Journal ArticleDOI
Quadrature Overlapped Raised-Cosine Modulation
M. Austin,Ming Chang +1 more
TLDR
Computer simulation results show that sidelobe regeneration caused by the channel nonlinearity is much less for SQORC than it is for the other modulation formats considered, and the power spectral density of QORC is shown to take on the form of the product of thePower spectral densities of MSK and QPSK.Abstract:
A variation of an old but neglected pulse shaping technique, raised-cosine, is investigated. By overlapping raised-cosine pulses in each of two data streams and then by quadrature combining them, a simple QPSK/MSK type modulation results. This quadrature overlapped raised-cosine (QORC) modulation exhibits a hybrid structure of QPSK and MSK modulations. The power spectral density of QORC is shown to take on the form of the product of the power spectral densities of MSK and QPSK. The obvious consequences are that the power spectral density main lobe retains the width of the spectral density main lobe of QPSK, but the sidelobes drop off much faster (1/f^{6}) . A simple QORC modulator can be implemented similar to an MSK modulator. Several correlation type receivers are investigated and their performances calculated. Computer simulation results are used to compare end-to-end system performance of QORC and staggered QORC (SQORC) with MSK, QPSK, and staggered QPSK (SQPSK) for both linear and nonlinear satellite channels. The performance of QORC and SQORC compares very favorably with QPSK, SQPSK, and MSK. QORC performs particularly well in the presence of a nonlinear channel. The effect of phase equalization of the channel filter was investigated with outstanding performance improvement. The simulation results show that sidelobe regeneration caused by the channel nonlinearity is much less for SQORC than it is for the other modulation formats considered.read more
Citations
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Journal ArticleDOI
Exact and Approximate Construction of Digital Phase Modulations by Superposition of Amplitude Modulated Pulses (AMP)
TL;DR: It is shown that any constant amplitude binary phase modulation can also be expressed as a sum of a finite number of time limited amplitude modulated pulses (AMP decomposition), and new methods for computing autocorrelation and power frequency spectrum are derived.
Journal ArticleDOI
Continuous phase modulation
TL;DR: A number of methods for constructing constant amplitude signals which significantly outperform MSK are considered, and at what level of complexity these improvements are obtained and realized.
Journal ArticleDOI
XPSK: A New Cross-Correlated Phase-Shift Keying Modulation Technique
TL;DR: It is shown that the baseband signal of the modulator, the P_{e} = f(E_{b}/N_{0}) performance, and the spectral characteristics of nonlinearly amplified (hard-limited or saturated) radio systems of XPSK and tamed frequency modems (TFM) are practically the same.
Book
Bandwidth-Efficient Digital Modulation with Application to Deep Space Communications
TL;DR: This paper presents a brief review of IJF-QPSK and SQORC and their Relation to FQ PSK, and describes the implementation of ISI-Based Transmitter Implementation, as well as some of the techniques used in this implementation.
Journal ArticleDOI
Peak power and bandwidth efficient linear modulation
Scott L. Miller,Robert J. O'dea +1 more
TL;DR: This paper looks into modulation formats which minimize peak power and retain high spectral efficiency, and a generalized phase shift keying (PSK) modulation format is developed and shown to offer superior peak power efficiency relative to that of commonly used linear modulation formats.
References
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Journal ArticleDOI
Maximum-likelihood sequence estimation of digital sequences in the presence of intersymbol interference
TL;DR: In this paper, a maximum likelihood sequence estimator for a digital pulse-amplitude-modulated sequence in the presence of finite intersymbol interference and white Gaussian noise is developed, which comprises a sampled linear filter, called a whitened matched filter, and a recursive nonlinear processor, called the Viterbi algorithm.
Journal ArticleDOI
Partial-Response Signaling
Peter Kabal,Subbarayan Pasupathy +1 more
TL;DR: A PRS system model is introduced which enables the investigation of PRS schemes from the viewpoint of spectral properties such as bandwidth, nulls, and continuity of derivatives and it is shown that eye width, a performance measure that has not been used previously in comparing PRS systems, can be calculated analytically in many cases.
Journal ArticleDOI
MSK and Offset QPSK Modulation
S. Gronemeyer,A. McBride +1 more
TL;DR: A Markov process representation is developed which is applicable to either the MSK or OK-QPSK waveform and is employed to illustrate the similarity between the modulation processes and to obtain the autocorrelations and power spectral densities of the two waveforms.
Journal ArticleDOI
Pulse and Spectrum Manipulation in the Minimum (Frequency) Shift Keying (MSK) Format
TL;DR: The minimum (frequency) shift keying format is generalized to enable further improvements in the spectrum while retaining the well-known constant envelope property and the excellent communications efficiency of MSK.
Journal ArticleDOI
A Generalization of Minimum-Shift-Keying (MSK)-Type Signaling Based Upon Input Data Symbol Pulse Shaping
TL;DR: The properties of minimum-shift-keying-type signals are the subject of this paper and specific examples are included as illustrations of the theory both for the binary and M -ary cases.