Pub Date : 2009-10-08DOI: 10.1109/APCC.2009.5375678
Wenhui Zong, Sen Shao, Qing-min Meng, Weiping Zhu
In this paper, we consider underlay cognitive radio systems in which secondary users coexist with users in primary networks whose radio band is licensed. The secondary subnetwork comprising the cognitive users utilizes the cognitive radio technology to make opportunistic access to the licensed spectrum that primary users own. In this scheme, we discuss the issue of joint user scheduling and beamforming in order to make sure that received interferences at the primary users maintain below an affordable threshold level. The user scheduling includes two procedures: 1)primary users scheduling; 2)secondary users scheduling. However, these two steps are carried out coordinately and the selected primary user and corresponding cognitive users can be obtained. In addition, Zero-forcing Beamforming (ZFBF) and antenna selection are integrated into our scheme where the former is used to support multiple concurrent streams transmission and the latter is used to reduce the feedback in the uplink of the secondary system. Our performance results show that the proposed scheme can significantly improve the throughput of the whole cognitive radio networks.
{"title":"Joint user scheduling and beamforming for underlay cognitive radio systems","authors":"Wenhui Zong, Sen Shao, Qing-min Meng, Weiping Zhu","doi":"10.1109/APCC.2009.5375678","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375678","url":null,"abstract":"In this paper, we consider underlay cognitive radio systems in which secondary users coexist with users in primary networks whose radio band is licensed. The secondary subnetwork comprising the cognitive users utilizes the cognitive radio technology to make opportunistic access to the licensed spectrum that primary users own. In this scheme, we discuss the issue of joint user scheduling and beamforming in order to make sure that received interferences at the primary users maintain below an affordable threshold level. The user scheduling includes two procedures: 1)primary users scheduling; 2)secondary users scheduling. However, these two steps are carried out coordinately and the selected primary user and corresponding cognitive users can be obtained. In addition, Zero-forcing Beamforming (ZFBF) and antenna selection are integrated into our scheme where the former is used to support multiple concurrent streams transmission and the latter is used to reduce the feedback in the uplink of the secondary system. Our performance results show that the proposed scheme can significantly improve the throughput of the whole cognitive radio networks.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"320 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132138730","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375700
Jing Zhang, Hongbo Zhu, Yan Cai
Mutual coupling effect affects capacity of compact MIMO system. Using scattering parameter matrix (S-Matrix), this paper analyzes capacity of compact MIMO system and makes simulations on capacity using three different structural antenna arrays and three matching networks. Numerical results based on method of moment (MOM) show that antenna space with half wavelength is the dividing point of tightly coupling and loose coupling. Polarization pattern and matching network can change the impact of coupling effect on capacity. Furthermore it indicates that multiport conjugate (MC) matching network is the best to reduce mutual coupling effect as well as enhance capacity of compact MIMO system. As to the antenna array, cross polarization does help to improve the capacity of compact MIMO system.
{"title":"Capacity analysis of compact MIMO system","authors":"Jing Zhang, Hongbo Zhu, Yan Cai","doi":"10.1109/APCC.2009.5375700","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375700","url":null,"abstract":"Mutual coupling effect affects capacity of compact MIMO system. Using scattering parameter matrix (S-Matrix), this paper analyzes capacity of compact MIMO system and makes simulations on capacity using three different structural antenna arrays and three matching networks. Numerical results based on method of moment (MOM) show that antenna space with half wavelength is the dividing point of tightly coupling and loose coupling. Polarization pattern and matching network can change the impact of coupling effect on capacity. Furthermore it indicates that multiport conjugate (MC) matching network is the best to reduce mutual coupling effect as well as enhance capacity of compact MIMO system. As to the antenna array, cross polarization does help to improve the capacity of compact MIMO system.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"288 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131855971","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375693
Lianghua Wu, Yuzhuo Fu, Liang Dong
In this paper, a simple yet efficient algorithm called Active Relinquish Scheme (ARS) is proposed to enhance the end-to-end throughput of multi-hop ad hoc networks. The principle of our scheme is to equalize the throughput of each node through a multi-hop flow. Consequently, the fairness of the network is improved. Simulation results through OPNET show that our scheme works well in different kinds of topologies, regardless of the scale of the network.
{"title":"End-to-end throughput optimization in multi-hop wireless ad hoc networks","authors":"Lianghua Wu, Yuzhuo Fu, Liang Dong","doi":"10.1109/APCC.2009.5375693","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375693","url":null,"abstract":"In this paper, a simple yet efficient algorithm called Active Relinquish Scheme (ARS) is proposed to enhance the end-to-end throughput of multi-hop ad hoc networks. The principle of our scheme is to equalize the throughput of each node through a multi-hop flow. Consequently, the fairness of the network is improved. Simulation results through OPNET show that our scheme works well in different kinds of topologies, regardless of the scale of the network.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127418813","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375686
Lei Wang, Chengkang Pan, Yueming Cai
A space sense based random access (SSRA) scheme is introduced for the uplink of time division duplex (TDD) WLANs with multiple receive antennas. In SSRA scheme, each user performs space sense process to predict the post-detection signal-to-interference-and-noise-ratio (SINR) of data packets. If the predicted SINR is larger than a given threshold, the user considers the channel idle and is permitted to transmit channel estimation sequence and data packet like Hybrid ALOHA. Successful channel estimation means successful packet reception. An approximation of the throughput of this SSRA scheme is given. We also make efforts to find the optimized system parameters by numerical simulations.
{"title":"Throughput analysis and system parameter optimization of space sense based random access for TDD WLANs","authors":"Lei Wang, Chengkang Pan, Yueming Cai","doi":"10.1109/APCC.2009.5375686","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375686","url":null,"abstract":"A space sense based random access (SSRA) scheme is introduced for the uplink of time division duplex (TDD) WLANs with multiple receive antennas. In SSRA scheme, each user performs space sense process to predict the post-detection signal-to-interference-and-noise-ratio (SINR) of data packets. If the predicted SINR is larger than a given threshold, the user considers the channel idle and is permitted to transmit channel estimation sequence and data packet like Hybrid ALOHA. Successful channel estimation means successful packet reception. An approximation of the throughput of this SSRA scheme is given. We also make efforts to find the optimized system parameters by numerical simulations.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117143449","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375659
Jinxiang Wang, Xin-chun Wu, Zhigang Mao, Bin Zhou
Time domain interleaved partitioning partial transmit sequence method (TD-IP-PTS) needs only one inverse fast Fourier transform (IFFT) to reduce peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system. However, for one long OFDM symbol, it will need waiting time and many registers to implement the combination of phase factor in TD-IP-PTS. Therefore, the speed of data processing may be lowered and hardware complexity still is higher. In order to improve this problem, we analyze the combination process of phase factor in TD-IP-PTS and find the characteristic of combination. Moreover, this paper proposes a pipeline scheme to implement the combination of phase factor in TD-IP-PTS, which requires only 16 registers and doesn't need waiting time.
{"title":"Phase factor combination scheme based on pipeline in time domain IP-PTS for PAPR reduction of OFDM systems","authors":"Jinxiang Wang, Xin-chun Wu, Zhigang Mao, Bin Zhou","doi":"10.1109/APCC.2009.5375659","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375659","url":null,"abstract":"Time domain interleaved partitioning partial transmit sequence method (TD-IP-PTS) needs only one inverse fast Fourier transform (IFFT) to reduce peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system. However, for one long OFDM symbol, it will need waiting time and many registers to implement the combination of phase factor in TD-IP-PTS. Therefore, the speed of data processing may be lowered and hardware complexity still is higher. In order to improve this problem, we analyze the combination process of phase factor in TD-IP-PTS and find the characteristic of combination. Moreover, this paper proposes a pipeline scheme to implement the combination of phase factor in TD-IP-PTS, which requires only 16 registers and doesn't need waiting time.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117349677","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375520
Seong-Cheol Hong, Jin Kim, Byungchul Park, Y. Won, J. W. Hong
The increasing popularity of P2P and multimedia applications around the world has resulted in significant global increases in network traffic. This paper investigates the traffic changes in our enterprise network by analyzing the day-long traffic traces from 2007 to 2009. We observe that there has been a substantial increase in traffic in the past few years; however, no single application type is a dominant cause. This paper analyzes the following categories: Traffic volume, flow characteristics and protocol usage, and the use of IP address space.
{"title":"Traffic growth analysis over three years in enterprise networks","authors":"Seong-Cheol Hong, Jin Kim, Byungchul Park, Y. Won, J. W. Hong","doi":"10.1109/APCC.2009.5375520","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375520","url":null,"abstract":"The increasing popularity of P2P and multimedia applications around the world has resulted in significant global increases in network traffic. This paper investigates the traffic changes in our enterprise network by analyzing the day-long traffic traces from 2007 to 2009. We observe that there has been a substantial increase in traffic in the past few years; however, no single application type is a dominant cause. This paper analyzes the following categories: Traffic volume, flow characteristics and protocol usage, and the use of IP address space.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"32 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121888940","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375487
K. Kim, Hyunduk Jung, Jaiyong Lee
This paper proposes the world first complete voice call handover scheme between the 3G LTE and 3G CS systems. To achieve seamless handover, a powerful network entity called FW_MME is proposed. Features of the FW_MME contribute to reducing handover service interruption time; hence the resulting voice call handover performance is also improved. The evaluation result shows that the proposed FW_MME exclusively meets the strict service interruption time requirement which is smaller than 300 ms, whereas other conventional handover schemes spend more than twice large time in voice call handover.
{"title":"A seamless voice call handover scheme for next generation cellular network","authors":"K. Kim, Hyunduk Jung, Jaiyong Lee","doi":"10.1109/APCC.2009.5375487","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375487","url":null,"abstract":"This paper proposes the world first complete voice call handover scheme between the 3G LTE and 3G CS systems. To achieve seamless handover, a powerful network entity called FW_MME is proposed. Features of the FW_MME contribute to reducing handover service interruption time; hence the resulting voice call handover performance is also improved. The evaluation result shows that the proposed FW_MME exclusively meets the strict service interruption time requirement which is smaller than 300 ms, whereas other conventional handover schemes spend more than twice large time in voice call handover.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121956360","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375623
J. Xu, Sheng Zhou, Z. Niu
We consider relay selection in a multiple source-destination cooperative network with multiple potential relays. Interference induced by simultaneous transmissions makes relay selection different from interference-free scenarios which has not been well addressed in literature. In this paper, we propose a new relay selection metric in interference-limited networks in order to improve network throughput. The proposed metric is interference-aware and abstracts the potential interference to the neighborhood as a penalty. Based on the metric, a centralized scheme is proposed to formulate the relay selection problem into a weighted matching problem. A distributed version is further designed based on negotiations which guarantees stability and quick convergence. Simulation results indicate a significant improvement in overall transmission rate over selection metrics of interference-free scenarios, i.e., about 10%.
{"title":"Interference-aware relay selection for multiple source-destination cooperative networks","authors":"J. Xu, Sheng Zhou, Z. Niu","doi":"10.1109/APCC.2009.5375623","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375623","url":null,"abstract":"We consider relay selection in a multiple source-destination cooperative network with multiple potential relays. Interference induced by simultaneous transmissions makes relay selection different from interference-free scenarios which has not been well addressed in literature. In this paper, we propose a new relay selection metric in interference-limited networks in order to improve network throughput. The proposed metric is interference-aware and abstracts the potential interference to the neighborhood as a penalty. Based on the metric, a centralized scheme is proposed to formulate the relay selection problem into a weighted matching problem. A distributed version is further designed based on negotiations which guarantees stability and quick convergence. Simulation results indicate a significant improvement in overall transmission rate over selection metrics of interference-free scenarios, i.e., about 10%.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124089489","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375588
Suwatchai Soonjun, Dokor Boontri, P. Cherntanomwong
In this paper, a novel approach for an indoor localization using a fingerprint technique is proposed. The UHF band Radio Frequency Identification (RFID) system is utilized. The passive RFID tags are employed as references attached to the ceiling at known locations and the RFID reader carrying on the vehicle of interest is the target to be localized. The basic principle of the fingerprint technique is to find the location of the target by comparing its signal (or information) pattern with a previously recoded database of known signal (or information)-location data. Therefore, there are two main steps to estimate the target location: (i) construction of database containing the signals (or information) and their corresponding locations, and (ii) estimation of the target location. In this paper, firstly, the detected tags found by the reader at each location of interest are collected and from now on the detected tags are called a fingerprint. Secondly, the location of the reader can be estimated using two proposed methods using the intersection between the detected tags and fingerprints. These two methods are compared to a simple method called the center of gravity (C.G.). The effectiveness of this method is verified by an indoor experiment. The result of location estimation error is less than 60 cm.
{"title":"A novel approach of RFID based indoor localization using fingerprinting techniques","authors":"Suwatchai Soonjun, Dokor Boontri, P. Cherntanomwong","doi":"10.1109/APCC.2009.5375588","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375588","url":null,"abstract":"In this paper, a novel approach for an indoor localization using a fingerprint technique is proposed. The UHF band Radio Frequency Identification (RFID) system is utilized. The passive RFID tags are employed as references attached to the ceiling at known locations and the RFID reader carrying on the vehicle of interest is the target to be localized. The basic principle of the fingerprint technique is to find the location of the target by comparing its signal (or information) pattern with a previously recoded database of known signal (or information)-location data. Therefore, there are two main steps to estimate the target location: (i) construction of database containing the signals (or information) and their corresponding locations, and (ii) estimation of the target location. In this paper, firstly, the detected tags found by the reader at each location of interest are collected and from now on the detected tags are called a fingerprint. Secondly, the location of the reader can be estimated using two proposed methods using the intersection between the detected tags and fingerprints. These two methods are compared to a simple method called the center of gravity (C.G.). The effectiveness of this method is verified by an indoor experiment. The result of location estimation error is less than 60 cm.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125089175","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 : 2009-10-08DOI: 10.1109/APCC.2009.5375612
Hsin-Yi Huang, Shyue-Win Wei
A modified deterministic structure based carrier frequency offset (CFO) estimation algorithm is presented for the interleaved orthogonal frequency division multiple access (OFDMA) uplink transmission. The presented algorithm combines the conventional deterministic structure algorithm with multiple access interference (MAI) cancellation method so that the estimation performance can be significantly improved. The presented iterative CFO estimation algorithm can work well on both AWGN and multi-path fading channels, especially when the system is fully loaded and the effective CFOs are very close to each other.
{"title":"Modified deterministic structure based carrier frequency offset estimation for interleaved OFDMA uplink","authors":"Hsin-Yi Huang, Shyue-Win Wei","doi":"10.1109/APCC.2009.5375612","DOIUrl":"https://doi.org/10.1109/APCC.2009.5375612","url":null,"abstract":"A modified deterministic structure based carrier frequency offset (CFO) estimation algorithm is presented for the interleaved orthogonal frequency division multiple access (OFDMA) uplink transmission. The presented algorithm combines the conventional deterministic structure algorithm with multiple access interference (MAI) cancellation method so that the estimation performance can be significantly improved. The presented iterative CFO estimation algorithm can work well on both AWGN and multi-path fading channels, especially when the system is fully loaded and the effective CFOs are very close to each other.","PeriodicalId":217893,"journal":{"name":"2009 15th Asia-Pacific Conference on Communications","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128208499","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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