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2008 International ITG Workshop on Smart Antennas最新文献

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Linear precoding in multiple antenna broadcast channels: Efficient computation of the achievable rate region 多天线广播信道中的线性预编码:可达速率区域的有效计算
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475532
Eduard Axel Jorswieck, E. Larsson
{"title":"Linear precoding in multiple antenna broadcast channels: Efficient computation of the achievable rate region","authors":"Eduard Axel Jorswieck, E. Larsson","doi":"10.1109/WSA.2008.4475532","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475532","url":null,"abstract":"This paper studies the achievable rate region of the two-user multiple antenna broadcast channel with linear precoding. It consists of two parts: In the first part, the set of beam- forming vectors which achieve points on the Pareto boundary are characterized by a single real valued parameter per user. It is shown that a certain linear combination of the zero-forcing (ZF) beamforming vector and the maximum- ratio-transmission (MRT) beamforming vector can achieve all Pareto boundary points of the rate region. In the second part, an iterative algorithm is proposed to compute the maximum sum-rate. Based on the characterization of the Pareto boundary, we develop an outer approximation algorithm for monotonic optimization using polyblocks. Numerical examples provide comparisons between rate and capacity regions as well as between the maximum sum-rate and maximum- capacity operating points.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"69 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":"132862542","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: 20
FPGA implementation of MMSE metric based efficient near-ML detection 基于MMSE度量的高效近ml检测的FPGA实现
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475549
M. Joham, L. G. Barbero, T. Lang, W. Utschick, J. Thompson, T. Ratnarajah
{"title":"FPGA implementation of MMSE metric based efficient near-ML detection","authors":"M. Joham, L. G. Barbero, T. Lang, W. Utschick, J. Thompson, T. Ratnarajah","doi":"10.1109/WSA.2008.4475549","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475549","url":null,"abstract":"We consider the problem of detecting a vector signal transmitted over a multiple input-multiple output (MIMO) channel. A number of suboptimal detectors have been proposed to solve that problem, given that maximum likelihood (ML) detection is NP-hard. After reviewing the main concepts of the ML and the minimum mean square error (MMSE) metrics, we introduce an unbiased MMSE metric that can be applied to existing MIMO detectors in order to improve their performance. Applying the biased and unbiased MMSE metrics together with a real-valued representation of the system, the performance and complexity of a number suboptimal MIMO detectors is compared in this paper, showing how the QR decomposition-M (QRD-M) can be used to approximate ML performance with low complexity. In order to further validate those results, the QRD-M algorithm has been implemented on a field-programmable gate array (FPGA) platform, showing an excellent fixed-point performance under real-time conditions. Finally, the resulting real-time detector has been compared to state-of-the-art detectors previously implemented, in terms of complexity, error performance and throughput.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"46 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":"133072135","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: 11
Non-WSSUS vehicular channel characterization in highway and urban scenarios at 5.2GHz using the local scattering function 基于局部散射函数的5.2GHz高速公路和城市场景下非wssus车辆信道特性研究
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475530
A. Paier, T. Zemen, L. Bernadó, G. Matz, J. Karedal, N. Czink, C. Dumard, F. Tufvesson, A. Molisch, C. Mecklenbräuker
{"title":"Non-WSSUS vehicular channel characterization in highway and urban scenarios at 5.2GHz using the local scattering function","authors":"A. Paier, T. Zemen, L. Bernadó, G. Matz, J. Karedal, N. Czink, C. Dumard, F. Tufvesson, A. Molisch, C. Mecklenbräuker","doi":"10.1109/WSA.2008.4475530","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475530","url":null,"abstract":"The fading process in high speed vehicular traffic telematic applications at 5 GHz is expected to fulfill the wide-sense stationarity uncorrelated scattering (WSSUS) assumption for very short time-intervals only. In order to test this assumption we apply the concept of a local time- and frequency-variant scattering function, which we estimate from measurements of vehicle-to-vehicle wave propagation channels by means of a multi-window spectrogram. The obtained temporal sequence of local scattering functions (LSF) is used to calculate a collinearity measure. We define the stationarity time as the support of the region where the collinearity exceeds a certain threshold. The stationarity time is the maximum time duration over which the WSSUS assumption is valid. Measurements from an highway with vehicles driving in opposite directions show stationarity times as small as 23 ms whereas vehicles driving in the same direction show stationarity times of 1479 ms.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"88 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":"133896887","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: 129
Multiuser diversity and beamforming gain in a fast fading MU-MISO downlink with many users 多用户快速衰落MU-MISO下行链路中的多用户分集和波束形成增益
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475576
M. Castañeda, M. Ivrlac, J. Nossek
{"title":"Multiuser diversity and beamforming gain in a fast fading MU-MISO downlink with many users","authors":"M. Castañeda, M. Ivrlac, J. Nossek","doi":"10.1109/WSA.2008.4475576","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475576","url":null,"abstract":"Multiuser diversity is an inherent form of diversity present in time-varying systems with several users, like for instance the broadcast channel. An opportunistic scheduler has to be used in order to exploit this type of diversity. Besides the number of users and speed of the channel fluctuations, the degree of multiuser diversity depends on the dynamic range of the channel. A scheme that increases the effective dynamic range of the channel by deploying multiple antennas at the transmitter is called opportunistic beamforming It has been shown that the deployment of multiple transmit antennas with opportunistic beamforming increases the degree of multiuser diversity in several scenarios, including in slow fading and correlated fading scenarios. However, in this work we show that even in a fast fading scenario the deployment of multiple transmit antennas with opportunistic beamforming also results in having beamforming gain when the number of users is large. In the present work, we have considered a multiuser multiple-output single-output (MU-MISO) downlink channel in a single cell scenario.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"19 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":"129988225","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
Smart antenna design for beamforming of UWB signals in Gaussian noise 高斯噪声下超宽带信号波束形成的智能天线设计
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475575
V. V. Mani, R. Bose
{"title":"Smart antenna design for beamforming of UWB signals in Gaussian noise","authors":"V. V. Mani, R. Bose","doi":"10.1109/WSA.2008.4475575","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475575","url":null,"abstract":"The paper looks at the problem of Ultra Wideband (UWB) impulse beamforming using linear array, when the desired signal and several interferences from different directions are received by the antenna array. These signals and interferences are UWB signals having Gaussian power spectral density form. The objective is to suppress the interferences, while keeping the power of desired signal unchanged. In this paper we propose a UWB smart antenna which points its main beam towards prestreed direction of the array and suppresses interference and noise coming from other than the look direction of the array. Antenna weights are calculated adaptively to meet the above conditions. We also analyze the SESfR (Signal to Interference noise ratio) of the array for different interference directions, when the desired signal is coming in prestreed direction. Finally simulation results show the suppression capabilities of the proposed smart antenna.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"1 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":"114154320","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: 15
MIMO SC-FDMA system performance for space time / frequency coding and spatial multiplexing MIMO SC-FDMA系统的空时频编码和空间复用性能
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475586
Nima Tavangaran, A. Wilzeck, T. Kaiser
{"title":"MIMO SC-FDMA system performance for space time / frequency coding and spatial multiplexing","authors":"Nima Tavangaran, A. Wilzeck, T. Kaiser","doi":"10.1109/WSA.2008.4475586","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475586","url":null,"abstract":"The 3GPP long term evolution (LTE) of the universal mobile telecommunications system (UMTS) employs single-carrier frequency division multiple access (SC-FDMA) for its uplink transmission [1]. SC-FDMA is motivated at mobile terminals by its low peak to average power ratio (PAPR) enabling the use of battery efficient power amplifiers. This contribution considers the effects of different pulse shaping roll-off factors and subcarrier mapping strategies on the PAPR and on the frame error rate (FER) performance of a by multiple input multiple output (MIMO) technologies extended SC-FDMA uplink system. Spatial multiplexing (SM) and space frequency coding (SFC) are considered, while the latter one is studied in a simplified LTE scheme.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"15 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":"130827974","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: 16
Time delay estimation in a spatially structured model using decoupled estimators for temporal and spatial parameters 基于时空参数解耦估计的空间结构模型时延估计
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475531
F. Antreich, J. Nossek, G. Seco-Granados, A. L. Swindlehurst
{"title":"Time delay estimation in a spatially structured model using decoupled estimators for temporal and spatial parameters","authors":"F. Antreich, J. Nossek, G. Seco-Granados, A. L. Swindlehurst","doi":"10.1109/WSA.2008.4475531","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475531","url":null,"abstract":"This paper deals with the joint estimation of time-delay and spatial (direction-of-arrival, DOA) parameters of several replicas of a known signal in an unknown spatially correlated field. Unstructured and structured models have been proposed for maximum likelihood (ML) estimators in the literature. The former suffers from a severe performance degradation in some scenarios, whereas the latter involves huge complexity. It is shown how the extended invariance principle (EXIP) can be applied to obtain estimates with the quality of those of the structured model, but with the complexity of the unstructured one. We present a method to improve the quality of the time-delay estimates obtained with an unstructured spatial model when an estimate of the DOAs is available. Exemplarily, simulation results for time-delay estimation for GPS (Global Positioning System) are included and confirm that our proposal approaches the Cramer-Rao lower bound (CRLB) of the structured model even when suboptimal DOA estimates obtained by ESPRIT are introduced.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"4 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":"123309565","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
Semi-orthogonal user selection for MISO systems with quantized feedback 具有量化反馈的MISO系统的半正交用户选择
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475554
H. Khanfir, D. L. Ruyet, Berna Özbek
{"title":"Semi-orthogonal user selection for MISO systems with quantized feedback","authors":"H. Khanfir, D. L. Ruyet, Berna Özbek","doi":"10.1109/WSA.2008.4475554","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475554","url":null,"abstract":"For MISO multi-user downlink wireless communication system with precoding at the transmission, the channel state information at the transmitter can provide tremendous capacity gains. However, the amount of feedback data increases with the number of users in the cell and the number of transmit antennas. In this paper, we study on different algorithms and criteria in order to significantly reduce the amount of feedback data. We associate the classical norm criterion with a criterion based on the orthogonality between the user channels. Without cooperation between the users, we only allow users that are semi-orthogonal to feedback their channel information (CQI and CDI) to the base station. The feedback CDI is quantized using a local grassmanian packing. We show that the proposed combined criterion with a finite feedback rate gives better performance compared to the norm criterion. Furthermore we show that the performance is not affected by CQI quantization.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"33 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":"132800845","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: 1
Beamforming and scheduling in a cellular OFDM system 蜂窝式OFDM系统中的波束形成与调度
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475559
H. Rohling, R. Grünheid, Alireza Tassoudji
{"title":"Beamforming and scheduling in a cellular OFDM system","authors":"H. Rohling, R. Grünheid, Alireza Tassoudji","doi":"10.1109/WSA.2008.4475559","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475559","url":null,"abstract":"This paper presents a system proposal for the downlink of cellular communication network which is based on the MIMO-OFDM transmission technique. The core idea is the combination of a self-organized beamforming approach with opportunistic scheduling algorithms. In the considered system, different beams are formed and grouped together. The space-time-frequency resources are then allocated to MTs by intelligent scheduling methods such that mobile terminals are assigned resources when a high instantaneous SINR is observed. Beside a fixed beamforming technique, an adaptive use of beams is also pursued. The performance of the system proposal is quantitatively assessed in terms of system throughput.","PeriodicalId":255495,"journal":{"name":"2008 International ITG Workshop on Smart Antennas","volume":"70 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":"127110480","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
Analysis of subcarrier pairing in a cellular OFDMA relay link 蜂窝OFDMA中继链路中子载波配对分析
2008 International ITG Workshop on Smart Antennas Pub Date : 2008-03-21 DOI: 10.1109/WSA.2008.4475544
T. Riihonen, R. Wichman, Jyri Hämäläinen, A. Hottinen
{"title":"Analysis of subcarrier pairing in a cellular OFDMA relay link","authors":"T. Riihonen, R. Wichman, Jyri Hämäläinen, A. Hottinen","doi":"10.1109/WSA.2008.4475544","DOIUrl":"https://doi.org/10.1109/WSA.2008.4475544","url":null,"abstract":"We consider a cellular OFDMA relay link consisting of a base station (BS), an infrastructure-based amplify-and-forward relay node (RN) and N active mobile user equipments (UEs). We study how to optimally pair the BS-RN subcarriers with the RN-UE subcarriers when the K subcarriers in the RN-UE channel are assigned for the UEs using round robin scheduling. The main contribution is to analyze the performance of the system by deriving closed-form expressions for average end-to-end SNR and capacity. The calculated measures facilitate performance evaluation that illustrates the benefit of channel-adaptive subcarrier pairing over fixed pairing.","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":"129247380","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: 22
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