to answer the question: how close is the performance of OFDM system to the performance of the optimal time-domain equalization when the LDPC code is used as the frequency-space code. It is shown that over the ensemble of MIMO fading channels, the performance degradation of OFDM is only about 2 dB, when two transmit and two receive antennas are used.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132892652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1207842
Jong-Ho Lee, Yong-Hwa Kim, Seong-Cheol Kim, J. Han
In this paper, we consider the iterative channel estimation and decoding algorithms for quadrature amplitude modulation (QAM) modulated orthogonal frequency division multiplexing (OFDM) signals. We first describe the optimal sequence estimation based on the expectation-maximization (EM) algorithm. Using some approximations, we propose a sub-optimal iterative channel estimation and decoding algorithm, which is shown to have reduced computational complexity. The bit error rate (BER) performances of the proposed algorithm are evaluated using computer simulations. The results show that the proposed algorithm performs nearly as well as the optimal EM algorithm, and outperforms the conventional minimum mean square error (MMSE) estimator.
{"title":"Pilot symbol initiated iterative channel estimation and decoding for QAM modulated OFDM signals","authors":"Jong-Ho Lee, Yong-Hwa Kim, Seong-Cheol Kim, J. Han","doi":"10.1109/VETECS.2003.1207842","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1207842","url":null,"abstract":"In this paper, we consider the iterative channel estimation and decoding algorithms for quadrature amplitude modulation (QAM) modulated orthogonal frequency division multiplexing (OFDM) signals. We first describe the optimal sequence estimation based on the expectation-maximization (EM) algorithm. Using some approximations, we propose a sub-optimal iterative channel estimation and decoding algorithm, which is shown to have reduced computational complexity. The bit error rate (BER) performances of the proposed algorithm are evaluated using computer simulations. The results show that the proposed algorithm performs nearly as well as the optimal EM algorithm, and outperforms the conventional minimum mean square error (MMSE) estimator.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130882902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1208776
Hyung-Rae Park, Yeon-Sil Yang, Sang-Sik Yoon, Sang-Ho Lee
The hybrid search algorithm, a combination of the maximum-likelihood search and serial search algorithms, is known as one of the most promising techniques that can be used for code acquisition in CDMA forward links. An efficient adaptive hybrid search code acquisition algorithm with embedded CFAR is designed in this paper, which employs two operating modes, i.e., search and verification modes with M-parallel correlators used for maximum-likelihood detection in search mode. An analytical expression for the mean acquisition time is obtained and the exact expressions on the probabilities of detection, miss, and false alarm are derived for slowly varying frequency-selective Rayleigh fading environments. Numerical evaluation shall be performed to investigate the effects of sub-window size, number of post-detection integration, and so on, in the forward link of cellular CDMA networks.
{"title":"Performance analysis of the adaptive hybrid search code acquisition algorithm for cellular CDMA systems","authors":"Hyung-Rae Park, Yeon-Sil Yang, Sang-Sik Yoon, Sang-Ho Lee","doi":"10.1109/VETECS.2003.1208776","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1208776","url":null,"abstract":"The hybrid search algorithm, a combination of the maximum-likelihood search and serial search algorithms, is known as one of the most promising techniques that can be used for code acquisition in CDMA forward links. An efficient adaptive hybrid search code acquisition algorithm with embedded CFAR is designed in this paper, which employs two operating modes, i.e., search and verification modes with M-parallel correlators used for maximum-likelihood detection in search mode. An analytical expression for the mean acquisition time is obtained and the exact expressions on the probabilities of detection, miss, and false alarm are derived for slowly varying frequency-selective Rayleigh fading environments. Numerical evaluation shall be performed to investigate the effects of sub-window size, number of post-detection integration, and so on, in the forward link of cellular CDMA networks.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127640148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1207771
Jing Cheng, Winston K.G. Seah
We present an innovative source-initiated on-demand routing for mobile ad hoc networking. This protocol does not introduce any new messages, e.g. RREQ in route discovery; routers can infer routes from broadcast messages. The protocol operates in an energy-efficient manner by minimizing flooding of messages after nodes have learned routes from messages, and eventually stop broadcasting after the route has been established. To support the new routing protocol, we have a new TDMA-based MAC protocol. Our simulation results show that this new MAC protocol performs better in the village radio network than the IEEE 802.11 MAC protocol does. Our simulation results also show that this new routing scheme is quite suitable for the original flooding-based village radio network, which no existing ad hoc routing protocol can be used. This routing scheme is also effective as it provides fairly high packet delivery at both high and low mobility settings. Furthermore, this routing scheme is energy-efficient as it eliminates packet flooding.
{"title":"A new routing protocol for village radio network","authors":"Jing Cheng, Winston K.G. Seah","doi":"10.1109/VETECS.2003.1207771","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1207771","url":null,"abstract":"We present an innovative source-initiated on-demand routing for mobile ad hoc networking. This protocol does not introduce any new messages, e.g. RREQ in route discovery; routers can infer routes from broadcast messages. The protocol operates in an energy-efficient manner by minimizing flooding of messages after nodes have learned routes from messages, and eventually stop broadcasting after the route has been established. To support the new routing protocol, we have a new TDMA-based MAC protocol. Our simulation results show that this new MAC protocol performs better in the village radio network than the IEEE 802.11 MAC protocol does. Our simulation results also show that this new routing scheme is quite suitable for the original flooding-based village radio network, which no existing ad hoc routing protocol can be used. This routing scheme is also effective as it provides fairly high packet delivery at both high and low mobility settings. Furthermore, this routing scheme is energy-efficient as it eliminates packet flooding.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128812423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1207600
W. Qiu, H. Troger, M. Meurer, C. A. Jotten
Recently, receiver oriented transmission schemes have been proposed for multi-user MIMO (multiple input multiple output) mobile radio downlinks. In such systems, the receiver algorithms are a priori chosen and the transmitter algorithms are a posteriori adapted under consideration of channel information and the receiver algorithms. This leads to the advantage of particularly simple receivers. A certain drawback of such schemes consists in a slight transmit energy increase as compared to conventional transmitter oriented systems. In order to overcome this drawback, in this paper a beneficial choice of the receiver algorithms based on space-time eigen-signatures is proposed for the receiver oriented transmission scheme joint transmission (JT). In this approach, not only the transmitter, but also the receivers exploit channel information, which leads to a channel oriented multi-user MIMO downlink. The analysis shows that the system performance strongly depends on the cross-correlation coefficients of the space-time eigen-signatures. Consequently, dependencies of these coefficients on the system performance are studied intensively. Analytical and numerical results show that the presented channel oriented multi-user MIMO downlink system performs near optimum with respect to the efficient use of the radiated transmit energy.
{"title":"Performance analysis of a channel oriented concept for multi-user MIMO downlinks with frequency selective channels","authors":"W. Qiu, H. Troger, M. Meurer, C. A. Jotten","doi":"10.1109/VETECS.2003.1207600","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1207600","url":null,"abstract":"Recently, receiver oriented transmission schemes have been proposed for multi-user MIMO (multiple input multiple output) mobile radio downlinks. In such systems, the receiver algorithms are a priori chosen and the transmitter algorithms are a posteriori adapted under consideration of channel information and the receiver algorithms. This leads to the advantage of particularly simple receivers. A certain drawback of such schemes consists in a slight transmit energy increase as compared to conventional transmitter oriented systems. In order to overcome this drawback, in this paper a beneficial choice of the receiver algorithms based on space-time eigen-signatures is proposed for the receiver oriented transmission scheme joint transmission (JT). In this approach, not only the transmitter, but also the receivers exploit channel information, which leads to a channel oriented multi-user MIMO downlink. The analysis shows that the system performance strongly depends on the cross-correlation coefficients of the space-time eigen-signatures. Consequently, dependencies of these coefficients on the system performance are studied intensively. Analytical and numerical results show that the presented channel oriented multi-user MIMO downlink system performs near optimum with respect to the efficient use of the radiated transmit energy.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126670884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1207544
M. Kießling, J. Speidel, I. Viering, M. Reinhardt
Fading correlation at the transmit antenna array of MIMO systems causes significant performance degradation, especially in case of non-adaptive transmitters and linear receivers. We propose statistical transmit matrix prefiltering schemes for zero forcing and minimum mean squared error receivers that are controlled by knowledge of the transmit correlation matrix only, thus avoiding the need for instantaneous channel state information at the transmitter. To this end, closed-form approximations are derived for average error probability and average mean squared error, respectively, under a flat Rayleigh fading channel assumption. Based on these results, the optimum linear matrix prefilters are derived for a well-known MIMO channel model. Monte-Carlo simulations demonstrate the effectiveness of the proposed statistical prefilters.
{"title":"Statistical prefiltering for MIMO systems with linear receivers in the presence of transmit correlation","authors":"M. Kießling, J. Speidel, I. Viering, M. Reinhardt","doi":"10.1109/VETECS.2003.1207544","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1207544","url":null,"abstract":"Fading correlation at the transmit antenna array of MIMO systems causes significant performance degradation, especially in case of non-adaptive transmitters and linear receivers. We propose statistical transmit matrix prefiltering schemes for zero forcing and minimum mean squared error receivers that are controlled by knowledge of the transmit correlation matrix only, thus avoiding the need for instantaneous channel state information at the transmitter. To this end, closed-form approximations are derived for average error probability and average mean squared error, respectively, under a flat Rayleigh fading channel assumption. Based on these results, the optimum linear matrix prefilters are derived for a well-known MIMO channel model. Monte-Carlo simulations demonstrate the effectiveness of the proposed statistical prefilters.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123346337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1208831
Qing Xu, R. Segupta, D. Jiang, D. Chrysler
We study the wireless communication among highway vehicles in the newly-assigned 5.9 GHz dedicated short range communication (DSRC) spectrum. A vehicle-vehicle location-based broadcast (LBB) communication protocol is designed to meet highway safety applications' communication requirements. The analytical expressions of the performance of the protocol in terms of probability of transmission failure and channel occupancy are derived with commonly satisfied assumptions. The optimal relation between the performance and design parameters is obtained from the expressions. The sensitivity of the protocol performance is tested for various communication conditions as well as highway traffic conditions. Feasible combinations of the communication and highway traffic parameters are found for certain requirements on protocol performance.
{"title":"Design and analysis of highway safety communication protocol in 5.9 GHz dedicated short range communication spectrum","authors":"Qing Xu, R. Segupta, D. Jiang, D. Chrysler","doi":"10.1109/VETECS.2003.1208831","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1208831","url":null,"abstract":"We study the wireless communication among highway vehicles in the newly-assigned 5.9 GHz dedicated short range communication (DSRC) spectrum. A vehicle-vehicle location-based broadcast (LBB) communication protocol is designed to meet highway safety applications' communication requirements. The analytical expressions of the performance of the protocol in terms of probability of transmission failure and channel occupancy are derived with commonly satisfied assumptions. The optimal relation between the performance and design parameters is obtained from the expressions. The sensitivity of the protocol performance is tested for various communication conditions as well as highway traffic conditions. Feasible combinations of the communication and highway traffic parameters are found for certain requirements on protocol performance.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"345 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123401783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-04-22DOI: 10.1109/VETECS.2003.1207121
Zhongbang Yao, Junfeng Jiang, Pingyi Fan, Z. Cao, V.O.K. Li
Due to station mobility, the network topology is continuously changing in mobile ad hoc networks. In this paper, we propose a neighbor-table-based multipath routing (NTBMR) protocol to track the dynamic topology changes. Distinguished from prior work on multipath protocols employing disjoint paths, NTBMR does not require the routes to be disjoint. In order to verify the different capabilities against dynamic topology changes for disjoint and non-disjoint multipath routings, we make an attempt to analyze their route reliabilities. Theoretical analysis reveals that non-disjoint multipath routing has higher route reliability when the wireless links are unreliable. In NTBMR scheme, we also present a technique to estimate the mean and variance of the lifetime of a wireless link, which can be used to aid route discovery and maintenance. Simulation results show that our multipath routing scheme is relatively robust in an environment with frequent topology changes and can improve the end-to-end delay and packet delivery ratio performance substantially compared to unipath routing.
{"title":"A neighbor-table-based multipath routing in ad hoc networks","authors":"Zhongbang Yao, Junfeng Jiang, Pingyi Fan, Z. Cao, V.O.K. Li","doi":"10.1109/VETECS.2003.1207121","DOIUrl":"https://doi.org/10.1109/VETECS.2003.1207121","url":null,"abstract":"Due to station mobility, the network topology is continuously changing in mobile ad hoc networks. In this paper, we propose a neighbor-table-based multipath routing (NTBMR) protocol to track the dynamic topology changes. Distinguished from prior work on multipath protocols employing disjoint paths, NTBMR does not require the routes to be disjoint. In order to verify the different capabilities against dynamic topology changes for disjoint and non-disjoint multipath routings, we make an attempt to analyze their route reliabilities. Theoretical analysis reveals that non-disjoint multipath routing has higher route reliability when the wireless links are unreliable. In NTBMR scheme, we also present a technique to estimate the mean and variance of the lifetime of a wireless link, which can be used to aid route discovery and maintenance. Simulation results show that our multipath routing scheme is relatively robust in an environment with frequent topology changes and can improve the end-to-end delay and packet delivery ratio performance substantially compared to unipath routing.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122210887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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