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Improving the Performance of Chaos-Based modulations Via Serial Concatenation

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2010年第2期57卷 448-459页

作者： Escribano, Francisco J. Lopez, Luis Sanjuan, Miguel A. F. Univ Alcala de Henares Escuela Politecn Super Dept Teoria Senal & Comunicac Alcala De Henares 28805 Spain Univ Rey Juan Carlos Dept Sistemas Telemat & Computac Mostoles 28933 Spain Univ Rey Juan Carlos Dept Fis Mostoles 28933 Spain

This paper proposes a serially concatenated system with an outer convolutional channel encoder and an inner chaos-based coded modulator. With the help of the principles of symbolic dynamics, the chaotic modulation can be described in terms of a trellis. Owing to this, we show that the resulting system can be designed and analyzed following developments made for serially concatenated channel codes (SCCCs) or bit-interleaved coded-modulation systems. We show how the iterative decoding algorithm used in this concatenated framework can be analyzed through the well-known extrinsic information transfer chart device and how the bit error rate can be bounded using the transfer function of the convolutional channel encoder. Comparison with a related SCCC system in both additive white Gaussian noise and frequency-nonselective fading channels shows that this kind of chaos-based systems keeps the potential advantages of coded-modulation-based systems. We are thus confident that the principles shown here can lead to the design of competitive chaotic discrete communication systems.

关键词： Channel coding chaos concatenated coding fading channels modulation coding

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Discrete Time Faster-than-Nyquist Signalling

Discrete Time Faster-than-Nyquist Signalling

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IEEE Global Telecommunications Conference (GLOBECOM 2010)

作者： McGuire, Michael Sima, Mihai Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 3P6 Canada

ISBN: (纸本)9781424456383

Increasing the symbol rate up to 25% faster than the Nyquist criteria for a digital communications system with QPSK modulation with AWGN channel does not significantly increase the bit error rate or required transmission bandwidth. This so-called Faster-than-Nyquist (FTN) signalling has not been used in commercially deployed communications systems since the previously proposed implementation schemes required large receiver complexity. This paper introduces a reformulation of FTN signalling in terms of a non-square matrix multiplied by a sample vector of modulated QPSK symbols. It is shown that with this formulation the receiver complexity to detect the transmitted data for an AWGN channel is well within the complexity bounds for standard digital communication systems. This formulation enables an analysis of FTN signalling directly comparing it to standard higher order modulation and data coding techniques.

关键词： modulation coding Faster than Nyquist signalling

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On the Efficiency of Persistent Scheduling for Non-periodic Real-time Services in IEEE 802.16e System

On the Efficiency of Persistent Scheduling for Non-periodic ...

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21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Jin, Hu Lee, Ju Young Sung, Dan Keun Korea Adv Inst Sci & Technol Dept EE Taejon 305701 South Korea SK Broandband Seoul South Korea

ISBN: (纸本)9781424480166

In order to reduce MAP overhead for periodic small-sized services such as voice over IP (VoIP) service, a persistent scheduling scheme has been proposed in IEEE 802.16e/m. Although this persistent scheduling scheme is designed for periodic services, we propose to adopt the persistent scheduling for non-periodic real-time services with small-sized packets by considering the advantage of MAP overhead reduction. Assuming Poisson packet arrivals which show a typical non-periodic property, we mathematically analyze the average delay performance and derive the optimal resource allocation period of the persistent scheduling with a given delay requirement. In this paper, we also compare the average occupied resources per frame between the persistent scheduling and the conventional scheduling both in downlink and uplink. Analysis and numerical results show that for the non-periodic services, the persistent scheduling shows more efficient resource usage than that of the conventional scheduling with a smaller packet size and higher modulation and coding scheme.

关键词： IEEE 802.16e system MAP overhead reduction Poisson packet arrivals WiMax average delay performance modulation coding modulation-coding scheme nonperiodic real-time services optimal resource allocation persistent scheduling scheme resource allocation scheduling stochastic processes voice over IP services

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A Novel Spatial modulation Technique with Interference Free Simultaneous Transmission

A Novel Spatial Modulation Technique with Interference Free ...

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21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： ElKalagy, A. AlSusa, E. Univ Manchester Sch Elect & Elect Engn MACS Grp Manchester M60 1QD Lancs England

ISBN: (纸本)9781424480166

A performance-enhanced two-transmit antenna spatial modulation (SM) technique is introduced and analysed. Specifically, this paper modifies the conventional spatial modulation technique by utilising simultaneous transmission from two antennas, couple with the utilisation of short orthogonal codes for antenna identification. A unique symbol to antenna assignment to enable the receiver to distinguish between the different possible constellation points is also presented. To highlight the achieved gains, the paper compares the performances of the proposed technique to those of the conventional SM technique in OFDM systems. The results show that the proposed technique outperforms the conventional one in terms of BER performance. Furthermore we develop analytical analysis for the symbol error ratio (SER) of the proposed technique and show that the analytical and simulation results closely match.

关键词： BER performance antenna identification error statistics interference free simultaneous transmission modulation coding orthogonal codes orthogonal codes symbol error ratio transmitting antennas two-transmit antenna spatial modulation technique

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A Low-Complexity Semi-Analytical Approximation to the Block Error Rate in Nakagami-m Block Fading Channels

A Low-Complexity Semi-Analytical Approximation to the Block ...

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IEEE 72nd Vehicular Technology Conference Fall 2010

作者： Toyserkani, Arash T. Lakshmana, Tilak Rajesh Strom, Erik G. Svensson, Arne Chalmers Commun Syst Grp Dept Signals & Syst SE-41296 Gothenburg Sweden

ISBN: (纸本)9781424435746

There are few analytical formulas that can be used for calculating the block error rate (BLER) in block fading channels. Thus, an estimate of the BLER is often obtained using numerical methods. One such method is the threshold method which assigns 0 or 1 to the instantaneous BLER given the signal to noise ratio (SNR) level. It has been shown that utilizing such a method results in an accurate approximation of the BLER in Nakagami-m block fading channels for a wide range of m. In this work, we consider a recently proposed simple method of obtaining the threshold and study the effect of adopting different physical layer and channel parameters on that threshold. We show that, while the value of this threshold depends on the modulation, coding, and block size, it is almost unaffected by the m parameter of Nakagami-m channels for a wide range of practical values. In addition, for a given modulation and coding method, the threshold is shown to be a simple function of block size. As a result, the computational complexity required to obtain the threshold can be significantly reduced.

关键词： block error probability modulation coding THRESHOLDING METHOD Fading channels signal to noise ratios simple function wide-range

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A Novel Self Organizing Framework for Adaptive Frequency Reuse and Deployment in Future Cellular Networks

A Novel Self Organizing Framework for Adaptive Frequency Reu...

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21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Imran, A. Imran, M. A. Tafazolli, R. Univ Surrey Ctr Commun Syst Res Guildford GU2 5XH Surrey England

ISBN: (纸本)9781424480166

Recent research on Frequency Reuse (FR) schemes for OFDM/OFDMA based cellular networks (OCN) suggest that a single fixed FR cannot be optimal to cope with spatiotemporal dynamics of traffic and cellular environments in a spectral and energy efficient way. To address this issue this paper introduces a novel Self Organizing framework for adaptive Frequency Reuse and Deployment (SO-FRD) for future OCN including both cellular (e. g. LTE) and relay enhanced cellular networks (e. g. LTE Advance). In this paper, an optimization problem is first formulated to find optimal frequency reuse factor, number of sectors per site and number of relays per site. The goal is designed as an adaptive utility function which incorporates three major system objectives;1) spectral efficiency 2) fairness, and 3) energy efficiency. An appropriate metric for each of the three constituent objectives of utility function is then derived. Solution is provided by evaluating these metrics through a combination of analysis and extensive system level simulations for all feasible FRD's. Proposed SO-FRD framework uses this flexible utility function to switch to particular FRD strategy, which is suitable for system's current state according to predefined or self learned performance criterion. The proposed metrics capture the effect of all major optimization parameters like frequency reuse factor, number of sectors and relay per site, and adaptive coding and modulation. Based on the results obtained, interesting insights into the tradeoff among these factors is also provided.

关键词： OFDM based cellular network OFDM modulation OFDMA based cellular network adaptive codes adaptive coding adaptive frequency deployment adaptive frequency reuse adaptive modulation adaptive utility function cellular environment cellular radio energy efficiency objective fairness objective flexible utility function frequency allocation frequency division multiple access future cellular network modulation coding optimal frequency reuse factor optimization problem relay enhanced cellular network self organizing framework spatiotemporal dynamics spectral efficiency objective telecommunication traffic traffic

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CONSTANT MODULUS ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING

CONSTANT MODULUS ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING

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MILCOM Military Communications Conference

作者： Koese, Cenk Chugg, Keith M. Halford, Thomas R. TrellisWare Technol Inc San Diego CA 92127 USA

ISBN: (纸本)9781424481804

Orthogonal frequency domain multiplexing (OFDM) is the signal format of choice for spectrally efficient communications over time-invariant, frequency-selective channels. OFDM has a large peak-to-average power ratio, however, which makes it incompatible with transmitter non-linearities (e.g., saturated power amplifiers (PAs)). Conversely, single-carrier constant envelope modulations can be used with a saturated PA, but exhibit limited spectral efficiency and requiring more complex receiver processing (i.e., channel equalization). This paper presents a method of modulation coding that results in an OFDM signal with constant modulus (CM-OFDM). A method of decoding this modulation code is developed and the resulting CM-OFDM system performance is compared to that of OFDM via simulation. The results suggest that CM-OFDM may provide a waveform uniquely qualified for some operational scenarios.

关键词： OFDM modulation channel equalization constant modulus orthogonal frequency division multiplexing frequency-selective channels modulation coding modulation coding peak-to-average power ratio single-carrier constant envelope modulations spectral efficiency

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A Protocol for Adaptive Multicast Transmission in Packet Radio Networks

A Protocol for Adaptive Multicast Transmission in Packet Rad...

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MILCOM Military Communications Conference

作者： Boyd, Steven W. Ellis, Jason D. Pursley, Michael B.

ISBN: (纸本)9781424481804

Adaptation is required for efficient transmission in a wireless communications network because of the fluctuations in propagation conditions that occur on the links. In a half-duplex packet radio network, the use of unicast transmission typically permits the receiving radio to send packet-by-packet acknowledgments and include a small amount of feedback information in each acknowledgment. For multicast transmission in such a network, it is usually not feasible for all receiving radios to send packet-by-packet acknowledgments, so a receiving radio has fewer opportunities to provide feedback. We present a low-complexity adaptive multicast transmission protocol that compensates for time-varying propagation losses in a packet radio network by adjusting the modulation and coding. Simple receiver statistics furnish the necessary control information for the adaptive protocol;no channel estimation, training, or pilot symbols are needed. The protocol's throughput performance is evaluated for dynamic channels and compared with the throughput of hypothetical ideal protocols that are given perfect channel-state information. We demonstrate that our protocol performs nearly as well as the ideal protocols.

关键词： channel estimation channel-state information half-duplex packet radio network hypothetical ideal protocols low-complexity adaptive multicast transmission protocol modulation coding multicast protocols packet radio networks packet-by-packet acknowledgments

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Unified Theoretical Expressions for the Average Error Rate of Selection Diversity with Arbitrary Coded and Uncoded modulation in Slow Rayleigh Fading and Their Application to Analytical, Semi-Analytical and Simulation Performance Evaluation

Unified Theoretical Expressions for the Average Error Rate o...

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IEEE Global Telecommunications Conference (GLOBECOM 2010)

作者： Beaulieu, Norman C. Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2V4 Canada

ISBN: (纸本)9781424456383

A unified theory for selection combining diversity in Rayleigh fading channels is derived. It is shown that the performance of arbitrary systems used with selection combining diversity can be expressed in terms of only the performance of the system on a single branch Rayleigh fading channel. The results are valid for coded and uncoded transmission as well as for balanced (equal power) diversity branches and unbalanced (unequal power) diversity branches. The unified theory encompasses both general noise and general interference.

关键词： Rayleigh channels Rayleigh fading channels arbitrary coded modulation average error rate diversity reception general interference general noise interference (signal) modulation coding selection combining diversity uncoded modulation

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Rank modulation with Multiplicity

Rank Modulation with Multiplicity

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Globecom Workshops

作者： Jiang, Anxiao (Andrew) Wang, Yue Texas A&M Univ Comp Sci & Eng Dept College Stn TX 77843 USA

ISBN: (纸本)9781424488650

Rank modulation is a scheme that uses the relative order of cell levels to represent data. Its applications include flash memories, phase-change memories, etc. An extension of rank modulation is studied in this paper, where multiple cells can have the same rank. We focus on the rewriting of data based on this new scheme, and study its basic properties.

关键词： data rewriting error correction codes flash memories modulation coding multiple cell multiplicity phase change memories rank modulation rewriting systems

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