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发表于 2006-6-7 10:49
英文资料
28.An Integrated Subchannel Scheduling Algorithm for Adaptive Modulation and Coding (AMC) MIMO-OFDM Wireless Systems
(下载）
In this paper, we develop an integrated subchannel scheduling algorithm to maximize the system throughput while guarantee minimum data rate requirements for multimedia users in multiuser MIMO-OFDM systems downlink transmission utilizing adaptive modulation and coding (AMC) with limited channel state information feedback. By integrated subchannel scheduling, we apply the mathematical equivalence between antennas and subcarriers in the analysis, getting multiple parallel transmit subchannels, and then evaluate the channel state from the viewpoint of receivers. Joint space-frequency diversity as well as multiuser diversity is exploited simultaneously by the subchannel allocation algorithm. A modified proportional fair scheduling is proposed and a fast algorithm for more practical implementation is also proposed. By numerical examples, system throughput and fairness superiority of the our scheduling scheme are verified .
29.A Simulation Study on Channel Estimation for MIMO-OFDM Based Beyond 3GMobile Systems
Abstract :Multi-Input Multi-Output antennas based Orthogonal Frequency-Division Multiplexing (MIMO-OFDM) has been chosen as the ai r interf ace technology f or Chinaps beyond 3G Time-Division Duplex ( TDD) mobile system in the FuTURE research project . Channel estimation plays a key role on the perf ormance of the MIMO-OFDM receiver. In this paper , we present f ive channel estimation algorithms and study thei r perf ormance in a simulated beyond 3G TDD mobile system. Simulation results show that the adaptive 2D-LMS algorithm we proposed recently has the best perf ormance when the signal to noise ratio is lower than 8 dB.
Key words : OFDM; channel estimation ; mobile communication ; beyond 3G
30.An MIMO-OFDM Technique for High-Speed Mobile Channels
Abstract—In this letter,a new orthogonal frequency-division multiplexing(OFDM) technique for multiple-input multiple output (MIMO) channels is proposed to reduce interchannel interference (ICI) caused by high-speed mobiles in cellular environments. After analyzing the ICI caused by high speed mobile channels using a simple curve fitting technique,the weighting factor for group transmission is optimized.Then,a new MIMO-OFDM technique,based on the weighting factor optimization,is proposed for reducing ICI caused by time varying channels.Performances of the proposed technique is verified by using the I-METRA channel,proposed for an MIMO channel to 3GPP,and an MIMO-OFDM simulator designed for macrocelluar mobile communication.It is shown by computer simulation that the proposed MIMO-OFDM technique is effective in reducing ICI and noise as well as in obtaining diversity gain even under highly-correlated fast fading channels,compared with the conventional MIMO-OFDM schemes.
IndexTerms—MIMO-OFDM,ICI,time-varying channel.
31.Capacity Limits of MIMO Channels
Abstract—We provide an overview of the extensive recent results on the Shannon capacity of single-user and multiuser<br>multiple-input multiple-output (MIMO) channels. Although enormous capacity gains have been predicted for such channels,<br>these predictions are based on somewhat unrealistic assumptions about the underlying time-varying channel model and how well<br>it can be tracked at the receiver, as well as at the transmitter. <br>More realistic assumptions can dramatically impact the potential capacity gains of MIMO techniques. For time-varying MIMO channels there are multiple Shannon theoretic capacity definitions and, for each definition, different correlation models and channel information assumptions that we consider. We first provide a comprehensive summary of ergodic and capacity versus outage results for single-user MIMO channels. These results indicate that the capacity gain obtained from multiple antennas heavily depends on the available channel information at either the receiver or transmitter, the channel signal-to-noise ratio, and the correlation between the channel ains on each antenna element.We then focus attention on the capacity region of the multiple-access channels (MACs) and the largest known achievable rate region for the broadcast channel. In contrast to single-user MIMO channels, capacity results for these multiuser MIMO channels are quite difficult to obtain, even for constant channels. We summarize results for the MIMO broadcast and MAC for channels that are either constant or fading with perfect instantaneous knowledge of the antenna gains at both transmitter(s) and receiver(s). We show that the capacity region of the MIMO multiple access and the largest known achievable rate region (called the dirty-paper region) for the MIMO broadcast channel are intimately related via a duality transformation. This transformation facilitates<br>finding the transmission strategies that achieve a point on the boundary of the MIMO MAC capacity region in terms of the transmission strategies of the MIMO broadcast dirty-paper region and vice-versa. Finally, we discuss capacity results for multicell MIMO channels with base station cooperation. The base stations then act as a spatially diverse antenna array and transmission strategies that exploit this structure exhibit significant capacity gains. This section also provides a brief discussion of system level issues associated with MIMO cellular. Open problems in this field abound and are discussed throughout the paper.
Index Terms—Antenna correlation, beamforming, broadcast channels (BCs), channel distribution information (CDI), channel state information (CSI), multicell systems, multiple-access channels (MACs), multiple-input multiple-output (MIMO) channels, multiuser systems, Shannon capacity.
32.LDPC based differential unitary space-frequency coding for MIMO-OFDM systems
Abstract: This paper proposes a novel LDPC based differential unitary space-frequency coding (DUSFC) scheme for MIMO-OFDM systems when neither the transmitter nor the receiver has access to the channel state information (CSI). The new DUSFC strategy basically consists of coding across transmit antennas and OFDM tones simultaneously as well as differential modulation in the time-domain. It can fully exploit the inherent advantages provided by the multipath fading channels, resulting in<br>a high degree of diversity. The state-of-the-art low-density parity-check (LDPC) codes are concatenated with our DUSFC as channel coding to improve the bit error rate (BER) performance considerably. Owing to the maximum multipath diversity and large coding advantages, LDPC-DUSFC strongly outperforms the differential unitary space-time coded OFDM chniques recently proposed in literature. The corresponding iterative decoding algorithm without channel estimation is finally provided to offer significant performance gain. Simulation results illustrate the merits of the proposed scheme.<br>Key words: Differential modulation, Unitary space-time codes, Space-frequency coding, MIMO, OFDM, LDPC
33.MIMO 的基本知识介绍
The Provision of an Initial Study of Multiple In Multiple Out Technology
有参考价值，共85页。
The suitability of OFDM as a modulation technique for wireless telecommunications, with a CDMA comparison.
早期的OFDM研究文章，共110页，为国外Eric Lawrey博士撰写。
这是第二版，于2001年10月发表。
34.MIMO+SC-FDE 在B3G/4G中的应用
摘要: 在介绍下一代移动通信B3/ 4G 的性能与OFDM 的实现原理基础上, 针对多载波系统载频同步比较敏感和峰平比PAPR 大两大不足, 提出了一种基于OFDM 系统的单载波系统实现方案, 并对SC- FDE+MIMO 在B3G/ 4G系统中的应用进行讨论。
关键词: 正交频分复用; 下一代移动通信; 单载波; 频域均衡; 多输入多输出
35.MIMO基础和性能简介
Communications in wireless MIMO channels: Channel models, baseband algorithms, and system design
36.Bandwidth-Efficient Wireless OFDM
Abstract—Due to ever-increasing bandwidth demands in future wireless service, the radio frequency band becomes more and more invaluable. In this paper, we address channel equalization for bandwidth-efficient wireless orthogonal frequency-division multiplexing (OFDM). First, we show that in order to be free of both interchannel interference and interblock interference,<br>wireless OFDM has to occupy a bandwidth wider than the Nyquist rate and use insufficient statistics in symbol demodulation. Thus,the conventional OFDM gains computational efficiency using discrete Fourier transform (DFT) in demodulation at the cost of low efficiency of bandwidth usage and degradation in symbol error performance. Then we consider the OFDM that achieves high efficiency of bandwidth usage, allows interchannel interference and interblock interference to exist, and uses sufficient statistics in symbol demodulation. A one-tap decision feedback equalizer<br>(DFE) is proposed for equalization of the bandwidth-efficient OFDM system. Simulation and numerical evaluation for an indoor wireless asynchronous transfer mode network are carried out. It is demonstrated that though occupying a narrower bandwidth, the one-tap DFE-based bandwidth-efficient OFDM system achieves lower symbol error rate and higher mutual information than the conventional DFT-based OFDM system. The proposed OFDM system presents a monotonically increasing symbol error rate, and a convex-down achieved mutual information with respect to increasing efficiency of bandwidth usage.
37.MIMO系统的天线选择
ABSTRACT：Multiple-antenna systems, also known as multiple-input multiple-output radio, can improve the capacity and reliability of radio communication.<br>However, the multiple RF chains associated with multiple antennas are costly in terms of size, power, and hardware. Antenna selection is a low-cost low-complexity alternative to capture many of the advantages of MIMO systems. This article reviews classic results on selection diversity, followed by a discussion of antenna selection algorithms at the transmit and receive sides. Extensions of classical results to antenna subset selection are presented. Finally, several open problems in this area are pointed out.
38.Intercarrier Interference in MIMO OFDM
Abstract—In this paper, we examine multicarrier transmission over time-varying channels. We first develop a model for such a transmission scheme and focus particularly on multiple-input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM). Using this method, we analyze the impact of time variation within a transmission block (time variation could arise both from Doppler spread of the channel and from synchronization errors). To mitigate the effects of such time variations, we propose a time-domain approach. We design ICI-mitigating block linear filters, and we examine how they are modified in the context of space-time block-coded transmissions. Our approach reduces to the familiar single-tap frequency-domain equalizer when the channel is block time invariant. Channel estimation in rapidly time-varying scenarios becomes critical, and we propose a scheme for estimating channel parameters varying within a transmission block. Along with the channel estimation scheme, we also examine the issue of pilot tone acement and show that in time-varying channels, it may be better to group pilot tones together into clumps that are equispaced onto the FFT grid; this placement technique is in contrast to the common wisdom for time-invariant channels. Finally, we provide numerical results illustrating the performance of these schemes, both for uncoded and space-time block-coded systems.
Index Terms—Channel estimation, Doppler, fast fading channels,intercarrier interference, MIMO, multicarrier smission,<br>pilot tones, wireless transmission.
39.Frequency Synchronization for MIMO OFDM Wireless LAN Systems
Abstract—This paper proposes an accurate and time-efficient technique for frequency synchronization of multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. The technique uses a preamble and is thus especially suitable for burst mode communication. The preamble consists of training sequences simultaneously transmitted from the various transmit antennas. From analysis, it is shown that the accuracy of frequency synchronization is close to the Cram´er-Rao lower bound and increases for increasing rms delay spreads and number of receive antennas. Furthermore, application of the proposed algorithm in MIMO OFDM wireless<br>local-area-network (WLAN) systems leads to a BER that is only slightly higher than that of a perfectly synchronized system, making it highly applicable.
40.Power allocation for MIMO2OFDM systems with multi2user decoupl ing and schedul ing
Abstract : A power allocation scheme for multi2user multiple2input multiple2output orthogonal frequency division multiplexing (MI2<br>MO2OFDM) systems with channel state information (CSI) on transmitter and receiver is presened. Multi2user power allocation can<br>be decoupled into single user power allocation throughout null space mapping of multi2user channel and power allocation can be per2<br>formed throughout spatial2spectral water2filling for per user. To deal with more users in system and fading correlation , scheduling is<br>performed to maintain the gain of power allocation. The proposed scheme can substantially improve system’s spectral efficiency with<br>low complexity. Simulation results validate the accuracy of theoretic analyses.<br>Key words : power allocation , multi2user information theory , radio resource management , MIMO , OFDM.
41.基于导频和变换域的SISO/MIMO-OFDM系统自适应信道估计
评价：一般
摘要:根据导频信号在变换域中的频响特性,将系统的变换域滤波器设计成具有更好滤波效果的“带阻滤波器”;在小信噪比和大信噪比条件下,分析了变换域能量参数对系统信道估计性能的影响,推导了新的能量参数表达式,理论证明了根据接收端检测到的信噪比自适应选择能量参数可以显著改善信道估计的性能. 仿真结果表明,提出的信道估计算法具有较好的性能,在一定程度上可以接近于理想信道估计的性能,适用于SISO OFDM系统和M IMO OFDM系统.
关键词:自适应信道估计;正交频分复用(OFDM) ;发射分集
42.<a href="https://www.anywlan.com/show.asp?id=289" target="_blank" ><FONT color=#ff0000>Effects of HPA Non Linearity on Frequency Multiplexed OFDM </A>
Abstract—The paper analyzes the performance of the downlink channel of a multimedia interactive service system which transmits the desired information by the frequency multiplexing of several OFDM signals compliant with the DVB-T standard. The effects of the nonlinear distortions introduced by a High Power Amplifier on the system performance are evaluated both in terms of the Bit Error Rate (BER) degradation in AWGN channels and of the spectral regrowth. The performance comparison to the case of a single DVB-T signal as well as the benefits of an ideal predistortion is also considered by comparing analytical results to computer simulations.
Index Terms—CABSINET, communication system nonlinearities,DVB-T, non linear distortions, OFDM, predistortion.
43.Mixed BB–IF Predistortion of OFDM Signals in Non-Linear Channels
Abstract—It is well known that power amplifier induced nonlinear distortions produce a signal spectral regrowth at the<br>transmitter output of digital radio communication systems. This effect is responsible for both adjacent channel interference and BER degradation. Signal predistortion is a technique that counteracts such phenomena. Technological advances in the last decade, renewing the interest in this technique, led to the realization<br>of digital baseband (BB) predistorters that overcome the performance of the existing analog IF (Intermediate Frequency) ones. However, the substitution of an analog IF predistorter with a digital BB one forces to partially redesign the system architecture. An alternative approach is proposed in this paper, based on digital and analog techniques, which combines the precision of the digital BB solution with the practicality of an IF architecture.<br>This solution is particularly interesting to substitute an old analog IF predistorter simply plugging-in the new digital one,<br>without further changes in the transmitter architecture. Critical aspects, predistortion algorithms and simulation performance are presented with respect to a Digital Video Broadcasting system which is based on an OFDM modulation and is very sensitive to nonlinear distortions because of the adopted multicarrier modulation.<br>Index Terms—Digital broadcasting, IF predistortion,nonlinearity.
44.相关MIMO最优合并系统性能分析
Performance Analysis of MIMO-OC Systems with and without Co-channel Interference
摘要：在有或没有同信道干扰情况下,本文研究了相关瑞利信道下MIMO最优合并系统性能. 基于复数域上多元统计理论, 给出了统一的性能分析方法, 并推导出了系统中断概率的一般闭合表达式。 本文还显示已有的相关结果均是我们结果的特例。
Abstract:, we investigate performance of multiple-input /multiple-output (MIMO) systems employing optimum combining over spatial correlated Rayleigh fading channels with and without co-channel interference. Based on the theory of complex matrix variate distributions, we give a unified approach to the performance analysis for such MIMO systems, and derive exact closed-form expressions for the system outage probability, which are very general including some of existing related results as special cases and allowing for the correlated structures of both signal andinterferers to be arbitrary at both transmitter and receiver ends.
45.一种基于MIMO信道的准最优联合解调解码算法
我们提出了一种基于MIMO信道的联合解调解码算法，在较多的发射天线环境下我们的算法能够显著的降低计算复杂度，因而可以获得较好的性能复杂度比特性。通过计算机仿真，我们对最优联合解调解码算法，准最优联合解调解码算法和分离的软输出软输入解调解码算法作了比较。
Abstract－We propose a suboptimal joint demodulation decoding (JDD) algorithm for<br>multiple-input, multiple-output (MIMO) channels. Compared with the optimal JDD, our<br>algorithm can decrease the computational complexity significantly in the large number of transmit antennas, thus offering favorable performance/complexity characteristics.<br>Computer simulation results are provided to compare the performance of the optimal JDD, suboptimal JDD, and the conventional separable soft-input soft-output demodulation decoding (SSDD).
47.基于802.16d的宽带无线接入
（网友 lzming 提供）
ABSTRACT<br>Broadband wireless access is the most challenging segment of the wireless revolution since it has to demonstrate a viable alternative to the cable modem and DSL technologies that are strongly entrenched in the last mile access environment. The Analysis, Research, and Consultancy (ARC) Group forecasts that the fixed wireless deployments in both homes and businesses<br>will reach almost 28 million by 2005, with North America and Western Europe accounting for 24 percent and 27 percent of these, respectively.Whether the promise of BWA will materialize depends on its appeal to telecom operators<br>from the perspective of deployment economics, where the critical factor is the ease of installation of broadband wireless subscriber units. This<br>ultimately leads to nonprofessional installation of integrated all-indoor BWSUs. Consequently the physical layer (PHY) has to mitigate the very tough impairments that characterize these nonline-of-sight environments. In this context we shall overview the work of the one of the IEEE 802.16 standard subcommittee projects that deals with a BWA solution based on OFDM access (OFDMA) aiming at the most challenging NLOS scenarios.
48.具有相关干扰的MIMO相关瑞利衰落信道容量研究
摘要：本文探讨具有同信道干扰的MIMO信道容量问题。论文考虑一般相关瑞利/相关瑞利模型，并假定接收端有完美信道状态信息，而发送端没有信道状态信息。利用矩阵变量分布理论， 论文推导出一些典型情况下交互信息的矩生成函数精确封闭表达式，然后利用这些表达式，给出了相应情况下平均信道容量的精确封闭表式。
Abstract<br>In this paper, we investigate the capacity of multiple-input/multiple-output (MIMO) systems, which is a general Rayleigh/Rayleigh model including spatially correlated channels as well as spatially correlated interferers. Perfect channel information is assumed to be available to the receiver, but the transmitter has no channel information. Based on the theory of matrix variate distribution, we derive exact closed-form expressions of the moment generating function (MGF) of mutual information of MIMO channels with interference. Then we obtain further exact closed-form expressions of the MIMO ergodic capacity with these MGF formulas of mutual information.
49.Mixed BB–IF Predistortion of OFDM Signals in Non-Linear Channels
Abstract—It is well known that power amplifier induced nonlinear distortions produce a signal spectral regrowth at the<br>transmitter output of digital radio communication systems. This effect is responsible for both adjacent channel interference and BER degradation. Signal predistortion is a technique that counteracts such phenomena. Technological advances in the last decade, renewing the interest in this technique, led to the realization of digital baseband (BB) predistorters that overcome the performance of the existing analog IF (Intermediate Frequency) ones. However, the substitution of an analog IF predistorter with a digital BB one forces to partially redesign the system architecture. An alternative approach is proposed in this paper, based on digital and analog techniques, which combines the precision of the digital BB solution with the practicality of an IF architecture.This solution is particularly interesting to substitute an old analog IF predistorter simply plugging-in the new digital one,<br>without further changes in the transmitter architecture. Critical aspects, predistortion algorithms and simulation performance are presented with respect to a Digital Video Broadcasting system which is based on an OFDM modulation and is very sensitive to nonlinear distortions because of the adopted multicarrier modulation.
50.Space-Time Coding and Signal Processing for MIMO Communications.
51.A New Method of Phase Noise Detection and Compensation in OFDM Systems
Abstract-- Phase noise introduced by the receiver local oscillator has effects on the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems severely. The common compensation method can only correct common phase error (CPE) caused by the low-frequency part of the phase-noise spectrum, and can’t compensate phase noise thoroughly. In this paper, a new method, Per-symbol phase noise detection and compensation method, is proposed. Based on a frequency-domain linearized parametric model for phase noise, the method not only deals with CPE more effectively, but also compensates most of inter-carrier interference (ICI) induced by the high-frequency part of the phase-noise spectrum. As will be seen, this method well compensates phase noise in higher SNRs and lower quality tuners.<br>Keywords: Per-symbol, CPE, phase noise, OFDM
52.Broadband MIMO-OFDM Wireless Communications
Orthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and/or to enhance the system capacity on time-variant and frequency-selective channels, resulting in a multiple-input multiple-output (MIMO) configuration.This paper explores various physical layer research challenges in MIMO-OFDM system design, including physical channel measurements and modeling, analog beam forming techniques using adaptive antenna arrays, space–time techniques for MIMO-OFDM, error control coding techniques, OFDM preamble and packet design, and signal processing algorithms used for performing time and frequency synchronization, channel estimation, and channel tracking in MIMO-OFDM systems. Finally, the paper considers a software radio implementation of MIMO-OFDM.
Keywords—Adaptive antennas, broadband wireless, multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), software radio, space–time coding, synchronization. |
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发表于 2006-6-13 20:48
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