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2008 International ITG Workshop on Smart Antennas最新文献

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Closed-loop real-time MIMO-OFDM system for adaptive transmissions 闭环实时MIMO-OFDM自适应传输系统
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475582
A. Camargo, Romeo Lopez Soto, Anand Kakad, Sandeep Laddha, A. Czylwik
{"title":"Closed-loop real-time MIMO-OFDM system for adaptive transmissions","authors":"A. Camargo, Romeo Lopez Soto, Anand Kakad, Sandeep Laddha, A. Czylwik","doi":"10.1109/WSA.2008.4475582","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475582","url":null,"abstract":"This contribution reports the development of a closed-loop MIMO-OFDM system. Requiring no physical connection between the transmitter and receiver stations, for the feedback link, it permits a large flexibility in the experimental investigation of MIMO algorithms with transmit channel state information (CSI) over many propagation scenarios. The analog front ends have been carefully designed for a very good signal quality at high data rates. The hardware and software has been partitioned in such a way that new MIMO processing algorithms using CSI at the transmitter can be easily integrated.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124937386","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}
引用次数: 2
A per-survivor processing algorithm for maximum likelihood equalization of MIMO channels with unknown order 一种未知阶数MIMO信道最大似然均衡的每幸存者处理算法
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475587
M. A. Vázquez, J. Míguez
{"title":"A per-survivor processing algorithm for maximum likelihood equalization of MIMO channels with unknown order","authors":"M. A. Vázquez, J. Míguez","doi":"10.1109/WSA.2008.4475587","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475587","url":null,"abstract":"In the equalization of frequency-selective multiple-input multiple-output (MIMO) channels it is usually assumed that the length of the channel impulse response (CIR), also referred to as the channel order, is known. However, this is not true in most practical situations and, in order to avoid the serious performance degradation that occurs when the CIR length is underestimated, a channel with \"more than enough\" taps is usually considered. This possibly means overestimating the channel order, and is not desirable since the computational complexity of maximum likelihood sequence detection (MLSD) in frequency-selective channels grows exponentially with the channel order. In addition to that, the higher the channel order considered, the more the number of channel coefficients that need to be estimated from the same set of observations. In this paper, we introduce an algorithm for MLSD that incorporates the full estimation of the MIMO CIR parameters, including its order. The proposed technique is based on the per survivor processing (PSP) methodology, it admits both blind and semiblind implementations, depending on the availability of pilot data, and is designed to work with time-selective channels. Besides the analytical derivation of the algorithm, we provide computer simulation results that illustrate the effectiveness of the resulting receiver.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132660517","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}
引用次数: 0
Resource allocation and linear precoding for relay assisted multiuser MIMO systems 中继辅助多用户MIMO系统的资源分配和线性预编码
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475553
A. Wolfgang, N. Seifi, T. Ottosson
{"title":"Resource allocation and linear precoding for relay assisted multiuser MIMO systems","authors":"A. Wolfgang, N. Seifi, T. Ottosson","doi":"10.1109/WSA.2008.4475553","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475553","url":null,"abstract":"In this paper we investigate the use of infrastructure half-duplex amplify-and-forward (AF) relays in the downlink of a multi-user (MU) multiple-input multiple-output (MIMO) system, which uses linear precoding based on block-diagonalization. Owing to the half-duplex mode of the relay, the communication is divided into two time-slots. During the first time-slot the relay nodes are treated as an additional mobile station (MS), while during the second time-slot the base-station (BS) and the relays form a distributed, virtual antenna array. In contrast to many relay applications, the purpose of the proposed scheme is not to increase diversity, but rather to increase the system throughput at the borders of a communication cell or in areas with a high user density. The performance of the proposed architecture is investigated by examining the sum-capacity of the system as well as the distribution of the capacity over the cell-area.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124824661","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}
引用次数: 12
Time-sharing solutions in MIMO broadcast channel utility maximization MIMO广播信道效用最大化中的分时解决方案
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475551
J. Brehmer, Qing Bai, W. Utschick
{"title":"Time-sharing solutions in MIMO broadcast channel utility maximization","authors":"J. Brehmer, Qing Bai, W. Utschick","doi":"10.1109/WSA.2008.4475551","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475551","url":null,"abstract":"The problem of maximizing a utility function over the set of achievable rate vectors in a MIMO broadcast channel is considered. If the optimum rate vector lies in a time-sharing region, it is necessary to identify a set of corner points of the time-sharing region such that the optimum rate vector is a convex combination of these corner points. In a if user MIMO BC, the maximum number of corner points is K!, thus enumerating all corner points is only feasible for small K. In this work, an efficient algorithm for identifying a subset of relevant corner points is proposed. Simulation results show that in a scenario where the time-sharing region has K! corner points, out of which K are required to construct the optimum rate, the proposed algorithm on average computes less than K+1 corner points until convergence.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125505404","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}
引用次数: 3
Convex optimization strategies for precoding of broadcast channels 广播信道预编码的凸优化策略
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475535
Monica Rossi, S. Sorrentino, U. Spagnolini, L. Moretti
{"title":"Convex optimization strategies for precoding of broadcast channels","authors":"Monica Rossi, S. Sorrentino, U. Spagnolini, L. Moretti","doi":"10.1109/WSA.2008.4475535","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475535","url":null,"abstract":"This work tackles the non-convex maximization of throughput for a multiuser MISO wireless system where the transmitter is provided with long-term channel state information and leverages joint multiuser linear precoding and orthogonal space-time block coding (OSTBC). The original problem is reduced here to convex optimization by means of two different strategies. The first solution is based on constrained optimization so that the global problem is split into multiple simple and convex optimizations. Convexity is achieved by setting additional constraints on the mutual interference between the users. The second solution is based on game theory and reaches the Nash equilibrium (i.e., the equilibrium point for non-cooperative games). Numerical results show that the optimized system based on OSTBC and multiuser linear precoding outperforms the conventional TDMA system when the users to be simultaneously served are carefully chosen according to their channels properties.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"202 1-6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120930309","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}
引用次数: 4
Performance of space-time-coded OFDM with sectorized antenna reception 扇区天线接收空时编码OFDM的性能研究
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475574
P. Klenner, K. Kammeyer
{"title":"Performance of space-time-coded OFDM with sectorized antenna reception","authors":"P. Klenner, K. Kammeyer","doi":"10.1109/WSA.2008.4475574","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475574","url":null,"abstract":"Diversity is a well-known means to counter the detrimental effect of fading. Against this background, space-time codes have been designed to facilitate transmit diversity with a suitable receiver. Furthermore, space-time codes combined with OFDM allow for the utilization of frequency selective channels. However, a general assumption underlying the design of space-time codes is the time-invariance of the channel, which is violated in a high mobility environment. Large Doppler spread causing rapidly time-varying channels can be compensated at the receiver by sectorized antennas, which restrict the angle of incidence of imping waves to a finite range. Compared to an omnidirectional antenna, the resulting Doppler spread of a sector antenna and the channels time-variance are reduced. In this paper, we demonstrate the benefits of Doppler compensating sectorized antennas for space-time coded OFDM.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124563588","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}
引用次数: 3
Finite rate feedback schemes for the MIMO OFDM broadcast channel MIMO OFDM广播信道的有限速率反馈方案
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475539
C. Guthy, W. Utschick, G. Dietl
{"title":"Finite rate feedback schemes for the MIMO OFDM broadcast channel","authors":"C. Guthy, W. Utschick, G. Dietl","doi":"10.1109/WSA.2008.4475539","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475539","url":null,"abstract":"Full channel state information at the transmitter leads to large performance gains in multiuser wireless communication systems. However, in practice this assumption cannot be justified, especially when the transmitter cannot directly estimate the channel. For this reason we consider finite rate feedback schemes in this paper, where the channel state information is fed back to the transmitter after quantization. We show performance in terms of sum rate in the MIMO OFDM broadcast channel and present a new combination of lossless and lossy compression of channel state information and subsequent quantization at the receivers.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130608386","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}
引用次数: 10
Downlink performance and capacity of distributed antenna systems based on realistic channel model 基于真实信道模型的分布式天线系统下行性能与容量
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475566
N. Seifi, A. Wolfgang, T. Ottosson
{"title":"Downlink performance and capacity of distributed antenna systems based on realistic channel model","authors":"N. Seifi, A. Wolfgang, T. Ottosson","doi":"10.1109/WSA.2008.4475566","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475566","url":null,"abstract":"Recent academic studies of distributed antenna system (DAS) using a frequency-flat fading channel model show that DAS outperforms standard systems, where the base-station (BS) antenna elements are centralized at one location. In this paper the performance of a DAS under time-varying frequency-selective fading based on a realistic channel model is investigated. Specifically, we show that if we shift the hexagonal cellular layout in the conventional system and use sectorized antennas instead of omnidirectional antennas at each BS, the performance in terms of outage probability and outage capacity will improve by a large extent without a need for additional BS towers. The results show that with the same total transmit power and bandwidth DAS can reduce the inter-cell interference (ICI) in a multicell environment and improve the outage capacity especially near the cell boundary.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127036901","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}
引用次数: 9
Power allocation in service area interference channels 业务区域干扰信道的功率分配
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475545
Shiyang Deng, T. Weber, A. Ahrens
{"title":"Power allocation in service area interference channels","authors":"Shiyang Deng, T. Weber, A. Ahrens","doi":"10.1109/WSA.2008.4475545","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475545","url":null,"abstract":"Adaptive power allocation is an effective means for interference management. This paper addresses transmit power allocation in interference channels with a total power constraint. In particular, realistic service area networks which can be modeled as interference channels are considered for investigation. Various power allocation strategies in service area interference channels are discussed, among which the proposed iterative waterfilling algorithm is verified to be a favorable approach in terms of sum capacity, especially for universal frequency reuse.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123701314","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}
引用次数: 0
Block diagonalization for multiuser MIMO TDD downlink and uplink in time-varying channel 时变信道中多用户MIMO TDD下行链路和上行链路的块对角化
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475540
P. Komulainen, M. Latva-aho, M. Juntti
{"title":"Block diagonalization for multiuser MIMO TDD downlink and uplink in time-varying channel","authors":"P. Komulainen, M. Latva-aho, M. Juntti","doi":"10.1109/WSA.2008.4475540","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475540","url":null,"abstract":"Block diagonalization (BD) is a downlink multiuser multiple-input multiple-output (MIMO) communication strategy that utilizes transmitter channel state information (CSI). This paper proposes a practical uplink MIMO scheme for time division duplex (TDD) systems to co-exist with BD so that the CSI of the BD channel is used also in the uplink transmission. It is shown that the precoded pilot symbols are sufficient in both uplink and downlink to satisfy the needs of both transmission and reception. The capacity of the system is analyzed in conjunction with linear receivers in a time-varying fading channel. The effect of using transmit and receive CSI estimated from noisy pilot symbols is studied. According to the results the proposed uplink transmission strategy provides capacity gain over non-precoded transmission, without being sensitive to channel time variations and CSI estimation errors.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"103 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113992912","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}
引用次数: 4
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