Pub Date : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683195
J. Sullivan, N. Charbonneau, V. Vokkarane
Random contentions occur in optical burst-switched (OBS) networks because of one-way signaling and lack of optical buffers. These contentions can occur at low loads and are not necessarily an indication of congestion. The loss caused by them, however, causes TCP at the transport layer to reduce its send rate drastically, which is unnecessary and reduces overall performance. In this paper, we propose coordinated burst cloning and forward segment redundancy, a proactive technique to prevent data loss during random contentions in the optical core. With forward segment redundancy (FSR), redundant segments are appended to each burst at the edge and redundant burst segmentation (RBS) is implemented in the core so that when a contention occurs, primarily redundant data is dropped. With burst cloning, an entire redundant burst is created at the edge and sent at the same time as the original burst. Coordinated burst cloning and FSR creates clones of bursts (with FSR) and transmits them independently, creating a second-level of redundancy. We evaluate the performance of our proposed loss recovery technique through extensive simulations. We observe that the proposed hybrid technique significantly improves TCP performance at both low and high network loads.
{"title":"Performance Evaluation of TCP over Optical Burst Switched (OBS) Networks Using Coordinated Burst Cloning and Forward-Segment Redundancy","authors":"J. Sullivan, N. Charbonneau, V. Vokkarane","doi":"10.1109/GLOCOM.2010.5683195","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683195","url":null,"abstract":"Random contentions occur in optical burst-switched (OBS) networks because of one-way signaling and lack of optical buffers. These contentions can occur at low loads and are not necessarily an indication of congestion. The loss caused by them, however, causes TCP at the transport layer to reduce its send rate drastically, which is unnecessary and reduces overall performance. In this paper, we propose coordinated burst cloning and forward segment redundancy, a proactive technique to prevent data loss during random contentions in the optical core. With forward segment redundancy (FSR), redundant segments are appended to each burst at the edge and redundant burst segmentation (RBS) is implemented in the core so that when a contention occurs, primarily redundant data is dropped. With burst cloning, an entire redundant burst is created at the edge and sent at the same time as the original burst. Coordinated burst cloning and FSR creates clones of bursts (with FSR) and transmits them independently, creating a second-level of redundancy. We evaluate the performance of our proposed loss recovery technique through extensive simulations. We observe that the proposed hybrid technique significantly improves TCP performance at both low and high network loads.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"4 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74091854","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683306
A. Bianco, P. Giaccone, G. Masera, Marco Ricca
We consider an NxN input-queued switch based on a crossbar switching fabric implemented on a single chip. The thermal power produced by the crossbar chip grows as N R^3, where R is the maximum bit rate. Power dissipation is becoming more and more challenging, limiting the crossbar scalability for high performance switches. We propose to exploit Dynamic Voltage and Frequency Scaling (DVFS) techniques, quite commonly used in integrated circuit design, to control packet transmissions through each crosspoint of the switching fabric. Our thermal control operates independently of the packet scheduler and it is based on short-term traffic measurements. We propose a family of control algorithms to reduce the thermal power dissipation in non-overloaded conditions.
{"title":"Thermal Control for Crossbar-Based Input-Queued Switches","authors":"A. Bianco, P. Giaccone, G. Masera, Marco Ricca","doi":"10.1109/GLOCOM.2010.5683306","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683306","url":null,"abstract":"We consider an NxN input-queued switch based on a crossbar switching fabric implemented on a single chip. The thermal power produced by the crossbar chip grows as N R^3, where R is the maximum bit rate. Power dissipation is becoming more and more challenging, limiting the crossbar scalability for high performance switches. We propose to exploit Dynamic Voltage and Frequency Scaling (DVFS) techniques, quite commonly used in integrated circuit design, to control packet transmissions through each crosspoint of the switching fabric. Our thermal control operates independently of the packet scheduler and it is based on short-term traffic measurements. We propose a family of control algorithms to reduce the thermal power dissipation in non-overloaded conditions.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"44 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74098471","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683302
J. Alonso-Zarate, L. Alonso, C. Skianis, C. Verikoukis
In this paper we analyze the performance of a distributed queuing medium access control (MAC) protocol designed to execute cooperative ARQ (C-ARQ) schemes at the MAC layer. Due to the broadcast nature of the wireless channel, a user that receives a data packet with unrecoverable errors can request retransmission from any of the other users in the transmission range of the transmitter that overheard the original transmission. These users can act as spontaneous relays and provide the communication with cooperative diversity gains. Upon retransmission request, the relays have to contend for the access to the channel. The DQCOOP protocol has been proposed in the literature as a high-performance MAC protocol for this kind of scenario. In this paper we theoretically evaluate its performance. The analytical results are supported by computerbased simulation that show the accuracy of the analysis.
{"title":"Analysis of a Distributed Queuing Medium Access Control Protocol for Cooperative ARQ","authors":"J. Alonso-Zarate, L. Alonso, C. Skianis, C. Verikoukis","doi":"10.1109/GLOCOM.2010.5683302","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683302","url":null,"abstract":"In this paper we analyze the performance of a distributed queuing medium access control (MAC) protocol designed to execute cooperative ARQ (C-ARQ) schemes at the MAC layer. Due to the broadcast nature of the wireless channel, a user that receives a data packet with unrecoverable errors can request retransmission from any of the other users in the transmission range of the transmitter that overheard the original transmission. These users can act as spontaneous relays and provide the communication with cooperative diversity gains. Upon retransmission request, the relays have to contend for the access to the channel. The DQCOOP protocol has been proposed in the literature as a high-performance MAC protocol for this kind of scenario. In this paper we theoretically evaluate its performance. The analytical results are supported by computerbased simulation that show the accuracy of the analysis.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"21 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74119874","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}
To improve the performance of a relay system with multiple channels, the following issues should be addressed. Namely, how to allocate the power at source and relay to subchannels, how to pair subchannels of the first and second hops, and which users should be scheduled to which subchannel pair. Considering these issues in the design of an optimal joint resource allocation scheme in orthogonal channels, in this paper we study a multi-user network with single regenerative relay node. A stochastic optimization problem to maximize system ergodic throughput with joint transmission power constraint and user average data rate is formulated. To satisfy user average data rate request, a scheme with a weighted factor associated to each user at each time slot is proposed. The stochastic approximation method is utilized to estimate this weighted factor and the proof of optimality is given. With the help of this weighted factor, the problem is converted into a deterministic optimization problem in each time slot and the Lagrange dual method can be employed to derive the optimal solution. Finally, the Stochastic Optimal Programming (SOP) is used to evaluate the performance by computer simulations.
{"title":"Stochastic Optimization for Joint Resource Allocation in OFDMA-Based Relay System","authors":"Rui Yin, Yu Zhang, Hsiao-Hwa Chen, Guanding Yu, Zhaoyang Zhang","doi":"10.1109/GLOCOM.2010.5684244","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5684244","url":null,"abstract":"To improve the performance of a relay system with multiple channels, the following issues should be addressed. Namely, how to allocate the power at source and relay to subchannels, how to pair subchannels of the first and second hops, and which users should be scheduled to which subchannel pair. Considering these issues in the design of an optimal joint resource allocation scheme in orthogonal channels, in this paper we study a multi-user network with single regenerative relay node. A stochastic optimization problem to maximize system ergodic throughput with joint transmission power constraint and user average data rate is formulated. To satisfy user average data rate request, a scheme with a weighted factor associated to each user at each time slot is proposed. The stochastic approximation method is utilized to estimate this weighted factor and the proof of optimality is given. With the help of this weighted factor, the problem is converted into a deterministic optimization problem in each time slot and the Lagrange dual method can be employed to derive the optimal solution. Finally, the Stochastic Optimal Programming (SOP) is used to evaluate the performance by computer simulations.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"20 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75151614","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683637
Qing Li, Mingwei Xu, Qi Li, Dan Wang, Yong Cui
Network survivability is an important topic for the Internet. To improve the performance of the Internet during failure, IP Fast Reroute (IPFRR) mechanisms are proposed to establish backup routes for failure-affected packets. NotVia, a most prominent one, provides 100% protection coverage for single-node failures. However, it brings in nontrivial computing and memory pressure to routers with special NotVia addresses, in which only some are necessary for a specific router. Besides, the protection path of NotVia is 20% longer than the optimal path on average. In this paper, we propose early decapsulated NotVia (ED-NotVia) handling the aforementioned problems and thus making NotVia more practical. We first analyze the properties of necessary NotVia addresses to any specific node. Then we develop a heuristic Nec-NotVia Algorithm for a node to find the necessary NotVia addresses and compute routes for them, where unnecessary addresses are eliminated. Based on this elimination, early decapsulation is imported to optimize the protection path with marginal overhead. We evaluate our algorithm and demonstrate the effectiveness of ED-NotVia using topologies from Rocketfuel and Brite. The results show that 1) only 5% to 20% of SPT(Shortest Path Tree)-related NotVia addresses (1.23% to 6.41% of all the NotVia addresses) in an AS are necessary for a node; 2) by computing the routes for 15% to 40% SPT-related NotVia addresses, ED-NotVia provides 98% protection coverage; and 3) the protection path stretch ratio of ED-NotVia is only 1.03 on average as compared to 1.20 for NotVia.
{"title":"IP Fast Reroute: NotVia with Early Decapsulation","authors":"Qing Li, Mingwei Xu, Qi Li, Dan Wang, Yong Cui","doi":"10.1109/GLOCOM.2010.5683637","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683637","url":null,"abstract":"Network survivability is an important topic for the Internet. To improve the performance of the Internet during failure, IP Fast Reroute (IPFRR) mechanisms are proposed to establish backup routes for failure-affected packets. NotVia, a most prominent one, provides 100% protection coverage for single-node failures. However, it brings in nontrivial computing and memory pressure to routers with special NotVia addresses, in which only some are necessary for a specific router. Besides, the protection path of NotVia is 20% longer than the optimal path on average. In this paper, we propose early decapsulated NotVia (ED-NotVia) handling the aforementioned problems and thus making NotVia more practical. We first analyze the properties of necessary NotVia addresses to any specific node. Then we develop a heuristic Nec-NotVia Algorithm for a node to find the necessary NotVia addresses and compute routes for them, where unnecessary addresses are eliminated. Based on this elimination, early decapsulation is imported to optimize the protection path with marginal overhead. We evaluate our algorithm and demonstrate the effectiveness of ED-NotVia using topologies from Rocketfuel and Brite. The results show that 1) only 5% to 20% of SPT(Shortest Path Tree)-related NotVia addresses (1.23% to 6.41% of all the NotVia addresses) in an AS are necessary for a node; 2) by computing the routes for 15% to 40% SPT-related NotVia addresses, ED-NotVia provides 98% protection coverage; and 3) the protection path stretch ratio of ED-NotVia is only 1.03 on average as compared to 1.20 for NotVia.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"3 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75221236","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683135
Md. Shahriar Rahman, Yonghui Li, B. Vucetic
Distributed coding has been shown to be an efficient scheme to improve the performance of wireless relay networks. In this paper we propose an analog distributed channel coding (ADC) scheme. In the proposed scheme, the intermediate relays directly process the received analog noisy signals without making the hard estimation and performs analog channel encoding of the noisy soft estimates of the transmitted symbols, so that the processed signals forwarded by all relays can form an analog distributed convolutional codeword. Assuming the source packet is encoded by a channel code, the ADC scheme can form serial concatenated codes and iterative decoding can be applied at the destination. We compare our proposed scheme with other existing schemes under Additive White Gaussian Noise (AWGN) and fast Rayleigh fading channel and validate the simulation results with the aid of Extrinsic Information Transfer (EXIT) chart analysis. Simulation results show that the proposed ADC scheme can effectively overcome the error propagation due to the erroneous decoding at the relay in the conventional decodeforward (DF) scheme and provide considerable coding gains, thus considerably outperforming the conventional soft information relaying protocols. The coding gains increase as the number of state in the relay encoder increases.
{"title":"Distributed Analog Channel Coding for Wireless Relay Networks","authors":"Md. Shahriar Rahman, Yonghui Li, B. Vucetic","doi":"10.1109/GLOCOM.2010.5683135","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683135","url":null,"abstract":"Distributed coding has been shown to be an efficient scheme to improve the performance of wireless relay networks. In this paper we propose an analog distributed channel coding (ADC) scheme. In the proposed scheme, the intermediate relays directly process the received analog noisy signals without making the hard estimation and performs analog channel encoding of the noisy soft estimates of the transmitted symbols, so that the processed signals forwarded by all relays can form an analog distributed convolutional codeword. Assuming the source packet is encoded by a channel code, the ADC scheme can form serial concatenated codes and iterative decoding can be applied at the destination. We compare our proposed scheme with other existing schemes under Additive White Gaussian Noise (AWGN) and fast Rayleigh fading channel and validate the simulation results with the aid of Extrinsic Information Transfer (EXIT) chart analysis. Simulation results show that the proposed ADC scheme can effectively overcome the error propagation due to the erroneous decoding at the relay in the conventional decodeforward (DF) scheme and provide considerable coding gains, thus considerably outperforming the conventional soft information relaying protocols. The coding gains increase as the number of state in the relay encoder increases.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"1 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75854569","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683396
Yuefei Zhu, Xinbing Wang
This paper studies the scaling law of the data gathering capacity of large-scale wireless sensor networks. Many previous researches on data gathering capacity focus on a many-to-one scheme, but we study the capacity in a multi-session data gathering paradigm, where some of the nodes in the network act as sinks and each sink has a set of source nodes to collect data. The analysis of this paradigm is meaningful in that it may be more commonplace in wireless sensor networks, because in real world, we often hope different sinks to get different kinds of data from sensors deployed in the same region. In the multicast scenario, a source node just sends the same data to all of its destinations, while in multi-session data gathering, the sink node has to receive different data from all its sensor nodes, which makes the last hop to the sink become a capacity bottleneck. We use compressive sensing (CS), a newly introduced sampling theory, to simplify the analysis of data gathering capacity into a similar way as the situation of multicast. Meanwhile, compressive sensing can achieve a capacity gain of $k/M$ for each data gathering session.
{"title":"Multi-Session Data Gathering with Compressive Sensing for Large-Scale Wireless Sensor Networks","authors":"Yuefei Zhu, Xinbing Wang","doi":"10.1109/GLOCOM.2010.5683396","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683396","url":null,"abstract":"This paper studies the scaling law of the data gathering capacity of large-scale wireless sensor networks. Many previous researches on data gathering capacity focus on a many-to-one scheme, but we study the capacity in a multi-session data gathering paradigm, where some of the nodes in the network act as sinks and each sink has a set of source nodes to collect data. The analysis of this paradigm is meaningful in that it may be more commonplace in wireless sensor networks, because in real world, we often hope different sinks to get different kinds of data from sensors deployed in the same region. In the multicast scenario, a source node just sends the same data to all of its destinations, while in multi-session data gathering, the sink node has to receive different data from all its sensor nodes, which makes the last hop to the sink become a capacity bottleneck. We use compressive sensing (CS), a newly introduced sampling theory, to simplify the analysis of data gathering capacity into a similar way as the situation of multicast. Meanwhile, compressive sensing can achieve a capacity gain of $k/M$ for each data gathering session.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"60 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74390686","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}
Cognitive Radio is a promising technology to solve the problem of increasing spectrum shortage in wireless communication. It allows secondary users(SUs) to opportunistically access idle spectrum of primary users(PUs) while ensuring collision perceived by PUs under a specific requirement. Testbed is essential to advance the development of cognitive radio networks. This paper presents a real time testbed for the evaluation of the cognitive radio MAC algorithm. The testbed supports the necessary components of cognitive radio including programmable RF transceiver, software-defined MAC layer and adaptive network layer to support multi-PU multi-SU cognitive radio networks. It is much easier to configure and control than the traditional FPGA-based testbed by using system-on-chip(SoC) programmable processors. We present the main features and the implementation details of the testbed in this paper. We also introduce an experiment using the testbed to evaluate the performance of an adaptive CR MAC algorithm proposed by us.
{"title":"A Real Time Testbed for the Evaluation of Cognitive Radio MAC","authors":"Shen Gu, Pengchao Xu, Xinbing Wang, Xiaoying Gan, Hui Yu","doi":"10.1109/GLOCOM.2010.5683324","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683324","url":null,"abstract":"Cognitive Radio is a promising technology to solve the problem of increasing spectrum shortage in wireless communication. It allows secondary users(SUs) to opportunistically access idle spectrum of primary users(PUs) while ensuring collision perceived by PUs under a specific requirement. Testbed is essential to advance the development of cognitive radio networks. This paper presents a real time testbed for the evaluation of the cognitive radio MAC algorithm. The testbed supports the necessary components of cognitive radio including programmable RF transceiver, software-defined MAC layer and adaptive network layer to support multi-PU multi-SU cognitive radio networks. It is much easier to configure and control than the traditional FPGA-based testbed by using system-on-chip(SoC) programmable processors. We present the main features and the implementation details of the testbed in this paper. We also introduce an experiment using the testbed to evaluate the performance of an adaptive CR MAC algorithm proposed by us.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"242 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74490962","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5684078
Pu-Hsuan Lin, S. Tsai, Chun-Hsiung Chuang
In this paper, we propose a low-complexity transmit antenna selection algorithm for MIMO multiuser channels. This algorithm greedily finds the optimal transmit antenna subset in base station. When the transmit power for individual data streams is equal, the proposed algorithm can be applied to the zero-forcing and the MMSE precoding schemes to further simplify the computational complexity. Simulation results show that the proposed low-complexity suboptimal antenna selections can achieve very close performance with the optimal antenna selection scheme in [6]. As a result, a good trade-off between complexity and performance is attained by the proposed antenna selection schemes.
{"title":"Transmit Antenna Selection with Linear Precoding in MIMO Multiuser Systems","authors":"Pu-Hsuan Lin, S. Tsai, Chun-Hsiung Chuang","doi":"10.1109/GLOCOM.2010.5684078","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5684078","url":null,"abstract":"In this paper, we propose a low-complexity transmit antenna selection algorithm for MIMO multiuser channels. This algorithm greedily finds the optimal transmit antenna subset in base station. When the transmit power for individual data streams is equal, the proposed algorithm can be applied to the zero-forcing and the MMSE precoding schemes to further simplify the computational complexity. Simulation results show that the proposed low-complexity suboptimal antenna selections can achieve very close performance with the optimal antenna selection scheme in [6]. As a result, a good trade-off between complexity and performance is attained by the proposed antenna selection schemes.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"61 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74653954","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 : 2010-12-01DOI: 10.1109/GLOCOM.2010.5683775
Ranjitha Prasad, C. Murthy
The impulse response of a typical wireless multipath channel can be modeled as a tapped delay line filter whose non-zero components are sparse relative to the channel delay spread. In this paper, a novel method of estimating such sparse multipath fading channels for OFDM systems is explored. In particular, Sparse Bayesian Learning (SBL) techniques are applied to jointly estimate the sparse channel and its second order statistics, and a new Bayesian Cramer-Rao bound is derived for the SBL algorithm. Further, in the context of OFDM channel estimation, an enhancement to the SBL algorithm is proposed, which uses an Expectation Maximization (EM) framework to jointly estimate the sparse channel, unknown data symbols and the second order statistics of the channel. The EM-SBL algorithm is able to recover the support as well as the channel taps more efficiently, and/or using fewer pilot symbols, than the SBL algorithm. To further improve the performance of the EM-SBL, a threshold-based pruning of the estimated second order statistics that are input to the algorithm is proposed, and its mean square error and symbol error rate performance is illustrated through Monte-Carlo simulations. Thus, the algorithms proposed in this paper are capable of obtaining efficient sparse channel estimates even in the presence of a small number of pilots.
{"title":"Bayesian Learning for Joint Sparse OFDM Channel Estimation and Data Detection","authors":"Ranjitha Prasad, C. Murthy","doi":"10.1109/GLOCOM.2010.5683775","DOIUrl":"https://doi.org/10.1109/GLOCOM.2010.5683775","url":null,"abstract":"The impulse response of a typical wireless multipath channel can be modeled as a tapped delay line filter whose non-zero components are sparse relative to the channel delay spread. In this paper, a novel method of estimating such sparse multipath fading channels for OFDM systems is explored. In particular, Sparse Bayesian Learning (SBL) techniques are applied to jointly estimate the sparse channel and its second order statistics, and a new Bayesian Cramer-Rao bound is derived for the SBL algorithm. Further, in the context of OFDM channel estimation, an enhancement to the SBL algorithm is proposed, which uses an Expectation Maximization (EM) framework to jointly estimate the sparse channel, unknown data symbols and the second order statistics of the channel. The EM-SBL algorithm is able to recover the support as well as the channel taps more efficiently, and/or using fewer pilot symbols, than the SBL algorithm. To further improve the performance of the EM-SBL, a threshold-based pruning of the estimated second order statistics that are input to the algorithm is proposed, and its mean square error and symbol error rate performance is illustrated through Monte-Carlo simulations. Thus, the algorithms proposed in this paper are capable of obtaining efficient sparse channel estimates even in the presence of a small number of pilots.","PeriodicalId":6448,"journal":{"name":"2010 IEEE Global Telecommunications Conference GLOBECOM 2010","volume":"13 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74674953","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：