Pub Date : 2000-12-17DOI: 10.1109/ICPWC.2000.905782
M. Ghogho, A. Swami, T. Durrani
We address the problem of blind estimation of carrier offset in the presence of an unknown multipath propagation channel for linearly modulated signals. The goal is to decouple the two estimation problems. Here, we capitalize on the second and higher (typically fourth-) order noncircularity of the transmitted signals. We focus on QAM and PSK-type signals. We analyze both frequency and phase estimators. We study the performance of the proposed estimators, and compare them with the corresponding Cramer-Rao bounds which are also derived. The theoretical results are verified via simulations.
{"title":"Blind estimation of frequency offset in the presence of unknown multipath","authors":"M. Ghogho, A. Swami, T. Durrani","doi":"10.1109/ICPWC.2000.905782","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905782","url":null,"abstract":"We address the problem of blind estimation of carrier offset in the presence of an unknown multipath propagation channel for linearly modulated signals. The goal is to decouple the two estimation problems. Here, we capitalize on the second and higher (typically fourth-) order noncircularity of the transmitted signals. We focus on QAM and PSK-type signals. We analyze both frequency and phase estimators. We study the performance of the proposed estimators, and compare them with the corresponding Cramer-Rao bounds which are also derived. The theoretical results are verified via simulations.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127895636","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905835
M. Sugano, T. Araki, M. Murata, T. Hatauchi, Y. Hosooka
In an ad hoc wireless network system, wireless terminals can autonomously construct a network and directly communicate with each other without using a wired network. A flexible radio network is one of the ad hoc wireless network systems which has been operational in recent years. In the flexible radio network, an original communication protocol is implemented to obtain reliability of communication. We evaluate the performance by means of simulations for the data-link protocol and routing protocol of the flexible radio network. We first show the performance when system parameters are changed to examine how these parameters affect the system performance. Furthermore, we investigate the performance improvement by changing the network configuration.
{"title":"Performance evaluation of a wireless ad hoc network: flexible radio network (FRN)","authors":"M. Sugano, T. Araki, M. Murata, T. Hatauchi, Y. Hosooka","doi":"10.1109/ICPWC.2000.905835","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905835","url":null,"abstract":"In an ad hoc wireless network system, wireless terminals can autonomously construct a network and directly communicate with each other without using a wired network. A flexible radio network is one of the ad hoc wireless network systems which has been operational in recent years. In the flexible radio network, an original communication protocol is implemented to obtain reliability of communication. We evaluate the performance by means of simulations for the data-link protocol and routing protocol of the flexible radio network. We first show the performance when system parameters are changed to examine how these parameters affect the system performance. Furthermore, we investigate the performance improvement by changing the network configuration.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"07 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127195801","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905788
R. van der Hofstad, M. J. Klok
For a direct-sequence code division multiple access system with hard decision parallel interference cancellation (DS-CDMA with HD-PIC), we derive analytical results concerning the probability of a bit error. More precisely, we investigate the exponential rate H/sub k//sup (s)/ of a CDMA system with s stages of HD-PIC, with k users and processing gain equal to n, as n/spl rarr//spl infin/. The rate is a good measure of performance and allows us to compare the performance after applying several stages of HD-PIC. Furthermore, we derive results for the asymptotic behaviour of the exponential rates H/sub k//sup (s)/ as k/spl rarr//spl infin/. Finally, we investigate what happens when, for k fixed, we perform many stages of HD-PIC. These results can be used to guarantee a small BEP by applying a number of HD-PIC stages that depends on the number of users. The results show analytically that HD-PIC significantly improves performance. This conference paper is based upon and extends results and techniques of Van der Hofstad et al. (2000), that we briefly discuss.
针对硬决策并行干扰消除的直接序列码分多址系统(DS-CDMA + HD-PIC)，给出了误码概率的分析结果。更准确地说，我们研究了具有5级HD-PIC、k个用户、处理增益等于n的CDMA系统的指数速率H/sub / k/ sup (s)/为n/spl rarr//spl infin/。速率是性能的一个很好的衡量标准，允许我们在应用HD-PIC的几个阶段后比较性能。进一步，我们得到了指数速率H/sub k//sup (s)/和k/spl rarr//spl infin/的渐近行为的结果。最后，我们研究了当k固定时，我们执行HD-PIC的许多阶段时会发生什么。这些结果可用于通过根据用户数量应用若干HD-PIC阶段来保证较小的BEP。分析结果表明，HD-PIC显著提高了性能。这篇会议论文是基于并扩展了Van der Hofstad et al.(2000)的结果和技术，我们将简要讨论。
{"title":"Performance analysis for DS-CDMA systems with multistage HD-PIC","authors":"R. van der Hofstad, M. J. Klok","doi":"10.1109/ICPWC.2000.905788","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905788","url":null,"abstract":"For a direct-sequence code division multiple access system with hard decision parallel interference cancellation (DS-CDMA with HD-PIC), we derive analytical results concerning the probability of a bit error. More precisely, we investigate the exponential rate H/sub k//sup (s)/ of a CDMA system with s stages of HD-PIC, with k users and processing gain equal to n, as n/spl rarr//spl infin/. The rate is a good measure of performance and allows us to compare the performance after applying several stages of HD-PIC. Furthermore, we derive results for the asymptotic behaviour of the exponential rates H/sub k//sup (s)/ as k/spl rarr//spl infin/. Finally, we investigate what happens when, for k fixed, we perform many stages of HD-PIC. These results can be used to guarantee a small BEP by applying a number of HD-PIC stages that depends on the number of users. The results show analytically that HD-PIC significantly improves performance. This conference paper is based upon and extends results and techniques of Van der Hofstad et al. (2000), that we briefly discuss.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114503271","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905805
K. Soyjaudah, G. Ramsawock
We design and implement the partitioned convolutional code (PCC) and the parallel-concatenated nonrecursive convolutional code (PCNCC). A comparison of the two codes is then carried out based on the following aspects: BER, encoder and decoder complexity, effective code rate, and throughput. It is shown that the PCNCC has identical error performance to the PCC but with less hardware complexity and a slightly higher effective code rate. Also, puncturing is used to increase the code rate of the PCNCC and computer simulation results show that the best PCNCC are those in which the component encoders are derived from the basic encoder.
{"title":"Comparative study of partitioned and parallel concatenated convolutional codes with puncturing","authors":"K. Soyjaudah, G. Ramsawock","doi":"10.1109/ICPWC.2000.905805","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905805","url":null,"abstract":"We design and implement the partitioned convolutional code (PCC) and the parallel-concatenated nonrecursive convolutional code (PCNCC). A comparison of the two codes is then carried out based on the following aspects: BER, encoder and decoder complexity, effective code rate, and throughput. It is shown that the PCNCC has identical error performance to the PCC but with less hardware complexity and a slightly higher effective code rate. Also, puncturing is used to increase the code rate of the PCNCC and computer simulation results show that the best PCNCC are those in which the component encoders are derived from the basic encoder.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126180865","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905904
Ma Yu-chu, Gu Xuemai, Zhang Nai-tong
A nonzero intermediate frequency (IF) likelihood acquisition scheme for PN codes is introduced in this paper. The received signal is first downconverted to IF, and then direct sampled in IF using a 1-bit A/D converter. After the digitalization, the sampled data is detected using a hybrid likelihood acquisition scheme. Using this structure, problems, due to large noise figure of the analog mixer or active filters or due to amplitude and phase imbalance between low-frequency in-phase and quadrature-phase channels, can be avoided. An algorithm which allows easy implementation of the acquisition scheme is also derived. The performance and algorithm are verified by computer simulation.
{"title":"A nonzero intermediate frequency likelihood acquisition scheme for CDMA system","authors":"Ma Yu-chu, Gu Xuemai, Zhang Nai-tong","doi":"10.1109/ICPWC.2000.905904","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905904","url":null,"abstract":"A nonzero intermediate frequency (IF) likelihood acquisition scheme for PN codes is introduced in this paper. The received signal is first downconverted to IF, and then direct sampled in IF using a 1-bit A/D converter. After the digitalization, the sampled data is detected using a hybrid likelihood acquisition scheme. Using this structure, problems, due to large noise figure of the analog mixer or active filters or due to amplitude and phase imbalance between low-frequency in-phase and quadrature-phase channels, can be avoided. An algorithm which allows easy implementation of the acquisition scheme is also derived. The performance and algorithm are verified by computer simulation.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122972958","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905819
S. Mitra, S. DasBit
A simple load balancing technique is proposed. It is basically a combination of both the dynamic channel assignment and channel borrowing techniques. All the cells of the system are divided into six groups, each group under one mobile switching centre (MSC). Initially a fixed number of channels are assigned to each cell under each mobile switching centre. Finally the channels are distributed among the cells as per their requirement. In the case of sudden channel demand under one mobile switching centre, the cell which needs more channel can borrow a channel from one of its compact pattern cells belonging to the same group (to be defined) with it by exchanging a negligible number of messages among the different components of the network. If there is no probable lender cell in the group, the MSC of the borrower cell can lend it from another MSC.
{"title":"A load balancing strategy using dynamic channel assignment and channel borrowing in cellular mobile environment","authors":"S. Mitra, S. DasBit","doi":"10.1109/ICPWC.2000.905819","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905819","url":null,"abstract":"A simple load balancing technique is proposed. It is basically a combination of both the dynamic channel assignment and channel borrowing techniques. All the cells of the system are divided into six groups, each group under one mobile switching centre (MSC). Initially a fixed number of channels are assigned to each cell under each mobile switching centre. Finally the channels are distributed among the cells as per their requirement. In the case of sudden channel demand under one mobile switching centre, the cell which needs more channel can borrow a channel from one of its compact pattern cells belonging to the same group (to be defined) with it by exchanging a negligible number of messages among the different components of the network. If there is no probable lender cell in the group, the MSC of the borrower cell can lend it from another MSC.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":" 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113949081","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905801
A. Ramesh, A. Chockalingam
We derive the system throughput and outage probability performance of adaptive modulation with optimal power control in log-normal shadowing and multipath Rayleigh fading channels. We propose two objective functions, namely, maximum SIR optimum power control and minimum outage probability optimum power control. A dynamic programming-based solution to find the optimum transmit power vector is presented. System performance achieved using the proposed objective functions is compared with the performance achieved using other objective functions considered by Qiu et al., (1999). Our results show that: (a) in terms of total system throughput, adaptive modulation with optimum power control gives the best performance compared to other schemes; (b) in terms of outage probability, minimum outage probability optimum power control gives the best performance; and (c) maximum SIR optimum power control benefits every user in the system by evenly distributing the system capacity.
{"title":"Performance analysis of adaptive modulation with optimum power control in cellular systems","authors":"A. Ramesh, A. Chockalingam","doi":"10.1109/ICPWC.2000.905801","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905801","url":null,"abstract":"We derive the system throughput and outage probability performance of adaptive modulation with optimal power control in log-normal shadowing and multipath Rayleigh fading channels. We propose two objective functions, namely, maximum SIR optimum power control and minimum outage probability optimum power control. A dynamic programming-based solution to find the optimum transmit power vector is presented. System performance achieved using the proposed objective functions is compared with the performance achieved using other objective functions considered by Qiu et al., (1999). Our results show that: (a) in terms of total system throughput, adaptive modulation with optimum power control gives the best performance compared to other schemes; (b) in terms of outage probability, minimum outage probability optimum power control gives the best performance; and (c) maximum SIR optimum power control benefits every user in the system by evenly distributing the system capacity.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122465056","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905846
S. Jamadagni, M. Umesh
A software defined radio (SDR) is a completely configurable radio that can be programmed in software to define its functionality. An SDR handset can be modified to perform different functions at different times through software downloads. Software radios give the ability to add or remove software components or allow plug and play of software components. This allows the SDR handset to be specifically tailored to the applications expected to run on the handset resulting in great flexibility. The downloadable software components can be signal processing components, protocol components or application components. The SDR forum is evolving a download protocol in liaison with the MExE (mobile execution environment) activities of the ETSI forum. Software download overheads are an important issue in realizing viable software radios. Download requests can be initiated by the user terminal, which is termed as a PULL operation or the base station (or the download server) can initiate the download process which is termed as a PUSH operation. We assert that PUSH is an important mode of software download and explore a download architecture that involves PUSH.
{"title":"A PUSH download architecture for software defined radios","authors":"S. Jamadagni, M. Umesh","doi":"10.1109/ICPWC.2000.905846","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905846","url":null,"abstract":"A software defined radio (SDR) is a completely configurable radio that can be programmed in software to define its functionality. An SDR handset can be modified to perform different functions at different times through software downloads. Software radios give the ability to add or remove software components or allow plug and play of software components. This allows the SDR handset to be specifically tailored to the applications expected to run on the handset resulting in great flexibility. The downloadable software components can be signal processing components, protocol components or application components. The SDR forum is evolving a download protocol in liaison with the MExE (mobile execution environment) activities of the ETSI forum. Software download overheads are an important issue in realizing viable software radios. Download requests can be initiated by the user terminal, which is termed as a PULL operation or the base station (or the download server) can initiate the download process which is termed as a PUSH operation. We assert that PUSH is an important mode of software download and explore a download architecture that involves PUSH.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124558931","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905772
S. Medidi, E.A. Ashcroft
Route augmentation based connection rerouting techniques for handoff provide a level of speed and simplicity that can potentially reduce handoff latency and signaling costs, but can become terribly inefficient if the connection route begins to loop itself. We address this issue in this paper by introducing a framework for efficient handoff in which the route information of the call is integrated in the decision process of connection rerouting. A key feature in our approach is that during the handoff the switch covering the mobile host determines the type of handoff that needs to be initiated based on the existing route information of the call that is being handed off and the location of the mobile host. In current handoff techniques in the literature, the switches are not capable of making such choices. This algorithm is aimed at improving the efficiency of the route in the route augmentation technique by avoiding loops.
{"title":"Handoff in mobile wireless ATM networks: an integrated approach","authors":"S. Medidi, E.A. Ashcroft","doi":"10.1109/ICPWC.2000.905772","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905772","url":null,"abstract":"Route augmentation based connection rerouting techniques for handoff provide a level of speed and simplicity that can potentially reduce handoff latency and signaling costs, but can become terribly inefficient if the connection route begins to loop itself. We address this issue in this paper by introducing a framework for efficient handoff in which the route information of the call is integrated in the decision process of connection rerouting. A key feature in our approach is that during the handoff the switch covering the mobile host determines the type of handoff that needs to be initiated based on the existing route information of the call that is being handed off and the location of the mobile host. In current handoff techniques in the literature, the switches are not capable of making such choices. This algorithm is aimed at improving the efficiency of the route in the route augmentation technique by avoiding loops.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127653934","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 : 2000-12-17DOI: 10.1109/ICPWC.2000.905913
Jay P. Singh, S. Adlakha, Subrat Kar, S. Prasad
With the ever increasing demand for easy portability and mobility of devices supporting diverse mobile multimedia applications, the need for the adaptation of a broadband infrastructure to a wireless scenario has arisen. Mobile multimedia networks like the wireless ATM are faced with challenges relating to wireless channel access. In this paper, we propose and simulate policies vis-a-vis medium access in wireless ATM networks. We also discuss the modelling of traffic generators, the evaluation of delay and buffer length bounds and the implementation of a WATM MAC simulator.
{"title":"Proposal, simulation and performance appraisal of an optimal medium access protocol for wireless ATM networks","authors":"Jay P. Singh, S. Adlakha, Subrat Kar, S. Prasad","doi":"10.1109/ICPWC.2000.905913","DOIUrl":"https://doi.org/10.1109/ICPWC.2000.905913","url":null,"abstract":"With the ever increasing demand for easy portability and mobility of devices supporting diverse mobile multimedia applications, the need for the adaptation of a broadband infrastructure to a wireless scenario has arisen. Mobile multimedia networks like the wireless ATM are faced with challenges relating to wireless channel access. In this paper, we propose and simulate policies vis-a-vis medium access in wireless ATM networks. We also discuss the modelling of traffic generators, the evaluation of delay and buffer length bounds and the implementation of a WATM MAC simulator.","PeriodicalId":260472,"journal":{"name":"2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127929904","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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