Topic

# Continuous phase modulation

About: Continuous phase modulation is a(n) research topic. Over the lifetime, 3199 publication(s) have been published within this topic receiving 37245 citation(s). The topic is also known as: CPM.

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30 Sep 1986

TL;DR: The first text in bandwidth-efficient digital coded communication was published in this article, where the authors introduced the method of continuous phase modulation (CPM) coding, with full treatment of spectrum, minimum distance, trasnmitters and receivers.

Abstract: First text in bandwidth-efficient digital coded communication. Introduced the method of continuous phase modulation (CPM) coding, with full treatment of spectrum, minimum distance, trasnmitters and receivers.

1,058 citations

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TL;DR: Several workers have recently proposed digital techniques for high-resolution imaging through the turbulent atmosphere to calculate and average phase angles of a series of image Fourier transforms to suppress the unwanted atmospheric effects on image resolution.

Abstract: Several workers have recently proposed digital techniques for high-resolution imaging through the turbulent atmosphere. The basic concept of these algorithms is to calculate and average phase angles of a series of image Fourier transforms to suppress the unwanted atmospheric effects on image resolution. Since computed phase angles contain the ambiguities of integral multiples of 2 pirad, it is necessary to obtain continuous phase curves without the ambiguities before averaging. This process of eliminating the ambiguities is called phase tracking or unwrapping. A similar problem has been discussed by Oppenheim and Schafer and Tribolet in the context of realization of a certain homomorphic signal processing system.

583 citations

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07 Oct 1990

TL;DR: In this paper, the authors explore the dependency of the conduction losses of a bridge leg of a PWM power converter system with a high pulse rate on the shape of the phase modulation functions.

Abstract: The authors explore the dependency of the conduction losses of a bridge leg of a pulsewidth modulation (PWM) power converter system with a high pulse rate on the shape of the phase modulation functions. This is done for modulation methods that are optimized with respect to minimum harmonic current RMS values. The results are compared to the results gained for simple sinusoidal modulation. Besides conduction losses, the switching losses of the electric valves are calculated. The main topic is the determination of those power loss components of a PWM converter system that can be (besides the harmonic losses) influenced by the modulation method selected. As the calculations show, these modulation methods allow a significant increase of the effective switching frequency. The optimal modulation as calculated leads to a reduction of the harmonic power loss in the upper modulation region. Furthermore, due to the frequency modulation the spectrum is spread out to a wider frequency band as compared to operation with constant pulse frequency. >

529 citations

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Lund University

^{1}TL;DR: Comparisons are made with minimum shift keying (MSK) and systems have been found which are significantly better in E_{b}/N_{0} for a large signal-to-noise ratio (SNR) without expanded bandwidth, and schemes with the same bit error probability as MSK but with considerably smaller bandwidth have also been found.

Abstract: The continuous phase modulation (CPM) signaling scheme has gained interest in recent years because of its attractive spectral properties. Data symbol pulse shaping has previously been studied with regard to spectra, for binary data and modulation index 0.5. In this paper these results have been extended to the M -ary case, where the pulse shaping is over a one symbol interval, the so-called full response systems. Results are given for modulation indexes of practical interest, concerning both performance and spectrum. Comparisons are made with minimum shift keying (MSK) and systems have been found which are significantly better in E_{b}/N_{0} for a large signal-to-noise ratio (SNR) without expanded bandwidth. Schemes with the same bit error probability as MSK but with considerably smaller bandwidth have also been found. Significant improvement in both power and bandwidth are obtained by increasing the number of levels M from 2 to 4.

524 citations

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ETH Zurich

^{1}TL;DR: In this article, it was shown that any continuous-phase-modulation (CPM) system can be decomposed into a continuous phase encoder and a memoryless modulator in such a way that the former is a linear (modulo some integer P) time-invariant sequential circuit and the latter is also time invariant.

Abstract: It is shown that any continuous-phase-modulation (CPM) system can be decomposed into a continuous-phase encoder and a memoryless modulator in such a way that the former is a linear (modulo some integer P) time-invariant sequential circuit and the latter is also time invariant. This decomposition is exploited to obtain alternative realizations of the continuous-phase encoder (and hence of CPM) and also to obtain alternative forms of the optimum decoding algorithm. When P is a prime p so that the encoder is linear over the finite field GF(p), it is shown that cascading it with an outside convolutional encoder is equivalent to a single convolutional encoder. It is pointed out that the cascade of the modulator, the waveform channel (which it is assumed is characterized by additive white Gaussian noise), and the demodulator that operates over one symbol interval yield a discrete memoryless channel that can be studied without the distractions introduced by continuous-phase encoding. >

511 citations