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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Dissertation
Channel Estimation Strategies for Coded MIMO Systems
TL;DR: This thesis analyzes the system performance of coded multiple-input multiple-output (MIMO) systems for the quasi-static fading channel and focuses on developing channel estimation strategies for an iterative Vertical Bell-Labs Layered Space Time (V-BLAST) architecture.
Journal ArticleDOI
Multiuser receivers for code-division multiple-access systems with trellis-based modulation
U. Fawer,Behnaam Aazhang +1 more
TL;DR: A code-division multiple-access (CDMA) communication system is studied where a trellis-based scheme is used for data encoding and modulation, and the optimum detector is derived by maximizing the likelihood ratio and the suboptimum detectors are also capable of alleviating the near-far problem.
Journal ArticleDOI
Information Guided Precoding for OFDM
TL;DR: A practical precoding strategy is designed for P-OFDM-IM under the phase shift keying/quadrature amplitude modulation constraint, and a low-complexity log-likelihood ratio detector is proposed to ease the computational burden on the receiver.
Patent
Error-correction system for two-dimensional multilevel signals
TL;DR: In this article, an error correction system in which part of the data bits of first multilevel input data is differentially encoded to form second data comprising the differentially coded data bits and the remainder data bits is converted into third data in two-dimensional multi-level signal space according to a predetermined transfer function.
Journal ArticleDOI
An approach to Ungerboeck coding for rectangular signal sets (Corresp.)
G. Pottie,D. Taylor +1 more
TL;DR: It is shown that rate 2/3 encoders may be used to achieve most of the theoretically possible coding gain in the proposed scheme where the effect of the error coefficient on the coding gain has been considered.
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.