Pub Date : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258195
R. Dinis, A. Gusmão
Some promising techniques to reduce the envelope fluctuations of OFDM signals with a high number of subcarriers combine a nonlinear operation (e.g., an envelope clipping) with a frequency-domain filtering operation, so as to ensure the low-PMEPR (peak-to-mean envelope power ratio) goal while maintaining the spectral efficiency of the corresponding conventional OFDM scheme. However, the filtering operation leads to some envelope fluctuation regrowth, increasing the PMEPR of the transmitted signals. In this paper we consider the repeated use, in an iterative way, of an envelope clipping and a frequency-domain filtering for low-PMEPR OFDM transmission with high spectral efficiency. Based on semi-analytical, statistical characterization of the transmitted frequency-domain blocks, a set of performance results is presented and discussed, showing that the proposed iterative technique can provide improved tradeoffs between power efficiency, spectral efficiency and implementation simplicity.
{"title":"Performance evaluation of an iterative PMEPR-reducing technique for OFDM transmission","authors":"R. Dinis, A. Gusmão","doi":"10.1109/GLOCOM.2003.1258195","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258195","url":null,"abstract":"Some promising techniques to reduce the envelope fluctuations of OFDM signals with a high number of subcarriers combine a nonlinear operation (e.g., an envelope clipping) with a frequency-domain filtering operation, so as to ensure the low-PMEPR (peak-to-mean envelope power ratio) goal while maintaining the spectral efficiency of the corresponding conventional OFDM scheme. However, the filtering operation leads to some envelope fluctuation regrowth, increasing the PMEPR of the transmitted signals. In this paper we consider the repeated use, in an iterative way, of an envelope clipping and a frequency-domain filtering for low-PMEPR OFDM transmission with high spectral efficiency. Based on semi-analytical, statistical characterization of the transmitted frequency-domain blocks, a set of performance results is presented and discussed, showing that the proposed iterative technique can provide improved tradeoffs between power efficiency, spectral efficiency and implementation simplicity.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115414200","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258651
X. Doukopoulos, G. Moustakides
The problem of blind adaptive channel estimation, in code-division multiple-access (CDMA) systems, is considered. Using only the spreading code of the user of interest and the received data, adaptive techniques are proposed that blindly identify the impulse response of the multipath channel. In particular, we develop RLS and LMS implementations that exhibit rapid convergence combined with low computational complexity. Both versions were inspired by the iterative power method used in numerical analysis to compute the singular vector corresponding to the largest singular value of a matrix. This is the reason why our schemes exhibit performance comparable to SVD off-line techniques while outperforming, significantly, existing adaptive methods proposed in the literature.
{"title":"Power techniques for blind adaptive channel estimation in CDMA systems","authors":"X. Doukopoulos, G. Moustakides","doi":"10.1109/GLOCOM.2003.1258651","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258651","url":null,"abstract":"The problem of blind adaptive channel estimation, in code-division multiple-access (CDMA) systems, is considered. Using only the spreading code of the user of interest and the received data, adaptive techniques are proposed that blindly identify the impulse response of the multipath channel. In particular, we develop RLS and LMS implementations that exhibit rapid convergence combined with low computational complexity. Both versions were inspired by the iterative power method used in numerical analysis to compute the singular vector corresponding to the largest singular value of a matrix. This is the reason why our schemes exhibit performance comparable to SVD off-line techniques while outperforming, significantly, existing adaptive methods proposed in the literature.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115458190","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258776
Rajesh N. Rao, G. Kesidis
Ad hoc networks are gaining presence with the proliferation of cheap wireless devices and the need to keep them connected. Individual applications and larger missions, such as those of tactical sensor networks, require secure data transmission among wireless devices. Security remains a major challenge for such networks. Current protocols employ encryption and authentication techniques for secure message exchange, but given the limitations and innately insecure nature of ad-hoc networks, such mechanisms may not suffice. A security breach can, for example, be a network-level denial-of-service (DoS) attack, passive eavesdropping, or physical layer jamming to degrade communication channels. In a multihop network, an intruder node can degrade communication quality by simply dropping packets that are meant to be relayed (forwarded). The network could then misinterpret the cause of packet loss as congestion instead of malicious activity. In this paper, we suggest that traffic transmission patterns be selected to facilitate verification by a receiver. Such traffic patterns are used in concert with suboptimal MAC that preserves the statistical regularity from hop to hop. This general technique for intrusion detection is therefore suitable for networks that are not bandwidth limited but have strict security requirements, e.g., certain kinds of tactical sensor networks.
{"title":"Detecting malicious packet dropping using statistically regular traffic patterns in multihop wireless networks that are not bandwidth limited","authors":"Rajesh N. Rao, G. Kesidis","doi":"10.1109/GLOCOM.2003.1258776","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258776","url":null,"abstract":"Ad hoc networks are gaining presence with the proliferation of cheap wireless devices and the need to keep them connected. Individual applications and larger missions, such as those of tactical sensor networks, require secure data transmission among wireless devices. Security remains a major challenge for such networks. Current protocols employ encryption and authentication techniques for secure message exchange, but given the limitations and innately insecure nature of ad-hoc networks, such mechanisms may not suffice. A security breach can, for example, be a network-level denial-of-service (DoS) attack, passive eavesdropping, or physical layer jamming to degrade communication channels. In a multihop network, an intruder node can degrade communication quality by simply dropping packets that are meant to be relayed (forwarded). The network could then misinterpret the cause of packet loss as congestion instead of malicious activity. In this paper, we suggest that traffic transmission patterns be selected to facilitate verification by a receiver. Such traffic patterns are used in concert with suboptimal MAC that preserves the statistical regularity from hop to hop. This general technique for intrusion detection is therefore suitable for networks that are not bandwidth limited but have strict security requirements, e.g., certain kinds of tactical sensor networks.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"235 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115478022","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258376
Wing Ho A. Yuen, R. Yates, C. Sung
A mobile infostation network stipulates all transmissions to occur when nodes are in proximity. We evaluate the effect of mobility on highway mobile infostation networks. Each node enters a highway segment at a Poisson rate with a constant speed drawn from a known but arbitrary distribution. Both forward and reverse traffic are considered. For node speed that is uniformly distributed, the expected fraction of connection time, or expected number of connections in queueing terminology, is independent of observer node speed for reverse traffic, while it increases with observer node speed for forward traffic. We also extend our mobility model such that each node changes speed at each highway segment. The long run fraction of connection time of an observer node is dependent on the ratio of transmit range and connection time limit. Forward traffic connection yields better performance when the ratio is small and vice versa. We also compute the optimal transmit range and the corresponding data rate for both traffic types. We conclude that forward traffic connections yield much higher data rate in most scenarios.
{"title":"Performance evaluation of highway mobile infostation networks","authors":"Wing Ho A. Yuen, R. Yates, C. Sung","doi":"10.1109/GLOCOM.2003.1258376","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258376","url":null,"abstract":"A mobile infostation network stipulates all transmissions to occur when nodes are in proximity. We evaluate the effect of mobility on highway mobile infostation networks. Each node enters a highway segment at a Poisson rate with a constant speed drawn from a known but arbitrary distribution. Both forward and reverse traffic are considered. For node speed that is uniformly distributed, the expected fraction of connection time, or expected number of connections in queueing terminology, is independent of observer node speed for reverse traffic, while it increases with observer node speed for forward traffic. We also extend our mobility model such that each node changes speed at each highway segment. The long run fraction of connection time of an observer node is dependent on the ratio of transmit range and connection time limit. Forward traffic connection yields better performance when the ratio is small and vice versa. We also compute the optimal transmit range and the corresponding data rate for both traffic types. We conclude that forward traffic connections yield much higher data rate in most scenarios.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115703437","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258624
A. L. Moustakas, Pantelis Monogioudis
We propose a promising multi-antenna scheme specifically suitable for hybrid code and time division multiplexed (CTDM) high speed shared channels commonly employed in 3GPP and 3GPP2 standards, such as HS-DPA, 1xEVDO (HDR), and 1xEVDV. The scheme is called phase sweep transmit diversity (PSTD) and was originally proposed for power controlled dedicated voice channels. PSTD is shown to provide the benefits of beamforming without the requirement for channel or weight information feedback from the receiver to the transmitter. We evaluate the benefits of PSTD for two antenna configurations: (a) the so-called BF-2V configuration that encompasses two closely-spaced (/spl lambda//2) vertically polarized antenna columns: (b) the so-called DIV-2V antenna configurations, in which the two antenna columns are widely-spaced (10-20 /spl lambda/). When compared to selection transmit diversity (STD) and the baseline case of a single antenna transmission, PSTD offers significant gains for low-tier mobility users. In addition, the closely spaced antenna configuration produces consistently higher sector throughput as compared to the widely spaced configuration.
{"title":"Phase-sweep transmit diversity (PSTD) for shared data channels: a critical analysis","authors":"A. L. Moustakas, Pantelis Monogioudis","doi":"10.1109/GLOCOM.2003.1258624","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258624","url":null,"abstract":"We propose a promising multi-antenna scheme specifically suitable for hybrid code and time division multiplexed (CTDM) high speed shared channels commonly employed in 3GPP and 3GPP2 standards, such as HS-DPA, 1xEVDO (HDR), and 1xEVDV. The scheme is called phase sweep transmit diversity (PSTD) and was originally proposed for power controlled dedicated voice channels. PSTD is shown to provide the benefits of beamforming without the requirement for channel or weight information feedback from the receiver to the transmitter. We evaluate the benefits of PSTD for two antenna configurations: (a) the so-called BF-2V configuration that encompasses two closely-spaced (/spl lambda//2) vertically polarized antenna columns: (b) the so-called DIV-2V antenna configurations, in which the two antenna columns are widely-spaced (10-20 /spl lambda/). When compared to selection transmit diversity (STD) and the baseline case of a single antenna transmission, PSTD offers significant gains for low-tier mobility users. In addition, the closely spaced antenna configuration produces consistently higher sector throughput as compared to the widely spaced configuration.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114603246","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258329
G. Záruba, I. Chlamtac
The recent industry standard Bluetooth promises low cost replacement of communication cabling with moderate symbol-rate, short-range wireless links. The same specification also addresses the establishment of point-to-multipoint piconets and the interconnection of several of these piconets into scatternets, enabling Bluetooth to be used as a technology for realizing personal area networks. Establishing Bluetooth piconets requires nodes to discover each other by completing an inquiry phase. This paper investigates the inquiry phase; shows the shortcomings of the current inquiry procedure in multi node-PAN scenarios, and outlines and analyses a backwards Bluetooth compliant modification to accelerate Bluetooth inquiry. Extensive simulations comparing the original and the proposed Bluetooth inquiry schemes show improvements of more than an order of magnitude in device discovery times.
{"title":"Accelerating Bluetooth inquiry for personal area networks","authors":"G. Záruba, I. Chlamtac","doi":"10.1109/GLOCOM.2003.1258329","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258329","url":null,"abstract":"The recent industry standard Bluetooth promises low cost replacement of communication cabling with moderate symbol-rate, short-range wireless links. The same specification also addresses the establishment of point-to-multipoint piconets and the interconnection of several of these piconets into scatternets, enabling Bluetooth to be used as a technology for realizing personal area networks. Establishing Bluetooth piconets requires nodes to discover each other by completing an inquiry phase. This paper investigates the inquiry phase; shows the shortcomings of the current inquiry procedure in multi node-PAN scenarios, and outlines and analyses a backwards Bluetooth compliant modification to accelerate Bluetooth inquiry. Extensive simulations comparing the original and the proposed Bluetooth inquiry schemes show improvements of more than an order of magnitude in device discovery times.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115115831","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258692
Yuanqiu Luo, N. Ansari
This article proposes a survivability evaluation model for multifiber WDM networks, in which the extended layered graph is developed to jointly optimize the wavelength routing and wavelength assignment problems, and three different edge cost functions are evaluated in terms of traffic engineering. Linear programming (LP) equations are formulated to optimally determine the working lightpath and the corresponding protection lightpath under the schemes of shared protection and dedicated protection. The extensive simulations show that shared protection with the fiber and wavelength-based cost function provides the best survivability.
{"title":"Performance evaluation of survivable multifiber WDM network","authors":"Yuanqiu Luo, N. Ansari","doi":"10.1109/GLOCOM.2003.1258692","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258692","url":null,"abstract":"This article proposes a survivability evaluation model for multifiber WDM networks, in which the extended layered graph is developed to jointly optimize the wavelength routing and wavelength assignment problems, and three different edge cost functions are evaluated in terms of traffic engineering. Linear programming (LP) equations are formulated to optimally determine the working lightpath and the corresponding protection lightpath under the schemes of shared protection and dedicated protection. The extensive simulations show that shared protection with the fiber and wavelength-based cost function provides the best survivability.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116276629","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258485
R. Deng, F. Bao
A personal certification authority (CA) for personal area networks (PANs) was presented in (C. Gehrmann, et al., (2002)). In this paper, we propose an improved version of the Personal CA which is more robust and secure than the original system.
{"title":"An improved personal CA for personal area networks","authors":"R. Deng, F. Bao","doi":"10.1109/GLOCOM.2003.1258485","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258485","url":null,"abstract":"A personal certification authority (CA) for personal area networks (PANs) was presented in (C. Gehrmann, et al., (2002)). In this paper, we propose an improved version of the Personal CA which is more robust and secure than the original system.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121997914","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258751
Xiang Chen, Yuguang Fang
Next generation wireless networks target to provide quality of service (QoS) for multimedia applications. In this paper, the system supports two QoS criteria, i.e., the system should keep the handoff dropping probability always less than a predefined QoS bound, while maintaining the relative priorities of different traffic classes in terms of blocking probability. To achieve this goal, a dynamic multiple-threshold bandwidth reservation scheme is proposed, which is capable of granting differential priorities to different traffic class and to new ad handoff traffic for each class by dynamically adjusting bandwidth reservation thresholds. Moreover, in times of network congestion, a preventive measure by use of throttling new connection acceptance is taken. Another contribution of this paper is to generalize the concept of relative priority, hence giving the network operator more flexibility to adjust admission control policy by incorporating some dynamic factors such as offered load. The elaborate simulation is conducted to verify the performance of the scheme.
{"title":"An adaptive bandwidth reservation scheme in multimedia wireless networks","authors":"Xiang Chen, Yuguang Fang","doi":"10.1109/GLOCOM.2003.1258751","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258751","url":null,"abstract":"Next generation wireless networks target to provide quality of service (QoS) for multimedia applications. In this paper, the system supports two QoS criteria, i.e., the system should keep the handoff dropping probability always less than a predefined QoS bound, while maintaining the relative priorities of different traffic classes in terms of blocking probability. To achieve this goal, a dynamic multiple-threshold bandwidth reservation scheme is proposed, which is capable of granting differential priorities to different traffic class and to new ad handoff traffic for each class by dynamically adjusting bandwidth reservation thresholds. Moreover, in times of network congestion, a preventive measure by use of throttling new connection acceptance is taken. Another contribution of this paper is to generalize the concept of relative priority, hence giving the network operator more flexibility to adjust admission control policy by incorporating some dynamic factors such as offered load. The elaborate simulation is conducted to verify the performance of the scheme.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124018645","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 : 2003-12-01DOI: 10.1109/GLOCOM.2003.1258616
Hichem Besbes, Alex W. Paek
We present a low complexity blind receiver tailored for QAM signals. Various simplifications are introduced in carrier/phase recovery and adaptive equalizer algorithms. For blind equalization, the multi-modulus algorithm (MMA) and its generalized version (GMMA) are very promising. They combine the benefits of the reduced constellation algorithm (RCA) and the constant modulus algorithm (CMA) (Yang, J. et al., IEEE J. Select. Areas Commun., vol.20, no.5, p.997-1015, 2002). We propose a low-complexity version of these algorithms by modifying the error function and applying the sign data LMS algorithm for coefficient adaptation. The proposed algorithms use fewer multiplication operations than conventional ones, and ensure a good rate of convergence with an acceptable steady state. Convergence analysis, in the mean sense, of the proposed algorithm is presented. For carrier/phase recovery, we propose an algorithm that has two modes of operation - acquisition and tracking. The overall proposed scheme is promising, especially for applications dealing with a high baud rate over a severe channel, such as VDSL systems, where the required number of taps for the equalizer is large. Computer simulations are presented to support our approach.
提出了一种适合QAM信号的低复杂度盲接收机。在载波/相位恢复和自适应均衡器算法中引入了各种简化。对于盲均衡，多模算法(MMA)及其广义版本(GMMA)是很有前途的。它们结合了约简星座算法(RCA)和恒模算法(CMA)的优点(Yang, J. et al.， IEEE J. Select)。Commun领域。第20卷，没有。5, p.997-1015, 2002)。我们通过修改误差函数并应用符号数据LMS算法进行系数自适应，提出了这些算法的低复杂度版本。该算法比传统算法使用更少的乘法运算，并保证了良好的收敛速度和可接受的稳态。给出了该算法的均值收敛性分析。对于载波/相位恢复，我们提出了一种具有捕获和跟踪两种工作模式的算法。整个方案是有希望的，特别是在处理高波特率的应用程序在一个严峻的信道，如VDSL系统，其中均衡器所需的抽头数量很大。给出了计算机模拟来支持我们的方法。
{"title":"A low-complexity blind QAM receiver","authors":"Hichem Besbes, Alex W. Paek","doi":"10.1109/GLOCOM.2003.1258616","DOIUrl":"https://doi.org/10.1109/GLOCOM.2003.1258616","url":null,"abstract":"We present a low complexity blind receiver tailored for QAM signals. Various simplifications are introduced in carrier/phase recovery and adaptive equalizer algorithms. For blind equalization, the multi-modulus algorithm (MMA) and its generalized version (GMMA) are very promising. They combine the benefits of the reduced constellation algorithm (RCA) and the constant modulus algorithm (CMA) (Yang, J. et al., IEEE J. Select. Areas Commun., vol.20, no.5, p.997-1015, 2002). We propose a low-complexity version of these algorithms by modifying the error function and applying the sign data LMS algorithm for coefficient adaptation. The proposed algorithms use fewer multiplication operations than conventional ones, and ensure a good rate of convergence with an acceptable steady state. Convergence analysis, in the mean sense, of the proposed algorithm is presented. For carrier/phase recovery, we propose an algorithm that has two modes of operation - acquisition and tracking. The overall proposed scheme is promising, especially for applications dealing with a high baud rate over a severe channel, such as VDSL systems, where the required number of taps for the equalizer is large. Computer simulations are presented to support our approach.","PeriodicalId":301154,"journal":{"name":"GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124502816","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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