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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TL;DR: The use of adaptive decision feedback techniques in the joint estimation of data, carrier phase, and symbol timing is investigated for a 49-QPRS 90 Mbit/s digital radio.
Abstract: The use of adaptive decision feedback techniques in the joint estimation of data, carrier phase, and symbol timing is investigated for a 49-QPRS 90 Mbit/s digital radio. The performance of the carrier and timing recovery loops are analyzed, first in a multipathfree environment and then for the case of a multipath distorted signal and a fixed decision feedback equalizer. Finally, the joint problem of data recovery, estimation of carrier phase, and symbol timing for a
19 citations
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09 Jun 2013TL;DR: Simulation under the same symbol error rate and channel state shows the JPAPM can improve the PA energy efficiency significantly compared with the traditional quadrature amplitude modulation.
Abstract: A Joint Polarization-Amplitude-Phase Modulation (JPAPM) scheme in wireless communication is proposed to improve the Power Amplifier (PA) energy efficiency. The proposed scheme introduces the signal's Polarization State (PS), amplitude and phase as the information-bearing parameters. Thus, the data rate can be further enhanced on the basis of the traditional amplitude-phase modulation. Also, since the transmitted signal's PS completely manipulated by orthogonally dual-polarized antennas is unaffected by the PA, JPAPM can let PA work in its nonlinear region to acquire high PA conversion efficiency. Furthermore, to mitigate the polarization-based impairment to JPAPM caused by the wireless channel's polarization dependent loss effect, the optimal pre-compensation algorithm is also presented. Simulation under the same symbol error rate and channel state shows the JPAPM can improve the PA energy efficiency significantly compared with the traditional quadrature amplitude modulation.
19 citations
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22 Jun 1987TL;DR: In this paper, a non-linear method is proposed for transmitting digital data by means of continuous phase modulation (CPM), where the transmission signal s(t) is generated by retrieving stored digital values, which are allocated to a continuous sequence of symbols ai present at the transmitter input, from storage in a memory.
Abstract: A method for transmitting digital data by means of continuous phase modulation (CPM), wherein the transmission signal s(t) is generated by retrieving stored digital values, which are allocated to a continuous sequence of symbols ai present at the transmitter input, from storage in a memory. In contrast to the conventional method, these stored digital values are not calculated from a predetermined frequency-base-band pulse g(t) by linear superposition but are optimized with respect to the in-band power emitted by means of an iterative method. This non-linear method leads to distinctly improved spectral characteristics of the transmission signal s(t).
19 citations
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07 Jun 1995TL;DR: In this paper, the authors propose a method for phase encoding and decoding a CPM spread spectrum signal, where a transmitter divides a data stream into a data symbol portion and an associated phase information portion.
Abstract: A method and apparatus for phase encoding and decoding a CPM spread spectrum signal. A transmitter divides a data stream into a data symbol portion and an associated phase information portion. The data symbol portion is used to select one of a plurality of spread spectrum codes for transmission from a symbol table. The phase information portion is used to differentially phase encode the data symbol prior to transmission. The transmitter divides the phase encoded spread spectrum codes into a plurality of data streams (such as I and Q data streams), independently modulates the I and Q data streams using CPM or a related technique, and superposes the plurality of resultants for transmission. A receiver receives the superposed spread spectrum signal and simultaneously attempts to correlate for a plurality of chip sequences (such as I and Q chip sequences), and derives a real correlation signal and an imaginary correlation signal. For each received symbol, the receiver determines which of a plurality of phase sectors the phase angle lies in, and compares the difference between the present phase sector and the immediately preceding phase sector. For biphase encoding, if the difference in closer to 0°, then the receiver outputs a first bit, and if the difference is closer to 180°, the receiver outputs a second bit. In a particular embodiment, a plurality of correlators operate in parallel to carry out phase decoding of the received signal.
18 citations
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TL;DR: The disk-growing algorithm presented allows the inner and the outer propagation of the unwrapping from a growing disk and so avoids the main problem of anisotropic error propagation for noisy phase maps.
Abstract: Interferometric techniques combined with phase shifting allow computation of the phase that is linked to the displacement of the object under study. The phases before and after displacement are computed from three or more interferograms (called specklegrams when speckle is used as the information carrier). Subtraction of these two phase patterns leads to a raw phase map. Phase unwrapping restores the 2π discontinuities and gives a continuous phase map. The disk-growing algorithm presented allows the inner and the outer propagation of the unwrapping from a growing disk and so avoids the main problem of anisotropic error propagation for noisy phase maps. It works successfully in speckle interferometry.
18 citations