Results 251 to 260 of about 59,238 (279)

Pulse Position Modulation and Extended Pulse Position Modulation with Squeezed Light

Journal of Modern Optics, 1994
Abstract It is shown that the performance of optical communication systems that use pulse position modulation and direct photon counting can be improved with the use of squeezed states. The effect of noise is studied. An improved version of the pulse position modulation called extended position modulation is also considered.
A. Vourdas, J.R.F. da Rocha
openaire   +1 more source

Positive Modulators of Muscle Acetylcholine Receptor

Journal of Receptor Research, 1989
A solution of succinic anhydride (SA) in buffer N-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid (TES), the SATES solution, potentiates the effect of carbonyl containing agonists on frog muscle (del Castillo et al., Br. J. Pharmac. 84: 275-288, 1985). Here we report that the main compound in the SATES solution is a monosuccinyl ester of TES (MST)
V A, Eterovic, G, Escalona de Motta, R M, Hann, J A, Lasalde, J A, Prieto, P A, Ferchmin   +5 more
openaire   +2 more sources

Soliton pulse position modulation

IEE Proceedings J Optoelectronics, 1993
The phenomenon of a train of optical fibre solitons, modulated in some way by impressed disturbances, is increasingly being identified as a new type of dynamical system, with interesting dynamical behaviour which can be studied both experimentally and mathematically.
openaire   +1 more source

Pure-projective modules and positive constructibility

Journal of Symbolic Logic, 2000
In modules many ‘positive’ versions of model-theoretic concepts turn out to be equivalent to concepts known in classical module theory—by ‘positive’ we mean that instead of allowing arbitrary first-order formulas in the model-theoretic definitions only positive primitive formulas are taken into consideration.
Kucera, T. G., Rothmaler, Ph.
openaire   +2 more sources

Fused heterocyclic M1 positive allosteric modulators

Bioorganic & Medicinal Chemistry Letters, 2011
Fused aromatics such as naphthalene were identified as highly potent and CNS penetrant M(1) positive allosteric modulators during an SAR study to replace the phenyl B-ring linkage.
Scott D, Kuduk, Christina N, Di Marco, Victoria, Cofre, William J, Ray, Lei, Ma, Marion, Wittmann, Matthew A, Seager, Kenneth A, Koeplinger, Charles D, Thompson, George D, Hartman, Mark T, Bilodeau   +10 more
openaire   +2 more sources

Compound Pulse Position Modulation Codes

2006 IEEE International Symposium on Information Theory, 2006
A general class of nonlinear compound pulse position modulation (CPPM) codes is introduced to incorporate nonlinear low-rate PPM constraints directly into a Tanner-like code graph on which iterative decoding can be performed. The iterative decoding algorithm is specified for these codes, including the extrinsic message computations at the nonlinear ...
Sam Dolinar, Kenneth Andrews
openaire   +1 more source

Polarization differential pulse position modulation

Proceedings of the Seventh ACM International Conference on Underwater Networks and Systems - WUWNet '12, 2012
In underwater wireless optical communication links, pulse position modulation (PPM) and differential pulse position modulation (DPPM) are two typical modulation schemes. In this paper, we present an alternative modulation scheme to improve the communication performance compared with the traditional methods.
Xuedan Zhang, Yuhan Dong, Shijian Tang
openaire   +1 more source

Pulse position modulation acoustic communications

IEEE Transactions on Audio and Electroacoustics, 1971
Pulse position modulation (PPM) is a simple and effective technique for transmitting information via the underwater acoustic channel. In this paper engineering design considerations for an underwater acoustic PPM system, including the location of threshold and the effects of multipath, attenuation, and time dispersion, are discussed.
S. Riter, P. Boatright, M. Shay
openaire   +1 more source

Spatial Pulse Position Modulation for Optical Communications

Journal of Lightwave Technology, 2012
This paper proposes a low complexity spatial modulation (SM) scheme that combines spatial shift keying (SSK) with pulse position modulation (PPM) for optical wireless communication systems. SM is a multi-transmitter technique for achieving increased data rate over the traditional on-off keying (OOK) and PPM signalling methods.
Popoola, Wasiu O., Poves, Enrique, Haas, Harald   +2 more
openaire   +2 more sources

Pulse position modulation spectral investigation

International Journal of Electronics, 1993
Pulse position modulation (PPM) employing wide carrier pulse duration displays a frequency spectrum and signal-to-noise ratio (SNR) performance different from the case when the carrier pulse duration is extremely narrow. This paper investigates the PPM spectrum and its SNR ratio under these conditions.
openaire   +1 more source