Pub Date : 1996-10-15DOI: 10.1109/PIMRC.1996.568387
R. Vaughan, N. Scott
For frequency selective channels, the delay spread is one measure for the channel distortion. This channel characterization is possible by either a CW frequency sweep, which gives directly the transfer function, or by sounding the channel with pulses which results in the impulse response. When the sounding pulse becomes a chirp-type waveform, the two approaches are distinguished more by implementation rather than by concept. Simple rectangular pulses can be used for partial, but usually sufficient, channel characterization. In this paper, the process is described for resolving impulse response components into bins smaller than the duration of the sounding pulse and smaller than the reciprocal of the channel bandwidth. From such "super-resolution", the delay spread can be established accurately even when it is much less than the sounding pulse duration, allowing longer, higher-energy pulses to be used for channel characterization. The process is demonstrated by generating the super-resolved real-only impulse responses from the real-only responses of an experimental multipath channel. Two algorithms are presented and compared, These are subtractive deconvolution where a loop gain of unity is shown to be stable; and a modified inverse filter technique, in which the modification caters for the spectral zeros of the sounding pulse. The experiments demonstrate explicitly how receiving antennas can be used to control the amount of multipath channel degradation.
{"title":"Super-resolution of pulsed multipath channels for delay spread characterization","authors":"R. Vaughan, N. Scott","doi":"10.1109/PIMRC.1996.568387","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568387","url":null,"abstract":"For frequency selective channels, the delay spread is one measure for the channel distortion. This channel characterization is possible by either a CW frequency sweep, which gives directly the transfer function, or by sounding the channel with pulses which results in the impulse response. When the sounding pulse becomes a chirp-type waveform, the two approaches are distinguished more by implementation rather than by concept. Simple rectangular pulses can be used for partial, but usually sufficient, channel characterization. In this paper, the process is described for resolving impulse response components into bins smaller than the duration of the sounding pulse and smaller than the reciprocal of the channel bandwidth. From such \"super-resolution\", the delay spread can be established accurately even when it is much less than the sounding pulse duration, allowing longer, higher-energy pulses to be used for channel characterization. The process is demonstrated by generating the super-resolved real-only impulse responses from the real-only responses of an experimental multipath channel. Two algorithms are presented and compared, These are subtractive deconvolution where a loop gain of unity is shown to be stable; and a modified inverse filter technique, in which the modification caters for the spectral zeros of the sounding pulse. The experiments demonstrate explicitly how receiving antennas can be used to control the amount of multipath channel degradation.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114080054","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.568449
Sung-Kwon Hong, Y. You, Jong-Heon Kim, C. Kang
Multilevel trellis coded 16QAM with partially overlapped signal sets is introduced. It is shown with this scheme that one can achieve an asymptotic coding gain of 4.26 dB over QPSK with a bandwidth efficiency of 2.5 bit/sec/Hz. This result is due to the fact that multilevel trellis coding technique is more appropriate for utilizing the increased Euclidean distance of partially overlapped signal sets than its counterpart, TCM scheme. We explain this coding scheme in terms of performance, complexity, and set partitioning of partially overlapped 16QAM signals, and compare it with trellis coded 8PSK, 16QAM.
{"title":"Multilevel trellis coded 16QAM with partially overlapped signal sets","authors":"Sung-Kwon Hong, Y. You, Jong-Heon Kim, C. Kang","doi":"10.1109/PIMRC.1996.568449","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.568449","url":null,"abstract":"Multilevel trellis coded 16QAM with partially overlapped signal sets is introduced. It is shown with this scheme that one can achieve an asymptotic coding gain of 4.26 dB over QPSK with a bandwidth efficiency of 2.5 bit/sec/Hz. This result is due to the fact that multilevel trellis coding technique is more appropriate for utilizing the increased Euclidean distance of partially overlapped signal sets than its counterpart, TCM scheme. We explain this coding scheme in terms of performance, complexity, and set partitioning of partially overlapped 16QAM signals, and compare it with trellis coded 8PSK, 16QAM.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122354510","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567445
P. Whiting
Approximate capacity bounds are obtained by estimating the probability that the SNR equations for the received powers in a CDMA network have no solution, using large deviations techniques. The construction of the bounds is illustrated using a single micro cell example and extensions of this are given subsequently. The results suggest that micro cells are an effective method for extending the capacity of a CDMA cellular network.
{"title":"Capacity bounds for a hierarchical CDMA cellular network","authors":"P. Whiting","doi":"10.1109/PIMRC.1996.567445","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567445","url":null,"abstract":"Approximate capacity bounds are obtained by estimating the probability that the SNR equations for the received powers in a CDMA network have no solution, using large deviations techniques. The construction of the bounds is illustrated using a single micro cell example and extensions of this are given subsequently. The results suggest that micro cells are an effective method for extending the capacity of a CDMA cellular network.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124463589","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567481
J. Pereira, D. Fagen
In the scope of the National Intelligent Transportation Systems (ITS) Architecture Study, wide area wireless data requirements have been assessed for three time frames: 1997, 2002, and 2012. This assessment covered not only the expected wide area ITS data loads but also projections for the non-ITS data loads. The performance of a minimal cellular digital packet data (CDPD) deployment in a major metropolitan area, was analyzed using the data requirements assessed for the year 2002, under the assumption of shared use of the CDPD infrastructure by all wireless applications. To study the performance of CDPD, two proprietary GTE simulation packages, MOSS and GRANET, were used. Performance information obtained includes average reverse link delay and average throughput for each sector in the actual cellular deployment, the probability density function (PDF) of the delay. The observed performance confirms the adequacy of CDPD for wide area wireless data service, accommodating even the most demanding and time-critical applications.
{"title":"Performance of a minimal CDPD deployment in a major metropolitan area for the year 2002","authors":"J. Pereira, D. Fagen","doi":"10.1109/PIMRC.1996.567481","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567481","url":null,"abstract":"In the scope of the National Intelligent Transportation Systems (ITS) Architecture Study, wide area wireless data requirements have been assessed for three time frames: 1997, 2002, and 2012. This assessment covered not only the expected wide area ITS data loads but also projections for the non-ITS data loads. The performance of a minimal cellular digital packet data (CDPD) deployment in a major metropolitan area, was analyzed using the data requirements assessed for the year 2002, under the assumption of shared use of the CDPD infrastructure by all wireless applications. To study the performance of CDPD, two proprietary GTE simulation packages, MOSS and GRANET, were used. Performance information obtained includes average reverse link delay and average throughput for each sector in the actual cellular deployment, the probability density function (PDF) of the delay. The observed performance confirms the adequacy of CDPD for wide area wireless data service, accommodating even the most demanding and time-critical applications.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127697128","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567503
S. Kozono, S. Seino, H. Nakabayashi
In mobile communications, the received signal level of a wide-band transmission differs from that of a narrow-band transmission. Only a few studies have been done to clarify the received signal-level characteristics of a wide-band transmission. In order to normalize the signal-level distribution we propose a new propagation parameter called the equivalent received bandwidth 2/spl Delta/f/spl Delta/L/sub max/ which is a product of the received bandwidth 2/spl Delta/f and the maximum difference in the propagation path length /spl Delta/L/sub max/. We evaluated the relation between this new propagation parameter and the fading depth by computer simulation, and we found they are closely related. Further, we have examined the received signal-level autocorrelation dependence on the received bandwidth and difference in path length, theoretically and by computer simulation. The result showed that the autocorrelation was independent of both.
{"title":"Received signal-level, characteristics of wide-band transmission in mobile communications","authors":"S. Kozono, S. Seino, H. Nakabayashi","doi":"10.1109/PIMRC.1996.567503","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567503","url":null,"abstract":"In mobile communications, the received signal level of a wide-band transmission differs from that of a narrow-band transmission. Only a few studies have been done to clarify the received signal-level characteristics of a wide-band transmission. In order to normalize the signal-level distribution we propose a new propagation parameter called the equivalent received bandwidth 2/spl Delta/f/spl Delta/L/sub max/ which is a product of the received bandwidth 2/spl Delta/f and the maximum difference in the propagation path length /spl Delta/L/sub max/. We evaluated the relation between this new propagation parameter and the fading depth by computer simulation, and we found they are closely related. Further, we have examined the received signal-level autocorrelation dependence on the received bandwidth and difference in path length, theoretically and by computer simulation. The result showed that the autocorrelation was independent of both.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"233 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121413040","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567438
T. Huschka, M. Reinhardt, J. Lindner
Channel capacities of various channel models are investigated. We consider two frequency selective channels, the indoor radio channel, simulated with ray tracing, and the two path channel. Additionally Rayleigh-, Rice- and Nakagami-m-distributed stochastic channel models and the discrete-time additive Gaussian noise channel with binomial distributed input alphabet are treated.
{"title":"Channel capacities of fading radio channels","authors":"T. Huschka, M. Reinhardt, J. Lindner","doi":"10.1109/PIMRC.1996.567438","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567438","url":null,"abstract":"Channel capacities of various channel models are investigated. We consider two frequency selective channels, the indoor radio channel, simulated with ray tracing, and the two path channel. Additionally Rayleigh-, Rice- and Nakagami-m-distributed stochastic channel models and the discrete-time additive Gaussian noise channel with binomial distributed input alphabet are treated.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129332135","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567430
T. Kumpumäki, T. Poutanen, J. Talvitie
The performance of a non-coherent DLL based code tracking algorithm for CDMA land mobile satellite systems under realistic channel conditions is studied by computer simulations. In this study the channel models used correspond to LEO satellite systems, which are typically influenced by extremely high Doppler effects due to the relatively high speed of satellite movement. Four different channel conditions were considered: good urban, bad urban, light shadowed rural and medium shadowed rural state. To get the insight of the performance of the code tracking algorithm the mean and standard deviation values of steady state code tracking errors were calculated. Also the convergence time of the recovered code phase from initial code phase error of 0.5 chips was calculated. According to the simulation results the performance of the non-coherent DLL as a code tracking algorithm was found to be satisfactory in realistic mobile satellite channel.
{"title":"The performance of a DLL based code tracking algorithm in a realistic CDMA land mobile satellite channel","authors":"T. Kumpumäki, T. Poutanen, J. Talvitie","doi":"10.1109/PIMRC.1996.567430","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567430","url":null,"abstract":"The performance of a non-coherent DLL based code tracking algorithm for CDMA land mobile satellite systems under realistic channel conditions is studied by computer simulations. In this study the channel models used correspond to LEO satellite systems, which are typically influenced by extremely high Doppler effects due to the relatively high speed of satellite movement. Four different channel conditions were considered: good urban, bad urban, light shadowed rural and medium shadowed rural state. To get the insight of the performance of the code tracking algorithm the mean and standard deviation values of steady state code tracking errors were calculated. Also the convergence time of the recovered code phase from initial code phase error of 0.5 chips was calculated. According to the simulation results the performance of the non-coherent DLL as a code tracking algorithm was found to be satisfactory in realistic mobile satellite channel.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128407405","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567484
Thomas Y. C. Woo, T. L. Porta, Krishan K. Sabnani
A new class of wireless messaging service, called two-way paging, is emerging. Current research on wireless messaging has mostly been concerned with low-level physical layer transmission issues, e.g., modulation and access. Few efforts have addressed high-level issues such as new messaging functionalities, high layer protocols, and overall system design. Most existing wireless messaging systems are built as monolithic entities in a centralized manner. We contend that the current designs lack flexibility required to meet the demand of next generation messaging needs. Pigeon is our proposal of a two-way messaging system. The novelty of our system lies in (1) the techniques used in mitigating the wireless media and end device constraints, (2) the functionalities provided, and (3) its modular architecture. Examples of (1) include the use of asymmetric protocols and the introduction of user agents. Examples of (2) include group addressing, transaction support and flexible messages. The modularity of Pigeon is especially important when it is mapped onto a specific platform, in which case the components of Pigeon, as opposed to the system as is, may be individually adopted. A prototype of Pigeon has been implemented and is operational at Bell Laboratories. We describe the design of Pigeon. We pay particular attention to motivate its service and system concepts. We also present, as an example, a mapping of Pigeon to cellular messaging.
{"title":"Pigeon: a wireless two-way messaging system","authors":"Thomas Y. C. Woo, T. L. Porta, Krishan K. Sabnani","doi":"10.1109/PIMRC.1996.567484","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567484","url":null,"abstract":"A new class of wireless messaging service, called two-way paging, is emerging. Current research on wireless messaging has mostly been concerned with low-level physical layer transmission issues, e.g., modulation and access. Few efforts have addressed high-level issues such as new messaging functionalities, high layer protocols, and overall system design. Most existing wireless messaging systems are built as monolithic entities in a centralized manner. We contend that the current designs lack flexibility required to meet the demand of next generation messaging needs. Pigeon is our proposal of a two-way messaging system. The novelty of our system lies in (1) the techniques used in mitigating the wireless media and end device constraints, (2) the functionalities provided, and (3) its modular architecture. Examples of (1) include the use of asymmetric protocols and the introduction of user agents. Examples of (2) include group addressing, transaction support and flexible messages. The modularity of Pigeon is especially important when it is mapped onto a specific platform, in which case the components of Pigeon, as opposed to the system as is, may be individually adopted. A prototype of Pigeon has been implemented and is operational at Bell Laboratories. We describe the design of Pigeon. We pay particular attention to motivate its service and system concepts. We also present, as an example, a mapping of Pigeon to cellular messaging.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128575446","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}
An intelligent moving agent (IMA) group designed for a mobile host (MH) is presented. The concept of group communication, intelligence and moving code are introduced into the design of the IMA. By the operation of the IMA group, a MH can act as a computer on the wired network and the following goals can be achieved: (1) the MH on the wireless network can become a member on the internet; (2) the hand-off problem can be solved by the moving feature of an IMA; (3) the location problem can also be solved by introducing the concept of group communication among the IMAs, which resides on different base stations, serving the same MH; and (4) the reliability and bandwidth of wireless communication can be solved by the store and forward ability of the IMA.
{"title":"Solving location problem of a mobile host by an agent group","authors":"Chyi-Nan Chen, Chung-Fann Liou, Ching-Ruan Wu, Rey-Yu Wu, Ting-Wei Hou","doi":"10.1109/PIMRC.1996.567487","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567487","url":null,"abstract":"An intelligent moving agent (IMA) group designed for a mobile host (MH) is presented. The concept of group communication, intelligence and moving code are introduced into the design of the IMA. By the operation of the IMA group, a MH can act as a computer on the wired network and the following goals can be achieved: (1) the MH on the wireless network can become a member on the internet; (2) the hand-off problem can be solved by the moving feature of an IMA; (3) the location problem can also be solved by introducing the concept of group communication among the IMAs, which resides on different base stations, serving the same MH; and (4) the reliability and bandwidth of wireless communication can be solved by the store and forward ability of the IMA.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117085670","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 : 1996-10-15DOI: 10.1109/PIMRC.1996.567447
H. Furukawa, Y. Kamio, H. Sasaoka
Co-channel interference disturbs the spectral efficiency in cellular radio systems. A co-channel interference reduction method using a constant modulus algorithm (CMA) adaptive array antenna is proposed. When we apply an adaptive array antenna to reduce co-channel interference, a co-channel interference signal may be captured. In this method, the replica of the interference signal is generated and then eliminated from the received signal, and thus the desired signal can be obtained. Computer simulation results of GMSK modulation confirm that a CMA adaptive array antenna that uses this method can reduce co-channel interference more than a conventional CMA adaptive array antenna.
{"title":"Co-channel interference reduction method using CMA adaptive array antenna","authors":"H. Furukawa, Y. Kamio, H. Sasaoka","doi":"10.1109/PIMRC.1996.567447","DOIUrl":"https://doi.org/10.1109/PIMRC.1996.567447","url":null,"abstract":"Co-channel interference disturbs the spectral efficiency in cellular radio systems. A co-channel interference reduction method using a constant modulus algorithm (CMA) adaptive array antenna is proposed. When we apply an adaptive array antenna to reduce co-channel interference, a co-channel interference signal may be captured. In this method, the replica of the interference signal is generated and then eliminated from the received signal, and thus the desired signal can be obtained. Computer simulation results of GMSK modulation confirm that a CMA adaptive array antenna that uses this method can reduce co-channel interference more than a conventional CMA adaptive array antenna.","PeriodicalId":206655,"journal":{"name":"Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114147895","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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