Journal ArticleDOI
Channel coding with multilevel/phase signals
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TLDR
A coding technique is described which improves error performance of synchronous data links without sacrificing data rate or requiring more bandwidth by channel coding with expanded sets of multilevel/phase signals in a manner which increases free Euclidean distance.Abstract:
A coding technique is described which improves error performance of synchronous data links without sacrificing data rate or requiring more bandwidth. This is achieved by channel coding with expanded sets of multilevel/phase signals in a manner which increases free Euclidean distance. Soft maximum--likelihood (ML) decoding using the Viterbi algorithm is assumed. Following a discussion of channel capacity, simple hand-designed trellis codes are presented for 8 phase-shift keying (PSK) and 16 quadrature amplitude-shift keying (QASK) modulation. These simple codes achieve coding gains in the order of 3-4 dB. It is then shown that the codes can be interpreted as binary convolutional codes with a mapping of coded bits into channel signals, which we call "mapping by set partitioning." Based on a new distance measure between binary code sequences which efficiently lower-bounds the Euclidean distance between the corresponding channel signal sequences, a search procedure for more powerful codes is developed. Codes with coding gains up to 6 dB are obtained for a variety of multilevel/phase modulation schemes. Simulation results are presented and an example of carrier-phase tracking is discussed.read more
Citations
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Journal ArticleDOI
Geometrically uniform partitions of L*MPSK constellations and related binary trellis codes
TL;DR: Through suitable algorithms, geometrically uniform partitions of L*MPSK (M=4,8,16 and L=1,2,3,4) constellations are found, which present good characteristics in terms of the set of distances at a given partition level, the maximum obtainable rotational invariance, and the isomorphism of the quotient group associated with the partition.
Patent
Efficient partial response equalization
TL;DR: In this article, a reduced state maximum likelihood sequence estimator (RMSSE) is proposed for channels with severe attenuation and spectral nulls, which allows the use of improved equalization techniques.
Autonomous Software-Defined Radio Receivers for Deep Space Applications
TL;DR: In this paper, the authors introduce the concept of an autonomous software-defined radio (SDR) receiver and provide a mathematical derivation of an appropriate solution, a decision metric or loop-structure as appropriate, and performance results.
Patent
Methods and Apparatuses for Signaling with Geometric Constellations
TL;DR: In this article, the authors describe a communication system that uses specific geometric constellations that are capacity optimized at a specific SNR, where ranges within which the constellation points of a capacity optimized constellation can be perturbed and are still likely to achieve a given percentage of the optimal capacity increase compared to a constellation that maximizes dmin, are also described.
Journal ArticleDOI
Spectral efficiency of adaptive coded modulation in urban microcellular networks
Kjell Hole,Geir E. Oien +1 more
TL;DR: This tutorial paper describes a general adaptive coded modulation scheme for airlinks in urban wireless networks and shows why the ALSE of the adaptive coding scheme is larger than the fixed link spectral efficiency of a traditional nonadaptive coding scheme.
References
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Book
Information Theory and Reliable Communication
TL;DR: This chapter discusses Coding for Discrete Sources, Techniques for Coding and Decoding, and Source Coding with a Fidelity Criterion.
Journal ArticleDOI
The viterbi algorithm
TL;DR: This paper gives a tutorial exposition of the Viterbi algorithm and of how it is implemented and analyzed, and increasing use of the algorithm in a widening variety of areas is foreseen.
Book
Principles of Communication Engineering
I. M. Jacobs,J. M. Wozencraft +1 more
TL;DR: Textbook on communication engineering emphasizing random processes, information and detection theory, statistical communication theory, applications, etc.
Journal ArticleDOI
Convolutional codes I: Algebraic structure
TL;DR: Minimal encoders are shown to be immune to catastrophic error propagation and, in fact, to lead in a certain sense to the shortest decoded error sequences possible per error event.
Journal ArticleDOI
Coherent and Noncoherent Detection CPFSK
W. Osborne,M. Luntz +1 more
TL;DR: This work provides a complete analysis of the performance of CPFSK at high SNR as well as low SNR and thereby unifies and extends the results previously available.