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Patent

Multi-frequency differentially encoded digital communication for high data rate transmission through unequalized channels

Paul H. Moose
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TLDR
In this article, a differentially encoded digital signal waveform is generated as a discrete time representation of a desired analog signal utilizing multi-frequency modulation techniques, and the computational capability of present day, industry-standard microcomputers (57) equipped with a floating point array processor or digital signal processor chip is utilized to perform digital frequency encoding and compute both discrete Fourier transforms (31) and inverse discrete transform (25) to provide a transmitter (51) and receiver (53) system.
Abstract: 
A differentially encoded digital signal waveform is generated as a discrete time representation of a desired analog signal utilizing multi-frequency modulation techniques. The computational capability of present day, industry-standard microcomputers (57) equipped with a floating point array processor or digital signal processor chip is utilized to perform digital frequency encoding and compute both discrete Fourier transforms (31) and inverse discrete Fourier transforms (25) to provide a transmitter (51) and receiver (53) system utilizing suitably programmed microcomputers coupled by a communications channel.

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Citations
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Multi-carrier transmission systems

Mikael Isaksson, +14 more
TL;DR: In this article, a multi-carrier transmission system using DMT is described, where frame synchronization is handled separately from sampling clock synchronization, although the two processes are intimately related.
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Nee Richard D.J. Van
TL;DR: The scaleable OFDM system as discussed by the authors provides increased flexibility and adaptability by providing scaling of the operating parameters and/or characteristics for the OFDM systems. But, the scaling of OFDM symbol duration, the number of carriers, and the bits per symbol per carrier is not considered in this paper.
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TL;DR: In this paper, the authors proposed a modulation scheme that assigns up to N DSSS codes to an individual user where N is the number of chips per DssS code.
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Method and apparatus for frame synchronization in mobile OFDM data communication

Cyril Leung, +1 more
TL;DR: In this article, a method and apparatus for achieving symbol synchronization of digital data in an OFDM channel such as a OFDM/FM radio link is presented. But the required bandwidth overhead is less than 10 %.
References
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Book

Digital and analog communication systems

II Leon W. Couch
TL;DR: This book provides a broad introduction to basic analog and digital principles and their application to the design and analysis of real- world communication systems and provides readers with a working knowledge of how to use both classical mathematical and personal computer methods to analyze, design, and simulate modern communication systems.
Patent

Ensemble modem structure for imperfect transmission media

Dirk Hughes-Hartogs
TL;DR: In this paper, a high speed modem that transmits and receives digital data on an ensemble of carrier frequencies spanning the usable band of a dial-up telephone line is described, which includes a system for variably allocating data and power among the carriers to compensate for equivalent noise and to maximize the data rate.
Journal ArticleDOI

Digital sound broadcasting to mobile receivers

B. Le Floch, +2 more
- 01 Aug 1989 - 
TL;DR: The authors describe a system that combines the orthogonal frequency-division multiplexing technique and a coding strategy associated with diversity in the frequency domain that is suitable for digital broadcasting through a particularly hostile urban radio channel.
Patent

Differentially nonlinear convolutional channel coding with expanded set of signalling alphabets

Lee-Fang Wei
TL;DR: In this article, a technique for converting binary digits into a sequence of signalling alphabets of a modulated carrier signal for data transmission is presented, which results in a reduced error probability when maximum likelihood decoding and differential decoding are applied in the receiver.
Patent

Multidimensional, convolutionally coded communication systems

Lee-Fang Wei
TL;DR: In this paper, a family of multi-dimensional convolutionally coded modulation systems achieves enlarged minimum distance between possible sequences of signal points, reduced number of error events with the minimum distance, acceptable peak-to-average power ratio, and immunity to rapid carrier phase changes.