Pub Date : 2001-03-20DOI: 10.1109/SPAWC.2001.923887
Shuguang Cui, Z. Luo, Zhi Ding
Signal detection in multiuser CDMA systems is particularly attractive when the desired user signature and some interferer signatures are known and are not completely orthogonal at the receiver. As many multiuser systems must deal with the near-far problem, a weakness common to several known blind multiuser CDMA detectors is that the detection performance is very sensitive to signature waveform mismatch (SWM) which occurs a result of channel distortion. We consider the design of a partially blind multiuser CDMA detector that is robust to the SWM. We present a convex formulation of this problem by using second-order cone programming (SOCP). The resulting SOCP can be solved efficiently using the recently developed interior point methods. Computer simulations indicate that the performance of our new robust multiuser detector is superior to the one that does not utilize the interference information.
{"title":"Robust CDMA signal detection in the presence of user and interference signature mismatch","authors":"Shuguang Cui, Z. Luo, Zhi Ding","doi":"10.1109/SPAWC.2001.923887","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923887","url":null,"abstract":"Signal detection in multiuser CDMA systems is particularly attractive when the desired user signature and some interferer signatures are known and are not completely orthogonal at the receiver. As many multiuser systems must deal with the near-far problem, a weakness common to several known blind multiuser CDMA detectors is that the detection performance is very sensitive to signature waveform mismatch (SWM) which occurs a result of channel distortion. We consider the design of a partially blind multiuser CDMA detector that is robust to the SWM. We present a convex formulation of this problem by using second-order cone programming (SOCP). The resulting SOCP can be solved efficiently using the recently developed interior point methods. Computer simulations indicate that the performance of our new robust multiuser detector is superior to the one that does not utilize the interference information.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126050001","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923853
Jitendra Tugnait
Blind channel estimation and equalization for SIMO (single-input multiple-output) time-varying channels is considered using only the second-order statistics of the data. The time-varying channel is assumed to be described by a complex exponential basis expansion model (CE-BEM). The linear prediction error method for blind identification of time-invariant channels is extended to time-varying channels represented by a CE-BEM. Sufficient conditions for identifiability are investigated. The cyclostationary nature of the received signal is exploited for consistent estimation of the time-varying correlation function of the data from a single observation record. The focus of the paper is on certain theoretical issues.
{"title":"On blind equalization of SIMO time-varying channels","authors":"Jitendra Tugnait","doi":"10.1109/SPAWC.2001.923853","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923853","url":null,"abstract":"Blind channel estimation and equalization for SIMO (single-input multiple-output) time-varying channels is considered using only the second-order statistics of the data. The time-varying channel is assumed to be described by a complex exponential basis expansion model (CE-BEM). The linear prediction error method for blind identification of time-invariant channels is extended to time-varying channels represented by a CE-BEM. Sufficient conditions for identifiability are investigated. The cyclostationary nature of the received signal is exploited for consistent estimation of the time-varying correlation function of the data from a single observation record. The focus of the paper is on certain theoretical issues.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127872108","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923872
A. Hazmi, J. Rinne, M. Renfors
We study the quality of terrestrial digital video broadcasting (DVB-T) transmission over a cable TV network. Generally, when terrestrial digital TV signals are distributed by cable TV, a conversion from DVB-T (OFDM) to DVB-C (single carrier) is needed in the head-end. In order to avoid this costly conversion and to transmit the DVB-T signal directly in the existent cable channel, many requirements have to be satisfied. It is known that phase noise represents the main limitation for OFDM based systems. In this contribution, we demonstrate the sensitivity of the OFDM system to phase noise effects by using a dynamic model for the CATV channel. We conclude by giving the specifications for a converter that should allow the DVB-T system to function in the CATV network.
{"title":"DVB-T signal over cable TV network and phase noise requirements","authors":"A. Hazmi, J. Rinne, M. Renfors","doi":"10.1109/SPAWC.2001.923872","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923872","url":null,"abstract":"We study the quality of terrestrial digital video broadcasting (DVB-T) transmission over a cable TV network. Generally, when terrestrial digital TV signals are distributed by cable TV, a conversion from DVB-T (OFDM) to DVB-C (single carrier) is needed in the head-end. In order to avoid this costly conversion and to transmit the DVB-T signal directly in the existent cable channel, many requirements have to be satisfied. It is known that phase noise represents the main limitation for OFDM based systems. In this contribution, we demonstrate the sensitivity of the OFDM system to phase noise effects by using a dynamic model for the CATV channel. We conclude by giving the specifications for a converter that should allow the DVB-T system to function in the CATV network.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133759583","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923834
A. Swindlehurst, G. German, J. Wallace, M. Jensen
This paper presents the results of experiments obtained with a narrowband, multiple-input multiple-output (MIMO) channel probe in an indoor office/laboratory environment. The system employs ten transmit and ten receive antennas, and computes the 10/spl times/10 narrowband channel matrix at 2.4 GHz every 80 milliseconds. We use the data to study the distribution of the channel coefficients, their temporal variability, and the resulting effects on channel capacity. We also compare the empirical results with those predicted by WiSE, a state-of-the-art channel simulator based on ray-tracing from Lucent Technologies.
{"title":"Experimental measurements of capacity for MIMO indoor wireless channels","authors":"A. Swindlehurst, G. German, J. Wallace, M. Jensen","doi":"10.1109/SPAWC.2001.923834","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923834","url":null,"abstract":"This paper presents the results of experiments obtained with a narrowband, multiple-input multiple-output (MIMO) channel probe in an indoor office/laboratory environment. The system employs ten transmit and ten receive antennas, and computes the 10/spl times/10 narrowband channel matrix at 2.4 GHz every 80 milliseconds. We use the data to study the distribution of the channel coefficients, their temporal variability, and the resulting effects on channel capacity. We also compare the empirical results with those predicted by WiSE, a state-of-the-art channel simulator based on ray-tracing from Lucent Technologies.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132209660","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923851
M. Sirbu, J. Mannerkoski, V. Koivunen, Yinglu Zhang
The main goal of this paper is to find whether or not blind equalization can be used in EDGE (enhanced data rate for GSM evolution) systems in the perspective of increasing the data rate. An EDGE system uses 8-PSK modulation as well as the binary GMSK modulation defined for GSM. The main problem is that GMSK modulation is nonlinear, but most blind equalization techniques are derived for linear modulation. Linear approximation of the real GMSK signal has to be performed in order to apply blind equalization. It is of interest to determine if the input sequence resulting from linearisation and the derotation in the receiver is white, which is a key assumption in many blind equalization algorithms. We show that the whiteness property is preserved. We make a comparison among three blind algorithms: two fractionally spaced and one based on baud-rate HOS. The simulation results indicate that blind equalization performs well and the algorithms have potential as a feasible solution to channel tracking in EDGE systems.
{"title":"On the feasibility of blind equalization for EDGE systems","authors":"M. Sirbu, J. Mannerkoski, V. Koivunen, Yinglu Zhang","doi":"10.1109/SPAWC.2001.923851","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923851","url":null,"abstract":"The main goal of this paper is to find whether or not blind equalization can be used in EDGE (enhanced data rate for GSM evolution) systems in the perspective of increasing the data rate. An EDGE system uses 8-PSK modulation as well as the binary GMSK modulation defined for GSM. The main problem is that GMSK modulation is nonlinear, but most blind equalization techniques are derived for linear modulation. Linear approximation of the real GMSK signal has to be performed in order to apply blind equalization. It is of interest to determine if the input sequence resulting from linearisation and the derotation in the receiver is white, which is a key assumption in many blind equalization algorithms. We show that the whiteness property is preserved. We make a comparison among three blind algorithms: two fractionally spaced and one based on baud-rate HOS. The simulation results indicate that blind equalization performs well and the algorithms have potential as a feasible solution to channel tracking in EDGE systems.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134115724","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923879
A. Mahmoud, C. Thierry, S. Samir
A new interference cancellation (IC) scheme is proposed for the uplink of direct-sequence code division multiple access (DS-CDMA) systems communicating over mobile radio channels. The IC detector presented belongs to the subclass of multiuser detectors that employs a multi-stage successive interference cancellation (SIC), and the aim is to show that a low complexity detector can perform well in a mobile radio environment. The new multi-stage SIC scheme includes non-decision directed IC with a modified RAKE combiner to use the diversity in frequency-selective channels, and it works with a finite processing window sliding each iteration to process a new data symbol. The performance is evaluated with known asynchronous delays and channel parameters, in a multipath environment. The results show that the proposed detector is near-far resistant and the loss in performance compared to the single-user bound is small.
{"title":"Asynchronous multi-stage SIC detector for DS-CDMA systems over multipath fading channels","authors":"A. Mahmoud, C. Thierry, S. Samir","doi":"10.1109/SPAWC.2001.923879","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923879","url":null,"abstract":"A new interference cancellation (IC) scheme is proposed for the uplink of direct-sequence code division multiple access (DS-CDMA) systems communicating over mobile radio channels. The IC detector presented belongs to the subclass of multiuser detectors that employs a multi-stage successive interference cancellation (SIC), and the aim is to show that a low complexity detector can perform well in a mobile radio environment. The new multi-stage SIC scheme includes non-decision directed IC with a modified RAKE combiner to use the diversity in frequency-selective channels, and it works with a finite processing window sliding each iteration to process a new data symbol. The performance is evaluated with known asynchronous delays and channel parameters, in a multipath environment. The results show that the proposed detector is near-far resistant and the loss in performance compared to the single-user bound is small.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133465121","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923901
A. Alexiou
Space-time block coding-based transmit diversity (STTD) has been adopted by 3GPP as the open loop transmit diversity scheme aiming at improving the FDD downlink capacity. Although the assumption of independent channels corresponding to different transmitting antennas is commonly made when assessing theoretically the resulting improvement, in a practical system the actual correlation between antennas is highly dependent on the antenna separation, the angular spread and the multipath environment. A realistic spatio-temporal channel model is employed in order to quantify the impact of these factors on the actual STTD performance and compare it against the ideal case of independent channels.
{"title":"Realistic channel model considerations in UMTS downlink capacity with space-time block coding","authors":"A. Alexiou","doi":"10.1109/SPAWC.2001.923901","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923901","url":null,"abstract":"Space-time block coding-based transmit diversity (STTD) has been adopted by 3GPP as the open loop transmit diversity scheme aiming at improving the FDD downlink capacity. Although the assumption of independent channels corresponding to different transmitting antennas is commonly made when assessing theoretically the resulting improvement, in a practical system the actual correlation between antennas is highly dependent on the antenna separation, the angular spread and the multipath environment. A realistic spatio-temporal channel model is employed in order to quantify the impact of these factors on the actual STTD performance and compare it against the ideal case of independent channels.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114011273","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923832
F. Nunes, J. Leitao
Differential detection of phase-shift keying signals entails the ability to establish a phase reference based on previous symbol(s). In communications strongly affected by the Doppler effect, like those involving non-geostationary satellites, the carrier phase drift within the symbol interval may be significant; thus, a better strategy than averaging the phase over previous symbols is to continuously estimate it along the corresponding interval. We propose a receiver for M-DPSK signals in channels affected by fast fading and Doppler frequency shift. A bank of stochastic nonlinear filters estimates the carrier phase drift and the fading vector, which are modeled as stochastic processes within the symbol interval; a key algorithm driven by the filters' outputs estimates the carrier offset frequency, which is considered a constant parameter in each estimation interval (corresponding to at least two-symbol intervals). Simulations with 4-DPSK show that the receiver performs much better than conventional differential phase detectors; it exhibits short convergence times, being able to cope with large Doppler frequency shifts.
{"title":"M-DPSK receiver for Doppler-shift mobile communications","authors":"F. Nunes, J. Leitao","doi":"10.1109/SPAWC.2001.923832","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923832","url":null,"abstract":"Differential detection of phase-shift keying signals entails the ability to establish a phase reference based on previous symbol(s). In communications strongly affected by the Doppler effect, like those involving non-geostationary satellites, the carrier phase drift within the symbol interval may be significant; thus, a better strategy than averaging the phase over previous symbols is to continuously estimate it along the corresponding interval. We propose a receiver for M-DPSK signals in channels affected by fast fading and Doppler frequency shift. A bank of stochastic nonlinear filters estimates the carrier phase drift and the fading vector, which are modeled as stochastic processes within the symbol interval; a key algorithm driven by the filters' outputs estimates the carrier offset frequency, which is considered a constant parameter in each estimation interval (corresponding to at least two-symbol intervals). Simulations with 4-DPSK show that the receiver performs much better than conventional differential phase detectors; it exhibits short convergence times, being able to cope with large Doppler frequency shifts.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123974362","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923828
S. Tantikovit, M. Wang, A. Sheikh
In Tantikovit et al., (2000), we presented a signal model for interpath interference (IPI) in low spreading factor long-code wideband-CDMA (W-CDMA) systems and showed that the impact of IPI can be decomposed into branch correlation and co-channel interference similar to those in an adaptive array system. We consequently derived optimum and suboptimum combining schemes for the RAKE receiver, which provide significant improvement over the conventional maximum-ratio combining. In this paper, we derive the theoretical probability density function (pdf) of the signal-to-interference-plus-noise ratio and outage probability of the optimum combining scheme in a semi-analytical fashion. The obtained analytical results closely agree with simulation results.
在Tantikovit et al.，(2000)中，我们提出了低扩频因子长码宽带cdma (W-CDMA)系统中路径间干扰(IPI)的信号模型，并表明IPI的影响可以分解为分支相关和同信道干扰，类似于自适应阵列系统中的影响。因此，我们推导了RAKE接收机的最优和次优组合方案，它们比传统的最大比组合有了显著的改进。本文以半解析的方式导出了最佳组合方案的信噪比和中断概率的理论概率密度函数(pdf)。所得分析结果与仿真结果吻合较好。
{"title":"On combining schemes for W-CDMA RAKE reception in the presence of interpath interference","authors":"S. Tantikovit, M. Wang, A. Sheikh","doi":"10.1109/SPAWC.2001.923828","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923828","url":null,"abstract":"In Tantikovit et al., (2000), we presented a signal model for interpath interference (IPI) in low spreading factor long-code wideband-CDMA (W-CDMA) systems and showed that the impact of IPI can be decomposed into branch correlation and co-channel interference similar to those in an adaptive array system. We consequently derived optimum and suboptimum combining schemes for the RAKE receiver, which provide significant improvement over the conventional maximum-ratio combining. In this paper, we derive the theoretical probability density function (pdf) of the signal-to-interference-plus-noise ratio and outage probability of the optimum combining scheme in a semi-analytical fashion. The obtained analytical results closely agree with simulation results.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124084021","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 : 2001-03-20DOI: 10.1109/SPAWC.2001.923930
Chin-Ta Chen, Ching-Tai Chiang, Yuan-Hwang Chen
This letter integrates the Karhunen-Loeve (KL) transform with the overlapped subframe techniques for efficient speaker identification under an additive noise environment. Based on the overlapped subframe partition method, we present an efficient technique to construct an eigenvector matrix and achieve the advantages of the KL transform technique. Computer simulations demonstrate the effectiveness of the proposed technique.
{"title":"Efficient KLT based on overlapped subframes for speaker identification","authors":"Chin-Ta Chen, Ching-Tai Chiang, Yuan-Hwang Chen","doi":"10.1109/SPAWC.2001.923930","DOIUrl":"https://doi.org/10.1109/SPAWC.2001.923930","url":null,"abstract":"This letter integrates the Karhunen-Loeve (KL) transform with the overlapped subframe techniques for efficient speaker identification under an additive noise environment. Based on the overlapped subframe partition method, we present an efficient technique to construct an eigenvector matrix and achieve the advantages of the KL transform technique. Computer simulations demonstrate the effectiveness of the proposed technique.","PeriodicalId":435867,"journal":{"name":"2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131777640","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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