Topic
Continuous phase modulation
About: Continuous phase modulation is a research topic. Over the lifetime, 3199 publications have been published within this topic receiving 37245 citations. The topic is also known as: CPM.
Papers published on a yearly basis
Papers
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03 Jun 2007
TL;DR: In this article, a frequency domain cancellation technique was used to examine nonlinearities and associated memory effects of the modulation characteristics of RF power amplifiers (PAs) used in envelope elimination and restoration (EER) systems.
Abstract: A frequency domain cancellation technique was used to examine nonlinearities and associated memory effects of the modulation characteristics of RF power amplifiers (PAs) used in envelope elimination and restoration (EER) systems. Using offset sinusoidal modulation on the drain of a GaAs power amplifier (PA), a measure of the distortion in the amplitude modulation (AM) characteristic, as well as the undesired phase modulation (PM) may be obtained by examining the harmonics of the modulation sidebands. While care was taken to avoid significant frequency response variations in the envelope amplifier and bias feeds, phase deviation of the sideband harmonics relative to the carrier was still observed. Furthermore, it was found that proper termination of the second harmonic of the RF carrier at the PA output reduced this phase deviation, hence allowing for simpler static compensation of the amplitude modulation characteristic.
9 citations
21 Jun 2021
TL;DR: In this paper, the authors considered spatial-integrated Sidelobe level (ISLR) as the design metric and optimized it under continuous and discrete phase constraints, where the problem formulation leads to a quadratic fractional programming, where an effective Coordinate Descent (CD) -based method to solve the problem, which minimizes the objective function monotonically.
Abstract: In this paper we design transmit beampattern for 4D-imaging automotive radar systems. To this end, we consider spatial- Integrated Sidelobe Level (ISLR) as the design metric and optimize it under continuous and discrete phase constraints. The problem formulation leads to a quadratic fractional programming, where we propose an effective Coordinate Descent (CD) -based method to solve the problem, which minimizes the objective function monotonically. In every iterations of the proposed method, we find global optimum solution for a single variable problem under continuous phase constraint. Under discrete phase constraint, we use Fast Fourier Transform (FFT) to solve problem which is efficient in terms of implementation. Through numerical simulations, we illustrate the performance of our proposed method and compare it with state-of-the art.
9 citations
TL;DR: By expressing a CPM signal in its equivalent binary multi- form, a generalization of Laurent's result is derived for the general class of such waveforms that use noninteger modulation indices.
Abstract: The Laurent Decomposition expresses any binary single-h continuous phase modulated (CPM) signal as the summation of a finite number of pulse amplitude modulated (PAM) waveforms, and the resulting signal space is so constructed that the waveform can usually be synthesized with a reasonable degree of accuracy by using only the ldquomainrdquo component pulse. This derivation has been very useful for reduced complexity demodulation of binary CPM signals. Subsequent to Laurent's work, it was shown that commensurate expressions could be obtained for multilevel and multi-h CPM, but with an exponential increase in the total number of PAM component pulses in the signal representation. In this paper, we show that by expressing a CPM signal in its equivalent binary multi- form, we can derive a generalization of Laurent's result for the general class of such waveforms that use noninteger modulation indices. In this new signal representation, there is a clearly identifiable data-dependent ldquomainrdquo expansion pulse during each symbol interval which carries most of the signal energy. As in the Laurent Decomposition, the number of terms in this decomposition is only dependent on the CPM signal memory.
9 citations
TL;DR: It is possible to establish communication between different MSK modems employing different formulations of MSK by simple processing of the data, and how to convert from one formulation to another by manipulating the input or output data is shown.
Abstract: Minimum shift keying (MSK) is a digital modulation scheme which is suited to demanding applications requiring good bandwidth efficiency and error performance. It can be regarded as continuous phase frequency shift keying (CPFSK) with two signalling frequencies. In general, there is no unique mapping from the input data polarity to the particular signalling frequency during a given bit interval. The simplest formulation maps zeros of the data (marks) to the lower frequency, and ones (spaces) to the higher frequency. Other formulations of MSK employ more complex mappings. The article summarises the most commonly encountered mappings, then shows how to convert from one formulation to another by manipulating the input or output data. It is, therefore, possible to establish communication between different MSK modems employing different formulations of MSK by simple processing of the data.
9 citations
30 Sep 2004
TL;DR: A method of estimating the capacity for a Continuous Phase Modulation (CPM) system is proposed and techniques for design of codes for this system are described and utilized LDPC codes, since they can be designed to perform very close to capacity limit of the system.
Abstract: Capacity Estimation and Code Design Principles for Continuous Phase Modulation (CPM). (May 2003) Aravind Ganesan, B.Tech., Indian Institute of Technology, Madras Chair of Advisory Committee: Dr. Krishna R. Narayanan Continuous Phase Modulation is a popular digital modulation scheme for systems which have tight spectral efficiency and Peak-to-Average ratio (PAR) constraints. In this thesis we propose a method of estimating the capacity for a Continuous Phase Modulation (CPM) system and also describe techniques for design of codes for this system. We note that the CPM modulator can be decomposed into a trellis code followed by a memoryless modulator. This decomposition enables us to perform iterative demodulation of the signal and improve the performance of the system. Thus we have the option of either performing iterative demodulation, where the channel decoder and the demodulator are invoked in an iterative fashion, or a non-iterative demodulation, where the demodulation is performed only once followed by the decoding of the message. We highlight the recent results in the estimation of capacity for channels with memory and apply it to a CPM system. We estimate two different types of capacity of the CPM system over an Additive White Gaussian Noise (AWGN). The first capacity assumes that optimum demodulation and decoding is done, and the second one assumes that the demodulation is done only once. Having obtained the capacity of the system we try to approach this capacity by designing outer codes matched to the CPM system. We utilized LDPC codes, since they can be designed to perform very close to capacity limit of the system. The design complexity for LDPC codes
9 citations