Pub Date : 2015-12-03DOI: 10.1109/PIMRC.2015.7343272
Md. Sakir Hossain, T. Shimamura
Peak to Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) is a long-standing problem which has been hindering its performance for decades. In this paper, we propose a new PAPR reduction scheme based on shifting pilot locations among the data symbols. Since no side information is sent to the receiver about the pilot locations, a novel pilot detection algorithm is devised exploiting the pilot power and the relative constant distance property of pilots. The proposed scheme attains around 2 dB PAPR reduction. The pilot detection accuracy is shown to be very excellent ranging from 80% to 99% at 0 dB of Signal to Noise Ratio (SNR) in different parameters. This scheme is very spectrally efficient with reduced complexity without degrading BER performance significantly.
{"title":"PAPR reduction of OFDM through pilot shifting","authors":"Md. Sakir Hossain, T. Shimamura","doi":"10.1109/PIMRC.2015.7343272","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343272","url":null,"abstract":"Peak to Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) is a long-standing problem which has been hindering its performance for decades. In this paper, we propose a new PAPR reduction scheme based on shifting pilot locations among the data symbols. Since no side information is sent to the receiver about the pilot locations, a novel pilot detection algorithm is devised exploiting the pilot power and the relative constant distance property of pilots. The proposed scheme attains around 2 dB PAPR reduction. The pilot detection accuracy is shown to be very excellent ranging from 80% to 99% at 0 dB of Signal to Noise Ratio (SNR) in different parameters. This scheme is very spectrally efficient with reduced complexity without degrading BER performance significantly.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133386453","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343513
N. Shibata, K. Miyamoto, S. Kuwano, J. Terada, A. Otaka
In this paper, the system level performance of uplink transmission in the split-PHY processing (SPP) architecture is evaluated. The SPP architecture splits the PHY functions of the base station so that some PHY functions are implemented on the remote radio head (RRH). Compared to the centralized radio access network (C-RAN) architecture with common public radio interface (CPRI), the SPP architecture significantly reduces the required optical bandwidth in the mobile front-haul. Moreover, by implementing the FEC processing in the baseband unit (BBU), joint reception can be realized in uplink transmissions by forwarding the quantized log likelihood ratio (LLR) from RRHs to the BBU. System level evaluations show that the SPP architecture improves the cell-edge user throughput by 116 % compared with the MAC-PHY split architecture without coordinated operations while reducing the required optical bandwidth by 92 % compared with the C-RAN architecture.
{"title":"System level performance of uplink transmission in split-PHY processing architecture with joint reception for future radio access","authors":"N. Shibata, K. Miyamoto, S. Kuwano, J. Terada, A. Otaka","doi":"10.1109/PIMRC.2015.7343513","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343513","url":null,"abstract":"In this paper, the system level performance of uplink transmission in the split-PHY processing (SPP) architecture is evaluated. The SPP architecture splits the PHY functions of the base station so that some PHY functions are implemented on the remote radio head (RRH). Compared to the centralized radio access network (C-RAN) architecture with common public radio interface (CPRI), the SPP architecture significantly reduces the required optical bandwidth in the mobile front-haul. Moreover, by implementing the FEC processing in the baseband unit (BBU), joint reception can be realized in uplink transmissions by forwarding the quantized log likelihood ratio (LLR) from RRHs to the BBU. System level evaluations show that the SPP architecture improves the cell-edge user throughput by 116 % compared with the MAC-PHY split architecture without coordinated operations while reducing the required optical bandwidth by 92 % compared with the C-RAN architecture.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114983140","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343523
Xiang Wang, Wenjun Xu, Shengyu Li, Jiaru Lin
In this paper, we focus on whether and how the quality-of-service (QoS) requirements can be guaranteed in radio frequency (RF)-harvesting-powered cognitive orthogonal frequency division multiplexing (OFDM) relay systems, where the available energy is extremely limited by power transfer capability, and the available spectrum is greatly restricted by primary networks. Thus, the joint power splitting ratio, subcarrier assignment and power allocation problem is formulated under the interference constraints and QoS requirements. In addition, in order to maximize the capacity of the secondary network, an optimal power splitting and resource allocation scheme is proposed based on dual decomposition as well as time sharing conditions. Simulation results show that the proposed scheme can perfectly satisfy the QoS requirements in spite of limited energy and spectrum, and outperforms conventional methods in terms of capacity and QoS satisfaction.
{"title":"Joint power splitting and resource allocation with QoS guarantees in RF-harvesting-powered cognitive OFDM relay systems","authors":"Xiang Wang, Wenjun Xu, Shengyu Li, Jiaru Lin","doi":"10.1109/PIMRC.2015.7343523","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343523","url":null,"abstract":"In this paper, we focus on whether and how the quality-of-service (QoS) requirements can be guaranteed in radio frequency (RF)-harvesting-powered cognitive orthogonal frequency division multiplexing (OFDM) relay systems, where the available energy is extremely limited by power transfer capability, and the available spectrum is greatly restricted by primary networks. Thus, the joint power splitting ratio, subcarrier assignment and power allocation problem is formulated under the interference constraints and QoS requirements. In addition, in order to maximize the capacity of the secondary network, an optimal power splitting and resource allocation scheme is proposed based on dual decomposition as well as time sharing conditions. Simulation results show that the proposed scheme can perfectly satisfy the QoS requirements in spite of limited energy and spectrum, and outperforms conventional methods in terms of capacity and QoS satisfaction.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116763802","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343352
Kyeongyeon Kim, Y. Yun, Chanhong Kim, Z. Ho, Yong-Ho Cho, J. Seol
As a promising candidate to replace cyclic prefixed orthogonal frequency division multiplexing (CP-OFDM), a new quadrature amplitude modulation filter-bank multi-carrier (QAM-FBMC) has been proposed for enabling spectral efficiency increase and spectrum confinement while keeping near orthogonality. QAM transmission can combat intrinsic interference of conventional offset-QAM (OQAM)-FBMC, which is main bottleneck in channel estimator and multiple antenna transceiver design. Compared to existing single filter based QAM-FBMC, the new QAM-FBMC has more optimization freedom in multiple prototype filters to increase self signal-to-interference ratio (SIR). In this paper, the possibility of per-tone multiple input multiple output (MIMO) reception in the new QAM-FBMC system is exploited. Our MIMO receiver is constructed with per-tone MIMO equalization in oversampled signal domain and its soft-demapper in symbol domain. Not only the separate log likelihood ratio (LLR) calculation per stream but also joint LLR calculation (i.e., soft maximum likelihood (ML) detection) is implemented with pre-processing. Simulation results show that the per-tone MIMO reception in QAM-FBMC is comparable to that of CP-OFDM.
{"title":"Pre-processing based soft-demapper for per-tone MIMO operation in QAM-FBMC systems","authors":"Kyeongyeon Kim, Y. Yun, Chanhong Kim, Z. Ho, Yong-Ho Cho, J. Seol","doi":"10.1109/PIMRC.2015.7343352","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343352","url":null,"abstract":"As a promising candidate to replace cyclic prefixed orthogonal frequency division multiplexing (CP-OFDM), a new quadrature amplitude modulation filter-bank multi-carrier (QAM-FBMC) has been proposed for enabling spectral efficiency increase and spectrum confinement while keeping near orthogonality. QAM transmission can combat intrinsic interference of conventional offset-QAM (OQAM)-FBMC, which is main bottleneck in channel estimator and multiple antenna transceiver design. Compared to existing single filter based QAM-FBMC, the new QAM-FBMC has more optimization freedom in multiple prototype filters to increase self signal-to-interference ratio (SIR). In this paper, the possibility of per-tone multiple input multiple output (MIMO) reception in the new QAM-FBMC system is exploited. Our MIMO receiver is constructed with per-tone MIMO equalization in oversampled signal domain and its soft-demapper in symbol domain. Not only the separate log likelihood ratio (LLR) calculation per stream but also joint LLR calculation (i.e., soft maximum likelihood (ML) detection) is implemented with pre-processing. Simulation results show that the per-tone MIMO reception in QAM-FBMC is comparable to that of CP-OFDM.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115322179","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343277
Mohammed Almoneer, C. Rohde, K. Hassan, W. Gerstacker
Linear pilot-aided channel estimation in orthogonal-frequency division multiplexing (OFDM) systems is carried out optimally via 2D Wiener filters. The standard approach employed in conventional receivers is based on cascaded 2×1D Wiener filtering, which has a lower complexity but also suboptimal performance. The 2D+1D filtering scheme proposed in this paper combines the benefits of the two other schemes and is not affected by some restrictions of 2×1D filtering as shown by theoretical analysis of such schemes. For comparison, the mean-squared error (MSE) performance of the different channel estimation schemes is evaluated. Based on this analysis, results from full link-level simulations w.r.t. the digital video broadcasting standard for satellite services to handheld devices (DVB-SH) are presented applying adaptive channel estimation algorithms instead of the Wiener filters. The novel 2D+1D scheme shows enhanced bit error rate (BER) performance since it provides more accurate channel estimates in high Doppler channel conditions compared to the conventional cascaded 2×1D schemes.
{"title":"Robust 2D+1D adaptive channel estimation scheme in OFDM systems","authors":"Mohammed Almoneer, C. Rohde, K. Hassan, W. Gerstacker","doi":"10.1109/PIMRC.2015.7343277","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343277","url":null,"abstract":"Linear pilot-aided channel estimation in orthogonal-frequency division multiplexing (OFDM) systems is carried out optimally via 2D Wiener filters. The standard approach employed in conventional receivers is based on cascaded 2×1D Wiener filtering, which has a lower complexity but also suboptimal performance. The 2D+1D filtering scheme proposed in this paper combines the benefits of the two other schemes and is not affected by some restrictions of 2×1D filtering as shown by theoretical analysis of such schemes. For comparison, the mean-squared error (MSE) performance of the different channel estimation schemes is evaluated. Based on this analysis, results from full link-level simulations w.r.t. the digital video broadcasting standard for satellite services to handheld devices (DVB-SH) are presented applying adaptive channel estimation algorithms instead of the Wiener filters. The novel 2D+1D scheme shows enhanced bit error rate (BER) performance since it provides more accurate channel estimates in high Doppler channel conditions compared to the conventional cascaded 2×1D schemes.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114724706","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}
Two-path cancellation schemes have attracted much attention due to its effectiveness in suppressing intercarrier interference (ICI) in orthogonal frequency division multiplexing (OFDM) systems. In this paper, we derive the exact closed-form expressions of the signal-to-interference-plus-noise ratio for two-path cancellation schemes in multipath fading channels as well as their upper bounds, which are much simpler to formulate yet tight enough to provide useful insight. By properly approximating the residual ICI as Gaussian process, we further derive the closed-form expressions of bit error rate (BER) for an uncoded OFDM system with QPSK modulation in multipath fading channels. More importantly, the derived BER expressions take into account the important phase rotation effect. Monte-Carlo simulations are conducted to validate our analyses and derivations.
{"title":"Performance analysis of two-path transmission technique for intercarrier interference cancellation in OFDM systems","authors":"Weiqiang Pan, Yingzheng Han, Guoqiang Deng, Peijun Zhong","doi":"10.1109/PIMRC.2015.7343268","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343268","url":null,"abstract":"Two-path cancellation schemes have attracted much attention due to its effectiveness in suppressing intercarrier interference (ICI) in orthogonal frequency division multiplexing (OFDM) systems. In this paper, we derive the exact closed-form expressions of the signal-to-interference-plus-noise ratio for two-path cancellation schemes in multipath fading channels as well as their upper bounds, which are much simpler to formulate yet tight enough to provide useful insight. By properly approximating the residual ICI as Gaussian process, we further derive the closed-form expressions of bit error rate (BER) for an uncoded OFDM system with QPSK modulation in multipath fading channels. More importantly, the derived BER expressions take into account the important phase rotation effect. Monte-Carlo simulations are conducted to validate our analyses and derivations.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123853861","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343465
Jing Wang, Yan Zhang, Hui Hui, Ningbo Zhang
With the widespread application of wireless networks and the requirements of different user equipments (UEs), energy has become a scarcer resource as well as spectrum. In this paper, considering the actual scenarios of imperfect channel state information (CSI), we study a resource allocation scheme in the downlink orthogonal frequency division multiple access (OFDMA) systems. To balance between energy efficiency (EE) and proportional fairness (PF), the problem is formulated as maximizing average achievable EE with the constraints of PF of users and QoS assurance. To solve the optimal problem, we divide it into two layers. The sub-problem P1 of inner layer is solved to maximize PF, with the parameter of total transmit power which is updated by the sub-problem P2 of outer layer. In outer layer, with the allocation scheme from P1, a gradient-based adaptation resource allocation algorithm is proposed to achieve the maximum EE with total transmit power updated in every gradient iteration. Moreover, the impacts of the imperfect CSI on EE and PF are analysed. Simulation results are presented to show the superior performance of the proposed algorithms and verify the analytical findings.
{"title":"QoS-aware proportional fair energy-efficient resource allocation with imperfect CSI in downlink OFDMA systems","authors":"Jing Wang, Yan Zhang, Hui Hui, Ningbo Zhang","doi":"10.1109/PIMRC.2015.7343465","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343465","url":null,"abstract":"With the widespread application of wireless networks and the requirements of different user equipments (UEs), energy has become a scarcer resource as well as spectrum. In this paper, considering the actual scenarios of imperfect channel state information (CSI), we study a resource allocation scheme in the downlink orthogonal frequency division multiple access (OFDMA) systems. To balance between energy efficiency (EE) and proportional fairness (PF), the problem is formulated as maximizing average achievable EE with the constraints of PF of users and QoS assurance. To solve the optimal problem, we divide it into two layers. The sub-problem P1 of inner layer is solved to maximize PF, with the parameter of total transmit power which is updated by the sub-problem P2 of outer layer. In outer layer, with the allocation scheme from P1, a gradient-based adaptation resource allocation algorithm is proposed to achieve the maximum EE with total transmit power updated in every gradient iteration. Moreover, the impacts of the imperfect CSI on EE and PF are analysed. Simulation results are presented to show the superior performance of the proposed algorithms and verify the analytical findings.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124423375","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343319
Yi Wang, Wenting Song, Yongming Huang, Chunguo Li, Shidang Li, Luxi Yang
This paper considers a downlink massive MIMO frequency division duplexing (FDD) system. Due to the large number of antennas, the required length of training sequence for downlink training significantly increases in FDD mode, which leads to prohibitive overhead in real system. Thus, in this work we investigate how the length of training sequence affects the system performance. For this purpose, we derive an analytical expression of the ergodic achievable rate from a worst case viewpoint with the the training sequence length as a parameter in it. It is revealed from the analytical results that i.) the length of training sequence divided by the number of base station antennas approaches to zero yet the achievable rate can increase to infinity as long as the antenna number is sufficient large; ii.) there is a ceiling effect on the achievable rate if the antenna number grows large with any fixed training length. Furthermore, we propose a guideline for the selection of the training length. Numerical results validate the derivations and analysis.
{"title":"Effects of the length of training sequence on the achievable rate in FDD massive MIMO system","authors":"Yi Wang, Wenting Song, Yongming Huang, Chunguo Li, Shidang Li, Luxi Yang","doi":"10.1109/PIMRC.2015.7343319","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343319","url":null,"abstract":"This paper considers a downlink massive MIMO frequency division duplexing (FDD) system. Due to the large number of antennas, the required length of training sequence for downlink training significantly increases in FDD mode, which leads to prohibitive overhead in real system. Thus, in this work we investigate how the length of training sequence affects the system performance. For this purpose, we derive an analytical expression of the ergodic achievable rate from a worst case viewpoint with the the training sequence length as a parameter in it. It is revealed from the analytical results that i.) the length of training sequence divided by the number of base station antennas approaches to zero yet the achievable rate can increase to infinity as long as the antenna number is sufficient large; ii.) there is a ceiling effect on the achievable rate if the antenna number grows large with any fixed training length. Furthermore, we propose a guideline for the selection of the training length. Numerical results validate the derivations and analysis.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121599689","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343600
Sébastien Auroux, H. Karl
The growing number of network mechanisms results in a large amount of data flow processing to be performed in future wireless access networks. Determining suitable locations for data processing in a network is important for a good network performance but also a non-trivial task as data processing imposes many requirements on network resources. Further, data flows and network load generally change over time, possibly very quickly, so that a static, one-time placement is not an adequate solution. Hence, a framework that determines these locations should also flexibly reassign them over time. We address this need by a flexible flow processing-aware controller placement framework (FlexFCPF), which places and flexibly reassigns controller devices that are able to perform both network control (conventional SDN) and data flow processing for an efficient management of future wireless networks. We have developed and implemented a fast heuristic framework and we prove its efficiency by providing evaluation results of FlexFCPF's performance in a dynamic network simulation.
{"title":"Flexible reassignment of flow processing-aware controllers in future wireless networks","authors":"Sébastien Auroux, H. Karl","doi":"10.1109/PIMRC.2015.7343600","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343600","url":null,"abstract":"The growing number of network mechanisms results in a large amount of data flow processing to be performed in future wireless access networks. Determining suitable locations for data processing in a network is important for a good network performance but also a non-trivial task as data processing imposes many requirements on network resources. Further, data flows and network load generally change over time, possibly very quickly, so that a static, one-time placement is not an adequate solution. Hence, a framework that determines these locations should also flexibly reassign them over time. We address this need by a flexible flow processing-aware controller placement framework (FlexFCPF), which places and flexibly reassigns controller devices that are able to perform both network control (conventional SDN) and data flow processing for an efficient management of future wireless networks. We have developed and implemented a fast heuristic framework and we prove its efficiency by providing evaluation results of FlexFCPF's performance in a dynamic network simulation.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120839087","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 : 2015-12-03DOI: 10.1109/PIMRC.2015.7343276
P. Aggarwal, Anubha Gupta, V. Bohara
IEEE 802.11p standard is a wireless vehicular communication standard meant for outdoor applications. This standard suffers from the challenge of robust channel estimation due to rapid time-varying nature of the channel This paper proposes a novel scheme of channel estimation by utilizing the guard interval of every orthogonal frequency division multiplexing (OFDM) symbol. For a typical vehicular wireless communication where the channel fades quite rapidly, inter-symbol-interference (ISI) may not be as significant a problem as time varying nature of the channel due to Doppler effect. Hence, the proposed scheme utilizes the redundant space of guard interval (GI) (other than that required for cyclic prefix (CP) to combat ISI) to insert pseudo-random sequence (PRS)for channel estimation. A decision-directed time-domain least squares channel estimation method is proposed using the inserted PRS with CP. Simulation results show that the proposed scheme can considerably improve the bit error rate (BER) performance compared to the existing techniques.
{"title":"A guard interval assisted OFDM symbol-based channel estimation for rapid time-varying scenarios in IEEE 802.lip","authors":"P. Aggarwal, Anubha Gupta, V. Bohara","doi":"10.1109/PIMRC.2015.7343276","DOIUrl":"https://doi.org/10.1109/PIMRC.2015.7343276","url":null,"abstract":"IEEE 802.11p standard is a wireless vehicular communication standard meant for outdoor applications. This standard suffers from the challenge of robust channel estimation due to rapid time-varying nature of the channel This paper proposes a novel scheme of channel estimation by utilizing the guard interval of every orthogonal frequency division multiplexing (OFDM) symbol. For a typical vehicular wireless communication where the channel fades quite rapidly, inter-symbol-interference (ISI) may not be as significant a problem as time varying nature of the channel due to Doppler effect. Hence, the proposed scheme utilizes the redundant space of guard interval (GI) (other than that required for cyclic prefix (CP) to combat ISI) to insert pseudo-random sequence (PRS)for channel estimation. A decision-directed time-domain least squares channel estimation method is proposed using the inserted PRS with CP. Simulation results show that the proposed scheme can considerably improve the bit error rate (BER) performance compared to the existing techniques.","PeriodicalId":274734,"journal":{"name":"2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128457714","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：