Pub Date : 2007-12-04DOI: 10.1109/ISWCS.2007.4392301
A. Knopp, R. Schwarz, C. Hofmann, M. Chouayakh, B. Lankl
The channel capacity of indoor line-of-sight MIMO channels is affected by the geometrical antenna setup. In theory there exist rules for the design of LOS channels with optimum channel eigenvalue profile providing maximum capacity. These prescripts are only valid in the absence of multipath signals. By measurements we investigate the relevance of such design rules in real-world MIMO channels consisting of a LOS signal component as well as multipath parts. For that purpose two new performance measures are introduced and shown to be very adequate to distinguish capacity variations which are caused by changes in receive power from those that are caused by differing eigenvalue profiles of the channel matrix. Even sparse multipath signals turn out to be capable of distinctly enhancing the measured spectral efficiency in low-rank channels, while for the high-rank case any multipath components get almost negligible. More important, the geometrical antenna setup not only affects the LOS signal, but also the remaining signal parts. Moreover, the angles of arrival determine, how multipath components affect the LOS channel capacity.
{"title":"Measurements on the Impact of Sparse Multipath Components on the LOS MIMO Channel Capacity","authors":"A. Knopp, R. Schwarz, C. Hofmann, M. Chouayakh, B. Lankl","doi":"10.1109/ISWCS.2007.4392301","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392301","url":null,"abstract":"The channel capacity of indoor line-of-sight MIMO channels is affected by the geometrical antenna setup. In theory there exist rules for the design of LOS channels with optimum channel eigenvalue profile providing maximum capacity. These prescripts are only valid in the absence of multipath signals. By measurements we investigate the relevance of such design rules in real-world MIMO channels consisting of a LOS signal component as well as multipath parts. For that purpose two new performance measures are introduced and shown to be very adequate to distinguish capacity variations which are caused by changes in receive power from those that are caused by differing eigenvalue profiles of the channel matrix. Even sparse multipath signals turn out to be capable of distinctly enhancing the measured spectral efficiency in low-rank channels, while for the high-rank case any multipath components get almost negligible. More important, the geometrical antenna setup not only affects the LOS signal, but also the remaining signal parts. Moreover, the angles of arrival determine, how multipath components affect the LOS channel capacity.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130820854","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392316
Widyawan, M. Klepal, D. Pesch
The proliferation of Wireless LAN and Wireless Sensor Network make the technologies become an attractive proposition for indoor localisation. Both technologies have provided communication infrastructure and hence RF-based localisation with WLAN and WSN becomes a software-only solution. WLAN-based localisation generally provides room accuracy, therefore sensor data fusion with WSN is proposed when better location accuracy is needed. This paper will describe a Bayesian approach for indoor localisation. A suboptimal sequential Bayesian method of Particle Filter combined with Map Filtering technique is used for sensor data fusion between WLAN and WSN. The location system performance also will be evaluated.
{"title":"A Bayesian Approach for RF-Based Indoor Localisation","authors":"Widyawan, M. Klepal, D. Pesch","doi":"10.1109/ISWCS.2007.4392316","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392316","url":null,"abstract":"The proliferation of Wireless LAN and Wireless Sensor Network make the technologies become an attractive proposition for indoor localisation. Both technologies have provided communication infrastructure and hence RF-based localisation with WLAN and WSN becomes a software-only solution. WLAN-based localisation generally provides room accuracy, therefore sensor data fusion with WSN is proposed when better location accuracy is needed. This paper will describe a Bayesian approach for indoor localisation. A suboptimal sequential Bayesian method of Particle Filter combined with Map Filtering technique is used for sensor data fusion between WLAN and WSN. The location system performance also will be evaluated.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116376311","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392295
L. Yin, Changmian Wang, G. Øien
In this paper, we focus on the energy consumption issues of data transmission from correlated sensor nodes, and an optimization algorithm is proposed for minimizing the total energy consumption of the hardware and the physical link. We perform a detailed trade-off analysis of the circuit energy consumption, the transmission energy consumption, the transmission time, the QAM constellation size, and the channel coding rate over transmission distance and correlation values, thus a new optimized transmission schedule with much lower energy consumption is obtained. Compared to the optimized uncorrelated uncoded transmission scheme, the total energy consumption may be reduced by more than 83.5% for a correlation value of 0.6 and a transmission distance of 100 meters when using the results from the proposed optimization, which is significant with respect to increasing the lifetime of a wireless sensor network.
{"title":"Energy Consumption Optimization in Data Transmission from Correlated Sensor Nodes","authors":"L. Yin, Changmian Wang, G. Øien","doi":"10.1109/ISWCS.2007.4392295","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392295","url":null,"abstract":"In this paper, we focus on the energy consumption issues of data transmission from correlated sensor nodes, and an optimization algorithm is proposed for minimizing the total energy consumption of the hardware and the physical link. We perform a detailed trade-off analysis of the circuit energy consumption, the transmission energy consumption, the transmission time, the QAM constellation size, and the channel coding rate over transmission distance and correlation values, thus a new optimized transmission schedule with much lower energy consumption is obtained. Compared to the optimized uncorrelated uncoded transmission scheme, the total energy consumption may be reduced by more than 83.5% for a correlation value of 0.6 and a transmission distance of 100 meters when using the results from the proposed optimization, which is significant with respect to increasing the lifetime of a wireless sensor network.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123151322","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392452
Chia-Mu Yu, Chun-Shien Lu, S. Kuo
Routing protocol is an important issue in opportunistic networks. We propose a novel idea of exploiting animal's habitual behaviors to enhance routing performance.
路由协议是机会网络中的一个重要问题。我们提出了一种利用动物的习惯行为来提高路由性能的新思路。
{"title":"Habitual Behavior-Based Opportunistic Data Forwarding in Wildlife Tracking","authors":"Chia-Mu Yu, Chun-Shien Lu, S. Kuo","doi":"10.1109/ISWCS.2007.4392452","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392452","url":null,"abstract":"Routing protocol is an important issue in opportunistic networks. We propose a novel idea of exploiting animal's habitual behaviors to enhance routing performance.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121878553","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392433
S. Jeon, Younghyun Jeon, Sanghoon Lee
A strategy for avoiding the ICI (Inter Cell Interference) termed LBLC (Location-Based Loading Control) for downlink FH-OFDMA (Frequency Hopping Orthogonal Frequency Division Multiple Access) systems over multi-cell environments with a frequency reuse factor of 1 is described. To mitigate the effect of the ICI, a closed form of outage probability is derived and is utilized as a criterion for obtaining an optimal set of loading parameters. For a given target QoS (Quality of Service), region partitioning is performed and a carrier loading ratio at each region is obtained. An optimal set of loading parameters according to each region can be obtained from the simulations. In addition, the feasibility of the LBLC technique is demonstrated.
描述了一种用于多小区环境下跳频正交频分多址(FH-OFDMA)下行链路频率复用系数为1的避免ICI(小区间干扰)的策略LBLC(基于位置的加载控制)。为了减轻ICI的影响，导出了停电概率的封闭形式，并将其作为获得最优加载参数集的准则。对于给定的目标QoS (Quality of Service)，进行区域划分，得到每个区域的载波负载比。通过仿真，可以得到各区域的最优加载参数集。此外，还论证了LBLC技术的可行性。
{"title":"Performance Analysis of Location-Based Loading Control for Downlink FH-OFDMA Systems","authors":"S. Jeon, Younghyun Jeon, Sanghoon Lee","doi":"10.1109/ISWCS.2007.4392433","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392433","url":null,"abstract":"A strategy for avoiding the ICI (Inter Cell Interference) termed LBLC (Location-Based Loading Control) for downlink FH-OFDMA (Frequency Hopping Orthogonal Frequency Division Multiple Access) systems over multi-cell environments with a frequency reuse factor of 1 is described. To mitigate the effect of the ICI, a closed form of outage probability is derived and is utilized as a criterion for obtaining an optimal set of loading parameters. For a given target QoS (Quality of Service), region partitioning is performed and a carrier loading ratio at each region is obtained. An optimal set of loading parameters according to each region can be obtained from the simulations. In addition, the feasibility of the LBLC technique is demonstrated.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116543593","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392426
Lingyang Song, A. Hjørungnes, M. Bhatnagar
Most work on space-time block codes (STBC) assumes block fading. However, time selectivity does exists in practise for codes with big block length. In this paper, we propose a linear pre-whitening filter based signal detector for STBC when the channel changes within the coding block. The main idea is to utilize the principle of a pre-whitening filter to realize single symbol detection, virtual single input and single output (SISO), by removing the effects of past decisions. Both analytical and simulation results show that our scheme can provide performance very close to ML decoding with extremely low computational complexity. Extension to V-BLAST is given in order to make the proposed detector applicable to other MIMO schemes.
{"title":"Linear Pre-Whitening Detector for Space-Time Block Codes over Time-Selective Fading Channels","authors":"Lingyang Song, A. Hjørungnes, M. Bhatnagar","doi":"10.1109/ISWCS.2007.4392426","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392426","url":null,"abstract":"Most work on space-time block codes (STBC) assumes block fading. However, time selectivity does exists in practise for codes with big block length. In this paper, we propose a linear pre-whitening filter based signal detector for STBC when the channel changes within the coding block. The main idea is to utilize the principle of a pre-whitening filter to realize single symbol detection, virtual single input and single output (SISO), by removing the effects of past decisions. Both analytical and simulation results show that our scheme can provide performance very close to ML decoding with extremely low computational complexity. Extension to V-BLAST is given in order to make the proposed detector applicable to other MIMO schemes.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125420235","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392371
B. Maham, A. Hjørungnes
User cooperation can provide spatial transmit diversity gains, enhance coverage, and potentially increase capacity. In this paper, incremental relaying protocol is developed. This protocol uses a limited feedback from the destination to transmitters to choose between direct transmission or cooperation. The incremental relaying protocol is examined in a space-time coded cooperation under the amplify-and-forward model. The exact bit error rate of the system is derived. Furthermore, the bit error rate of amplify-and-forward based space-time cooperation is derived, when the source-destination link is considered in both phases. Simulations demonstrate that the proposed scheme can substantially improve the spectral efficiency of the system comparing to the conventional two-phased cooperative schemes. Moreover, it is shown that the proposed scheme can achieve an outstanding coding gain in comparison to direct transmission.
{"title":"Amplify-and-Forward Space-Time Coded Cooperation via Incremental Relaying","authors":"B. Maham, A. Hjørungnes","doi":"10.1109/ISWCS.2007.4392371","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392371","url":null,"abstract":"User cooperation can provide spatial transmit diversity gains, enhance coverage, and potentially increase capacity. In this paper, incremental relaying protocol is developed. This protocol uses a limited feedback from the destination to transmitters to choose between direct transmission or cooperation. The incremental relaying protocol is examined in a space-time coded cooperation under the amplify-and-forward model. The exact bit error rate of the system is derived. Furthermore, the bit error rate of amplify-and-forward based space-time cooperation is derived, when the source-destination link is considered in both phases. Simulations demonstrate that the proposed scheme can substantially improve the spectral efficiency of the system comparing to the conventional two-phased cooperative schemes. Moreover, it is shown that the proposed scheme can achieve an outstanding coding gain in comparison to direct transmission.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125313726","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392363
D. Vukobratović, V. Šenk
In this paper, we analyze the application of asymptotic and finite-length analysis and design of low-density parity-check (LDPC) codes for the large scale content distribution systems over packet based networks, such as MBMS or DVB-H. We show connections of the classical coding theory performance measure, the bit error rate (BER) performance, and the measure called the overhead factor which is of interest in the content distribution systems. We point out to LDPC codes design methods that can provide an excellent overhead factor performance. Particularly, we are interested in performance limits of the class of patent-free LDPC codes.
{"title":"On the Optimized Patent-Free LDPC Code Design for Content Distribution Systems","authors":"D. Vukobratović, V. Šenk","doi":"10.1109/ISWCS.2007.4392363","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392363","url":null,"abstract":"In this paper, we analyze the application of asymptotic and finite-length analysis and design of low-density parity-check (LDPC) codes for the large scale content distribution systems over packet based networks, such as MBMS or DVB-H. We show connections of the classical coding theory performance measure, the bit error rate (BER) performance, and the measure called the overhead factor which is of interest in the content distribution systems. We point out to LDPC codes design methods that can provide an excellent overhead factor performance. Particularly, we are interested in performance limits of the class of patent-free LDPC codes.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126202244","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392349
R. Rugin, A. Dejonghe, G. Mazzini, V. Tralli
In the design of modern mobile wireless networks the effort for performance improvement has to be balanced with the effort in more effective energy management strategies. In fact, the capacity of batteries is not increasing as new devices and multimedia applications requires. In this paper a new approach to routing optimization in ad-hoc wireless networks supporting multimedia communication is investigated. It exploits an energy model for the radio interface and cross-layer information to dynamically determine routing paths connecting wireless nodes, in order to reduce energy consumption and prolong network lifetime, while preserving quality of service. A network architecture based on a modified 802.11a wireless physical interface with multi-channel capability is considered. We investigate a multi-hop environment where network devices collect cross- layers information and periodically update a central repository located on a network node elected as network coordinator. The coordinator exploits the recorded information to provide best quality routing paths to devices that need to send sensible data over the network. We propose here an algorithm for routing path optimization and compare the optimized strategy with a reference implementation of the OLSR routing protocol. The numerical results show benefits in terms of increased network life-time.
{"title":"Energy-aware routing optimization in ad-hoc wireless networks under QoS constraints","authors":"R. Rugin, A. Dejonghe, G. Mazzini, V. Tralli","doi":"10.1109/ISWCS.2007.4392349","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392349","url":null,"abstract":"In the design of modern mobile wireless networks the effort for performance improvement has to be balanced with the effort in more effective energy management strategies. In fact, the capacity of batteries is not increasing as new devices and multimedia applications requires. In this paper a new approach to routing optimization in ad-hoc wireless networks supporting multimedia communication is investigated. It exploits an energy model for the radio interface and cross-layer information to dynamically determine routing paths connecting wireless nodes, in order to reduce energy consumption and prolong network lifetime, while preserving quality of service. A network architecture based on a modified 802.11a wireless physical interface with multi-channel capability is considered. We investigate a multi-hop environment where network devices collect cross- layers information and periodically update a central repository located on a network node elected as network coordinator. The coordinator exploits the recorded information to provide best quality routing paths to devices that need to send sensible data over the network. We propose here an algorithm for routing path optimization and compare the optimized strategy with a reference implementation of the OLSR routing protocol. The numerical results show benefits in terms of increased network life-time.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133299961","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392427
M. Talonen, S. Lindfors
Signal and transmit power dependent power consumption models for linear, class-A and class-B RF power amplifiers are derived. The power consumption of a class-B amplifier displays a square root dependency with respect to transmit power. The effect of signal statistics is studied for root- raised cosine filtered and M-QAM modulated signals. While the order of the modulation and filter roll-off have a strong effect on the maximum transmit power they are found to have only marginal impact on the power consumption below the maximum.
{"title":"Power Consumption Model for Linear RF Power Amplifiers with Rectangular M-QAM Modulation","authors":"M. Talonen, S. Lindfors","doi":"10.1109/ISWCS.2007.4392427","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392427","url":null,"abstract":"Signal and transmit power dependent power consumption models for linear, class-A and class-B RF power amplifiers are derived. The power consumption of a class-B amplifier displays a square root dependency with respect to transmit power. The effect of signal statistics is studied for root- raised cosine filtered and M-QAM modulated signals. While the order of the modulation and filter roll-off have a strong effect on the maximum transmit power they are found to have only marginal impact on the power consumption below the maximum.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133825603","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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