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International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service (TELSIKS)

作者： D. Bandjur M. Mirkovic M. Bandjur M. Andjelkovic Faculty of Mechanical Engineering Pristina Yugoslavia Telekom Srbija A. D Pristina Yugoslavia

In this paper is proposed a new code procedure for coding of two-level facsimile pictures in systems for transmission based on digital modulation of signals. This code procedure provides a very efficient (high compres... 详细信息

关键词： Facsimile Digital modulation Iterative decoding Code standards Testing modulation coding Bit rate Phase shift keying Quadrature amplitude modulation Mechanical engineering

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Joint detection and estimation in space-time coding and modulation

Joint detection and estimation in space-time coding and modu...

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Asilomar Conference on Signals, Systems & Computers

作者： C. Cozzo B.L. Hughes Center for Advanced Computing and Communication Department of Electrical and Computer Engineering North Carolina State University Raleigh NC USA

We consider joint channel estimation and data symbol detection for multipath radio channels with multiple antennas at the transmitter and receiver. An iterative space-time receiver is proposed, based on the expectation-maximization algorithm. We examine the performance of this receiver on the Rayleigh fading channel for transmit diversity and space-time coding methods. Simulation results show that the proposed receiver can often achieve near-coherent performance with modest complexity (2-3 iterations) and using very few training symbols.

关键词： modulation coding Receivers Transmitting antennas Receiving antennas Iterative algorithms Channel estimation Fading Antenna arrays Radio transmitters Wireless communication

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Digital terrestrial television (COFDM 8K system) field trials and coverage measurements in Spain

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IEEE TRANSACTIONS ON BROADCASTING 1999年第2期45卷 171-176页

作者： Arrinda, A Vélez, MM Angueira, P de la Vega, D Ordiales, JL Univ Basque Country ETSII & IT Bilbao Bilbao 48013 Spain

This contribution presents the results of the first digital terrestrial television field trials and coverage measurements in spain. First of all the VIDITER project is presented. The main objective of this work is to study the behavior of a whole digital terrestrial television network, from source coding up to the final signal reception, At this point, the experimental network installed in Madrid-will be described. Next, the measurement campaign is explained, first, by describing the network configuration used for these first field trials, and then, paying attention to the criteria used to select the measurement points and the parameter set to be tested. Some of the results obtained will be shown as a first approach to the figures needed to develop and plan a fully operational digital terrestrial television service.

关键词： TV Radio transmitters Digital modulation modulation coding System testing Interference Laboratories Frequency synchronization Antenna measurements Sea measurements

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Service and system enhancements for TDMA digital cellular systems

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IEEE PERSONAL COMMUNICATIONS 1999年第3期6卷 20-33页

作者： Austin, M Buckley, A Coursey, C Hartman, P Kobylinski, R Majmundar, M Raith, K Seymour, JP Lucent Technol Whippany NJ USA Ericsson Res Triangle Pk NC 27709 USA

Throughout 1998, the TDMA community investigated and defined an enhanced suite of voice and data services for TIA/EIA-136 while also improving its basic system capabilities. These enhancements, collectively named 136+, provide improved voice quality, increased capacity, higher data rates, and improved tools for RF system engineering. The enhancements are obtained by introducing a new modulation scheme (8-PSK), new slot formals, and the addition of several new interleaving and coding options. As a result, TIA/EIA-136 now supports a new vocoder mode, the GSM Enhanced Full-Rate (US1) for improved fidelity applications, a robust IS-641 vocoder mode with a 4 dB FER enhancement on the IS136 downlink, and a new packet data service capable of providing usable data rates of 14.4, 28.8, or 43.2 kb/s on a full-rate, double full-rate, or triple full-rate channel, respectively. The packet data service is truly evolutionary in nature, having a new medium access control layer with a network layer very similar to that used for the existing digital control channel. In addition, it maximizes commonalities among TDMA technologies, using identical higher layers and network architecture to the General Packet Radio Service specified in GSM. furthermore, by using a concept known as tunneling to pass TIA/EIA-136 messages through the GPRS network elements, the existing features defined on the DCCH are maintained. This article provides an overview of these 136+-applications, as well as insight into additional near-term improvements, such as the ability to support six voice users per 30 kHz (TDMA6), downlink time diversity, and fast power control.

关键词： Time division multiple access Vocoders GSM Downlink Radio frequency Data engineering Systems engineering and theory modulation coding Interleaved codes Robustness

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Reduction of decoding complexity of trellises for BCM

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IEE PROCEEDINGS-COMMUNICATIONS 1999年第2期146卷 82-88页

作者： Petronio, MA Carrasco, RA Staffordshire Univ Sch Engn & Adv Technol Beaconside ST18 0AD Staffs England

Block-coded modulation (BCM) combines bandwidth-efficient modulation techniques with error-correction capabilities to allow efficient data transmission over communication channels. The disadvantage of this technique, however, is the complexity of the trellis used in the Viterbi decoding, process. The authors address this problem and propose a method for the reduction of decoding complexity. Optimal sectionalisation has been identified as an appropriate technique and it is applied to trellises of BCM schemes based on a set of new objective functions. The resulting sectionalisation algorithm has been applied to various BCM schemes including 4-PSK, 8-PSK and 16-PSK and a complexity reduction of approximately 20% is achieved. Extensive simulation las shown that both original and sectionalised trellises have the same performance: over Rayleigh, K = 6 Rician and K = 10 Rician fading channels. Furthermore, a comparison between the considered BCM schemes and ring-TCM is provided in term of code performance and decoding complexity.

关键词： computational complexity modulation coding communication channels error-correction capabilities objective functions block-coded modulation data transmission 16-PSK Rician channels block codes Rayleigh fading channels modulation and coding methods Rayleigh channels bandwidth-efficient modulation techniques Rician fading channels Viterbi decoding optimal sectionalisation BCM phase shift keying trellises 8-PSK Codes ring-TCM 4-PSK decoding complexity reduction

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Broad-band OFDM radio transmission for multimedia applications

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PROCEEDINGS OF THE IEEE 1999年第10期87卷 1778-1789页

作者： Rohling, H May, T Brüninghaus, K Grünheid, R Tech Univ Carolo Wilhelmina Braunschweig Dept Telecommun D-38092 Braunschweig Germany

Future multimedia services will require the transmission of very high data rates over broad-band radio channels. In order to provide these services to mobile users, anl appropriate transmission technique has to cope with frequency-selective and time-variant radio channels. The computation complexity for an equalizer increases in a frequency-selective radio channel for high data-rate applications. Furthermore, the overhead for channel estimation procedures increases in time-variant channels. To overcome these drawbacks orthogonal frequency division multiplexing (OFDM) has been considered for broad-band applications in many publications. The objective of this paper is to describe the large potential, the flexibility and adaptivity of the OFDM transmission technique in frequency-selective and time-variant radio channels. In this paper several technical aspects of OFDM transmission systems are discussed, especially the topics of differential modulation for which we compare different demodulation methods and channel coding with soft decision decoding. For higher level differential modulation, multilevel coding is taken into consideration.

关键词： better differential modulation broad-band communication convolutional codes differential amplitude and phase shift keying modulation modulation coding multimedia systems orthogonal frequency division multiplexing (OFDM)

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Signal design for transmitter diversity wireless communication systems over Rayleigh fading channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 1999年第4期47卷 527-537页

作者： Guey, JC Fitz, MP Bell, MR Kuo, WY Ericsson Inc Res Triangle Pk NC 27709 USA Ohio State Univ Dept Elect Engn Columbus OH 43210 USA Purdue Univ Sch Elect Engn W Lafayette IN 47907 USA Lucent Technol Whippany NJ 07981 USA

In this paper, transmitter diversity wireless communication systems over Rayleigh fading channels using pilot symbol assisted modulation (PSAM) are studied. Unlike conventional transmitter diversity systems with PSAM that estimate the superimposed fading process, we are able to estimate each individual fading process corresponding to the multiple transmitters by using appropriately designed pilot symbol sequences. With such sequences, special coded modulation schemes can then be designed to access the diversity provided by the multiple transmitters without having to use an interleaver or expand the signal bandwidth, The notion of code matrix is introduced for the coded modulation scheme, and its design criteria are also established. In addition to the reduction in receiver complexity, simulation results are compared to, and shown to be superior to, that of an intentional frequency offset system over a wide range of system parameters.

关键词： Wireless telecommunication systems Rayleigh fading Diversity reception Signal encoding Communication channels (information theory) modulation Radio transmitters Bandwidth Computer simulation Channel coding Rayleigh fading channels Diversity methods Pilot symbol assisted modulation Raleigh fading channels Transmitter Signal design system parameter RADIO TRANSMITTERS Channel coding Bandwidth diversity reception Rayleigh fading modulation coding Diversity methods Signal encoding Wireless communication systems

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Optical fiber data bus modulation techniques for military avionics

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IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE 1999年第4期14卷 31-37页

作者： Zhang, JG Asian Inst Technol Sch Adv Technol Telecommun Program Pathum Thani 12120 Thailand

In this paper, we propose several modulation techniques for use in military avionics optical fiber data buses, namely, Extended Manchester II Pi-Phase coding with Beginning-Stopping Flags, Partial Trilevel Manchester II Bi-Phase coding, Four-ary Pulse Width modulation, Two-ary Pulse Width modulation with Amplitude-Distinguished Syne Field, Two-ary Message Pulse Width modulation and Two-ary Syne Pulse Amplitude modulation, respectively. Compared with an existing modulation scheme of MIL-STD-1773 avionics data buses, the proposed techniques can be effectively used to overcome the difficulty in recognizing the correct operation states of an active transmitter at the output of optical receivers. The feasibility of proposed modulation schemes are discussed, and their performance is also evaluated.

关键词： Optical fibers Aerospace electronics Pulse width modulation Amplitude modulation modulation coding Optical pulses Space vector pulse width modulation Data buses Optical transmitters Optical receivers

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Advanced channels for DVD with d=2 modulation coding

Advanced channels for DVD with d=2 modulation coding

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Optical Data Storage

作者： S. Gopalaswamy R. Wood Data Storage Institute NUS Singapore Singapore Storage Systems Division IBM San Jose CA USA Electrical and Computer Engineering NUS Singapore Singapore

modulation codes with d>0 are essential in optical recording to enable useful densities, since the minimum mark size achievable is limited by the diffraction-limited spot size. The EFMPLus modulation code is a coding scheme adopted for the digital video disk (DVD). This is a run-length limited code with constraints d=2 and k=10. It is appropriate to exploit this knowledge of the coding scheme in the detection strategies, to sustain high performance at higher densities and data rates. This paper presents the performance of two simple equalizers, one of which uses decision feedback, to achieve a target response that enables optimal detection by simple thresholding. The evaluations are done using a channel model. Equalization strategies that exploit the d=2 RLL constraint in the DVD channel provide improved performance of about 2 to 4 db for the DVD specifications.

关键词： DVD modulation coding Decision feedback equalizers Finite impulse response filter Electron optics Optical feedback Optical filters Optical recording Optical saturation Optical sensors

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Trellis codes for transition jitter noise

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IEEE TRANSACTIONS ON MAGNETICS 1999年第5期35卷 2328-2330页

作者： Wilson, BA Wang, SX Stanford Univ Dept Elect Engn Stanford CA 94305 USA

We present a trellis code which reduces the probability that transition jitter will cause one allowed sequence to be decoded as another allowed sequence. This code requires that transition times mod 4 be in the code of a 4-state convolutional encoder. We also exclude adjacent transitions (d = 1). Sequences satisfying this constraint have capacity of approx. 4/9. This code can be implemented using a finite state encoder, Viterbi detector and sliding-block decoder. Tn the presence of pure jitter noise this code realizes a gain of approximately 3 dB over uncoded recording at the same user density.

关键词： Convolutional codes Jitter Pulse width modulation Magnetic noise Magnetic recording Magnetic modulators modulation coding Saturation magnetization Decoding Convolution

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