Though there is still a heated discussion on what is cyber-physical systems, CPS is complex system which combines continuous dynamics and discrete dynamics. Among all the unsolved problems, time constraints are critical issues for CPS especially the time-security issues. The interaction of continuous and discrete dynamics in CPS must be specified correctly due to this reason. Unfortunately, the existed methods for modeling CPS can't fullfill the requirements. Clock Theory, which is proposed by Jifeng He, can be used to specify the time constraints for dynamics of CPS. In this paper, we introduced Clock Theory and proposed case studies for specifying and modeling the time constraints of CPS with Clock Theory.
{"title":"A Clock Based Framework for Specifying and Modeling the Time Constraints of Cyber Physical Systems","authors":"Bingqing Xu, Lichen Zhang","doi":"10.1109/DASC.2013.77","DOIUrl":"https://doi.org/10.1109/DASC.2013.77","url":null,"abstract":"Though there is still a heated discussion on what is cyber-physical systems, CPS is complex system which combines continuous dynamics and discrete dynamics. Among all the unsolved problems, time constraints are critical issues for CPS especially the time-security issues. The interaction of continuous and discrete dynamics in CPS must be specified correctly due to this reason. Unfortunately, the existed methods for modeling CPS can't fullfill the requirements. Clock Theory, which is proposed by Jifeng He, can be used to specify the time constraints for dynamics of CPS. In this paper, we introduced Clock Theory and proposed case studies for specifying and modeling the time constraints of CPS with Clock Theory.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126014339","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}
Junshi Wang, Xiaohang Wang, Letian Huang, T. Mak, Guangjun Li
As technology scaling, reliability has became one of the key challenges of Network-on-Chip (NoC). Many fault-tolerant routing algorithms for NoC are developed to overcome fault components and provide reliable transmission. But proposed routing algorithms do not pay enough attention to find the shortest paths, which increases latency and power consumption. In this paper, a fault-tolerant routing algorithm using new component states diffusion method based on Farthest Reachable Router (FRR) is proposed. This algorithm can reduce latency by finding the shortest paths between source and destination routers. Experiment results verify that FRR routing algorithm can tolerate 79% fault patterns within 3 × 3 and reduce latency by 16-44% compared with FON.
{"title":"A Fault-Tolerant Routing Algorithm for NoC Using Farthest Reachable Routers","authors":"Junshi Wang, Xiaohang Wang, Letian Huang, T. Mak, Guangjun Li","doi":"10.1109/DASC.2013.54","DOIUrl":"https://doi.org/10.1109/DASC.2013.54","url":null,"abstract":"As technology scaling, reliability has became one of the key challenges of Network-on-Chip (NoC). Many fault-tolerant routing algorithms for NoC are developed to overcome fault components and provide reliable transmission. But proposed routing algorithms do not pay enough attention to find the shortest paths, which increases latency and power consumption. In this paper, a fault-tolerant routing algorithm using new component states diffusion method based on Farthest Reachable Router (FRR) is proposed. This algorithm can reduce latency by finding the shortest paths between source and destination routers. Experiment results verify that FRR routing algorithm can tolerate 79% fault patterns within 3 × 3 and reduce latency by 16-44% compared with FON.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128893998","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}
Recently, there has been increasing interest in using mobile robots within spaces where humans reside, and safe navigation by effective sensing becomes an important issue. In this paper, we describe a method to detect moving objects that exist in front of an autonomously navigating robot by analyzing images of a monocular color camera mounted on the robot. In particular, detecting humans who walk in a direction opposite to the robot's motion is studied because this increases the danger of collision between the pedestrians and the robot. Although moving object detection and obstacle avoidance have been actively studied in the fields of computer vision and intelligent robotics, respectively, analyzing the images of a moving camera is still challenging. One method presented in this paper is based on comparing the current image and a past image in order to find moving objects in the scene. Assuming that the speed of the robot is known, a correspondence between a certain part of the current image and a matching part of a past image is established. Approaching objects can then be detected for a case in which the degree of mismatch between the two corresponding image parts is high. Another method we employ is the detection of human faces. Since a human face has unique features in color and shape, we can search faces in images in order to detect approaching humans. We propose a fast and simple masking method for face detection in a small search region specified from appearance-based foot detection. These two proposed methods were combined to effectively find approaching humans in our experiments. We could get promising test results.
{"title":"Moving Object's Detect in a Monocular Moving Camera","authors":"Ye-gang Chen, Xiao-rong Diao","doi":"10.1109/DASC.2013.96","DOIUrl":"https://doi.org/10.1109/DASC.2013.96","url":null,"abstract":"Recently, there has been increasing interest in using mobile robots within spaces where humans reside, and safe navigation by effective sensing becomes an important issue. In this paper, we describe a method to detect moving objects that exist in front of an autonomously navigating robot by analyzing images of a monocular color camera mounted on the robot. In particular, detecting humans who walk in a direction opposite to the robot's motion is studied because this increases the danger of collision between the pedestrians and the robot. Although moving object detection and obstacle avoidance have been actively studied in the fields of computer vision and intelligent robotics, respectively, analyzing the images of a moving camera is still challenging. One method presented in this paper is based on comparing the current image and a past image in order to find moving objects in the scene. Assuming that the speed of the robot is known, a correspondence between a certain part of the current image and a matching part of a past image is established. Approaching objects can then be detected for a case in which the degree of mismatch between the two corresponding image parts is high. Another method we employ is the detection of human faces. Since a human face has unique features in color and shape, we can search faces in images in order to detect approaching humans. We propose a fast and simple masking method for face detection in a small search region specified from appearance-based foot detection. These two proposed methods were combined to effectively find approaching humans in our experiments. We could get promising test results.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116118370","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}
Wireless sensor network consists of a large number of nodes with limited energy. As the wireless sensor nodes' battery cannot be replaced, therefore, reducing energy consumption, improve the node survival rate of the wireless sensor networks is one of the key issues. In this paper after analyzing the present routing protocol based on clustering, it proposes a new improved routing protocol which is cluster-based low-power adaptive routing protocol based on cluster head when transferring data using multi-hop technology in order to evenly assign the cluster head energy and realize load balance. Simulation results show that the improved scheme is better in prolonging the network lifetime.
{"title":"Multi-hop Transmission Applied in Wireless Network","authors":"Wensheng Zou","doi":"10.1109/DASC.2013.143","DOIUrl":"https://doi.org/10.1109/DASC.2013.143","url":null,"abstract":"Wireless sensor network consists of a large number of nodes with limited energy. As the wireless sensor nodes' battery cannot be replaced, therefore, reducing energy consumption, improve the node survival rate of the wireless sensor networks is one of the key issues. In this paper after analyzing the present routing protocol based on clustering, it proposes a new improved routing protocol which is cluster-based low-power adaptive routing protocol based on cluster head when transferring data using multi-hop technology in order to evenly assign the cluster head energy and realize load balance. Simulation results show that the improved scheme is better in prolonging the network lifetime.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123114328","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}
In network measurement, one-way delay is an important network performance indicators, during the measurement, to synchronize the time of different nodes has a great influence on the results of measurement, especially in the large-scale network measurement. This paper propose a time synchronization stability comparison method based on NTP after research the time synchronization technology. In the one-way delay measurement, in order to eliminate measurement errors caused by the frequency difference between nodes, this paper propose a one-way delay corrective algorithm based on forward and reverse delay measurement after research existing time corrective algorithm. Finally, the measurement platform deployed in Planetlab and measure one-way delay. The measurement select more stable nodes based on NTP stability comparison algorithm, and correct one-way delay measurement results through clock corrective algorithm mentioned above. Experiments show that the results of corrective measurement algorithm are more accurate.
{"title":"The One-Way Delay Measurement Algorithm on to Time Synchronization of NTP","authors":"Ruijie Ou, Wenyu Chen, LinLi Guo, WeiShun Li","doi":"10.1109/DASC.2013.92","DOIUrl":"https://doi.org/10.1109/DASC.2013.92","url":null,"abstract":"In network measurement, one-way delay is an important network performance indicators, during the measurement, to synchronize the time of different nodes has a great influence on the results of measurement, especially in the large-scale network measurement. This paper propose a time synchronization stability comparison method based on NTP after research the time synchronization technology. In the one-way delay measurement, in order to eliminate measurement errors caused by the frequency difference between nodes, this paper propose a one-way delay corrective algorithm based on forward and reverse delay measurement after research existing time corrective algorithm. Finally, the measurement platform deployed in Planetlab and measure one-way delay. The measurement select more stable nodes based on NTP stability comparison algorithm, and correct one-way delay measurement results through clock corrective algorithm mentioned above. Experiments show that the results of corrective measurement algorithm are more accurate.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114743312","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}
With the interesting of researchers to develop the scheduling of multiprocessor and distributed system in hard real time embedded systems, we present a new locking protocol called Minimizing multiple-Priority Inversion Protocol (MPIP), in this protocol, we proposed a novel mechanism to turn from preemptive to non-preemptive state to minimize multiple-priority inversion caused by low priority task on local processor. We focus on distributed locking semaphore and we showed its ability to lock the shared memory, thus, working in Multi-processor environment. We assumed all shared resources as global to avoid resource nested. With properties of our protocol, we define a new upper bound blocking time. We submit our proposal to experimental evaluation to compare it with MPCP protocol in term of hard real time schedulability.
{"title":"Minimizing Multiple-Priority Inversion Protocol in Hard Real Time System","authors":"Furkan Rabee, Yong Liao, Maolin Yang","doi":"10.1109/DASC.2013.62","DOIUrl":"https://doi.org/10.1109/DASC.2013.62","url":null,"abstract":"With the interesting of researchers to develop the scheduling of multiprocessor and distributed system in hard real time embedded systems, we present a new locking protocol called Minimizing multiple-Priority Inversion Protocol (MPIP), in this protocol, we proposed a novel mechanism to turn from preemptive to non-preemptive state to minimize multiple-priority inversion caused by low priority task on local processor. We focus on distributed locking semaphore and we showed its ability to lock the shared memory, thus, working in Multi-processor environment. We assumed all shared resources as global to avoid resource nested. With properties of our protocol, we define a new upper bound blocking time. We submit our proposal to experimental evaluation to compare it with MPCP protocol in term of hard real time schedulability.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129082138","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}
The motion capture technologies have been widely used in the following areas: human movement science, human-computer interaction and control, medical analysis, film, game production, and etc. This paper presented a motion capture system based on inertial sensors. The system is mainly composed of the inertial sensor unit and real-time monitoring unit on PC. Meanwhile, Sensor units exchange data with PC through BSN (body sensor network). One sensor measurement unit contains a three-axis gyroscope, a three-axis accelerometer, a three-axis magnetometer and a network communication unit. The inertial sensor units are installed on the different parts of body. In the system, the inertial sensor data are collected, and then adaptive Kalman Filter algorithm is used to estimate the body gesture. The Experiments show that this way have some advantages such as: high precision, dynamic, and almost no drift. Furthermore, the data can be changed smoothly.
{"title":"The Research of Motion Capture Technology Based on Inertial Measurement","authors":"Bo Feng, Xianggang Zhang, Hui-yuan Zhao","doi":"10.1109/DASC.2013.69","DOIUrl":"https://doi.org/10.1109/DASC.2013.69","url":null,"abstract":"The motion capture technologies have been widely used in the following areas: human movement science, human-computer interaction and control, medical analysis, film, game production, and etc. This paper presented a motion capture system based on inertial sensors. The system is mainly composed of the inertial sensor unit and real-time monitoring unit on PC. Meanwhile, Sensor units exchange data with PC through BSN (body sensor network). One sensor measurement unit contains a three-axis gyroscope, a three-axis accelerometer, a three-axis magnetometer and a network communication unit. The inertial sensor units are installed on the different parts of body. In the system, the inertial sensor data are collected, and then adaptive Kalman Filter algorithm is used to estimate the body gesture. The Experiments show that this way have some advantages such as: high precision, dynamic, and almost no drift. Furthermore, the data can be changed smoothly.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131233072","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}
Xiangfei Li, Xuzhi Wang, W. Wan, Xiaoqiang Zhu, Xiaoqing Yu
Particle systems' greatest advantage is well suited for modeling complex fuzzy phenomena, such as explosions, fountain, tornado and fireworks, etc. in 3D graphics. With the increasing requirements on the number of particles and particle-particle interactions, the computational complexity of simulation in particle systems has increased rapidly. Particle systems are traditionally implemented on a general-purpose CPU, and the computational complexity of particle systems limits the number of particles that can be computed at interactive rates. This paper focuses on real-time simulation of large-scale particle systems. We discuss optional integration algorithms based on CUDA (Compute Unified Device Architecture) for both graphic and scientific simulation. The speed of particle systems has been greatly improved, with parallel-core GPUs working in tandem with multi-core CPUs. In order to provide a scalable and portable API library, the object-oriented programming method is adopted to encapsulate the functions of parallel particle system. Results show that our proposed APIs are user-friendly and the parallel implementations are significantly efficient.
{"title":"Parallel Simulation of Large-Scale Universal Particle Systems Using CUDA","authors":"Xiangfei Li, Xuzhi Wang, W. Wan, Xiaoqiang Zhu, Xiaoqing Yu","doi":"10.1109/DASC.2013.128","DOIUrl":"https://doi.org/10.1109/DASC.2013.128","url":null,"abstract":"Particle systems' greatest advantage is well suited for modeling complex fuzzy phenomena, such as explosions, fountain, tornado and fireworks, etc. in 3D graphics. With the increasing requirements on the number of particles and particle-particle interactions, the computational complexity of simulation in particle systems has increased rapidly. Particle systems are traditionally implemented on a general-purpose CPU, and the computational complexity of particle systems limits the number of particles that can be computed at interactive rates. This paper focuses on real-time simulation of large-scale particle systems. We discuss optional integration algorithms based on CUDA (Compute Unified Device Architecture) for both graphic and scientific simulation. The speed of particle systems has been greatly improved, with parallel-core GPUs working in tandem with multi-core CPUs. In order to provide a scalable and portable API library, the object-oriented programming method is adopted to encapsulate the functions of parallel particle system. Results show that our proposed APIs are user-friendly and the parallel implementations are significantly efficient.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121309288","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}
Nowadays SIMD extensions became ubiquitous for computational platform, being widely used in signal processing, multimedia, and scientific applications. However, compilers still have difficult in vectorizing some applications, such as computations on non-contiguous and especially interleaved data, and loop nest for which inner loops that carry all the dependencies and external loops with strided memory accesses. In order to solve these problems, we adopt Isomorphic Statements Grouping (ISG) after extending group following UD and DU chains, which group isomorphic computation statements that perform the same operation. And correspondingly, we generate vector permutation instructions according to the target ISA SIMD instructions at the SIMD code generation phase. This approach has been implemented in a compiler based on Open64 which translate C source program to C source program with SIMD intrinsic functions. Experiments with this compiler show that ISG Super Level Parallelism(ISG-SLP) can be used to compile a number of real-world kernels, achieving up to 3.11 speedup.
目前SIMD扩展在计算平台中无处不在，被广泛应用于信号处理、多媒体和科学应用中。然而，编译器在向量化一些应用程序方面仍然存在困难，例如对不连续和特别是交错数据的计算，以及携带所有依赖关系的内部循环和具有跨行内存访问的外部循环的循环巢。为了解决这些问题，我们在扩展了UD链和DU链之后的组后采用ISG (Isomorphic Statements Grouping)，将执行相同操作的同构计算语句分组。相应地，我们在SIMD代码生成阶段根据目标ISA SIMD指令生成向量置换指令。该方法已在基于Open64的编译器中实现，该编译器将C源程序转换为具有SIMD固有函数的C源程序。使用该编译器进行的实验表明，ISG Super Level Parallelism(ISG- slp)可用于编译许多真实的内核，实现高达3.11的加速。
{"title":"A New Algorithm to Exploit Superword Level Parallelism","authors":"Peng Liu, Rongcai Zhao, Wei Gao, Shuai Wei","doi":"10.1109/DASC.2013.118","DOIUrl":"https://doi.org/10.1109/DASC.2013.118","url":null,"abstract":"Nowadays SIMD extensions became ubiquitous for computational platform, being widely used in signal processing, multimedia, and scientific applications. However, compilers still have difficult in vectorizing some applications, such as computations on non-contiguous and especially interleaved data, and loop nest for which inner loops that carry all the dependencies and external loops with strided memory accesses. In order to solve these problems, we adopt Isomorphic Statements Grouping (ISG) after extending group following UD and DU chains, which group isomorphic computation statements that perform the same operation. And correspondingly, we generate vector permutation instructions according to the target ISA SIMD instructions at the SIMD code generation phase. This approach has been implemented in a compiler based on Open64 which translate C source program to C source program with SIMD intrinsic functions. Experiments with this compiler show that ISG Super Level Parallelism(ISG-SLP) can be used to compile a number of real-world kernels, achieving up to 3.11 speedup.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115419392","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}
Multiple input multiple output (MIMO) technology has been considered as one of the essential technologies to enhance the performance of Long Term Evolution (LTE) system with the limited bandwidth and transmit power. For indoor coverage, it is difficult to implement MIMO technology since the challenges of engineering and cost in doubling the number of installed antennas and feeders. Therefore, two indoor MIMO distributed antenna system (DAS) solutions are proposed by using frequency converting and signal comibing and separating by upgrading the existing indoor DASs. Frequency converting is employed to decrease the carrier frequency of LTE system when it is higher than 2500MHz since most of the existing feeders can only support the frequency of the transmit signals from 800MHz to 2500MHz. In the proposed schemes, two branches' MIMO signals can be loaded into the feeder of the existing DAS by combining them together after converting the original LTE frequency into two different lower frequency bands, and a dual-polarized indoor antenna is used at remote site to reduce the number of antenna locations. Some simulations show the effect of difference on transmit power and time delay between two LTE MIMO branches. Our field measurement results reveal that the proposed schemes can provide the comparable level of performance but more simpler and pratical to be deployed.
{"title":"MIMO DAS Solutions in LTE Indoor System","authors":"Youxiang Wang, Fuchang Li","doi":"10.1109/DASC.2013.112","DOIUrl":"https://doi.org/10.1109/DASC.2013.112","url":null,"abstract":"Multiple input multiple output (MIMO) technology has been considered as one of the essential technologies to enhance the performance of Long Term Evolution (LTE) system with the limited bandwidth and transmit power. For indoor coverage, it is difficult to implement MIMO technology since the challenges of engineering and cost in doubling the number of installed antennas and feeders. Therefore, two indoor MIMO distributed antenna system (DAS) solutions are proposed by using frequency converting and signal comibing and separating by upgrading the existing indoor DASs. Frequency converting is employed to decrease the carrier frequency of LTE system when it is higher than 2500MHz since most of the existing feeders can only support the frequency of the transmit signals from 800MHz to 2500MHz. In the proposed schemes, two branches' MIMO signals can be loaded into the feeder of the existing DAS by combining them together after converting the original LTE frequency into two different lower frequency bands, and a dual-polarized indoor antenna is used at remote site to reduce the number of antenna locations. Some simulations show the effect of difference on transmit power and time delay between two LTE MIMO branches. Our field measurement results reveal that the proposed schemes can provide the comparable level of performance but more simpler and pratical to be deployed.","PeriodicalId":179557,"journal":{"name":"2013 IEEE 11th International Conference on Dependable, Autonomic and Secure Computing","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129433551","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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