Pub Date : 2009-04-22DOI: 10.1109/WTS.2009.5068933
Z. Andalibi, Ha H. Nguyen, J. Salt
This paper proposes an iterative estimator for bit interleaved coded modulation (BICM) with an iterative soft-input soft-output (SISO) receiver over time-varying flat fading channels. More specifically, the system implements signal space diversity (SSD) where the QAM symbols are rotated. The use of an iterative Kalman filter shows good results using superimposed training sequence and Gauss-Markov channel model for fast tracking of the channel variation. The proposed soft iterative estimator uses the soft extrinsic information from the decoder as well as the superimposed training sequence to update the channel coefficients for data detection. To analyze the results, an analytical bound for the asymptotic bit error rate (BER) for BICM-ID-SSD over correlated fading channels is computed with perfect channel state information (CSI).
{"title":"Soft iterative channel estimator for BICM-ID-SSD over time-varying flat fading channels","authors":"Z. Andalibi, Ha H. Nguyen, J. Salt","doi":"10.1109/WTS.2009.5068933","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068933","url":null,"abstract":"This paper proposes an iterative estimator for bit interleaved coded modulation (BICM) with an iterative soft-input soft-output (SISO) receiver over time-varying flat fading channels. More specifically, the system implements signal space diversity (SSD) where the QAM symbols are rotated. The use of an iterative Kalman filter shows good results using superimposed training sequence and Gauss-Markov channel model for fast tracking of the channel variation. The proposed soft iterative estimator uses the soft extrinsic information from the decoder as well as the superimposed training sequence to update the channel coefficients for data detection. To analyze the results, an analytical bound for the asymptotic bit error rate (BER) for BICM-ID-SSD over correlated fading channels is computed with perfect channel state information (CSI).","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130893281","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068963
Vasily Aristarkhov
The developed as whole signal detection algorithm is presented in this paper. The proposed algorithm is practical advancement of existent maximum-likelihood sequence estimator (MLSE) and transmitting reference technology. Made mathematical modeling presents performance benchmark over time-invariant intersymbol interference (ISI) and close to real indoor multipath channel models. The proposed algorithm can be widely adopted for ultra wideband (UWB) high-speed wireless networks because of low computation complexity and significant ISI mitigation.
{"title":"Low complexity as whole signal detection algorithm for frequency-selective fading channels.","authors":"Vasily Aristarkhov","doi":"10.1109/WTS.2009.5068963","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068963","url":null,"abstract":"The developed as whole signal detection algorithm is presented in this paper. The proposed algorithm is practical advancement of existent maximum-likelihood sequence estimator (MLSE) and transmitting reference technology. Made mathematical modeling presents performance benchmark over time-invariant intersymbol interference (ISI) and close to real indoor multipath channel models. The proposed algorithm can be widely adopted for ultra wideband (UWB) high-speed wireless networks because of low computation complexity and significant ISI mitigation.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131214790","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068935
A. Y. Hassan, Ayman M. Hassan, A. Hussian
Code Division Multiple Access (CDMA) is a widely used multiple access method in a lot of nowadays vital applications. The systems that are designed based on CDMA are suffering from multiple access interference (MAI) problem [1]. A lot of CDMA detectors are designed to overcome the (MAI) problem. But as the capability of CDMA detector in (MAI) cancellation increases, the complexity of the detector increases too [2]. This paper gives a proposal of a new linear CDMA detector that has the same multiple access interference (MAI) cancellation capability as CDMA decorrelator detector. The structure complexity of this new proposed detector is as simple as the matched filter detector structure. Solving the (MAI) problem in CDMA system with simple detector structure at the receiver helps on increasing the CDMA system capacity. The new proposed detector operation is based on the symmetry property of CDMA signatures' codes cross-correlation matrix.
{"title":"Two signatures' codes linear decorrelator detector for CDMA systems","authors":"A. Y. Hassan, Ayman M. Hassan, A. Hussian","doi":"10.1109/WTS.2009.5068935","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068935","url":null,"abstract":"Code Division Multiple Access (CDMA) is a widely used multiple access method in a lot of nowadays vital applications. The systems that are designed based on CDMA are suffering from multiple access interference (MAI) problem [1]. A lot of CDMA detectors are designed to overcome the (MAI) problem. But as the capability of CDMA detector in (MAI) cancellation increases, the complexity of the detector increases too [2]. This paper gives a proposal of a new linear CDMA detector that has the same multiple access interference (MAI) cancellation capability as CDMA decorrelator detector. The structure complexity of this new proposed detector is as simple as the matched filter detector structure. Solving the (MAI) problem in CDMA system with simple detector structure at the receiver helps on increasing the CDMA system capacity. The new proposed detector operation is based on the symmetry property of CDMA signatures' codes cross-correlation matrix.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116948952","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068975
Adem Coskun, I. Kale
In this paper, the correlation-based Decision Feedback Equalizer (DFE), where the received data from multiple antennas are processed by a multi-dimensional matched filter and then combined prior to the equalization with a single input single output DFE, is discussed and its blind implementation is introduced. To perform the correlation-based DFE blindly, the multi-dimensional matched filter is replaced by an adaptive filter and the DFE filter weights are calculated via manipulating over the second order statistics of the received data. In the blind architecture, the adaptive filter converges to matched filter equivalents, therefore the matched filters of the corresponding communication channels are also blindly be estimated in addition to the blind equalization process. The mean-squared error of the estimation of matched filters and the equalization performance of the proposed blind architecture are also studied and simulated.
{"title":"Blind correlation-based DFE receiver for the equalization of single input multi output communication channels","authors":"Adem Coskun, I. Kale","doi":"10.1109/WTS.2009.5068975","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068975","url":null,"abstract":"In this paper, the correlation-based Decision Feedback Equalizer (DFE), where the received data from multiple antennas are processed by a multi-dimensional matched filter and then combined prior to the equalization with a single input single output DFE, is discussed and its blind implementation is introduced. To perform the correlation-based DFE blindly, the multi-dimensional matched filter is replaced by an adaptive filter and the DFE filter weights are calculated via manipulating over the second order statistics of the received data. In the blind architecture, the adaptive filter converges to matched filter equivalents, therefore the matched filters of the corresponding communication channels are also blindly be estimated in addition to the blind equalization process. The mean-squared error of the estimation of matched filters and the equalization performance of the proposed blind architecture are also studied and simulated.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114143621","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068988
Eduardo Cassano, Francesco Florio, F. Rango, S. Marano
In sensor networks 802.15.4 WPAN, the most common technique used to calculate the distance between two nodes is the RSSI (Received Signal Strength Indicator) technique, because it has the advantage of not requiring additional hardware and synchronization on nodes. Some studies show that the RSSI index is fairly unreliable and often produces significant errors about the location of the nodes in the network. In this paper an approach to the problem of nodes localization in outdoor environment is proposed. In order to obtain more accurate distance estimation a scenario dependent ranging technique has been adopted. The goodness of the ranging model is estimated through a comparison with the classic model based on the path-loss log-distance; then two localization techniques such as Triangulation and RocRssi+ are used in order to test the improvement obtained for the estimated positions of nodes within the network.
{"title":"A performance comparison between ROC-RSSI and trilateration localization techniques for WPAN sensor networks in a real outdoor testbed.","authors":"Eduardo Cassano, Francesco Florio, F. Rango, S. Marano","doi":"10.1109/WTS.2009.5068988","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068988","url":null,"abstract":"In sensor networks 802.15.4 WPAN, the most common technique used to calculate the distance between two nodes is the RSSI (Received Signal Strength Indicator) technique, because it has the advantage of not requiring additional hardware and synchronization on nodes. Some studies show that the RSSI index is fairly unreliable and often produces significant errors about the location of the nodes in the network. In this paper an approach to the problem of nodes localization in outdoor environment is proposed. In order to obtain more accurate distance estimation a scenario dependent ranging technique has been adopted. The goodness of the ranging model is estimated through a comparison with the classic model based on the path-loss log-distance; then two localization techniques such as Triangulation and RocRssi+ are used in order to test the improvement obtained for the estimated positions of nodes within the network.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123998191","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068950
Abhishek Joshi, N. Cho
In this paper we propose a new adaptive equalization technique for Turbo Decision Feedback Equalizers (TDFE) and dual-mode blind equalizers, that takes the advantage of quantization in the probabilistic scheme. In generating the error signal the proposed technique considers the likelihood between the quantized equalizer output and all the constellation points, thus making the receiver insensitive to the decoding errors. The proposed technique achieves lower BER with less computations than other TDFE algorithms. Also a more reliable soft transition between start-up and Decision Directed (DD) mode in blind equalizers is proposed. This technique has been compared with Benveniste-Goursat, Stop-and-Go and Lim's soft transition algorithm. It is shown that the proposed approach is superior and more robust under different channel and SNR conditions.
{"title":"Quantization based reliable equalization algorithm for turbo DFE and dual-mode blind equalizers","authors":"Abhishek Joshi, N. Cho","doi":"10.1109/WTS.2009.5068950","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068950","url":null,"abstract":"In this paper we propose a new adaptive equalization technique for Turbo Decision Feedback Equalizers (TDFE) and dual-mode blind equalizers, that takes the advantage of quantization in the probabilistic scheme. In generating the error signal the proposed technique considers the likelihood between the quantized equalizer output and all the constellation points, thus making the receiver insensitive to the decoding errors. The proposed technique achieves lower BER with less computations than other TDFE algorithms. Also a more reliable soft transition between start-up and Decision Directed (DD) mode in blind equalizers is proposed. This technique has been compared with Benveniste-Goursat, Stop-and-Go and Lim's soft transition algorithm. It is shown that the proposed approach is superior and more robust under different channel and SNR conditions.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124243191","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068958
Jaeyeon Lee, Jihoon Lee, Taewan Kim, Hyungkee Kim
In this paper, we propose a radio resource scheduling algorithm for a scheduler in IEEE 802.16 Orthogonal Frequency Division Multiple Access (OFDMA) specification. The scheduler dynamically allocates slots considering wireless channel conditions of subscriber stations to improve radio resource utilization efficiency. The results show that with the proposed algorithm, smaller radio resources are used to maintain the same data traffic rate than a constant bandwidth allocation algorithm without considering characteristics of OFDMA systems. Therefore, the scheduler can serve wider bandwidth to established connections, or may use saved radio resources for other purpose.
{"title":"A radio resource scheduling algorithm considering wireless channel characteristics in IEEE 802.16 OFDMA systems","authors":"Jaeyeon Lee, Jihoon Lee, Taewan Kim, Hyungkee Kim","doi":"10.1109/WTS.2009.5068958","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068958","url":null,"abstract":"In this paper, we propose a radio resource scheduling algorithm for a scheduler in IEEE 802.16 Orthogonal Frequency Division Multiple Access (OFDMA) specification. The scheduler dynamically allocates slots considering wireless channel conditions of subscriber stations to improve radio resource utilization efficiency. The results show that with the proposed algorithm, smaller radio resources are used to maintain the same data traffic rate than a constant bandwidth allocation algorithm without considering characteristics of OFDMA systems. Therefore, the scheduler can serve wider bandwidth to established connections, or may use saved radio resources for other purpose.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123192426","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068987
K. Katsaros, N. Fotiou, George C. Polyzos, G. Xylomenos
The architecture of the current Internet was not originally designed to support either mobility or multicast. In particular, its coupling of host identification and location identification has hindered the provision of effective mobile services. At the same time, its lack of support for multicast distribution causes a multitude of redundant unicast transmissions, leading to an inefficient utilization of network resources. Both these limitations are especially apparent in the case of real-time continuous media distribution. The publish/subscribe paradigm has been proposed as a promising alternative to the current send/receive paradigm for a future Internet architecture. In future publish/subscribe networks, multicast will be the norm, and this change of the end-to-end communication semantics will lead to a networking environment more suitable for mobility. In the context of this paradigm, this paper considers a prototype architecture based on the Scribe overlay multicast scheme. Preliminary simulation results show that our publish/subscribe network implementation achieves better performance during mobility compared to Mobile IPv6 in all relevant metrics, such as hand-off delay (or resume time) and loss of real-time traffic during disconnections, at the cost of a slight increase of the end-to-end delay due to the routing stretch imposed by the overlay.
{"title":"Supporting Mobile streaming services in future publish/subscribe networks","authors":"K. Katsaros, N. Fotiou, George C. Polyzos, G. Xylomenos","doi":"10.1109/WTS.2009.5068987","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068987","url":null,"abstract":"The architecture of the current Internet was not originally designed to support either mobility or multicast. In particular, its coupling of host identification and location identification has hindered the provision of effective mobile services. At the same time, its lack of support for multicast distribution causes a multitude of redundant unicast transmissions, leading to an inefficient utilization of network resources. Both these limitations are especially apparent in the case of real-time continuous media distribution. The publish/subscribe paradigm has been proposed as a promising alternative to the current send/receive paradigm for a future Internet architecture. In future publish/subscribe networks, multicast will be the norm, and this change of the end-to-end communication semantics will lead to a networking environment more suitable for mobility. In the context of this paradigm, this paper considers a prototype architecture based on the Scribe overlay multicast scheme. Preliminary simulation results show that our publish/subscribe network implementation achieves better performance during mobility compared to Mobile IPv6 in all relevant metrics, such as hand-off delay (or resume time) and loss of real-time traffic during disconnections, at the cost of a slight increase of the end-to-end delay due to the routing stretch imposed by the overlay.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122814499","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068997
T. Sung, A. Bojanczyk
We consider packet transmission policies in the cross-layer perspective that minimize the average power consumed by the transmitter under the average delay constraints. We present a simple packet scheduling policy which is influenced by both the queue and the channel state and that can be utilized to trade-off characteristic between queueing delay and transmission power policy. The near-optimal scheduler adopts a low-complexity modified-linear-rule (MLR) which tends to make the queue evolve as a stable feed-back linear system. The parameter is chosen so as to reach the desired compromise between delay and power consumption. Throughout the extensive simulations, we generalize the scheme of MLR scheduler to the multiuser wireless fading environments and compare it with the performance of the optimal scheduler and the log-linear scheduler.
{"title":"Cross-layer delay-constrained packet scheduling over multiuser wireless channels","authors":"T. Sung, A. Bojanczyk","doi":"10.1109/WTS.2009.5068997","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068997","url":null,"abstract":"We consider packet transmission policies in the cross-layer perspective that minimize the average power consumed by the transmitter under the average delay constraints. We present a simple packet scheduling policy which is influenced by both the queue and the channel state and that can be utilized to trade-off characteristic between queueing delay and transmission power policy. The near-optimal scheduler adopts a low-complexity modified-linear-rule (MLR) which tends to make the queue evolve as a stable feed-back linear system. The parameter is chosen so as to reach the desired compromise between delay and power consumption. Throughout the extensive simulations, we generalize the scheme of MLR scheduler to the multiuser wireless fading environments and compare it with the performance of the optimal scheduler and the log-linear scheduler.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133801071","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068956
Mingkwan Somphruek, R. Carrasco, S. L. Goff
Cooperative communication represents a new class of diversity techniques in which multiple nodes each with a single antenna cooperate to generate a virtual multiple-antenna transmission system and thus offer the benefits of spatial diversity. This paper proposes suitable array codes used as low-density parity-check (LDPC) codes to be applied in the cooperative amplify-and-forward (AF) network. A mathematical description of the construction of suitable array codes for a relay fading channel is also presented. Compared with quasi-cyclic (QC) LDPC codes, the array codes have similar encoding complexity and can adaptively generate various desired girth values. This paper shows that array codes with large girths can achieve substantial system performance improvements. Simulation results in this paper show that using array codes as LDPC codes for cooperative relay transmission provides a significant performance improvement over direct transmission. Moreover, it is also shown that its performance is superior to some structured LDPC codes such as QC-LDPC codes, particularly, a coding gain of about 1dB at BER of 10−3 can be provided over its counterpart.
{"title":"Cooperative relay channel with LDPC codes constructed from array codes","authors":"Mingkwan Somphruek, R. Carrasco, S. L. Goff","doi":"10.1109/WTS.2009.5068956","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068956","url":null,"abstract":"Cooperative communication represents a new class of diversity techniques in which multiple nodes each with a single antenna cooperate to generate a virtual multiple-antenna transmission system and thus offer the benefits of spatial diversity. This paper proposes suitable array codes used as low-density parity-check (LDPC) codes to be applied in the cooperative amplify-and-forward (AF) network. A mathematical description of the construction of suitable array codes for a relay fading channel is also presented. Compared with quasi-cyclic (QC) LDPC codes, the array codes have similar encoding complexity and can adaptively generate various desired girth values. This paper shows that array codes with large girths can achieve substantial system performance improvements. Simulation results in this paper show that using array codes as LDPC codes for cooperative relay transmission provides a significant performance improvement over direct transmission. Moreover, it is also shown that its performance is superior to some structured LDPC codes such as QC-LDPC codes, particularly, a coding gain of about 1dB at BER of 10−3 can be provided over its counterpart.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133006995","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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