Pub Date : 2015-04-27DOI: 10.1109/ICT.2015.7124665
S. Rostami, K. Arshad, P. Rapajic
Carrier aggregation has been introduced by 3rd Generation Partnership project (3GPP) in order to meet the IMT-Advanced requirements. Using carrier aggregation, multiple component carriers with a different bandwidth, dispersed within intra or inter bands can be simultaneously utilised to provide higher data rates, better coverage and lower latency resulting a better user experience. However, carrier aggregation functionality requires modification to the radio resource management function of the network. In this paper, we propose an efficient resource allocation and link adaptation algorithm to support carrier aggregation functionality for downlink 5G LTE-Advanced (LTE-A) network. We consider a non-guaranteed bit rate bearers (best effort traffic), which can be used for non realtime applications such as file downloads. Most of the existing work considered resource allocation, component carrier selection and link adaptation as separate problems. We define a joint radio resource management problem with carrier aggregation functionality and propose a sub-optimal solution with a low computational complexity. Simulation results show clearly that our algorithm outperforms state-of-the-art algorithms.
{"title":"A joint resource allocation and link adaptation algorithm with carrier aggregation for 5G LTE-Advanced network","authors":"S. Rostami, K. Arshad, P. Rapajic","doi":"10.1109/ICT.2015.7124665","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124665","url":null,"abstract":"Carrier aggregation has been introduced by 3rd Generation Partnership project (3GPP) in order to meet the IMT-Advanced requirements. Using carrier aggregation, multiple component carriers with a different bandwidth, dispersed within intra or inter bands can be simultaneously utilised to provide higher data rates, better coverage and lower latency resulting a better user experience. However, carrier aggregation functionality requires modification to the radio resource management function of the network. In this paper, we propose an efficient resource allocation and link adaptation algorithm to support carrier aggregation functionality for downlink 5G LTE-Advanced (LTE-A) network. We consider a non-guaranteed bit rate bearers (best effort traffic), which can be used for non realtime applications such as file downloads. Most of the existing work considered resource allocation, component carrier selection and link adaptation as separate problems. We define a joint radio resource management problem with carrier aggregation functionality and propose a sub-optimal solution with a low computational complexity. Simulation results show clearly that our algorithm outperforms state-of-the-art algorithms.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116902317","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124719
Zhang Siyu, W. Muqing, Lin Xiangli
In this paper, the measurements of 2 × 2 MIMO channel were performed at 2.6 GHz with 20 MHz bandwidth along the Harbin-Dalian passenger dedicated railway line. To improve the accuracy of multipath searching, we propose a multipath components (MCPs) extraction method based on this measurement, using the statistical properties of the data to reduce dependence on certain specific parameter. Numerical analyses of small and large scale parameter fading characteristics in hilly terrain scenarios are presented such as channel impulse response (OR), power delay profile (PDP), time delay spread, Doppler spread, path loss and shadow fading which are significant to the study of wireless channel modeling in specific scenario applied in LTE-R system. All these analyses promote the verification and evaluation of wireless wideband communications on LTE-R system in high speed railway.
{"title":"Results and analysis based on a novel LTE-R channel measurement at 2.6 GHz","authors":"Zhang Siyu, W. Muqing, Lin Xiangli","doi":"10.1109/ICT.2015.7124719","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124719","url":null,"abstract":"In this paper, the measurements of 2 × 2 MIMO channel were performed at 2.6 GHz with 20 MHz bandwidth along the Harbin-Dalian passenger dedicated railway line. To improve the accuracy of multipath searching, we propose a multipath components (MCPs) extraction method based on this measurement, using the statistical properties of the data to reduce dependence on certain specific parameter. Numerical analyses of small and large scale parameter fading characteristics in hilly terrain scenarios are presented such as channel impulse response (OR), power delay profile (PDP), time delay spread, Doppler spread, path loss and shadow fading which are significant to the study of wireless channel modeling in specific scenario applied in LTE-R system. All these analyses promote the verification and evaluation of wireless wideband communications on LTE-R system in high speed railway.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123547559","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124704
Dong Chen, J. Khan, Jason Brown
Energy constrained devices, operating on short-range wireless networking standards such as IEEE802.15.4 and IEEE802.11x, are expected to be deployed for the IoT (Internet of Things) applications. However, co-located deployment of such devices based on different standards using the same 2.4 GHz license free Industrial, Scientific and Medical (ISM) spectrum, introduces coexistence issues, specifically intra-and inter cluster interference. The latter would create a much more adverse impact on these devices than the former, resulting in significant performance degradation. To overcome this problem, we propose a novel area packet scheduler that allows co-located 802.15.4 and 802.11 devices to share the transmission channel and coexist with minimal inter-cluster interference any inter cluster interference. A new OPNET simulation model was developed to evaluate the performance of this scheduler. Simulation results show that the packet scheduler can mitigate the coexistence problem while maintaining high throughput and low end-to-end delay, thereby increasing the overall network QoS.
能源受限的设备，运行在短距离无线网络标准，如IEEE802.15.4和IEEE802.11x，预计将部署在物联网(Internet of Things)应用。但是，基于不同的标准，使用相同的2.4 GHz免许可证工业、科学和医疗(ISM)频谱，在同一地点部署此类设备，会引入共存问题，特别是集群内部和集群间的干扰。后者将对这些设备产生比前者更不利的影响，导致显著的性能下降。为了克服这个问题，我们提出了一种新的区域分组调度程序，它允许位于同一位置的802.15.4和802.11设备共享传输通道，并以最小的集群间干扰共存。建立了一个新的OPNET仿真模型来评估该调度程序的性能。仿真结果表明，该数据包调度程序能够在保持高吞吐量和低端到端延迟的同时缓解共存问题，从而提高整个网络的QoS。
{"title":"An area packet scheduler to mitigate coexistence issues in a WPAN/WLAN based hetergeneous network","authors":"Dong Chen, J. Khan, Jason Brown","doi":"10.1109/ICT.2015.7124704","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124704","url":null,"abstract":"Energy constrained devices, operating on short-range wireless networking standards such as IEEE802.15.4 and IEEE802.11x, are expected to be deployed for the IoT (Internet of Things) applications. However, co-located deployment of such devices based on different standards using the same 2.4 GHz license free Industrial, Scientific and Medical (ISM) spectrum, introduces coexistence issues, specifically intra-and inter cluster interference. The latter would create a much more adverse impact on these devices than the former, resulting in significant performance degradation. To overcome this problem, we propose a novel area packet scheduler that allows co-located 802.15.4 and 802.11 devices to share the transmission channel and coexist with minimal inter-cluster interference any inter cluster interference. A new OPNET simulation model was developed to evaluate the performance of this scheduler. Simulation results show that the packet scheduler can mitigate the coexistence problem while maintaining high throughput and low end-to-end delay, thereby increasing the overall network QoS.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122462536","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124659
R. Hunjet
Wireless network capacity has been studied extensively in the literature. Due to its dependence on traffic profile there are many variations in how the capacity of a wireless network is defined. The traffic profile is heavily influenced by the MAC layer, and in a CSMA implementation, RTS and CTS messaging rules dictate which nodes are able to transmit to others and when. In this manner the RTS/CTS protocol directly affects the capacity of the network. This paper proposes a modification to the CTS transmission range in the RTS/CTS protocol. It is shown that selection of an appropriate range is critical, with ranges too small or too large inhibiting capacity gains. Use of an appropriate range was found to provide an average increase in network capacity of between 18%-30% depending on the network size. A multi-objective optimisation is performed to show that adjusting the transmission powers of existing nodes and appropriately placing additional nodes within the network can increase these capacity gains further and introduce substantial power savings to the network.
{"title":"A capacity enhancing modification to RTS/CTS","authors":"R. Hunjet","doi":"10.1109/ICT.2015.7124659","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124659","url":null,"abstract":"Wireless network capacity has been studied extensively in the literature. Due to its dependence on traffic profile there are many variations in how the capacity of a wireless network is defined. The traffic profile is heavily influenced by the MAC layer, and in a CSMA implementation, RTS and CTS messaging rules dictate which nodes are able to transmit to others and when. In this manner the RTS/CTS protocol directly affects the capacity of the network. This paper proposes a modification to the CTS transmission range in the RTS/CTS protocol. It is shown that selection of an appropriate range is critical, with ranges too small or too large inhibiting capacity gains. Use of an appropriate range was found to provide an average increase in network capacity of between 18%-30% depending on the network size. A multi-objective optimisation is performed to show that adjusting the transmission powers of existing nodes and appropriately placing additional nodes within the network can increase these capacity gains further and introduce substantial power savings to the network.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124591590","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124697
Sanjeeb Shrestha, Gengfa Fang, E. Dutkiewicz, Xiaojing Huang
This paper focuses on the Medium Access Control (MAC) layer design for an inevitable Hidden Terminal problem in Multi User Multiple Input Multiple Output (MU-MIMO) Wireless Local Area Networks (WLANs). Specifically, our MAC design is supported by the precoding vectors obtained by Zeroforcing technique which are used to address the Hidden Terminals. An efficient channel sounding process is used by our MAC protocol to obtain the Channel State Information (CSI) from the desired and undesired clients which are used to calculate the precoding vectors at the transmitters (Access Points). Our MAC design then uses these precoding vectors in order to null interferences among the undesired clients to avoid collision of signals and to maintain the concurrent transmissions among the desired clients. The the parameters such as network capacity, signaling overheads and fairness are considered in the design. Our MAC layer design shows a slightly higher signaling overhead compared to RTS/CTS scheme. However, due to the concurrent transmissions after the handshaking process, the cost of singling overheads are compensated. The simulation study of our MAC layer design shows a remarkable constant network capacity gain of 4-5 times in comparison to traditional RTS/CTS. Moreover, the gain is irrespective to the available air-time.
{"title":"Zeroforcing precoding based MAC design to address hidden terminals in MU-MIMO WLANs","authors":"Sanjeeb Shrestha, Gengfa Fang, E. Dutkiewicz, Xiaojing Huang","doi":"10.1109/ICT.2015.7124697","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124697","url":null,"abstract":"This paper focuses on the Medium Access Control (MAC) layer design for an inevitable Hidden Terminal problem in Multi User Multiple Input Multiple Output (MU-MIMO) Wireless Local Area Networks (WLANs). Specifically, our MAC design is supported by the precoding vectors obtained by Zeroforcing technique which are used to address the Hidden Terminals. An efficient channel sounding process is used by our MAC protocol to obtain the Channel State Information (CSI) from the desired and undesired clients which are used to calculate the precoding vectors at the transmitters (Access Points). Our MAC design then uses these precoding vectors in order to null interferences among the undesired clients to avoid collision of signals and to maintain the concurrent transmissions among the desired clients. The the parameters such as network capacity, signaling overheads and fairness are considered in the design. Our MAC layer design shows a slightly higher signaling overhead compared to RTS/CTS scheme. However, due to the concurrent transmissions after the handshaking process, the cost of singling overheads are compensated. The simulation study of our MAC layer design shows a remarkable constant network capacity gain of 4-5 times in comparison to traditional RTS/CTS. Moreover, the gain is irrespective to the available air-time.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126700358","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124688
A. Omri, M. Hasna
In this paper, a cooperative communication scheme with inter-relay interference (IRI) cancellation is proposed for wireless multi-user multi-decode-and-forward (DF) relay networks. The scheme is based on a DF half-duplex (HD) relaying protocol and a relay selection method which maximizes the signal-to-noise ratio (SNR) of the second hop. To enhance the spectral efficiency and cancel the IRI, the proposed scheme (constellation real part (CRP)) uses a new virtual full-duplex relaying protocol based on the constellation real parts of the modulated signals and the two-path successive relay scheme. To assess the performance, we derive the expressions of the outage probability, and the average bit error rate (BER) for the CRP scheme. Simulations are used to validate the analytical expressions. The results confirm the advantage of the proposed scheme in enhancing the performance of wireless cooperative networks.
{"title":"Inter-relay interference cancellation for wireless multi-user multi-decode-and-forward relay networks","authors":"A. Omri, M. Hasna","doi":"10.1109/ICT.2015.7124688","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124688","url":null,"abstract":"In this paper, a cooperative communication scheme with inter-relay interference (IRI) cancellation is proposed for wireless multi-user multi-decode-and-forward (DF) relay networks. The scheme is based on a DF half-duplex (HD) relaying protocol and a relay selection method which maximizes the signal-to-noise ratio (SNR) of the second hop. To enhance the spectral efficiency and cancel the IRI, the proposed scheme (constellation real part (CRP)) uses a new virtual full-duplex relaying protocol based on the constellation real parts of the modulated signals and the two-path successive relay scheme. To assess the performance, we derive the expressions of the outage probability, and the average bit error rate (BER) for the CRP scheme. Simulations are used to validate the analytical expressions. The results confirm the advantage of the proposed scheme in enhancing the performance of wireless cooperative networks.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130120390","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124650
Rui Wu, Wenbin Guo, Feifei Wang
Cognitive Radio is utilized to exploit the existing wireless spectrum opportunistically, in which way to alleviate the spectrum shortage problem. It is of fundamental importance in cognitive radio adhoc networks for users to meet on a common channel via rendezvous and thereby establish communication links. In this paper, we investigate the probability analytic model to discuss the problem of rendezvous. Furthermore, a resulting Channel-Grouping based algorithm is proposed for decentralized rendezvous. The basic idea of the algorithm is to divide all channels into small sets, reducing the number of selectable channels in each round and thus improving the probability of successful rendezvous. Extensive simulations show that our proposed algorithm outperforms the other rendezvous schemes.
{"title":"Channel-Grouping based rendezvous algorithm for cognitive radio adhoc networks","authors":"Rui Wu, Wenbin Guo, Feifei Wang","doi":"10.1109/ICT.2015.7124650","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124650","url":null,"abstract":"Cognitive Radio is utilized to exploit the existing wireless spectrum opportunistically, in which way to alleviate the spectrum shortage problem. It is of fundamental importance in cognitive radio adhoc networks for users to meet on a common channel via rendezvous and thereby establish communication links. In this paper, we investigate the probability analytic model to discuss the problem of rendezvous. Furthermore, a resulting Channel-Grouping based algorithm is proposed for decentralized rendezvous. The basic idea of the algorithm is to divide all channels into small sets, reducing the number of selectable channels in each round and thus improving the probability of successful rendezvous. Extensive simulations show that our proposed algorithm outperforms the other rendezvous schemes.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128835720","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124673
Linyun Huang, Y. Hong, E. Viterbo
In many communications systems, the Gaussian mixture model is extensively used to characterize non-Gaussian man-made and natural interference. We study the capacity of the Gaussian mixture noise channel and its capacity-achieving input. In particular, we consider the symmetric and asymmetric Gaussian mixture noise cases. It is shown that, under average and peak power constraints, the capacity-achieving input is discrete with finitely many mass points. Furthermore, some properties of the capacity-achieving distribution are proved and demonstrated by simulations.
{"title":"On the capacity of the Gaussian mixture channel under average and peak power constraints","authors":"Linyun Huang, Y. Hong, E. Viterbo","doi":"10.1109/ICT.2015.7124673","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124673","url":null,"abstract":"In many communications systems, the Gaussian mixture model is extensively used to characterize non-Gaussian man-made and natural interference. We study the capacity of the Gaussian mixture noise channel and its capacity-achieving input. In particular, we consider the symmetric and asymmetric Gaussian mixture noise cases. It is shown that, under average and peak power constraints, the capacity-achieving input is discrete with finitely many mass points. Furthermore, some properties of the capacity-achieving distribution are proved and demonstrated by simulations.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127871839","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124653
Ou Bai, Gaoli Bi
In this paper, a novel opportunistic protocol is proposed for the two-way relaying systems with direct link. Unlike the existing protocols, the proposed protocol opportunistically exploits analog network coding and the direct link. The proposed protocol switches its strategies to support two traffic flows simultaneously or support only one traffic flow based on instantaneous channel conditions. An extremely tight lower bound of the outage probability is derived, which reveals that full diversity order two is achieved by the proposed protocol. It is demonstrated that the proposed protocol outperforms the existing protocols which also utilize the direct link in the two-way relaying systems in terms of both outage probability and sum-rate. In addition, it is indicated that the proposed protocol has a better outage performance than the analog network network coding (ANC) protocol and larger sum-rate than the opportunistic source selection (OSS) protocol.
{"title":"An opportunistic protocol for two-way relaying systems with direct link","authors":"Ou Bai, Gaoli Bi","doi":"10.1109/ICT.2015.7124653","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124653","url":null,"abstract":"In this paper, a novel opportunistic protocol is proposed for the two-way relaying systems with direct link. Unlike the existing protocols, the proposed protocol opportunistically exploits analog network coding and the direct link. The proposed protocol switches its strategies to support two traffic flows simultaneously or support only one traffic flow based on instantaneous channel conditions. An extremely tight lower bound of the outage probability is derived, which reveals that full diversity order two is achieved by the proposed protocol. It is demonstrated that the proposed protocol outperforms the existing protocols which also utilize the direct link in the two-way relaying systems in terms of both outage probability and sum-rate. In addition, it is indicated that the proposed protocol has a better outage performance than the analog network network coding (ANC) protocol and larger sum-rate than the opportunistic source selection (OSS) protocol.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115871500","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 : 2015-04-27DOI: 10.1109/ICT.2015.7124712
Tanairat Mata, Mio Hourai, K. Mori, Hideo Kobayashi, P. Boonsrimuang
Orthogonal Frequency Division Multiple Access (OFDMA) is considered as one of promising wireless access techniques which can accommodate multiple users flexibly and efficiently. In the uplink OFDMA system, it is required to estimate all users' channel frequency responses (CFRs) simultaneously which are used in the equalization for the data information at the base station (BS). To realize this requirement, the Discrete Fourier Transform interpolation based channel estimation (DFTI-CE) method was proposed in which all users transmit one scattered pilot symbol to the BS at the same time. The DFTI-CE method can achieve higher estimation accuracy for all users' CFRs only when the number of FFT points is equal to the number of data subcarriers which corresponds to the Nyquist rate. However the CFR estimation accuracy would be degraded in the actual OFDM system at the non-Nyquist rate in which null subcarriers (zero padding) are added at both ends of OFDM data subcarrier to reject the aliasing occurring at the output of digital to analogue (D/A) converter. To solve this problem, this paper proposes a time domain channel estimation (TD-CE) method which can achieve higher estimation accuracy even at the non-Nyquist rate. This paper presents various simulation results for the uplink OFDMA system in the time-varying fading channels to demonstrate the effectiveness of proposed estimation method.
{"title":"Time domain channel estimation method for uplink OFDMA system","authors":"Tanairat Mata, Mio Hourai, K. Mori, Hideo Kobayashi, P. Boonsrimuang","doi":"10.1109/ICT.2015.7124712","DOIUrl":"https://doi.org/10.1109/ICT.2015.7124712","url":null,"abstract":"Orthogonal Frequency Division Multiple Access (OFDMA) is considered as one of promising wireless access techniques which can accommodate multiple users flexibly and efficiently. In the uplink OFDMA system, it is required to estimate all users' channel frequency responses (CFRs) simultaneously which are used in the equalization for the data information at the base station (BS). To realize this requirement, the Discrete Fourier Transform interpolation based channel estimation (DFTI-CE) method was proposed in which all users transmit one scattered pilot symbol to the BS at the same time. The DFTI-CE method can achieve higher estimation accuracy for all users' CFRs only when the number of FFT points is equal to the number of data subcarriers which corresponds to the Nyquist rate. However the CFR estimation accuracy would be degraded in the actual OFDM system at the non-Nyquist rate in which null subcarriers (zero padding) are added at both ends of OFDM data subcarrier to reject the aliasing occurring at the output of digital to analogue (D/A) converter. To solve this problem, this paper proposes a time domain channel estimation (TD-CE) method which can achieve higher estimation accuracy even at the non-Nyquist rate. This paper presents various simulation results for the uplink OFDMA system in the time-varying fading channels to demonstrate the effectiveness of proposed estimation method.","PeriodicalId":375669,"journal":{"name":"2015 22nd International Conference on Telecommunications (ICT)","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114839072","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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