Pub Date : 2014-06-22DOI: 10.1109/SPAWC.2014.6941324
Lina Bariah, S. Muhaidat, A. Al-Dweik
Cooperative diversity is a transmission technique that utilizes distributed relays to improve power and spectral efficiencies by creating virtual a antenna arrays. A major challenge in cooperative systems is the time varying nature and the frequency selectivity of cooperative links. In this paper, we propose a novel technique to enhance the bit error rate (BER) performance of cooperative transmission systems with space-frequency block coded (SFBC) orthogonal frequency division multiplexing (OFDM). We assume the Amplify-and-Forward (AF) protocol jointly with the cooperative transmission protocol in. The proposed scheme eliminates the error floor caused by the difference in frequency response of the channel over two adjacent subcarriers due to the channel frequency-selectivity. Extensive Monte Carlo simulation results show that the system can reduce the BER error floor as compared to the conventional cooperative SFBC-OFDM systems.
{"title":"Efficient SFBC-OFDM technique for broadband cooperative wireless networks over mobile channels","authors":"Lina Bariah, S. Muhaidat, A. Al-Dweik","doi":"10.1109/SPAWC.2014.6941324","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941324","url":null,"abstract":"Cooperative diversity is a transmission technique that utilizes distributed relays to improve power and spectral efficiencies by creating virtual a antenna arrays. A major challenge in cooperative systems is the time varying nature and the frequency selectivity of cooperative links. In this paper, we propose a novel technique to enhance the bit error rate (BER) performance of cooperative transmission systems with space-frequency block coded (SFBC) orthogonal frequency division multiplexing (OFDM). We assume the Amplify-and-Forward (AF) protocol jointly with the cooperative transmission protocol in. The proposed scheme eliminates the error floor caused by the difference in frequency response of the channel over two adjacent subcarriers due to the channel frequency-selectivity. Extensive Monte Carlo simulation results show that the system can reduce the BER error floor as compared to the conventional cooperative SFBC-OFDM systems.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"304 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":"124332107","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.2014.6941550
Yingxiao Zhang, Y. Zhang
The revolutionary Cloud Radio Access Network (C-RAN) enables real-time physical-layer coordination over a large number of distributed remote radio heads (RRHs). Connected via high-bandwidth low-latency optics, RRHs can cooperate dynamically and seamlessly according to user locations or traffic loads. Without limitations on the RRH cooperation, the traditional cellular structure that associates mobile users with cells centered around base stations (or RRHs in C-RAN) needs to be revamped. This paper proposes a novel concept, namely, user-centric virtual cell, to associate each mobile user with a set of cooperative RRHs. In particular, a virtual cell is configured with a mobile user at the cell center and its serving RRHs located in a circular area around the user.With this concept, we are interested in the optimal radius of virtual cells that maximizes the system downlink capacity. In contrast to previous works, the active RRHs in CRAN not only cluster around mobile users, but also have correlated transmit powers due to efficient power allocation. We first characterize the distribution of the interference based on the mean and variance. We then apply the results to obtain the optimal cell radius and discuss its dependence on various system parameters such as user separation distance, RRH density, etc. Our work here provides an important guideline to the cell plan of C-RAN in future 5G wireless networks.
{"title":"User-centric virtual cell design for Cloud Radio Access Networks","authors":"Yingxiao Zhang, Y. Zhang","doi":"10.1109/SPAWC.2014.6941550","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941550","url":null,"abstract":"The revolutionary Cloud Radio Access Network (C-RAN) enables real-time physical-layer coordination over a large number of distributed remote radio heads (RRHs). Connected via high-bandwidth low-latency optics, RRHs can cooperate dynamically and seamlessly according to user locations or traffic loads. Without limitations on the RRH cooperation, the traditional cellular structure that associates mobile users with cells centered around base stations (or RRHs in C-RAN) needs to be revamped. This paper proposes a novel concept, namely, user-centric virtual cell, to associate each mobile user with a set of cooperative RRHs. In particular, a virtual cell is configured with a mobile user at the cell center and its serving RRHs located in a circular area around the user.With this concept, we are interested in the optimal radius of virtual cells that maximizes the system downlink capacity. In contrast to previous works, the active RRHs in CRAN not only cluster around mobile users, but also have correlated transmit powers due to efficient power allocation. We first characterize the distribution of the interference based on the mean and variance. We then apply the results to obtain the optimal cell radius and discuss its dependence on various system parameters such as user separation distance, RRH density, etc. Our work here provides an important guideline to the cell plan of C-RAN in future 5G wireless networks.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"29 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":"121290751","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.2014.6941337
V. Savic, E. Larsson, J. Ferrer-Coll, P. Stenumgaard
Accurate positioning in harsh environments can enable many application, such as search-and-rescue in emergency situations. For this problem, ultra-wideband (UWB) technology can provide the most accurate range estimates, which are required for range-based positioning. However, it still faces a problem in non-line-of-sight (NLOS) environments, in which range estimates based on time-of-arrival (TOA) are positively biased. There are many techniques that try to address this problem, mainly based on NLOS identification and NLOS error mitigation. However, these techniques do not exploit all available information from the UWB channel impulse response. In this paper, we propose a novel ranging technique based on kernel principal component analysis (kPCA), in which the selected channel parameters are projected onto nonlinear orthogonal high-dimensional space, and a subset of these projections is then used for ranging. We tested this technique using UWB measurements obtained in a basement tunnel of Linköping university, and found that it provides much better ranging performance comparing with standard techniques based on PCA and TOA.
{"title":"Kernel principal component analysis for UWB-based ranging","authors":"V. Savic, E. Larsson, J. Ferrer-Coll, P. Stenumgaard","doi":"10.1109/SPAWC.2014.6941337","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941337","url":null,"abstract":"Accurate positioning in harsh environments can enable many application, such as search-and-rescue in emergency situations. For this problem, ultra-wideband (UWB) technology can provide the most accurate range estimates, which are required for range-based positioning. However, it still faces a problem in non-line-of-sight (NLOS) environments, in which range estimates based on time-of-arrival (TOA) are positively biased. There are many techniques that try to address this problem, mainly based on NLOS identification and NLOS error mitigation. However, these techniques do not exploit all available information from the UWB channel impulse response. In this paper, we propose a novel ranging technique based on kernel principal component analysis (kPCA), in which the selected channel parameters are projected onto nonlinear orthogonal high-dimensional space, and a subset of these projections is then used for ranging. We tested this technique using UWB measurements obtained in a basement tunnel of Linköping university, and found that it provides much better ranging performance comparing with standard techniques based on PCA and TOA.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"5 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":"128737323","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.2014.6941321
J. Brady, A. Sayeed
Through orders-of-magnitude larger bandwidths and small wavelengths that enable high-dimensional multiple-input multiple-output (MIMO) operation, millimeter-wave (mm-wave) systems operating from 30-300 GHz provide a unique opportunity for meeting the exploding capacity demands on wireless networks. Previously, the performance of multiuser MIMO (MU-MIMO) precoders that exploit the concept of beamspace MIMO (B-MIMO) communication - multiplexing data onto orthogonal spatial beams - was explored for access points (APs) equipped with n-dimensional uniform linear arrays (ULAs). It was shown that APs using reduced complexity B-MIMO transceivers achieve near-optimal performance with complexity that tracks the number of mobile stations (MSs). In this paper we explore the application of the reduced complexity B-MIMO transceivers to APs equipped with uniform planar arrays (UPAs) serving small cells. First, we apply B-MIMO theory to develop a framework for analyzing the small cell in terms of the orthogonal beam footprints. We then examine the effect of several parameters on the system performance and demonstrate that the low-complexity transceivers enable 1000s of Gigabit/s aggregate rates in mm-wave small cells serving hundreds of MSs.
{"title":"Beamspace MU-MIMO for high-density gigabit small cell access at millimeter-wave frequencies","authors":"J. Brady, A. Sayeed","doi":"10.1109/SPAWC.2014.6941321","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941321","url":null,"abstract":"Through orders-of-magnitude larger bandwidths and small wavelengths that enable high-dimensional multiple-input multiple-output (MIMO) operation, millimeter-wave (mm-wave) systems operating from 30-300 GHz provide a unique opportunity for meeting the exploding capacity demands on wireless networks. Previously, the performance of multiuser MIMO (MU-MIMO) precoders that exploit the concept of beamspace MIMO (B-MIMO) communication - multiplexing data onto orthogonal spatial beams - was explored for access points (APs) equipped with n-dimensional uniform linear arrays (ULAs). It was shown that APs using reduced complexity B-MIMO transceivers achieve near-optimal performance with complexity that tracks the number of mobile stations (MSs). In this paper we explore the application of the reduced complexity B-MIMO transceivers to APs equipped with uniform planar arrays (UPAs) serving small cells. First, we apply B-MIMO theory to develop a framework for analyzing the small cell in terms of the orthogonal beam footprints. We then examine the effect of several parameters on the system performance and demonstrate that the low-complexity transceivers enable 1000s of Gigabit/s aggregate rates in mm-wave small cells serving hundreds of MSs.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"39 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":"115878599","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.2014.6941325
B. Su
In this paper, we study subspace-based (SS) methods for blind and semiblind channel estimation in OFDM systems with virtual carriers (VC) using few received received symbols. The methods work in both zero-padded (ZP) and cyclic-prefixed (CP) guard interval types, based on viewing the employment of VCs as precoding of the data matrix using a rank-deficient precoder whose columns represent polynomials that have a common divisor with a degree equal to the number of VCs. The proposed method is the first subspace method to work in CP-OFDM systems with VCs using a less-than-block-size number of received symbols. Simulation results demonstrated the effectiveness of the proposed methods.
{"title":"Subspace-based blind and semiblind channel estimation in OFDM systems with virtual carriers using few received symbols","authors":"B. Su","doi":"10.1109/SPAWC.2014.6941325","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941325","url":null,"abstract":"In this paper, we study subspace-based (SS) methods for blind and semiblind channel estimation in OFDM systems with virtual carriers (VC) using few received received symbols. The methods work in both zero-padded (ZP) and cyclic-prefixed (CP) guard interval types, based on viewing the employment of VCs as precoding of the data matrix using a rank-deficient precoder whose columns represent polynomials that have a common divisor with a degree equal to the number of VCs. The proposed method is the first subspace method to work in CP-OFDM systems with VCs using a less-than-block-size number of received symbols. Simulation results demonstrated the effectiveness of the proposed methods.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"28 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":"117274814","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.2014.6941350
Lishuai Jing, T. Pedersen, B. Fleury
OFDM ranging is becoming important for positioning using terrestrial wireless networks. Conventional ranging methods rely on a two-step approach: range related parameters, such as the time of arrival (TOA), the bias induced by non-line-of-sight (NLOS) propagations etc., are first estimated, based on which the range is then inferred. In multi-path conditions, two-step range estimators which employ the correlator-based estimator or the energy detector lead to poor ranging accuracy when applied in non-ultra-wideband scenarios due to bias. More advanced ranging schemes that estimate all multi-path components using a multidimensional search procedure provide higher ranging accuracy but have a prohibitive complexity. In this work, we propose a novel direct ranging technique that uses a point process formulated channel model. Based on this model, we derive an approximate maximum likelihood estimator of the range. In contrast to the estimator which requires a multidimensional search procedure, the proposed estimator does not demand the knowledge of the exact number of multi-path components and these components are separable. If the power delay spectrum of the multi-path channel and the signal-to-noise-ratio (SNR) are known, the complexity of the proposed estimator is tractable. We show by means of Monte Carlo simulations that this estimator outperforms the correlator-based estimator.
{"title":"Direct ranging in multi-path channels using OFDM pilot signals","authors":"Lishuai Jing, T. Pedersen, B. Fleury","doi":"10.1109/SPAWC.2014.6941350","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941350","url":null,"abstract":"OFDM ranging is becoming important for positioning using terrestrial wireless networks. Conventional ranging methods rely on a two-step approach: range related parameters, such as the time of arrival (TOA), the bias induced by non-line-of-sight (NLOS) propagations etc., are first estimated, based on which the range is then inferred. In multi-path conditions, two-step range estimators which employ the correlator-based estimator or the energy detector lead to poor ranging accuracy when applied in non-ultra-wideband scenarios due to bias. More advanced ranging schemes that estimate all multi-path components using a multidimensional search procedure provide higher ranging accuracy but have a prohibitive complexity. In this work, we propose a novel direct ranging technique that uses a point process formulated channel model. Based on this model, we derive an approximate maximum likelihood estimator of the range. In contrast to the estimator which requires a multidimensional search procedure, the proposed estimator does not demand the knowledge of the exact number of multi-path components and these components are separable. If the power delay spectrum of the multi-path channel and the signal-to-noise-ratio (SNR) are known, the complexity of the proposed estimator is tractable. We show by means of Monte Carlo simulations that this estimator outperforms the correlator-based estimator.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"6 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":"127119796","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.2014.6941671
Y. Fouad, R. Gohary, H. Yanikomeroglu
In future cellular networks, self-organizing relaying terminals (RTs) are expected to play a crucial role in assisting the communication between base stations and wireless terminals (WTs), which include, not only active user terminals, but also machine-type communication devices. In the absence of channel quality indicators, the effective utilization of RTs requires a mechanism by which these RTs can assign available resource blocks (RBs) to a potentially large number of WTs with minimal conflicts. This requires optimizing RB assignments over a large set of lengthy sequences, which is computationally prohibitive for networks with large numbers of RTs. To alleviate the difficulty in designing such sequences, we develop a greedy algorithm, whereby pairs of RB assignment sequences are selected in an efficient sequential manner. The performance of the sequences generated by this algorithm is comparable to that of the sequences generated by exhaustive search, but with a significantly less computational cost.
{"title":"An efficient greedy-based autonomous resource block assignment scheme for 5G cellular networks with self-organizing relaying terminals","authors":"Y. Fouad, R. Gohary, H. Yanikomeroglu","doi":"10.1109/SPAWC.2014.6941671","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941671","url":null,"abstract":"In future cellular networks, self-organizing relaying terminals (RTs) are expected to play a crucial role in assisting the communication between base stations and wireless terminals (WTs), which include, not only active user terminals, but also machine-type communication devices. In the absence of channel quality indicators, the effective utilization of RTs requires a mechanism by which these RTs can assign available resource blocks (RBs) to a potentially large number of WTs with minimal conflicts. This requires optimizing RB assignments over a large set of lengthy sequences, which is computationally prohibitive for networks with large numbers of RTs. To alleviate the difficulty in designing such sequences, we develop a greedy algorithm, whereby pairs of RB assignment sequences are selected in an efficient sequential manner. The performance of the sequences generated by this algorithm is comparable to that of the sequences generated by exhaustive search, but with a significantly less computational cost.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"41 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":"122735271","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.2014.6941333
S. Shakeri, G. Leus
In this work, a new fingerprinting-based localization algorithm is proposed for an underwater medium by utilizing ultra-wideband (UWB) signals. In many conventional underwater systems, localization is accomplished by utilizing acoustic waves. On the other hand, electromagnetic waves haven't been employed for underwater localization due to the high attenuation of the signal in water. However, it is possible to use UWB signals for short-range underwater localization. In this work, the feasibility of performing localization for an underwater medium is illustrated by utilizing a fingerprinting-based localization approach. By employing the concept of compressive sampling, we propose a sparsity-based localization method for which we define a system model exploiting the spatial sparsity.
{"title":"Underwater ultra-wideband fingerprinting-based sparse localization","authors":"S. Shakeri, G. Leus","doi":"10.1109/SPAWC.2014.6941333","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941333","url":null,"abstract":"In this work, a new fingerprinting-based localization algorithm is proposed for an underwater medium by utilizing ultra-wideband (UWB) signals. In many conventional underwater systems, localization is accomplished by utilizing acoustic waves. On the other hand, electromagnetic waves haven't been employed for underwater localization due to the high attenuation of the signal in water. However, it is possible to use UWB signals for short-range underwater localization. In this work, the feasibility of performing localization for an underwater medium is illustrated by utilizing a fingerprinting-based localization approach. By employing the concept of compressive sampling, we propose a sparsity-based localization method for which we define a system model exploiting the spatial sparsity.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"27 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":"114794473","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.2014.6941789
A. Cirik, Jianshu Zhang, M. Haardt, Y. Hua
We consider a full-duplex bi-directional communication between two nodes that suffer from self-interference, where the nodes are equipped with multiple antennas. We focus on the effect of a residual self-interference due to independent and identically distributed (i.i.d.) channel estimation errors and limited dynamic ranges of the transmitters and receivers. We consider the design of source covariance matrices at the nodes for sum-rate maximization problem subject to multiple generalized linear constraints. The non-convex sum-rate optimization problem is solved using two sup-optimal techniques, which are proven to converge to a local optimum point. These algorithms exploit both spatial and temporal freedoms of the source covariance matrices of the multiple-input multiple-output (MIMO) links between the nodes to achieve higher sum-rate.
{"title":"Sum-rate maximization for bi-directional full-duplex MIMO systems under multiple linear constraints","authors":"A. Cirik, Jianshu Zhang, M. Haardt, Y. Hua","doi":"10.1109/SPAWC.2014.6941789","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941789","url":null,"abstract":"We consider a full-duplex bi-directional communication between two nodes that suffer from self-interference, where the nodes are equipped with multiple antennas. We focus on the effect of a residual self-interference due to independent and identically distributed (i.i.d.) channel estimation errors and limited dynamic ranges of the transmitters and receivers. We consider the design of source covariance matrices at the nodes for sum-rate maximization problem subject to multiple generalized linear constraints. The non-convex sum-rate optimization problem is solved using two sup-optimal techniques, which are proven to converge to a local optimum point. These algorithms exploit both spatial and temporal freedoms of the source covariance matrices of the multiple-input multiple-output (MIMO) links between the nodes to achieve higher sum-rate.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"204 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":"132741739","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.2014.6941803
Le Zhang, S. Valaee
In order for the large-scale realization of vehicular networks to be feasible, the problem of congestion control must be addressed to ensure the reliability of safety applications. The latter rely on single-hop broadcasts of safety packets in the control channel to acquire up-to-date knowledge of the local neighbourhood. However, high transmission ranges of onboard radios and the highly dynamic mobility of vehicles may result in fast-forming pockets of high node density in the network. Subsequently, the excessive load caused by safety packets broadcasts may degrade the network performance and subsequently reduce the level safety provided by applications. Existing congestion control schemes in the literature aim to reach a fair rationing of available channel resources throughout the network. However, a particular vehicle, depending on its distance and relative velocity with respect to its neighbours may require less or more network resources than another vehicle to achieve the same level of safety benefit. We examine the problem of adapting the probability of transmission of each node under a slotted p-persistent vehicular broadcast medium access control (MAC) scheme. A network utility maximization (NUM) problem is formulated, in which utility incorporates both the expected delay and a notion of safety benefit. A distributed algorithm is proposed to solve this problem in a decentralized manner and its performance is studied through simulations.
{"title":"Safety context-aware congestion control for vehicular broadcast networks","authors":"Le Zhang, S. Valaee","doi":"10.1109/SPAWC.2014.6941803","DOIUrl":"https://doi.org/10.1109/SPAWC.2014.6941803","url":null,"abstract":"In order for the large-scale realization of vehicular networks to be feasible, the problem of congestion control must be addressed to ensure the reliability of safety applications. The latter rely on single-hop broadcasts of safety packets in the control channel to acquire up-to-date knowledge of the local neighbourhood. However, high transmission ranges of onboard radios and the highly dynamic mobility of vehicles may result in fast-forming pockets of high node density in the network. Subsequently, the excessive load caused by safety packets broadcasts may degrade the network performance and subsequently reduce the level safety provided by applications. Existing congestion control schemes in the literature aim to reach a fair rationing of available channel resources throughout the network. However, a particular vehicle, depending on its distance and relative velocity with respect to its neighbours may require less or more network resources than another vehicle to achieve the same level of safety benefit. We examine the problem of adapting the probability of transmission of each node under a slotted p-persistent vehicular broadcast medium access control (MAC) scheme. A network utility maximization (NUM) problem is formulated, in which utility incorporates both the expected delay and a notion of safety benefit. A distributed algorithm is proposed to solve this problem in a decentralized manner and its performance is studied through simulations.","PeriodicalId":420837,"journal":{"name":"2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)","volume":"45 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":"133241924","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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