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Guest editorial - modulation, coding and signal processing for wireless communications

IEEE Wireless Communications 2005年第2期12卷 6-7页

Presents the guest editorial for this issue of the publication.

关键词： modulation coding Signal processing Wireless communication Multiaccess communication Interference cancellation MIMO OFDM Multicarrier code division multiple access Peak to average power ratio Multipath channels

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Performance study of adaptive modulation/coding in MIMO-OFDM system

Performance study of adaptive modulation/coding in MIMO-OFDM...

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Canadian Conference on Electrical and Computer Engineering (CCECE)

作者： Shang Jing Gao Yan Li Zhen Man Yi Song Junde Electrical Engineering Department Beijing University of Posts and Telecommunications China

ISBN: (纸本)0780377818

MIMO/OFDM is one of the promising technologies to improve the spectral efficiency, enhance system capacity and mitigate intersymbol interference in the fourth generation broadband mobile communication system. In this paper, we aim at the study of a communication system that employs both MIMO-OFDM and adaptive modulation/coding technologies. In this article, the performance of different modulation schemes including fixed modulation/coding and adaptive modulation/coding is analyzed and compared by simulation. We also propose an adaptive modulation/coding algorithm for multiuser MIMO-OFDM system. This adaptive allocation algorithm assigns the subcarriers and bits for users in the system with the minimum total transmission power and targeted bit error rate (BER) based on the time-variant MIMO channel condition. Computer simulation results demonstrate that the proposed algorithm is not only simple but can also have a relative low transmission power compared with the fix BPSK, QPSK and 16QAM modulation schemes.

关键词： modulation coding OFDM modulation MIMO Bit error rate Intersymbol interference Broadband communication Mobile communication Performance analysis Computational modeling Analytical models

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A Type II Hybrid ARQ Protocol with Adaptive modulation and coding for Time-Correlated Fading Channels: Analysis and Design

A Type II Hybrid ARQ Protocol with Adaptive Modulation and C...

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IEEE International Conference on Communications (ICC)

作者： J. S. Harsini F. Lahouti M. Levorato M. Zorzi School of Electrical and Computer Engineering University of Tehran Tehran Iran Department of Electrical Engineering University of Stanford USA Department of Information Engineering University of Padova Padova Italy

This paper presents performance analysis and cross-layer design approaches for hybrid ARQ (HARQ) protocol in wireless networks which employ adaptive modulation and coding (AMC) at the physical layer and are subject to time-correlated fading channels. Utilizing a Markov channel model which accounts for the temporal correlation in successive parity transmissions by the adaptive rate HARQ protocol, we derive the system throughput and the packet loss probability based on a rate compatible punctured convolutional (RCPC) code family. As an application, we then present a cross-layer AMC design which takes into account the performance gain of the HARQ protocol at the link layer. The results illustrate that including AMC in the HARQ protocol leads to a substantial throughput gain, but the channel correlation strongly diminishes the performance of the HARQ protocol in terms of throughput and packet loss rate.

关键词： Automatic repeat request modulation coding Fading Throughput Performance gain Performance analysis Cross layer design Wireless application protocol Wireless networks Adaptive systems

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Combining adaptive modulation and coding with truncated ARQ enhances throughput

Combining adaptive modulation and coding with truncated ARQ ...

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IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC)

作者： Qingwen Liu Shengli Zhou G.B. Giannakis Department of ECE University of Minnesota Minneapolis MN USA

We develop a cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a truncated automatic repeat request (ARQ) protocol at the data link layer, in order to maximize spectral efficiency under prescribed delay and performance constraints. We derive the achieved spectral efficiency in closed-form for transmissions over Nakagami-m block fading channels. Numerical results reveal that retransmissions at the data link layer alleviate stringent error-control requirements at the physical layer, and thereby enable considerable spectral efficiency gains. Diminishing returns appear on the spectral efficiency improvement as the number of retransmissions increases, which suggests that a small number of retransmissions strikes a desirable delay-throughput tradeoff.

关键词： modulation coding Automatic repeat request Throughput Physical layer Delay Cross layer design Protocols Transmitters Fading Forward error correction

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Throughput performance of quantized proportional fair scheduling with adaptive modulation and coding

Throughput performance of quantized proportional fair schedu...

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Wireless Telecommunications Symposium, WTS

作者： Fumio Ishizaki Gang Uk Hwang Department of Systems Design and Engineering Nanzan University Seto Japan Department of Mathematical Sciences and Telecommunication Engineering Program Korea Advanced Institute of Science and Technology Daejeon South Korea

Assuming a logarithmic rate model for SISO (Single-Input Single-Output) systems, the information theoretic capacity under scheduling algorithms exploiting multiuser diversity in wireless networks has been studied so far. However, in many cases, the throughput achieved in real wireless networks is very different from (and is much less than) the information theoretic capacity obtained under the assumption of the logarithmic rate model, and the rate functions in real wireless networks are very different from the logarithmic rate model. Hence, to examine the usefulness of the scheduling algorithms exploiting multiuser diversity in real wireless networks, we should study the throughput performance under more realistic rate function model rather than the information theoretic capacity under the logarithmic rate model. In this paper, we consider a wireless network where QPF (Quantized Proportional Fair) scheduling and AMC (adaptive modulation and coding) scheme are employed. Assuming a realistic rate function of AMC, we then analyze the throughput performance under the QPF scheduling with the AMC scheme. We also provide numerical results to investigate the usefulness of the QPF scheduling with the AMC scheme.

关键词： Throughput Adaptive scheduling modulation coding Wireless networks Scheduling algorithm Quantization Design engineering Performance analysis Downlink Systems engineering and theory

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Adaptive modulation and coding scheme with intra- and inter-cell mobility for HSDPA system

Adaptive Modulation and Coding scheme with intra- and inter-...

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International Conference on Broadband Networks (BroadNets)

作者： K. Ibrahimi R. El-Azouzi S. K. Samanta E. H. Bouyakhf LIA/CERI University of Avignon France LIMIARF/FSR Mohammed V-Agdal University Avignon France LIA/CERI University of Avignon Avignon France LIMIARFIFSR Mohammed V-Agdal University Rabat Morocco

The Adaptive modulation and coding (AMC) scheme which handles user's mobility issue plays a significant role to improve the desired quality of service in high Speed Downlink Packet Access (HSDPA) networks. We develop a resource allocation which maintains constant bit rate for real-time (RT) and non-real-time (NRT) calls independently of the user position in the cell. We present analytical results relating to user performance in terms of blocking and dropping probabilities, and the results relating to the system performance in term of total throughput. We propose a call admission control scheme to derive a good trad-off between the blocking and dropping probabilities, and the choice of scheduling that efficiently utilizes the available resources.

关键词： modulation coding Multiaccess communication Adaptive systems Quality of service Downlink Resource management Bit rate Performance analysis System performance Throughput

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Power and bandwidth efficient modulation and coding for small satellite communication terminals

Power and bandwidth efficient modulation and coding for smal...

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IEEE International Conference on Communications (ICC)

作者： A. Tomlinson A. Ambroze G. Wade Department Communication & Electronic Engineering University of Plymouth UK Department Electrical and Computer Engineering University of Newcastle NSW Australia

ISBN: (纸本)0780374002

The objective of this project is to maximise the power and bandwidth efficiency of small satellite Earth communication terminals whose main limitation to satellite capacity is a nonlinear transmitting power amplifier. A form of envelope equalisation is presented in which regular QPSK modulation is used together with instantaneous data magnitude modulation so as to produce a near constant envelope signal when filtered with root 35% raised cosine filtering. The algorithm for deriving the magnitude values is presented along with results using a data lookup table approximation. Bit error rate figures are presented for envelope equalisation combined with a (4096,3249) binary product code and MAP decoding. It is shown that at 10/sup -6/ BER the E/sub b//N/sub 0/ is 3.52 dB, some 0.26 dB from the linear system. When used with a nonlinear power amplifier, the benefit of envelope equalisation is approximately 3 dB. The power spectrum is identical to that of the linear system with no spectral spreading and no increase in adjacent channel interference.

关键词： Bandwidth modulation coding Satellite communication Artificial satellites Power amplifiers Bit error rate Linear systems Satellite ground stations Quadrature phase shift keying Filtering

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Multi-Group Wireless Multicast Broadcast Services Using Adaptive modulation and coding: Modeling and Analysis

Multi-Group Wireless Multicast Broadcast Services Using Adap...

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IEEE Conference on Vehicular Technology (VTC)

作者： Yu-Cheng Liang Ching-Chun Chou Hung-Yu Wei Department of Electrical Engineering National Taiwan University Taiwan

Adaptive modulation and coding (AMC) is attracting research interest in wireless multicast broadcast services (MBS). AMC increases the system throughput by utilizing possible good channel states instead of using robust modulation and coding schemes. A model for the AMC in an MBS system with multiple MBS groups is provided, and stochastic analysis using Markov chain is also applied for modeling analysis. Simulation results show extremely high correspondence to the proposed mathematical model.

关键词： modulation coding Feedback Robustness Throughput Mathematical model Radio broadcasting Switches Base stations Data communication Stochastic systems

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A simplified technique for adaptive MIMO, modulation, and coding

A simplified technique for adaptive MIMO, modulation, and co...

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IEEE Radio and Wireless Symposium (RWS formerly RAWCON)

作者： C. Ian Phelps R. Michael Buehrer Mobile and Portable Radio Research Group (MPRG) Wireless@VT Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg VA USA

In this paper we develop a technique for adaptive configuration of multi-antenna systems including modulation, coding, and the multi-antenna scheme without channel state information at the transmitter (CSIT) and with minimal feedback. Using a combination of theoretical and simulation-based models, we develop and verify a set of multi-antenna-scheme specific distance metrics for adaptation. Further, we integrate these MIMO distance metrics with standard distance metrics for adaptive modulation and coding (AMC). We show that with these simple metrics the adaptive scheme can achieve performance that is close to channel capacity and within a fraction of a dB of the best throughput achievable for the transmissions modes considered. The focus of this work is adaptation for a fixed BER while maximizing the spectral efficiency using minimal feedback.

关键词： MIMO modulation coding Bit error rate Radio transmitters Feedback Adaptive arrays Transmitting antennas Covariance matrix Fading Mobile computing

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modulation and coding for land mobile satellite channels

Modulation and coding for land mobile satellite channels

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IEEE International Conference on Communications (ICC)

作者： W. Rafferty D. Divsalar Jet Propulsion Lab. California Inst. of Technol. Pasadena CA USA Jet Propulsion Laboratory California Institute of Technology USA

A summary is presented of the various modulation and coding techniques that have been investigated for 2.4/4.8-kb/s 5-kHz-spaced, land mobile satellite (LMS) channels. Two detection schemes are described which have many inherent advantages due to their common feed-forward processing structure. These are differentially coherent and pilot-aided detection. Based on the channel throughput and bit error rate (BER) performance requirements, i.e. 4.8 kb/s and 10/sup -3/ BER at 11 dB E/sub b//N/sub 0/, it is shown that rate-2/3, eight-phase-shift-keying (8PSK), trellis-coded modulation (TCM) with data symbol interleaving is the preferred modulation type. The receiver is implemented using differential detection augmented with feed-forward Doppler estimation.< >

关键词： modulation coding Satellite broadcasting Bit error rate Fading Laboratories Propulsion Space technology Frequency Speech Least squares approximation

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