Pub Date : 2014-06-22DOI: 10.1109/SPAWC.2014.6941597
Lennart Gerdes, L. Weiland, W. Utschick
In this paper, we consider the partial decode-and-forward (PDF) strategy for the Gaussian multiple-input multiple-output (MIMO) relay channel. The input distribution that maximizes the achievable PDF rate for this channel is still unknown in general. Therefore, it has so far only been possible to determine the maximum PDF rate if the best PDF strategy is equivalent to the decode-and-forward (DF) strategy, point-to-point (P2P) transmission from source to destination, or if PDF achieves the cut-set bound (CSB), i.e., for special cases where Gaussian channel inputs are known to be optimal. In this work, we exploit the properties of the generalized singular value decomposition (GSVD) to show that the maximum PDF rate for the Gaussian MIMO relay channel is also achieved by Gaussian inputs if the row spaces of the source-relay and the source-destination channel gain matrices are disjoint. Furthermore, we show that the optimal PDF rate can be determined as the solution of a convex optimization problem in that case.
{"title":"Optimal partial decode-and-forward rates for the Gaussian MIMO relay channel using the GSVD","authors":"Lennart Gerdes, L. Weiland, W. Utschick","doi":"10.1109/SPAWC.2014.6941597","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941597","url":null,"abstract":"In this paper, we consider the partial decode-and-forward (PDF) strategy for the Gaussian multiple-input multiple-output (MIMO) relay channel. The input distribution that maximizes the achievable PDF rate for this channel is still unknown in general. Therefore, it has so far only been possible to determine the maximum PDF rate if the best PDF strategy is equivalent to the decode-and-forward (DF) strategy, point-to-point (P2P) transmission from source to destination, or if PDF achieves the cut-set bound (CSB), i.e., for special cases where Gaussian channel inputs are known to be optimal. In this work, we exploit the properties of the generalized singular value decomposition (GSVD) to show that the maximum PDF rate for the Gaussian MIMO relay channel is also achieved by Gaussian inputs if the row spaces of the source-relay and the source-destination channel gain matrices are disjoint. Furthermore, we show that the optimal PDF rate can be determined as the solution of a convex optimization problem in that case.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117265506","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 : 2014-06-22DOI: 10.1109/SPAWC.2014.6941426
Zhi Chen, Teng Joon Lim, M. Motani
In this work, we consider a low-earth orbit (LEO) satellite communication system with a high-altitude platform (HAP) as a relay on the downlink. Both the satellite and the HAP are assumed to harvest solar energy to power their operations. The aim is to minimize the energy usage over one orbit, while delivering a given amount of information from the satellite. We first assume that the channel gains as well as the amount of harvested energy in each time slot are completely known at the beginning of each orbit. The associated energy-minimization problem for this non-causal case is formulated and solved. For the causal case where the amount of harvested energy is assumed to be known only up to the present transmission slot, a greedy algorithm for on-line scheduling is presented. Finally, we present numerical results to evaluate the performance of the proposed schemes.
{"title":"HAP-assisted LEO satellite downlink transmission: An energy harvesting perspective","authors":"Zhi Chen, Teng Joon Lim, M. Motani","doi":"10.1109/SPAWC.2014.6941426","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941426","url":null,"abstract":"In this work, we consider a low-earth orbit (LEO) satellite communication system with a high-altitude platform (HAP) as a relay on the downlink. Both the satellite and the HAP are assumed to harvest solar energy to power their operations. The aim is to minimize the energy usage over one orbit, while delivering a given amount of information from the satellite. We first assume that the channel gains as well as the amount of harvested energy in each time slot are completely known at the beginning of each orbit. The associated energy-minimization problem for this non-causal case is formulated and solved. For the causal case where the amount of harvested energy is assumed to be known only up to the present transmission slot, a greedy algorithm for on-line scheduling is presented. Finally, we present numerical results to evaluate the performance of the proposed schemes.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"111 3S 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134252200","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 : 2014-06-22DOI: 10.1109/SPAWC.2014.6941922
Reza Parseh, D. Slock, K. Kansanen
Uncoded transmission of a large dimensional Gauss-Markov vector process over a fading channel is considered. This problem is of interest in sensor network applications with data processing at the fusion center or in control and real-time monitoring where this method could be useful due to its simplicity and zero delay property. Assuming perfect channel knowledge at the receiver, the optimal estimator is the Kalman filter. In contrast to the classical Kalman filter, the prediction and estimation error covariance matrices are random. In this paper, by using Stieltjes transform analysis, we find an approximation to the pdf of the eigenvalue distribution of the estimation error covariance matrix for the high channel SNR regime. The approximated pdf is then used to obtain the mean estimation MSE of the Kalman filter.
{"title":"Mean estimation MSE for Kalman filtering of large dimensional sources sent over fading channels","authors":"Reza Parseh, D. Slock, K. Kansanen","doi":"10.1109/SPAWC.2014.6941922","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941922","url":null,"abstract":"Uncoded transmission of a large dimensional Gauss-Markov vector process over a fading channel is considered. This problem is of interest in sensor network applications with data processing at the fusion center or in control and real-time monitoring where this method could be useful due to its simplicity and zero delay property. Assuming perfect channel knowledge at the receiver, the optimal estimator is the Kalman filter. In contrast to the classical Kalman filter, the prediction and estimation error covariance matrices are random. In this paper, by using Stieltjes transform analysis, we find an approximation to the pdf of the eigenvalue distribution of the estimation error covariance matrix for the high channel SNR regime. The approximated pdf is then used to obtain the mean estimation MSE of the Kalman filter.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123064891","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 : 2014-06-22DOI: 10.1109/SPAWC.2014.6941881
A. Gholian, Yiming Ma, Y. Hua
Radio self-interference cancellation (SIC) is the fundamental enabler for full-duplex radios. While SIC methods based on baseband digital signal processing and/or beamforming are inadequate, an all-analog method is useful to drastically reduce the self-interference as the first stage of SIC. However, all-analog radio SIC has so far received very little academic attention in terms of its architectural design and performance limit. In this paper, we present such an early effort. We show that a recently used uniform architecture with uniformly distributed RF attenuators has a performance highly dependent on the carrier frequency. We also show that a new architecture with the attenuators distributed in a clustered fashion has important advantages over the uniform architecture. These advantages are shown numerically through random multipath interference channels, number of control bits in step attenuators, attenuation-dependent phases, single and multi-level structures, etc. These insights will be useful in guiding future hardware-based experiments.
{"title":"A numerical investigation of all-analog radio self-interference cancellation","authors":"A. Gholian, Yiming Ma, Y. Hua","doi":"10.1109/SPAWC.2014.6941881","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941881","url":null,"abstract":"Radio self-interference cancellation (SIC) is the fundamental enabler for full-duplex radios. While SIC methods based on baseband digital signal processing and/or beamforming are inadequate, an all-analog method is useful to drastically reduce the self-interference as the first stage of SIC. However, all-analog radio SIC has so far received very little academic attention in terms of its architectural design and performance limit. In this paper, we present such an early effort. We show that a recently used uniform architecture with uniformly distributed RF attenuators has a performance highly dependent on the carrier frequency. We also show that a new architecture with the attenuators distributed in a clustered fashion has important advantages over the uniform architecture. These advantages are shown numerically through random multipath interference channels, number of control bits in step attenuators, attenuation-dependent phases, single and multi-level structures, etc. These insights will be useful in guiding future hardware-based experiments.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122121956","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 : 2014-06-22DOI: 10.1109/SPAWC.2014.6941487
Shaofeng Zou, Yingbin Liang, H. V. Poor, Xinghua Shi
An anomaly detection problem is investigated, in which there are totally n sequences, with s anomalous sequences to be detected. Each normal sequence contains m independent and identically distributed (i.i.d.) samples drawn from a distribution p, whereas each anomalous sequence contains m i.i.d. samples drawn from a distribution q that is distinct from p. The distributions p and q are assumed to be unknown a priori. The scenario with a reference sequence generated by p is studied. Distribution-free tests are constructed using maximum mean discrepancy (MMD) as the metric, which is based on mean embeddings of distributions into a reproducing kernel Hilbert space (RKHS). It is shown that as the number n of sequences goes to infinity, if the value of s is known, then the number m of samples in each sequence should be of order O(log n) or larger in order for the developed tests to consistently detect s anomalous sequences. If the value of s is unknown, then m should be of order strictly larger than O(log n). The computational complexity of all developed tests is shown to be polynomial. Numerical results demonstrate that these new tests outperform (or perform as well as) tests based on other competitive traditional statistical approaches and kernel-based approaches under various cases.
{"title":"Kernel-based nonparametric anomaly detection","authors":"Shaofeng Zou, Yingbin Liang, H. V. Poor, Xinghua Shi","doi":"10.1109/SPAWC.2014.6941487","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941487","url":null,"abstract":"An anomaly detection problem is investigated, in which there are totally n sequences, with s anomalous sequences to be detected. Each normal sequence contains m independent and identically distributed (i.i.d.) samples drawn from a distribution p, whereas each anomalous sequence contains m i.i.d. samples drawn from a distribution q that is distinct from p. The distributions p and q are assumed to be unknown a priori. The scenario with a reference sequence generated by p is studied. Distribution-free tests are constructed using maximum mean discrepancy (MMD) as the metric, which is based on mean embeddings of distributions into a reproducing kernel Hilbert space (RKHS). It is shown that as the number n of sequences goes to infinity, if the value of s is known, then the number m of samples in each sequence should be of order O(log n) or larger in order for the developed tests to consistently detect s anomalous sequences. If the value of s is unknown, then m should be of order strictly larger than O(log n). The computational complexity of all developed tests is shown to be polynomial. Numerical results demonstrate that these new tests outperform (or perform as well as) tests based on other competitive traditional statistical approaches and kernel-based approaches under various cases.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128128860","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 : 2014-06-22DOI: 10.1109/SPAWC.2014.6941448
Ke Chen, J. Xin, Hao Tao, Nanning Zheng, A. Sano
In this paper, we investigate the number detection of a mixture of noncoherent and coherent signals impinging on a simple planar array consisting of two parallel uniform linear arrays (ULAs). Firstly, the numbers of noncoherent signals and coherent groups are obtained from the ranks of two outer-product matrices. Then a new oblique projector is obtained to suppress the noncoherent signals in the received array data and the number of coherent signals is obtained from the rank of another outer-product matrix which only contains the information of coherent signals. The number of noncoherent signals and that of coherent signals are estimated separately and the effectiveness of the proposed method is substantiated through numerical examples where the simulation results show that the proposed method performs well with a small number of snapshots and/or at relatively low signal-to-noise ratio (SNR).
{"title":"Detection of the number of noncoherent and coherent signals with a simple planar array","authors":"Ke Chen, J. Xin, Hao Tao, Nanning Zheng, A. Sano","doi":"10.1109/SPAWC.2014.6941448","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941448","url":null,"abstract":"In this paper, we investigate the number detection of a mixture of noncoherent and coherent signals impinging on a simple planar array consisting of two parallel uniform linear arrays (ULAs). Firstly, the numbers of noncoherent signals and coherent groups are obtained from the ranks of two outer-product matrices. Then a new oblique projector is obtained to suppress the noncoherent signals in the received array data and the number of coherent signals is obtained from the rank of another outer-product matrix which only contains the information of coherent signals. The number of noncoherent signals and that of coherent signals are estimated separately and the effectiveness of the proposed method is substantiated through numerical examples where the simulation results show that the proposed method performs well with a small number of snapshots and/or at relatively low signal-to-noise ratio (SNR).","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115262155","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 : 2014-06-22DOI: 10.1109/SPAWC.2014.6941726
Ahmad Beirami, Liling Huang, Mohsen Sardari, F. Fekri
Recently, we proposed a framework called memory-assisted compression that learns the statistical properties of the sequence-generating server at intermediate network nodes and then leverages the learnt models to overcome the inevitable redundancy (overhead) in the universal compression of the payloads of the short-length network packets. In this paper, we prove that when the content-generating server is comprised of a mixture of parametric sources, label-based clustering of the data to their original sequence-generating models from the mixture is optimal almost surely as it achieves the mixture entropy (which is the lower bound on the average codeword length). Motivated by this result, we present a K-means clustering technique as the proof of concept to demonstrate the benefits of memory-assisted compression performance. Simulation results confirm the effectiveness of the proposed approach by matching the expected improvements predicted by theory on man-made mixture sources. Finally, the benefits of the cluster-based memory-assisted compression are validated on real data traffic traces demonstrating more than 50% traffic reduction on average in data gathered from wireless users.
{"title":"On optimality of data clustering for packet-level memory-assisted compression of network traffic","authors":"Ahmad Beirami, Liling Huang, Mohsen Sardari, F. Fekri","doi":"10.1109/SPAWC.2014.6941726","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941726","url":null,"abstract":"Recently, we proposed a framework called memory-assisted compression that learns the statistical properties of the sequence-generating server at intermediate network nodes and then leverages the learnt models to overcome the inevitable redundancy (overhead) in the universal compression of the payloads of the short-length network packets. In this paper, we prove that when the content-generating server is comprised of a mixture of parametric sources, label-based clustering of the data to their original sequence-generating models from the mixture is optimal almost surely as it achieves the mixture entropy (which is the lower bound on the average codeword length). Motivated by this result, we present a K-means clustering technique as the proof of concept to demonstrate the benefits of memory-assisted compression performance. Simulation results confirm the effectiveness of the proposed approach by matching the expected improvements predicted by theory on man-made mixture sources. Finally, the benefits of the cluster-based memory-assisted compression are validated on real data traffic traces demonstrating more than 50% traffic reduction on average in data gathered from wireless users.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129744029","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 : 2014-06-01DOI: 10.1109/SPAWC.2014.6941318
Raphael Rolny, Celestine Mendler-Dünner, A. Wittneben
We consider a cellular network in which the base stations (BSs) are supported by a large amount of very low-complexity relays that are spread over the entire area, like a carpet. This carpet of relays enables massive antenna arrays and sophisticated multi-user MIMO transmission at the BSs, as they see only the static relays as the nodes they communicate with. On the other hand, the communication via the small relay cells allows to improve coverage and data rates by distributed signal processing. In order to control the residual interference caused by the massively deployed relay nodes, we apply power control to either minimize the transmit power at the BSs and relays required to achieve desired user rates, to maximize the minimum rate, or to minimize the outage probability. The proposed schemes are all of low complexity and show that the relay carpet is a promising concept for communication in future cellular networks.
{"title":"Power control for cellular networks with large antenna arrays and ubiquitous relaying","authors":"Raphael Rolny, Celestine Mendler-Dünner, A. Wittneben","doi":"10.1109/SPAWC.2014.6941318","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941318","url":null,"abstract":"We consider a cellular network in which the base stations (BSs) are supported by a large amount of very low-complexity relays that are spread over the entire area, like a carpet. This carpet of relays enables massive antenna arrays and sophisticated multi-user MIMO transmission at the BSs, as they see only the static relays as the nodes they communicate with. On the other hand, the communication via the small relay cells allows to improve coverage and data rates by distributed signal processing. In order to control the residual interference caused by the massively deployed relay nodes, we apply power control to either minimize the transmit power at the BSs and relays required to achieve desired user rates, to maximize the minimum rate, or to minimize the outage probability. The proposed schemes are all of low complexity and show that the relay carpet is a promising concept for communication in future cellular networks.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131187766","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 : 2014-04-20DOI: 10.1109/SPAWC.2014.6941329
C. Barati, S. A. Hosseini, S. Rangan, Pei Liu, T. Korakis, S. Panwar
Millimeter wave (mmW) bands between 30 and 300 GHz are considered a promising candidate for next-generation cellular networks to relieve spectral congestion in conventional cellular frequencies. However, cellular communication at these frequencies will likely require highly directional transmissions to achieve suitable signal range. This reliance on directional beamforming complicates initial cell search since the mobile and base station must jointly search over a potentially large angular directional space to locate a suitable path to initiate communication. This paper proposes a directional cell search procedure where each base station periodically transmits synchronization signals in randomly varying directions. Detectors are derived for this synchronization signal based on a Generalized Likelihood Ratio Test (GLRT) for the case where (i) the mobile has only analog beamforming (where the mobile can “look” in only direction at a time) and (ii) digital beamforming where the mobile has access to digital samples from all antennas. Simulations under realistic parameters demonstrate that mobiles may not be able to achieve suitable detection performance with analog beamforming alone. In contrast, digital beamforming offers dramatically better performance. We argue that the additional power consumption cost of digital beamforming can be offset by using very low quantization rates with minimal performance loss, thus arguing that low-rate fully digital front-ends may be a better design choice for directional cell search.
{"title":"Directional cell search for millimeter wave cellular systems","authors":"C. Barati, S. A. Hosseini, S. Rangan, Pei Liu, T. Korakis, S. Panwar","doi":"10.1109/SPAWC.2014.6941329","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941329","url":null,"abstract":"Millimeter wave (mmW) bands between 30 and 300 GHz are considered a promising candidate for next-generation cellular networks to relieve spectral congestion in conventional cellular frequencies. However, cellular communication at these frequencies will likely require highly directional transmissions to achieve suitable signal range. This reliance on directional beamforming complicates initial cell search since the mobile and base station must jointly search over a potentially large angular directional space to locate a suitable path to initiate communication. This paper proposes a directional cell search procedure where each base station periodically transmits synchronization signals in randomly varying directions. Detectors are derived for this synchronization signal based on a Generalized Likelihood Ratio Test (GLRT) for the case where (i) the mobile has only analog beamforming (where the mobile can “look” in only direction at a time) and (ii) digital beamforming where the mobile has access to digital samples from all antennas. Simulations under realistic parameters demonstrate that mobiles may not be able to achieve suitable detection performance with analog beamforming alone. In contrast, digital beamforming offers dramatically better performance. We argue that the additional power consumption cost of digital beamforming can be offset by using very low quantization rates with minimal performance loss, thus arguing that low-rate fully digital front-ends may be a better design choice for directional cell search.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133235209","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 : 2013-09-25DOI: 10.1109/SPAWC.2014.6941617
A. Nasir, H. Mehrpouyan, S. Durrani, S. Blostein, R. Kennedy
Two-way relaying networks (TWRNs) allow for more bandwidth efficient use of the available spectrum since they allow for simultaneous information exchange between two users with the assistance of an intermediate relay node. However, due to superposition of signals at the relay node, the received signal at the user terminals is affected by multiple impairments, i.e., channel gains, timing offsets, and carrier frequency offsets, that need to be jointly estimated and compensated. This paper presents a training-based system model for amplify-and-forward (AF) TWRNs in the presence of multiple impairments and proposes maximum likelihood and differential evolution based algorithms for joint estimation of these impairments. The Cramér-Rao lower bounds (CRLBs) for the joint estimation of multiple impairments are derived. A minimum mean-square error based receiver is then proposed to compensate the effect of multiple impairments and decode each user's signal. Simulation results show that the performance of the proposed estimators is very close to the derived CRLBs at moderate-to-high signal-to-noise-ratios. It is also shown that the bit-error rate performance of the overall AF TWRN is close to a TWRN that is based on assumption of perfect knowledge of the synchronization parameters.
{"title":"Training-based synchronization and channel estimation in AF two-way relaying networks","authors":"A. Nasir, H. Mehrpouyan, S. Durrani, S. Blostein, R. Kennedy","doi":"10.1109/SPAWC.2014.6941617","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941617","url":null,"abstract":"Two-way relaying networks (TWRNs) allow for more bandwidth efficient use of the available spectrum since they allow for simultaneous information exchange between two users with the assistance of an intermediate relay node. However, due to superposition of signals at the relay node, the received signal at the user terminals is affected by multiple impairments, i.e., channel gains, timing offsets, and carrier frequency offsets, that need to be jointly estimated and compensated. This paper presents a training-based system model for amplify-and-forward (AF) TWRNs in the presence of multiple impairments and proposes maximum likelihood and differential evolution based algorithms for joint estimation of these impairments. The Cramér-Rao lower bounds (CRLBs) for the joint estimation of multiple impairments are derived. A minimum mean-square error based receiver is then proposed to compensate the effect of multiple impairments and decode each user's signal. Simulation results show that the performance of the proposed estimators is very close to the derived CRLBs at moderate-to-high signal-to-noise-ratios. It is also shown that the bit-error rate performance of the overall AF TWRN is close to a TWRN that is based on assumption of perfect knowledge of the synchronization parameters.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130449259","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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