Pub Date : 2005-12-01DOI: 10.1109/GLOCOM.2005.1577958
Yang Xiao, Sakshi Sethi, Hsiao-Hwa Chen, Bo Sun
The IEEE 802.15.4 specification defines medium access control (MAC) layer and physical layer for wireless sensor networks. Furthermore, security mechanisms are also defined in the specification. This paper first surveys security services provided in the IEEE 802.15.4 wireless sensor networks. Then, some security enhancements are proposed to prevent same-nonce attack, denial-of-service attack, reply-protection attack, ACK attack, etc.
{"title":"Security services and enhancements in the IEEE 802.15.4 wireless sensor networks","authors":"Yang Xiao, Sakshi Sethi, Hsiao-Hwa Chen, Bo Sun","doi":"10.1109/GLOCOM.2005.1577958","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577958","url":null,"abstract":"The IEEE 802.15.4 specification defines medium access control (MAC) layer and physical layer for wireless sensor networks. Furthermore, security mechanisms are also defined in the specification. This paper first surveys security services provided in the IEEE 802.15.4 wireless sensor networks. Then, some security enhancements are proposed to prevent same-nonce attack, denial-of-service attack, reply-protection attack, ACK attack, etc.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"269 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130197360","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1577664
J. Cobb, Zhe Xu
In order to improve the scalability of scheduling protocols with bounded end-to-end delay, much effort has focused on reducing the amount of per-flow state at routers. One technique to reduce this state is flow aggregation, in which multiple individual flows are aggregated into a single aggregate flow. In addition to reducing per-flow state, flow aggregation has the advantage of a per-hop delay that is inversely proportional to the rate of the aggregate flow, while in the case of no aggregation, the per-hop delay is inversely proportional to the (smaller) rate of the individual flow. Flow aggregation in general is non-work-conserving. Recently, a work-conserving flow aggregation technique has been proposed. However, it has the disadvantage that the end-to-end delay of an individual flow is related to the burstiness of other flows sharing its aggregate flow. Here, we show how work-conserving flow aggregation may be performed without this drawback, that is, the end-to-end delay of an individual flow is independent of the burstiness of other flows.
{"title":"Maintaining flow isolation in work-conserving flow aggregation","authors":"J. Cobb, Zhe Xu","doi":"10.1109/GLOCOM.2005.1577664","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577664","url":null,"abstract":"In order to improve the scalability of scheduling protocols with bounded end-to-end delay, much effort has focused on reducing the amount of per-flow state at routers. One technique to reduce this state is flow aggregation, in which multiple individual flows are aggregated into a single aggregate flow. In addition to reducing per-flow state, flow aggregation has the advantage of a per-hop delay that is inversely proportional to the rate of the aggregate flow, while in the case of no aggregation, the per-hop delay is inversely proportional to the (smaller) rate of the individual flow. Flow aggregation in general is non-work-conserving. Recently, a work-conserving flow aggregation technique has been proposed. However, it has the disadvantage that the end-to-end delay of an individual flow is related to the burstiness of other flows sharing its aggregate flow. Here, we show how work-conserving flow aggregation may be performed without this drawback, that is, the end-to-end delay of an individual flow is independent of the burstiness of other flows.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130684101","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1578461
Ai-Chun Pang, Shun-Mao Wang
Based on multimedia broadcast/multicast service architecture(MBMS), this paper proposes an efficient QoS-based multicast approach for the universal mobile telecommunications system (UMTS). Our approach adopts the existing scalable-coding technique to provide multiple levels of service quality to diverse mobile devices in the UMTS system. In this approach, two kinds of transmission modes are developed to utilize fully the network resources for wireline and wireless links. An analytic model is presented to investigate the performance of our approach and the 3GPP 23.246 approach. The numerical results indicate that in terms of transmission costs of core/radio networks, our approach outperforms the 3GPP 23.246 approach
{"title":"QoS multicasting over mobile networks","authors":"Ai-Chun Pang, Shun-Mao Wang","doi":"10.1109/GLOCOM.2005.1578461","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578461","url":null,"abstract":"Based on multimedia broadcast/multicast service architecture(MBMS), this paper proposes an efficient QoS-based multicast approach for the universal mobile telecommunications system (UMTS). Our approach adopts the existing scalable-coding technique to provide multiple levels of service quality to diverse mobile devices in the UMTS system. In this approach, two kinds of transmission modes are developed to utilize fully the network resources for wireline and wireless links. An analytic model is presented to investigate the performance of our approach and the 3GPP 23.246 approach. The numerical results indicate that in terms of transmission costs of core/radio networks, our approach outperforms the 3GPP 23.246 approach","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127551123","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1577046
Hiroshi Yamamoto, T. Ohtsuki
In wireless sensor networks, if the local sensor node transmits wrong decided data to a fusion center, the energy-efficiency of the network is degraded. In this paper, we propose wireless sensor networks with local fusion to reduce the degradation caused by observation noise, channel noise, and fading. In the proposed systems, first, information transmitted from local sensor nodes are decided by a local fusion center allocated in the neighborhood of local sensor nodes. Here, we consider two signal decision schemes (local fusion) for use at the local fusion center: majority decision and likelihood decision. By using local fusion, even if the local sensor node makes an error in the decision of the event, the probability that the local fusion center makes an error in the decision of the event becomes small. Thus, the probability that the local fusion center transmits wrong decided data becomes small. Then, from the local fusion center to a destination node (a global fusion center), error correcting coded bits are transmitted in multihop communication. We show that the proposed systems can achieve good energy-efficiency as compared with the system without local fusion. We also show that the total energy consumption of the system with likelihood decision is smaller than that of the system with majority decision when the influence of observation noise is large. Moreover, we show that the optimal number of hops minimizing the total energy consumption of the proposed systems depends on the signal attenuation parameter k and a long-haul transmission distance between the local fusion center and the global fusion center.
{"title":"Wireless sensor networks with local fusion","authors":"Hiroshi Yamamoto, T. Ohtsuki","doi":"10.1109/GLOCOM.2005.1577046","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577046","url":null,"abstract":"In wireless sensor networks, if the local sensor node transmits wrong decided data to a fusion center, the energy-efficiency of the network is degraded. In this paper, we propose wireless sensor networks with local fusion to reduce the degradation caused by observation noise, channel noise, and fading. In the proposed systems, first, information transmitted from local sensor nodes are decided by a local fusion center allocated in the neighborhood of local sensor nodes. Here, we consider two signal decision schemes (local fusion) for use at the local fusion center: majority decision and likelihood decision. By using local fusion, even if the local sensor node makes an error in the decision of the event, the probability that the local fusion center makes an error in the decision of the event becomes small. Thus, the probability that the local fusion center transmits wrong decided data becomes small. Then, from the local fusion center to a destination node (a global fusion center), error correcting coded bits are transmitted in multihop communication. We show that the proposed systems can achieve good energy-efficiency as compared with the system without local fusion. We also show that the total energy consumption of the system with likelihood decision is smaller than that of the system with majority decision when the influence of observation noise is large. Moreover, we show that the optimal number of hops minimizing the total energy consumption of the proposed systems depends on the signal attenuation parameter k and a long-haul transmission distance between the local fusion center and the global fusion center.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126235498","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1577660
A. E. Lawabni, A. Tewfik
In this paper, the problem of allocating multiple finite resources to satisfy the quality of service (QoS) needs of multiple applications along multiple QoS dimensions is presented. A mathematical model that captures the dynamics of such adaptive problem is presented. This model formulates the problem as a multiple-choice multidimensional 0-1 knapsack problem (MMKP), an NP-hard optimization problem. A heuristic algorithm is then proposed to solve the MMKP. Experimental results demonstrate that our proposed algorithm finds 96% optimal solutions on average, and outperforms other heuristic algorithms for MMKP. Furthermore, the time required is on average 50% to 70% less than that required by other benchmark heuristics. These two properties make this heuristic a strong candidate for use in real-time multimedia applications
{"title":"Notice of Violation of IEEE Publication PrinciplesResource management and knapsack formulation in distributed multimedia networks","authors":"A. E. Lawabni, A. Tewfik","doi":"10.1109/GLOCOM.2005.1577660","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577660","url":null,"abstract":"In this paper, the problem of allocating multiple finite resources to satisfy the quality of service (QoS) needs of multiple applications along multiple QoS dimensions is presented. A mathematical model that captures the dynamics of such adaptive problem is presented. This model formulates the problem as a multiple-choice multidimensional 0-1 knapsack problem (MMKP), an NP-hard optimization problem. A heuristic algorithm is then proposed to solve the MMKP. Experimental results demonstrate that our proposed algorithm finds 96% optimal solutions on average, and outperforms other heuristic algorithms for MMKP. Furthermore, the time required is on average 50% to 70% less than that required by other benchmark heuristics. These two properties make this heuristic a strong candidate for use in real-time multimedia applications","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114376077","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1578335
D. Zheng, Junshan Zhang
The number of competing stations has great impact on the network performance of wireless LANs. It is therefore of great interest to obtain accurate estimation of the number of competing stations so that adaptive control mechanisms can be carried out accordingly. Based on the observation that this estimation problem is nonlinear/non-Gaussian in nature, we propose to use a sequential Monte Carlo technique, namely, the particle filtering to improve the estimation accuracy. One key step in the proposed scheme is to exploit the unscented particle filter, which combines the merits of unscented transformation and particle filtering. Our simulation results indicate that the unscented particle filter can increase the accuracy of the estimation upto 33% in terms of the root mean square error (RMSE), compared with the extended Kalman filter (EKF), the unscented Kalman filter (UKF) and the SIR-particle filter
{"title":"A unscented particle filtering approach to estimating competing stations in IEEE 802.11 WLANs","authors":"D. Zheng, Junshan Zhang","doi":"10.1109/GLOCOM.2005.1578335","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578335","url":null,"abstract":"The number of competing stations has great impact on the network performance of wireless LANs. It is therefore of great interest to obtain accurate estimation of the number of competing stations so that adaptive control mechanisms can be carried out accordingly. Based on the observation that this estimation problem is nonlinear/non-Gaussian in nature, we propose to use a sequential Monte Carlo technique, namely, the particle filtering to improve the estimation accuracy. One key step in the proposed scheme is to exploit the unscented particle filter, which combines the merits of unscented transformation and particle filtering. Our simulation results indicate that the unscented particle filter can increase the accuracy of the estimation upto 33% in terms of the root mean square error (RMSE), compared with the extended Kalman filter (EKF), the unscented Kalman filter (UKF) and the SIR-particle filter","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123483062","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1578330
S. Gandham, Milind Dawande, R. Prakash
Efficient use of the limited energy available with sensor nodes is an important consideration for routing protocols. In an attempt to improve the lifetime of a sensor network using energy-aware routing, existing protocols might route a packet along a longer path - thus increasing its latency. Many applications of sensor networks, e.g., surveillance and security, require that the maximum latency in routing a packet be bounded. We consider the problem of energy-aware routing with a bound on the maximum number of hops any packet can traverse to reach a base station. We formulate a linear program (LP) to minimize the maximum energy spent by any node in the network subject to a limit on the number of hops any packet may traverse. A solution to the LP yields routing information in terms of the number of packets to be forwarded along each edge; however, non-integral values of the flow variables might require splitting a packet across multiple routes. As packet splitting incurs additional overhead in tracking various fragments, it is desirable to have integral routing information. We, therefore, propose a rounding algorithm based on the minimum cost flow problem and prove that the energy spent by a node in the resulting integral solution is at most a constant more than the optimal LP solution
{"title":"Hop-constrained energy-aware routing in wireless sensor networks","authors":"S. Gandham, Milind Dawande, R. Prakash","doi":"10.1109/GLOCOM.2005.1578330","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578330","url":null,"abstract":"Efficient use of the limited energy available with sensor nodes is an important consideration for routing protocols. In an attempt to improve the lifetime of a sensor network using energy-aware routing, existing protocols might route a packet along a longer path - thus increasing its latency. Many applications of sensor networks, e.g., surveillance and security, require that the maximum latency in routing a packet be bounded. We consider the problem of energy-aware routing with a bound on the maximum number of hops any packet can traverse to reach a base station. We formulate a linear program (LP) to minimize the maximum energy spent by any node in the network subject to a limit on the number of hops any packet may traverse. A solution to the LP yields routing information in terms of the number of packets to be forwarded along each edge; however, non-integral values of the flow variables might require splitting a packet across multiple routes. As packet splitting incurs additional overhead in tracking various fragments, it is desirable to have integral routing information. We, therefore, propose a rounding algorithm based on the minimum cost flow problem and prove that the energy spent by a node in the resulting integral solution is at most a constant more than the optimal LP solution","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127545294","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 : 2005-12-01DOI: 10.1504/IJSN.2007.012828
T. Korkmaz, Chao Gong, K. Saraç, S. G. Dykes
Tracing IP packets to their sources, known as IP traceback, is an important task in defending against IP spoofing and DoS attacks. Log-based IP traceback technique is to log packets at routers in the network and then determine the network paths which packets traversed using data extraction techniques. The biggest advantage of log-based IP traceback is the potential to trace a single packet. Tracing a single packet in the Internet using log-based IP traceback involves cooperation among all autonomous systems (AS) traversed by the packet. The single packet traceback process may not reach the packet origin if some AS on the forwarding path does not support IP traceback. IP traceback mechanisms are deployed within each AS independently. It is not reasonable to assume all ASes begin to support the same IP traceback mechanism in a short period of time. In this paper, we study the effectiveness of log-based IP traceback in tracing a single packet under the environment where not every AS supports log-based IP traceback. We propose a scheme to conduct the single packet traceback process in AS-level partial deployment scenario. We evaluate the performance of single packet IP traceback in AS-level partial deployment scenario based on our scheme through simulation.
{"title":"Single packet IP traceback in AS-level partial deployment scenario","authors":"T. Korkmaz, Chao Gong, K. Saraç, S. G. Dykes","doi":"10.1504/IJSN.2007.012828","DOIUrl":"https://doi.org/10.1504/IJSN.2007.012828","url":null,"abstract":"Tracing IP packets to their sources, known as IP traceback, is an important task in defending against IP spoofing and DoS attacks. Log-based IP traceback technique is to log packets at routers in the network and then determine the network paths which packets traversed using data extraction techniques. The biggest advantage of log-based IP traceback is the potential to trace a single packet. Tracing a single packet in the Internet using log-based IP traceback involves cooperation among all autonomous systems (AS) traversed by the packet. The single packet traceback process may not reach the packet origin if some AS on the forwarding path does not support IP traceback. IP traceback mechanisms are deployed within each AS independently. It is not reasonable to assume all ASes begin to support the same IP traceback mechanism in a short period of time. In this paper, we study the effectiveness of log-based IP traceback in tracing a single packet under the environment where not every AS supports log-based IP traceback. We propose a scheme to conduct the single packet traceback process in AS-level partial deployment scenario. We evaluate the performance of single packet IP traceback in AS-level partial deployment scenario based on our scheme through simulation.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122503043","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1577838
C. Lo, S. Vishwanath, R. Heath
Relay channels plays a central role in next-generation multihop wireless systems. This paper considers the MIMO relay channel where multiple antennas are employed by each terminal. New lower bounds on the capacity of a Gaussian MIMO relay channel are derived under the assumption that the transmitter employs either superposition coding or dirty-paper coding. The proposed lower bounds improve on a previously proposed lower bound that arises from a simple transmit strategy.
{"title":"Rate bounds for MIMO relay channels using precoding","authors":"C. Lo, S. Vishwanath, R. Heath","doi":"10.1109/GLOCOM.2005.1577838","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577838","url":null,"abstract":"Relay channels plays a central role in next-generation multihop wireless systems. This paper considers the MIMO relay channel where multiple antennas are employed by each terminal. New lower bounds on the capacity of a Gaussian MIMO relay channel are derived under the assumption that the transmitter employs either superposition coding or dirty-paper coding. The proposed lower bounds improve on a previously proposed lower bound that arises from a simple transmit strategy.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"273 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131515396","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 : 2005-12-01DOI: 10.1109/GLOCOM.2005.1577897
Taeyoon Kim, J. Andrews
Orthogonal frequency division multiplexing (OFDM) can be used with a multiple-input multiple-output (MIMO) system to improve communication quality and capacity. Pilot-symbol-aided or decision-directed channel estimation must be used to track channel variations in MIMO-OFDM systems. While pilot symbols facilitate channel estimation, they reduce the transmit energy for data symbols under a fixed total transmit power constraint. We analyze the effects of pilot-symbol-aided channel estimation on the lower bound of the capacity and derive the optimal pilot-to-data power ratio (PDPR) in MIMO-OFDM systems with three different types of pilot patterns: independent, scattered, and orthogonal. The result implies that implementing the optimal PDPR in an actual MIMO-OFDM system should prove relatively straightforward, since there is a surprisingly broad range of PDPR values over which near optimal capacity is achieved.
{"title":"Optimal pilot-to-data power ratio for MIMO-OFDM","authors":"Taeyoon Kim, J. Andrews","doi":"10.1109/GLOCOM.2005.1577897","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577897","url":null,"abstract":"Orthogonal frequency division multiplexing (OFDM) can be used with a multiple-input multiple-output (MIMO) system to improve communication quality and capacity. Pilot-symbol-aided or decision-directed channel estimation must be used to track channel variations in MIMO-OFDM systems. While pilot symbols facilitate channel estimation, they reduce the transmit energy for data symbols under a fixed total transmit power constraint. We analyze the effects of pilot-symbol-aided channel estimation on the lower bound of the capacity and derive the optimal pilot-to-data power ratio (PDPR) in MIMO-OFDM systems with three different types of pilot patterns: independent, scattered, and orthogonal. The result implies that implementing the optimal PDPR in an actual MIMO-OFDM system should prove relatively straightforward, since there is a surprisingly broad range of PDPR values over which near optimal capacity is achieved.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134451897","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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