Pub Date : 2011-03-07DOI: 10.1109/RWS.2011.5725422
A. C. Durgun, Mark Reese, C. Balanis, C. Birtcher, D. Allee, S. Venugopal
This paper presents design, simulation, fabrication and measurement of a modified bow-tie antenna with reduced metallization. The antenna is mounted on a flexible substrate which is fabricated at the Flexible Display Center (FDC) of Arizona State University (ASU). The substrate is heat stabilized polyethylene naphthalate (PEN) which allows the antenna to be flexible. The antenna is fed by the aid of a microstrip-to-coplanar feed network balun. The reduction of the metallization is based on the observation that the majority of the current density is confined towards the edges of the regular bow-tie antenna. Hence, the centers of the triangular parts of the bow-tie antenna are removed. The radiation performance of the modified bow-tie is verified to be very close to the conventional bow-tie by simulations and measurements.
{"title":"Flexible bow-tie antennas with reduced metallization","authors":"A. C. Durgun, Mark Reese, C. Balanis, C. Birtcher, D. Allee, S. Venugopal","doi":"10.1109/RWS.2011.5725422","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725422","url":null,"abstract":"This paper presents design, simulation, fabrication and measurement of a modified bow-tie antenna with reduced metallization. The antenna is mounted on a flexible substrate which is fabricated at the Flexible Display Center (FDC) of Arizona State University (ASU). The substrate is heat stabilized polyethylene naphthalate (PEN) which allows the antenna to be flexible. The antenna is fed by the aid of a microstrip-to-coplanar feed network balun. The reduction of the metallization is based on the observation that the majority of the current density is confined towards the edges of the regular bow-tie antenna. Hence, the centers of the triangular parts of the bow-tie antenna are removed. The radiation performance of the modified bow-tie is verified to be very close to the conventional bow-tie by simulations and measurements.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133255025","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725465
M. Kojima, A. Hashimoto, Yoichi Suzuki, Takeshi Kimura, S. Tanaka
We are studying 16APSK and 32APSK, which can transmit more HDTV programs per channel or be applied for high quality services beyond HDTV. Multi-level modulations such as these APSK schemes are vulnerable to the non-linear distortion of a satellite transponder. We propose a compensation technique for estimating the signal point error vectors over a satellite simulator in advance and compensating for the error vectors of each signal point at the transmitter. We report on both 16APSK and 32APSK performances in terms of the required C/N and optimum operating point of the traveling wave tube amplifier (TWTA) by using a computer simulation on the effect of this compensation technique.
{"title":"Study on non-linear compensation technique based on signal point error estimation over satellite transponder","authors":"M. Kojima, A. Hashimoto, Yoichi Suzuki, Takeshi Kimura, S. Tanaka","doi":"10.1109/RWS.2011.5725465","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725465","url":null,"abstract":"We are studying 16APSK and 32APSK, which can transmit more HDTV programs per channel or be applied for high quality services beyond HDTV. Multi-level modulations such as these APSK schemes are vulnerable to the non-linear distortion of a satellite transponder. We propose a compensation technique for estimating the signal point error vectors over a satellite simulator in advance and compensating for the error vectors of each signal point at the transmitter. We report on both 16APSK and 32APSK performances in terms of the required C/N and optimum operating point of the traveling wave tube amplifier (TWTA) by using a computer simulation on the effect of this compensation technique.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130130642","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725477
G. Strauss, K. Breitsameter
By using open ended parallel plate waveguides (often called TEM horn antennas) a new concept for an electronically steerable phased array antenna is shown. The concept allows a usable bandwidth of more than 100% and is suitable for full duplex communication systems. It provides orthogonal polarizations (both linear and circular) for both the transmit and receive paths. Configured as a two-dimensional (flat) array, scan angles of more than 55° can be achieved by good suppression of cross polarization. Easy integration of planar waveguides as well as rectangular waveguides provides a wide variety of system architectures. We present as examples arrays for X-band and for combined Ku- / Ka-band (17 … 31 sGHz ) which can be scanned electronically above one axis. Receive path uses LHC, transmit path RHC, polarization.
{"title":"A circular polarized tem horn antenna array with large scanning angle","authors":"G. Strauss, K. Breitsameter","doi":"10.1109/RWS.2011.5725477","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725477","url":null,"abstract":"By using open ended parallel plate waveguides (often called TEM horn antennas) a new concept for an electronically steerable phased array antenna is shown. The concept allows a usable bandwidth of more than 100% and is suitable for full duplex communication systems. It provides orthogonal polarizations (both linear and circular) for both the transmit and receive paths. Configured as a two-dimensional (flat) array, scan angles of more than 55° can be achieved by good suppression of cross polarization. Easy integration of planar waveguides as well as rectangular waveguides provides a wide variety of system architectures. We present as examples arrays for X-band and for combined Ku- / Ka-band (17 … 31 sGHz ) which can be scanned electronically above one axis. Receive path uses LHC, transmit path RHC, polarization.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131072905","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725492
Xiao Ma, M. Olama, S. Djouadi, C. Charalambous
In this paper, we are concerned with the estimation and identification of time-varying wireless long-term fading channels. The dynamics of the fading channels are captured using a mean-reverting linear stochastic differential equation driven by a Brownian motion. Recursive estimation and identification algorithms solely from received signal strength data are developed. These algorithms are based on combining the particle filter (PF) with the expectation maximization (EM) algorithm that estimate and identify the power path-loss of the channel and its parameters, respectively. Numerical results are provided to evaluate the accuracy of the proposed algorithms.
{"title":"Estimation and identification of time-varying long-term fading channels via the particle filter and the EM algorithm","authors":"Xiao Ma, M. Olama, S. Djouadi, C. Charalambous","doi":"10.1109/RWS.2011.5725492","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725492","url":null,"abstract":"In this paper, we are concerned with the estimation and identification of time-varying wireless long-term fading channels. The dynamics of the fading channels are captured using a mean-reverting linear stochastic differential equation driven by a Brownian motion. Recursive estimation and identification algorithms solely from received signal strength data are developed. These algorithms are based on combining the particle filter (PF) with the expectation maximization (EM) algorithm that estimate and identify the power path-loss of the channel and its parameters, respectively. Numerical results are provided to evaluate the accuracy of the proposed algorithms.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128456262","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725455
Won‐Sang Yoon, Hun-Sung Lee, Heejong Lee, Jongsik Lim, Young-Sik Kim, Sang‐Min Han
A frequency tunable super-regenerative oscillator (SRO) is proposed for channel selective receivers in short-range sensor networks. The SRO is designed with the voltage-controlled injection locked oscillator (VC-ILO) and an external quenching signal. A varactor diode is mounted on the resonator in order to achieve frequency tunability. From the experimental results, the proposed SRO has regenerated the output signal with excellent frequency selectivity from 2.41 to 2.50 GHz at tuning voltage of 0 V – 5 V. For injected On-Off Keying (OOK) modulated signal with a data rate of 50 kbps and sinusoidal quenching signal 200 kHz, the SRO has presented 10-MHz channel selectivity for ISM band of 2.41 – 2.50 GHz.
{"title":"A frequency tunable super-regenerative oscillator for channel selective receivers","authors":"Won‐Sang Yoon, Hun-Sung Lee, Heejong Lee, Jongsik Lim, Young-Sik Kim, Sang‐Min Han","doi":"10.1109/RWS.2011.5725455","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725455","url":null,"abstract":"A frequency tunable super-regenerative oscillator (SRO) is proposed for channel selective receivers in short-range sensor networks. The SRO is designed with the voltage-controlled injection locked oscillator (VC-ILO) and an external quenching signal. A varactor diode is mounted on the resonator in order to achieve frequency tunability. From the experimental results, the proposed SRO has regenerated the output signal with excellent frequency selectivity from 2.41 to 2.50 GHz at tuning voltage of 0 V – 5 V. For injected On-Off Keying (OOK) modulated signal with a data rate of 50 kbps and sinusoidal quenching signal 200 kHz, the SRO has presented 10-MHz channel selectivity for ISM band of 2.41 – 2.50 GHz.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123149275","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725430
H. Yoshida, T. Taniguchi, Y. Toriyama, Kazuya Kojima, T. Shirosaki, S. Nagamine, J. Kobayashi
In preparation for achieving the millimeter-wave ultra-broadband wireless system aimed at seamless connection with the optical communication network, in 2009 we have developed the key devices such as baseband signal processing SoC (System-On-Chip) with built-in ultrahigh-speed multi-level QAM (Quadrature amplitude modulation) modem (modulator and demodulator) and gigabit Ethernet MAC (Media Access Control). We have also prototyped the micro-mini and ultra-broadband 38 GHz band point-to-point wireless system and achieved the performance of effective throughput 600Mbps on 16QAM operation, furthermore, we evaluated the performance of this system by actual operation in the field. This time, we have upgraded the resolution of ADC/DAC (Analog to Digital Converter / Digital to Analog Converter) built in this SoC and improved the performance of RF characteristics, and achieved the development prototype System with this new SoC, which enables 64QAM operation and the effective throughput of 1Gbps.
为了准备实现毫米波超宽带无线系统与光通信网络的无缝连接，我们在2009年开发了基带信号处理SoC(片上系统)等关键器件，内置超高速多级QAM(正交调制器和解调器)调制解调器和千兆以太网MAC(媒体访问控制)。我们还实现了微型和超宽带38 GHz频段点对点无线系统的原型，并在16QAM工作下实现了600Mbps的有效吞吐量，并通过现场实际运行对系统的性能进行了评估。此次，我们升级了该SoC内置的ADC/DAC (Analog to Digital Converter / Digital to Analog Converter)的分辨率，提高了射频特性的性能，并实现了基于该SoC的开发原型系统，该系统可实现64QAM操作，有效吞吐量为1Gbps。
{"title":"Effective throughput 1Gbps wireless system by single-carrier 64QAM for millimeter-wave applications","authors":"H. Yoshida, T. Taniguchi, Y. Toriyama, Kazuya Kojima, T. Shirosaki, S. Nagamine, J. Kobayashi","doi":"10.1109/RWS.2011.5725430","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725430","url":null,"abstract":"In preparation for achieving the millimeter-wave ultra-broadband wireless system aimed at seamless connection with the optical communication network, in 2009 we have developed the key devices such as baseband signal processing SoC (System-On-Chip) with built-in ultrahigh-speed multi-level QAM (Quadrature amplitude modulation) modem (modulator and demodulator) and gigabit Ethernet MAC (Media Access Control). We have also prototyped the micro-mini and ultra-broadband 38 GHz band point-to-point wireless system and achieved the performance of effective throughput 600Mbps on 16QAM operation, furthermore, we evaluated the performance of this system by actual operation in the field. This time, we have upgraded the resolution of ADC/DAC (Analog to Digital Converter / Digital to Analog Converter) built in this SoC and improved the performance of RF characteristics, and achieved the development prototype System with this new SoC, which enables 64QAM operation and the effective throughput of 1Gbps.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121631911","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725485
Depeng Yang, Husheng Li, G. D. Peterson, A. Fathy
The theory of Compressed Sensing (CS) is applied to Ultra-Wideband (UWB) positioning systems to obtain high resolution UWB pulses and achieve high performance. A Fast Orthogonal Matching Pursuit (FOMP) algorithm is proposed and embedded in the Time Difference Of Arrival (TDOA) algorithm for fast object positioning. Our pipelined FOMP TDOA algorithm outperforms the traditional serial OMP TDOA method. Simulation results have demonstrated that the CS-based UWB positioning system using the FOMP TDOA algorithm has the potential to achieve sub-mm positioning accuracy while still using very low sampling rate ADCs. Additionally, results are not sensitive to the tag location relative to base stations which is unavoidable drawback of geometrical dilution of accuracy in the sequential sampling method.
{"title":"Compressive sensing TDOA for UWB positioning systems","authors":"Depeng Yang, Husheng Li, G. D. Peterson, A. Fathy","doi":"10.1109/RWS.2011.5725485","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725485","url":null,"abstract":"The theory of Compressed Sensing (CS) is applied to Ultra-Wideband (UWB) positioning systems to obtain high resolution UWB pulses and achieve high performance. A Fast Orthogonal Matching Pursuit (FOMP) algorithm is proposed and embedded in the Time Difference Of Arrival (TDOA) algorithm for fast object positioning. Our pipelined FOMP TDOA algorithm outperforms the traditional serial OMP TDOA method. Simulation results have demonstrated that the CS-based UWB positioning system using the FOMP TDOA algorithm has the potential to achieve sub-mm positioning accuracy while still using very low sampling rate ADCs. Additionally, results are not sensitive to the tag location relative to base stations which is unavoidable drawback of geometrical dilution of accuracy in the sequential sampling method.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116129696","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725435
S. Luo, N. Polu, Z. Chen, Jeff Slipp
Industrial applications of wireless sensor networks often involve radio-harsh environments. These industrial settings typically include an abundance of metallic structures which obstruct, reflect, refract and scatter signals. As a result, RF channel modeling for these environments becomes necessary and important. In this paper, a WSN testbed emulating realistic industrial environments was constructed and developed. With it, RF channel propagation properties were measured and analyzed in 2.4GHz and 5.8GHz ISM bands using vector network analyzer.
{"title":"RF channel modeling of a WSN testbed for industrial environment","authors":"S. Luo, N. Polu, Z. Chen, Jeff Slipp","doi":"10.1109/RWS.2011.5725435","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725435","url":null,"abstract":"Industrial applications of wireless sensor networks often involve radio-harsh environments. These industrial settings typically include an abundance of metallic structures which obstruct, reflect, refract and scatter signals. As a result, RF channel modeling for these environments becomes necessary and important. In this paper, a WSN testbed emulating realistic industrial environments was constructed and developed. With it, RF channel propagation properties were measured and analyzed in 2.4GHz and 5.8GHz ISM bands using vector network analyzer.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121817784","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725487
Raffat Khan, K. Kiasaleh
In this paper existing Land mobile satellite system (LMSS) fading models are validated for received Global Positioning System (GPS) signal. The results of GPS measurement1 made in shadowing/fading environment are used for this analysis. The existing LMSS models considered in this paper are Bi-state fading model [1], Lutz et al. model [2], Karsawa et al. model [3], and Bart and Stutzman model [4]. These models are used to fit the empirical data for probability density function and fade distribution. Furthermore, the relationships between the values of the fitted probability of shadowing parameter for the aforementioned channels and the corresponding satellite elevation angles are established.
{"title":"Experimental validation of LMSS fading models for GPS measurements in fading/shadowing environment","authors":"Raffat Khan, K. Kiasaleh","doi":"10.1109/RWS.2011.5725487","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725487","url":null,"abstract":"In this paper existing Land mobile satellite system (LMSS) fading models are validated for received Global Positioning System (GPS) signal. The results of GPS measurement1 made in shadowing/fading environment are used for this analysis. The existing LMSS models considered in this paper are Bi-state fading model [1], Lutz et al. model [2], Karsawa et al. model [3], and Bart and Stutzman model [4]. These models are used to fit the empirical data for probability density function and fade distribution. Furthermore, the relationships between the values of the fitted probability of shadowing parameter for the aforementioned channels and the corresponding satellite elevation angles are established.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122068855","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 : 2011-03-07DOI: 10.1109/RWS.2011.5725417
I. Nassar, T. Weller
An electrically small meandered microstrip line antenna was investigated. The antenna was designed, fabricated and measured for an operating frequency of 2.4 GHz with a 10 dB return loss bandwidth of 2%. In order to improve the efficiency and gain, a truncated ground plane was used, and its effect on balancing the antenna currents has been studied. A Wheeler Cap was designed for the efficiency measurement and the 3-antenna method was used for measuring the gain. Ka of this antenna is 0.26, it has a gain of −0.86 dB and an efficiency of 49.7%, making it one of the efficient and high gain small antennas.
{"title":"An electrically small meandered line antenna with truncated ground plane","authors":"I. Nassar, T. Weller","doi":"10.1109/RWS.2011.5725417","DOIUrl":"https://doi.org/10.1109/RWS.2011.5725417","url":null,"abstract":"An electrically small meandered microstrip line antenna was investigated. The antenna was designed, fabricated and measured for an operating frequency of 2.4 GHz with a 10 dB return loss bandwidth of 2%. In order to improve the efficiency and gain, a truncated ground plane was used, and its effect on balancing the antenna currents has been studied. A Wheeler Cap was designed for the efficiency measurement and the 3-antenna method was used for measuring the gain. Ka of this antenna is 0.26, it has a gain of −0.86 dB and an efficiency of 49.7%, making it one of the efficient and high gain small antennas.","PeriodicalId":250672,"journal":{"name":"2011 IEEE Radio and Wireless Symposium","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123326789","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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