Pub Date : 2002-08-07DOI: 10.1109/VTC.2002.1002664
Kai Liu, Jiandong Li, Pengyu Huang, A. Fukuda
This paper presents a new multiple access control (MAC) protocol called adaptive acquisition multiple access with common-transmission channel assignment (AAMA-CT) and its improved one (AAMA-ICT) for wireless multihop mobile ad hoc networks. In the protocol, every node adaptively chooses a usable channel as its transmission channel in advance in multihop mobile environment and takes advantage of request-to-send (RTS) packet transmitted on a common channel to evoke its recipient to complete their communication process on their transmission channels without packet collisions. With this protocol, resource reservation is flexibly and effectively made on multiple channels by half-duplex radios without any help of powerful central controllers and wired backbone networks in an asynchronous fashion. The protocol can solve hidden and exposed terminal problems perfectly as is validated through analysis and simulation results.
针对无线多跳移动自组网，提出了一种新的多址控制协议AAMA-CT (adaptive acquisition multiple access with common-transmission channel assignment)及其改进协议AAMA-ICT。该协议在多跳移动环境下，每个节点提前自适应地选择一个可用的信道作为自己的传输信道，并利用在公共信道上传输的RTS (request-to-send)分组，在不发生分组冲突的情况下，唤醒接收方在各自的传输信道上完成通信过程。使用该协议，可以在不需要任何强大的中央控制器和有线骨干网的帮助下，以异步方式通过半双工无线电在多个信道上灵活有效地进行资源预留。分析和仿真结果验证了该协议能够很好地解决终端隐藏和暴露问题。
{"title":"Adaptive acquisition multiple access protocol in wireless multihop mobile ad hoc networks","authors":"Kai Liu, Jiandong Li, Pengyu Huang, A. Fukuda","doi":"10.1109/VTC.2002.1002664","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002664","url":null,"abstract":"This paper presents a new multiple access control (MAC) protocol called adaptive acquisition multiple access with common-transmission channel assignment (AAMA-CT) and its improved one (AAMA-ICT) for wireless multihop mobile ad hoc networks. In the protocol, every node adaptively chooses a usable channel as its transmission channel in advance in multihop mobile environment and takes advantage of request-to-send (RTS) packet transmitted on a common channel to evoke its recipient to complete their communication process on their transmission channels without packet collisions. With this protocol, resource reservation is flexibly and effectively made on multiple channels by half-duplex radios without any help of powerful central controllers and wired backbone networks in an asynchronous fashion. The protocol can solve hidden and exposed terminal problems perfectly as is validated through analysis and simulation results.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133549709","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002875
R. Narasimha, S. Dianat
In this paper we propose a new blind adaptive decision-feedback multiuser detector (BADFP) for synchronous direct-sequence code-division multiple-access (DS-CDMA) systems. The BADFP algorithm is a stochastic adaptive gradient type algorithm that incorporates power estimation of the user of interest to enhance the performance of the detector. It is assumed that full power control is in place and all the users are equally powered. The proposed algorithm requires the knowledge of the signature sequence of the desired user. The simulation results show that the performance of the BADFP algorithm is comparable with the ideal blind linear minimum output energy (MOE) detector.
{"title":"Blind adaptive decision feedback multiuser detector for DS-CDMA with power estimation","authors":"R. Narasimha, S. Dianat","doi":"10.1109/VTC.2002.1002875","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002875","url":null,"abstract":"In this paper we propose a new blind adaptive decision-feedback multiuser detector (BADFP) for synchronous direct-sequence code-division multiple-access (DS-CDMA) systems. The BADFP algorithm is a stochastic adaptive gradient type algorithm that incorporates power estimation of the user of interest to enhance the performance of the detector. It is assumed that full power control is in place and all the users are equally powered. The proposed algorithm requires the knowledge of the signature sequence of the desired user. The simulation results show that the performance of the BADFP algorithm is comparable with the ideal blind linear minimum output energy (MOE) detector.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134474032","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002561
M. Ebrahimi, M. Nasiri-Kenari
We consider the multiuser capacity of a multicarrier frequency-hopping (MC-FH) CDMA system as first introduced by Lance and Kaleh (1997). We propose to use a practical low-rate convolutional error correcting code in this system which does not require any extra bandwidth further than needed by the frequency-hopping spread-spectrum modulation. We provide a multiuser performance analysis of the system for both uncoded and coded schemes in AWGN and fading channels based on a Gaussian distribution assumption for the multiuser interference term. We also derive the exact bit error rate (BER) of the system in an AWGN channel. Our numerical results first indicate that the coded scheme significantly outperforms the uncoded scheme in both AWGN and fading channels. Moreover, it shows that the Gaussian analysis in some cases does not predict accurately the number of users supported by the system.
{"title":"Performance analysis of multicarrier frequency-hopping (MC-FH) code division multiple-access systems: uncoded and coded schemes","authors":"M. Ebrahimi, M. Nasiri-Kenari","doi":"10.1109/VTC.2002.1002561","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002561","url":null,"abstract":"We consider the multiuser capacity of a multicarrier frequency-hopping (MC-FH) CDMA system as first introduced by Lance and Kaleh (1997). We propose to use a practical low-rate convolutional error correcting code in this system which does not require any extra bandwidth further than needed by the frequency-hopping spread-spectrum modulation. We provide a multiuser performance analysis of the system for both uncoded and coded schemes in AWGN and fading channels based on a Gaussian distribution assumption for the multiuser interference term. We also derive the exact bit error rate (BER) of the system in an AWGN channel. Our numerical results first indicate that the coded scheme significantly outperforms the uncoded scheme in both AWGN and fading channels. Moreover, it shows that the Gaussian analysis in some cases does not predict accurately the number of users supported by the system.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130310619","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002857
M. Howlader
Some previous research has demonstrated the feasibility of decoder-assisted frame synchronization and channel estimation as separate processes for coded systems. Here a joint decoder-assisted process of channel estimation and frame synchronization using the same sync word (SW) is proposed. In brief, the method entails using a SW embedded in the mid-packet for both channel estimation and frame synchronization. The method is based on a list-synchronization scheme, where a correlation-based frame synchronizer passes a list of possible delays to the turbo decoder. The turbo decoder makes the final decision about frame synchronization. The turbo decoder is draw upon pilot symbol assisted modulation (PSAM) techniques for channel estimation using the coded SW of frame synchronization. The performance of channel estimation technique using the SW is presented via simulation.
{"title":"Decoder-assisted channel estimation and frame synchronization of turbo coded systems","authors":"M. Howlader","doi":"10.1109/VTC.2002.1002857","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002857","url":null,"abstract":"Some previous research has demonstrated the feasibility of decoder-assisted frame synchronization and channel estimation as separate processes for coded systems. Here a joint decoder-assisted process of channel estimation and frame synchronization using the same sync word (SW) is proposed. In brief, the method entails using a SW embedded in the mid-packet for both channel estimation and frame synchronization. The method is based on a list-synchronization scheme, where a correlation-based frame synchronizer passes a list of possible delays to the turbo decoder. The turbo decoder makes the final decision about frame synchronization. The turbo decoder is draw upon pilot symbol assisted modulation (PSAM) techniques for channel estimation using the coded SW of frame synchronization. The performance of channel estimation technique using the SW is presented via simulation.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115369252","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002807
Zheng Zhao, Qinye Yin, Aigang Feng, Ke Deng
In this paper, we propose a subspace tracking method for blind signature waveform estimation. In practice, the signature waveform can not change suddenly. So, we can take use of the past information of the signal subspace to update the signal subspace gradually for blind signature waveform estimation. After the algorithm proposed in this paper, the computation complexity is reduced substantially.
{"title":"Fast blind signature waveform tracking under imperfect carrier recovery in DS-CDMA systems","authors":"Zheng Zhao, Qinye Yin, Aigang Feng, Ke Deng","doi":"10.1109/VTC.2002.1002807","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002807","url":null,"abstract":"In this paper, we propose a subspace tracking method for blind signature waveform estimation. In practice, the signature waveform can not change suddenly. So, we can take use of the past information of the signal subspace to update the signal subspace gradually for blind signature waveform estimation. After the algorithm proposed in this paper, the computation complexity is reduced substantially.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"22 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114112197","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002785
S. Z. Ali
In order to track the location of a mobile terminal in a cellular mobile network, the radio coverage area of a network is partitioned into clusters of base stations, called location areas. As mobile terminals cross the boundaries of location areas, a significant overhead location-updating traffic is injected into the controlling signaling network. The intent of this paper is to solve the problem of designing location areas for a given network such that the load of location-update-signaling traffic on the signaling network is minimized in the context that the intracluster communication is less expensive than the inter-cluster communications. In order to solve the problem, a two-phase matrix-decomposition based recursive algorithm is presented in the present paper. The proposed algorithm partitions a cellular network into required number of location areas in a hierarchical fashion, and is capable of generating an optimal or near optimal solution in very short times. By considering a range of network problems, it is demonstrated that the proposed algorithm can be applied to solve large-scale location area design problems.
{"title":"Design of location areas for cellular mobile radio networks","authors":"S. Z. Ali","doi":"10.1109/VTC.2002.1002785","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002785","url":null,"abstract":"In order to track the location of a mobile terminal in a cellular mobile network, the radio coverage area of a network is partitioned into clusters of base stations, called location areas. As mobile terminals cross the boundaries of location areas, a significant overhead location-updating traffic is injected into the controlling signaling network. The intent of this paper is to solve the problem of designing location areas for a given network such that the load of location-update-signaling traffic on the signaling network is minimized in the context that the intracluster communication is less expensive than the inter-cluster communications. In order to solve the problem, a two-phase matrix-decomposition based recursive algorithm is presented in the present paper. The proposed algorithm partitions a cellular network into required number of location areas in a hierarchical fashion, and is capable of generating an optimal or near optimal solution in very short times. By considering a range of network problems, it is demonstrated that the proposed algorithm can be applied to solve large-scale location area design problems.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"165 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114519188","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002826
P. Kafle, A. Sesay
Iterative multiuser detection is a powerful signal processing technique to increase performance and capacity of coded CDMA systems. However, previously proposed iterative multiuser receivers have been based on complete knowledge of spreading codes of all users in the system. Performance of these receivers degrades significantly in the presence of unknown interference, caused by out-of-cell users whose spreading codes are not known. A significant part of the interference in a typical uplink system is often due to such unknown users. In this paper, we propose an iterative semi-blind receiver for a coded system in such an uplink environment. It is based on the minimum mean square error criterion. The proposed iterative receiver utilizes known users' information for the computation of log-likelihood ratios, while blindly suppressing unknown interference. We consider a multicarrier CDMA system, which has received considerable attention for future high-speed wireless systems. Turbo code is used for channel coding, with log-MAP decoding. Simulation results demonstrate that the proposed iterative semi-blind method offers substantial performance gain over that of the conventional noniterative and non blind iterative receivers.
{"title":"An iterative semi-blind multiuser detector for coded MC-CDMA uplink","authors":"P. Kafle, A. Sesay","doi":"10.1109/VTC.2002.1002826","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002826","url":null,"abstract":"Iterative multiuser detection is a powerful signal processing technique to increase performance and capacity of coded CDMA systems. However, previously proposed iterative multiuser receivers have been based on complete knowledge of spreading codes of all users in the system. Performance of these receivers degrades significantly in the presence of unknown interference, caused by out-of-cell users whose spreading codes are not known. A significant part of the interference in a typical uplink system is often due to such unknown users. In this paper, we propose an iterative semi-blind receiver for a coded system in such an uplink environment. It is based on the minimum mean square error criterion. The proposed iterative receiver utilizes known users' information for the computation of log-likelihood ratios, while blindly suppressing unknown interference. We consider a multicarrier CDMA system, which has received considerable attention for future high-speed wireless systems. Turbo code is used for channel coding, with log-MAP decoding. Simulation results demonstrate that the proposed iterative semi-blind method offers substantial performance gain over that of the conventional noniterative and non blind iterative receivers.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114481838","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002984
Rahl E. Sequeira, K. Stewart
Partial interference cancellation offers potential performance improvements for DS-CDMA receivers in the reverse link (end-user to base station). In practice, as a result of the high error rate of the elements in the coded information sequence, "brute-force" cancellation is doomed to failure; however, partial cancellation can be effective. The results here show performance improvements that can be expected with partial interference cancellation under more-realistic scenarios than simple uncoded BPSK modulation in the AWGN channel-including coded data, channel estimation, and power control.
{"title":"Improved performance of pilot-assisted DS-CDMA receivers through partial interference cancellation","authors":"Rahl E. Sequeira, K. Stewart","doi":"10.1109/VTC.2002.1002984","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002984","url":null,"abstract":"Partial interference cancellation offers potential performance improvements for DS-CDMA receivers in the reverse link (end-user to base station). In practice, as a result of the high error rate of the elements in the coded information sequence, \"brute-force\" cancellation is doomed to failure; however, partial cancellation can be effective. The results here show performance improvements that can be expected with partial interference cancellation under more-realistic scenarios than simple uncoded BPSK modulation in the AWGN channel-including coded data, channel estimation, and power control.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116667691","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002621
Hyunsoo Cheon, Byungjoo Park, C. Kang, D. Hong
In this paper, we examine the performance degradation due to the imperfect channel information in orthogonal frequency division multiplexing (OFDM)-based wireless LAN (WLAN). The average effective SNR and average bit error probabilities are derived in Rayleigh fading channels.
{"title":"The performance impairment due to the imperfect channel information in OFDM-based WLAN","authors":"Hyunsoo Cheon, Byungjoo Park, C. Kang, D. Hong","doi":"10.1109/VTC.2002.1002621","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002621","url":null,"abstract":"In this paper, we examine the performance degradation due to the imperfect channel information in orthogonal frequency division multiplexing (OFDM)-based wireless LAN (WLAN). The average effective SNR and average bit error probabilities are derived in Rayleigh fading channels.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117326584","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 : 2002-08-07DOI: 10.1109/VTC.2002.1002714
I. Han, Sung-Kwan Jung, D. Cho
To efficiently support mobility of users on transportation systems, we propose a distributed group location tracking (DGLT) scheme based on several virtual visitor location registers (VVLRs) and representative identities. We analyze the DGLT scheme in view of the database (DB) access cost and the signaling cost under a one-dimensional network architecture. Compared with the IS-41 scheme, the DGLT scheme using distributed group management has a lower signaling cost as well as a lower DB access cost. As the user mobility-increases or the number of users on a TS increases, the outperformance of the DGLT scheme increases. Generally, the DGLT scheme in which a corresponding home location register selects an optimum VVLR among several VVLRs has a lower signaling cost, although a DB access cost is increased slightly compared with the GLT scheme.
{"title":"Distributed group location tracking based on several RIDs and virtual VLRs for transportation systems","authors":"I. Han, Sung-Kwan Jung, D. Cho","doi":"10.1109/VTC.2002.1002714","DOIUrl":"https://doi.org/10.1109/VTC.2002.1002714","url":null,"abstract":"To efficiently support mobility of users on transportation systems, we propose a distributed group location tracking (DGLT) scheme based on several virtual visitor location registers (VVLRs) and representative identities. We analyze the DGLT scheme in view of the database (DB) access cost and the signaling cost under a one-dimensional network architecture. Compared with the IS-41 scheme, the DGLT scheme using distributed group management has a lower signaling cost as well as a lower DB access cost. As the user mobility-increases or the number of users on a TS increases, the outperformance of the DGLT scheme increases. Generally, the DGLT scheme in which a corresponding home location register selects an optimum VVLR among several VVLRs has a lower signaling cost, although a DB access cost is increased slightly compared with the GLT scheme.","PeriodicalId":159750,"journal":{"name":"Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367)","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115763096","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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