Pub Date : 2008-07-06DOI: 10.1109/SPAWC.2008.4641565
Xu Chen, D. Schonfeld, A. Khokhar
In this paper, we propose a robust novel approach with closed-form estimator for object tracking based on a non-linear measurement model over time from a single sensor with arbitrary noise degradation. Relying on the widely-used dynamic motion model for arbitrary moving targets, tracking of moving objects can be formulated using received signal strength (RSS) measurements. We provide a closed-form solution that integrates localization and filtering for both an ideal channel as well as noisy channel. We first derive an exact linear model from the non-linear system of equations provided by the RSS measurements. We subsequently present an iterative method to estimate the unknown parameters and the error covariance matrix. Moreover, we prove that the estimator gives more accuracy when the number of samples increases. The Cramer-Rao bound (CRB) for the estimator are determined in Gaussian case. Computer simulation demonstrates that the proposed approach not only achieves more accuracy than traditional methods but also saves significant computation time.
{"title":"Robust closed-form localization of mobile targets using a single sensor based on a non-linear measurement model","authors":"Xu Chen, D. Schonfeld, A. Khokhar","doi":"10.1109/SPAWC.2008.4641565","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641565","url":null,"abstract":"In this paper, we propose a robust novel approach with closed-form estimator for object tracking based on a non-linear measurement model over time from a single sensor with arbitrary noise degradation. Relying on the widely-used dynamic motion model for arbitrary moving targets, tracking of moving objects can be formulated using received signal strength (RSS) measurements. We provide a closed-form solution that integrates localization and filtering for both an ideal channel as well as noisy channel. We first derive an exact linear model from the non-linear system of equations provided by the RSS measurements. We subsequently present an iterative method to estimate the unknown parameters and the error covariance matrix. Moreover, we prove that the estimator gives more accuracy when the number of samples increases. The Cramer-Rao bound (CRB) for the estimator are determined in Gaussian case. Computer simulation demonstrates that the proposed approach not only achieves more accuracy than traditional methods but also saves significant computation time.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133133312","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641601
J. Potman, R. Schiphorst, C. Slump
This paper describes a novel on-demand receive filter in an UMTS terminal. The receive filter is the first function after the Analog-to-Digital converter and is for that reason one of the most computation intensive parts in a receiver. The proposed filter architecture measures the out-of-band interference and calculates the required attenuation, which is used to select the appropriate filter. To assess the advantages of this on-demand receive filter, we have carried out field strength measurements in the UMTS FDD downlink band (2.1 GHz). These measurements were carried out in Amsterdam, a dense urban area with 5 active UMTS operators. Our measurement results show that in a live network configuration there is almost no out-of-band interference. Moreover, an on-demand filter would save in this case more than 68% power compared to a fixed conventional receive filter.
{"title":"On-demand receive filtering in an UMTS terminal","authors":"J. Potman, R. Schiphorst, C. Slump","doi":"10.1109/SPAWC.2008.4641601","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641601","url":null,"abstract":"This paper describes a novel on-demand receive filter in an UMTS terminal. The receive filter is the first function after the Analog-to-Digital converter and is for that reason one of the most computation intensive parts in a receiver. The proposed filter architecture measures the out-of-band interference and calculates the required attenuation, which is used to select the appropriate filter. To assess the advantages of this on-demand receive filter, we have carried out field strength measurements in the UMTS FDD downlink band (2.1 GHz). These measurements were carried out in Amsterdam, a dense urban area with 5 active UMTS operators. Our measurement results show that in a live network configuration there is almost no out-of-band interference. Moreover, an on-demand filter would save in this case more than 68% power compared to a fixed conventional receive filter.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129638250","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641679
E. Katranaras, M. Imran, C. Tzaras
In this paper we investigate the information theoretic capacity of the uplink of a cellular system where all base station receivers jointly decode the received signals (ldquohyper-receiverrdquo). Considering a distance depended power-law path loss and a more realistic Rician fading environment, we model a variable cell density network with geographically distributed user terminals. Multiple tiers of interference are considered and using an average path loss approximation model the analytical result for the per cell sum-rate capacity is found. We examine the various parameters that are affecting the capacity of the system. Especially the effect of the user distribution across the cells and the density of the cells in the cellular system is investigated. We validate the numerical solutions with Monte Carlo simulations for random fading realizations and we interpret the results for the real-world systems.
{"title":"Information theoretic capacity of the cellular uplink - average path loss approximation","authors":"E. Katranaras, M. Imran, C. Tzaras","doi":"10.1109/SPAWC.2008.4641679","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641679","url":null,"abstract":"In this paper we investigate the information theoretic capacity of the uplink of a cellular system where all base station receivers jointly decode the received signals (ldquohyper-receiverrdquo). Considering a distance depended power-law path loss and a more realistic Rician fading environment, we model a variable cell density network with geographically distributed user terminals. Multiple tiers of interference are considered and using an average path loss approximation model the analytical result for the per cell sum-rate capacity is found. We examine the various parameters that are affecting the capacity of the system. Especially the effect of the user distribution across the cells and the density of the cells in the cellular system is investigated. We validate the numerical solutions with Monte Carlo simulations for random fading realizations and we interpret the results for the real-world systems.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131955944","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641580
R. Sámano-Robles, M. Ghogho, D. McLernon
The study of random access protocols has recently regained attention due to new cross-layer schemes such as multipacket reception (MPR) systems and network diversity multiple access protocols (NDMA). Despite their relevance, these two systems have only been simultaneously studied employing finite user population models and considering perfect detection of the active users, which are assumptions only useful in scenarios with low numbers of users and high values of the SNR. The purpose of this paper is to introduce an infinite user population model, valid for scenarios with large numbers of users and finite traffic loads, which allows us to extend the available results on ALOHA MPR protocols to systems that use retransmission diversity (RD). Unlike existing approaches our model includes both the effects of packet decoding errors and the effects of imperfect detection of the active users, which considerably affect the performance of conventional NDMA systems in finite SNR environments. Additionally, the proposed model provides a better approximation to the queuing delay of NDMA protocols than the conventional formula of an M/G/1 queue with vacations. Finally, the proposed algorithm also represents an extension and generalization of contention binary tree algorithms assisted by signal processing tools such as SICTA (successive interference cancellation tree algorithm) and other algorithms assisted by source separation. The benefits of the proposed model are assessed using simulation and analytic results.
{"title":"An infinite user model for random access protocols assisted by multipacket reception and retransmission diversity","authors":"R. Sámano-Robles, M. Ghogho, D. McLernon","doi":"10.1109/SPAWC.2008.4641580","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641580","url":null,"abstract":"The study of random access protocols has recently regained attention due to new cross-layer schemes such as multipacket reception (MPR) systems and network diversity multiple access protocols (NDMA). Despite their relevance, these two systems have only been simultaneously studied employing finite user population models and considering perfect detection of the active users, which are assumptions only useful in scenarios with low numbers of users and high values of the SNR. The purpose of this paper is to introduce an infinite user population model, valid for scenarios with large numbers of users and finite traffic loads, which allows us to extend the available results on ALOHA MPR protocols to systems that use retransmission diversity (RD). Unlike existing approaches our model includes both the effects of packet decoding errors and the effects of imperfect detection of the active users, which considerably affect the performance of conventional NDMA systems in finite SNR environments. Additionally, the proposed model provides a better approximation to the queuing delay of NDMA protocols than the conventional formula of an M/G/1 queue with vacations. Finally, the proposed algorithm also represents an extension and generalization of contention binary tree algorithms assisted by signal processing tools such as SICTA (successive interference cancellation tree algorithm) and other algorithms assisted by source separation. The benefits of the proposed model are assessed using simulation and analytic results.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132170051","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641633
R.B. Moreira, F. Cavalcanti
Interference management is one of effective means of improving system throughput, which is particularly important for the emerging 4G wireless networks that demand increasing data rates. In order to mitigate the inter-cell interference we evaluate the performance of an hierarchical centralized inter-cell scheduling method which aims at improving the system throughput. The proposed algorithm, which is based on an existing one, besides selecting the BSs allowed to transmit, performs an exhaustive power control in order to find the optimal power levels of transmitting BSs. Simulation results show that the proposed method outperforms classical approaches in terms of spectral efficiency improvements.
{"title":"An hierarchical approach for inter-cell scheduling in interference-limited cellular networks","authors":"R.B. Moreira, F. Cavalcanti","doi":"10.1109/SPAWC.2008.4641633","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641633","url":null,"abstract":"Interference management is one of effective means of improving system throughput, which is particularly important for the emerging 4G wireless networks that demand increasing data rates. In order to mitigate the inter-cell interference we evaluate the performance of an hierarchical centralized inter-cell scheduling method which aims at improving the system throughput. The proposed algorithm, which is based on an existing one, besides selecting the BSs allowed to transmit, performs an exhaustive power control in order to find the optimal power levels of transmitting BSs. Simulation results show that the proposed method outperforms classical approaches in terms of spectral efficiency improvements.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"34 1-2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131923676","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641684
F. Aounallah, R. Amara, M. Alouane
Distributed estimation is a major feature in wireless sensor networks (WSNs). Recently, hard quantized observations based on sign of innovation (SOI) were used to perform optimal distributed filtering involving thus the SOI Kalman filter (KF)/extended KF (EKF) [1]. In this paper, a SOI-particle filter (SOIPF) is derived to enhance the performance of the distributed estimation procedure. On one hand, the use of the particle filter avoids the imperative linearization in the EKF and on the other hand it guarantees a part of optimality for nonlinear/non Gaussian state models. The SOIPF proposed in this paper is applied in the target tracking context. The experimental results obtained for different simulations demonstrate the good tracking ability of the SOIPF compared to the SOIEKF as well as the consistency of the so given trajectory estimate.
{"title":"Particle filtering based on sign of innovation for distributed estimation in binary Wireless Sensor Networks","authors":"F. Aounallah, R. Amara, M. Alouane","doi":"10.1109/SPAWC.2008.4641684","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641684","url":null,"abstract":"Distributed estimation is a major feature in wireless sensor networks (WSNs). Recently, hard quantized observations based on sign of innovation (SOI) were used to perform optimal distributed filtering involving thus the SOI Kalman filter (KF)/extended KF (EKF) [1]. In this paper, a SOI-particle filter (SOIPF) is derived to enhance the performance of the distributed estimation procedure. On one hand, the use of the particle filter avoids the imperative linearization in the EKF and on the other hand it guarantees a part of optimality for nonlinear/non Gaussian state models. The SOIPF proposed in this paper is applied in the target tracking context. The experimental results obtained for different simulations demonstrate the good tracking ability of the SOIPF compared to the SOIEKF as well as the consistency of the so given trajectory estimate.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116449619","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641558
Jianfeng Hu, Tiejun Lv
In this paper, a low complexity blind synchronization algorithm is proposed for ultra wideband (UWB) communication systems in the multipath environment. Using the first order statistics of the received signal, the proposed algorithm is carried out without aided data. The synchronization parameter and nuisance ones are separated from each other on account of the structure of the Vandermonde matrix, and their estimates are obtained by one-dimensional searching according to the orthogonality among vectors. During the searching process, relative path delays and attenuations come out as by-products. Most importantly, the proposed algorithm has a very low complexity, because the computational requirements are determined mainly by simple additions and inner products among vectors. Simulations and comparisons are performed to illustrate the promising performance of the proposed algorithm.
{"title":"A low-complexity blind synchronization algorithm for UWB systems","authors":"Jianfeng Hu, Tiejun Lv","doi":"10.1109/SPAWC.2008.4641558","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641558","url":null,"abstract":"In this paper, a low complexity blind synchronization algorithm is proposed for ultra wideband (UWB) communication systems in the multipath environment. Using the first order statistics of the received signal, the proposed algorithm is carried out without aided data. The synchronization parameter and nuisance ones are separated from each other on account of the structure of the Vandermonde matrix, and their estimates are obtained by one-dimensional searching according to the orthogonality among vectors. During the searching process, relative path delays and attenuations come out as by-products. Most importantly, the proposed algorithm has a very low complexity, because the computational requirements are determined mainly by simple additions and inner products among vectors. Simulations and comparisons are performed to illustrate the promising performance of the proposed algorithm.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115347864","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641661
C. Medina, T. Vinhoza, R. Sampaio-Neto
In this paper we propose a blind adaptive channel estimator for multicarrier CDMA systems. The proposed algorithm is derived from the stochastic gradient solution for the linearly constrained minimum variance detector and it is shown to present lower computational complexity when compared to a well-known solution. It is shown through computer simulations that both the channel estimation and receiver filter achieve a slightly better performance than previously proposed methods.
{"title":"Reduced complexity blind channel estimation for adaptive constrained minimum variance receivers in MC-CDMA systems","authors":"C. Medina, T. Vinhoza, R. Sampaio-Neto","doi":"10.1109/SPAWC.2008.4641661","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641661","url":null,"abstract":"In this paper we propose a blind adaptive channel estimator for multicarrier CDMA systems. The proposed algorithm is derived from the stochastic gradient solution for the linearly constrained minimum variance detector and it is shown to present lower computational complexity when compared to a well-known solution. It is shown through computer simulations that both the channel estimation and receiver filter achieve a slightly better performance than previously proposed methods.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115764946","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641645
A. Agustin, J. Vidal
The half-duplex multiple relay-assisted channel is investigated, where the relays work under decode-and-forward (DF) in time/frequency orthogonal resources. Achievable rates are optimized with respect to the transmitted powers and with respect to the fraction of time/bandwidth allocated to the relay-receive and the relay-transmit phases. Different transmission strategies associated to different complexities at the receivers are considered. For each case we take into account either the synchronous or asynchronous transmission of the terminals, depending on the availability of channel state information (CSI) in transmission from all links. We find that all the cases can be formulated as a unique convex problem, and we compare the achievable rates thus obtained. We finally derive under which conditions the use of two DF relays brings significant gains over the use of one.
{"title":"Resource optimization in the decode-and-forward half-duplex multiple relay-assisted channel","authors":"A. Agustin, J. Vidal","doi":"10.1109/SPAWC.2008.4641645","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641645","url":null,"abstract":"The half-duplex multiple relay-assisted channel is investigated, where the relays work under decode-and-forward (DF) in time/frequency orthogonal resources. Achievable rates are optimized with respect to the transmitted powers and with respect to the fraction of time/bandwidth allocated to the relay-receive and the relay-transmit phases. Different transmission strategies associated to different complexities at the receivers are considered. For each case we take into account either the synchronous or asynchronous transmission of the terminals, depending on the availability of channel state information (CSI) in transmission from all links. We find that all the cases can be formulated as a unique convex problem, and we compare the achievable rates thus obtained. We finally derive under which conditions the use of two DF relays brings significant gains over the use of one.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121191023","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641675
M. Beko, J. Xavier, V. Barroso
The non-coherent single-user multiple-input multiple-output (MIMO) channel in the low signal-to-noise ratio (SNR) regime is analyzed from the capacity point of view. We investigate the impact of channel and noise correlation on the mutual information for the on-off and Gaussian signaling schemes. The novelty is that we allow an arbitrary structure for both the channel and noise correlation matrices. Our results establish that, in the low SNR regime, mutual information is maximized when the channel correlation matrix is of rank one.
{"title":"Low SNR analysis of the non-coherent MIMO channel under arbitrary channel and noise correlation structures","authors":"M. Beko, J. Xavier, V. Barroso","doi":"10.1109/SPAWC.2008.4641675","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641675","url":null,"abstract":"The non-coherent single-user multiple-input multiple-output (MIMO) channel in the low signal-to-noise ratio (SNR) regime is analyzed from the capacity point of view. We investigate the impact of channel and noise correlation on the mutual information for the on-off and Gaussian signaling schemes. The novelty is that we allow an arbitrary structure for both the channel and noise correlation matrices. Our results establish that, in the low SNR regime, mutual information is maximized when the channel correlation matrix is of rank one.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123534102","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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