Stefan M. Moser


Last Name

Moser

First Name

Stefan M.

ORCID

0000-0003-4833-8679

Organisational unit

03529 - Lapidoth, Amos / Lapidoth, Amos

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Publications 1 - 10 of 12
  • On the capacity of free-space optical intensity channels
    Item type: Conference Paper
    Lapidoth, Amos; Moser, Stefan M.; Wigger, Michèle A. (2008)
    2008 IEEE International Symposium on Information Theory
    New upper and lower bounds are presented on the capacity of the free-space optical intensity channel. This channel is characterized by inputs that are nonnegative (representing the transmitted optical intensity) and by outputs that are corrupted by additive white Gaussian noise (because in free space the disturbances arise from many independent sources). Due to battery and safety reasons the inputs are simultaneously constrained in both their average and peak power. For a fixed ratio of the average power to the peak power the difference between the upper and the lower bounds tends to zero as the average power tends to infinity, and the ratio of the upper and lower bounds tends to one as the average power tends to zero. The case where only an average-power constraint is imposed on the input is treated separately. In this case, the difference of the upper and lower bound tends to 0 as the average power tends to infinity, and their ratio tends to a constant as the power tends to zero.
  • Advanced Topics in Information Theory
    Item type: Educational Material
    Moser, Stefan M. (2022)
  • A Generalization of the Equal Coding Theorem
    Item type: Conference Paper
    Shen, Hui-An; Moser, Stefan M.; Pfister, Jean-Pascal (2023)
    2023 IEEE Information Theory Workshop (ITW)
    We reformulate the Equal Coding Theorem in sensory neural encoding with ON- and OFF-neurons as a channel capacity problem. We then present a capacity-based proof of the Equal Coding Theorem, and generalize it to neurons with different firing probabilities. We also briefly discuss the biological implications of this generalization.
  • How to Typeset Equatations in LaTeX
    Item type: Educational Material
    Moser, Stefan M. (2017)
  • Signaling for MISO Channels Under First- and Second-Moment Constraints
    Item type: Conference Paper
    Ma, Shuai; Moser, Stefan M.; Wang, Ligong; et al. (2022)
    2022 IEEE International Symposium on Information Theory (ISIT)
    Consider a multiple-input single-output system, where the nonnegative, peak-limited inputs X1,. .. , Xn T ∈ [0, A] are subject to first-and second-moment sum-constraints on all antennas. The paper characterizes all probability distributions that can be induced for the "channel image," which is given by the inner product of the input vector with a given channel vector. Key to this result is the description of input vectors that achieve a given deterministic channel image with the smallest energy, where "energy" of an input vector refers to a weighted sum of its one-and two-norms. Minimum-energy input vectors have an interesting structure: depending on the desired channel image, some of the weakest antennas are silenced, and the remaining antennas are chosen according to a shifted and amplitudeconstrained beamforming rule.
  • Expected Logarithm and Negative Integer Moments of a Noncentral χ2-Distributed Random Variable†
    Item type: Journal Article
    Moser, Stefan M. (2020)
    Entropy
    Closed-form expressions for the expected logarithm and for arbitrary negative integer moments of a noncentral χ2-distributed random variable are presented in the cases of both even and odd degrees of freedom. Moreover, some basic properties of these expectations are derived and tight upper and lower bounds on them are proposed.
  • The Geometry of Uncoded Transmission for Symmetric Continuous Log-Concave Distributions
    Item type: Conference Paper
    Shen, Hui-An; Moser, Stefan M.; Pfister, Jean-Pascal (2022)
    International Zurich Seminar on Information and Communication (IZS 2022). Proceedings
    We present a geometric picture for optimal single-letter uncoded transmission for source-channel duals, where the source and distortion measure are dual to the channel and cost function. In particular, we investigate an additive noise channel with the conditional channel distribution and capacity-achieving input distribution both being symmetric, continuous log-concave densities. We show that under these assumptions, a Gaussian source transmitted over an additive Gaussian channel is the only possible choice for optimal single-letter uncoded transmission. We explain the uniqueness of Gaussian uncoded transmission through a homothetic property for the channel input and output typical sets, and illustrate the geometry of single-letter uncoded transmission as opposed to communication based on the classical source-channel separation principle.
  • Design Methodology of Camshaft Driven Charge Valves for Pneumatic Engine Starts
    Item type: Conference Paper
    Moser, Stefan M.; Voser, Christoph; Onder, Christopher H.; et al. (2015)
    Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles
    Idling losses constitute a significant amount of the fuel consumption of internal combustion engines. Therefore, shutting down the engine during idling phases can improve its overall efficiency. For driver acceptance a fast restart of the engine must be guaranteed. A fast engine start can be performed using a powerful electric starter and an appropriate battery which are found in hybrid electric vehicles, for example. However, these devices involve additional cost and weight. An alternative method is to use a tank with pressurized air that can be injected directly into the cylinders to start the engine pneumatically. In this paper, pneumatic engine starts using camshaft driven charge valves are discussed. A general methodology for an air-optimal charge valve design is presented which can deal with various requirements. The proposed design methodology is based on a process model representing pneumatic engine operation. A design example for a two-cylinder engine is shown, and the resulting optimized pneumatic start is experimentally verified on a test bench engine. The engine’s idling speed of 1200 rpm can be reached within 350 ms for an initial pressure in the air tank of 10 bar. A detailed system analysis highlights the characteristics of the optimal design found.
  • On the Capacity of Block Fading Optical Wireless Channels
    Item type: Conference Paper
    Li, Longguang; Moser, Stefan M.; Wang, Ligong; et al. (2019)
    2019 IEEE Global Communications Conference (GLOBECOM)
    This paper investigates the capacity of block fading optical intensity channels with more transmit than receive antennas under different assumptions on the transmitter's channel state information (CSI). Lower and upper bounds on the capacities are derived using the entropy power inequality (EPI) and a dual expression for capacity. Our lower bounds for perfect and partial CSI utilize a transmit-antenna cooperation strategy based on minimum-energy signaling, which we proposed recently. For perfect CSI, this lower bound matches the upper bound asymptotically in the high signal-to-noise ratio (SNR) regime. For imperfect CSI, our lower bound is close to its perfect-CSI counterpart.
  • Rate-Distortion Problems of the Poisson Process: a Group-Theoretic Approach
    Item type: Conference Paper
    Shen, Hui-An; Moser, Stefan M.; Pfister, Jean-Pascal (2021)
    2021 IEEE Information Theory Workshop (ITW)
    We study rate-distortion problems of a Poisson process using a group theoretic approach. By describing a realization of a Poisson point process with either point timings or inter-point intervals and by choosing appropriate distortion measures, we establish rate-distortion problems of a homogeneous Poisson process as ball-or sphere-covering problems for realizations of the hyperoctahedral group in Rn. Specifically, the realizations we investigate are a hypercube and a hyperoctahedron. Thereby we unify three known rate-distortion problems of a Poisson process (with different distortion measures, but resulting in the same rate-distortion function) with the Laplacian-ℓ1 rate-distortion problem.
Publications 1 - 10 of 12