Leben als Teilnehmen. Überlegungen im Anschluss an Johann Gottfried Herder

This article aims to revise the well-established self-conception of the modern man based on the combination between self-preservation and autonomy. On a systematic level, the attempt to revise this self-conception is based on the notions of participation and sympathy; it explores their bearings for social philosophy, the philosophy of language and the idea of a moral sentimentalism. In a historical perspective, this article focuses on Johann Gottfried Herder, criticizes the readings put forward by Isaiah Berlin and Charles Taylor, discusses Herder′s opposition to Immanuel Kant, and re-contextualizes his work in relation to Hutcheson, Burke, Rousseau, and other

SPECTRAL CORRELATION MEASUREMENT

A concise description of the correlation theory for cyclostationary random signals is given. It is based on a time-frequency cyclic correlation function and on a bifrequent spectral correlation function (SCF). The relations to conventional stationary correlation, Wigner distribution and spectrogram analysis are emphasized. The cyclic transfer properties of linear time-invariant and linear periodically time-variant systems are outlined. Simple examples give a feeling for performance and applications of spectral correlation measure- ment. The basic schemes of SCF estimation are mentioned briefly

Analysis of the Local Quasi-Stationarity of Measured Dual-Polarized MIMO Channels

It is common practice in wireless communications to assume strict or wide-sense stationarity of the wireless channel in time and frequency. While this approximation has some physical justification, it is only valid inside certain time-frequency regions. This paper presents an elaborate characterization of the non-stationarity of wireless dual-polarized channels in time. The evaluation is based on urban macrocell measurements performed at 2.53 GHz. In order to define local quasi-stationarity (LQS) regions, i.e., regions in which the change of certain channel statistics is deemed insignificant, we resort to the performance degradation of selected algorithms specific to channel estimation and beamforming. Additionally, we compare our results to commonly used measures in the literature. We find that the polarization, the antenna spacing, and the opening angle of the antennas into the propagation channel can strongly influence the non-stationarity of the observed channel. The obtained LQS regions can be of significant size, i.e., several meters, and thus the reuse of channel statistics over large distances is meaningful (in an average sense) for certain algorithms. Furthermore, we conclude that, from a system perspective, a proper non-stationarity analysis should be based on the considered algorithm

Dual-Polarized Ricean MIMO Channels: Modeling and Performance Assessment

In wireless communication systems, dual-polarized (DP) instead of single-polarized (SP) multiple-input multiple-output (MIMO) transmission is used to improve the spectral efficiency under certain conditions on the channel and the signal-to-noise ratio (SNR). In order to identify these conditions, we first propose a novel channel model for DP mobile Ricean MIMO channels for which statistical channel parameters are readily obtained from a moment-based channel decomposition. Second, we derive an approximation of the mutual information (MI), which can be expressed as a function of those statistical channel parameters. Based on this approximation, we characterize the required SNR for a DP MIMO system to outperform an SP MIMO system in terms of the MI. Finally, we apply our results to channel measurements at 2.53 GHz. We find that, using the proposed channel decomposition and the approximation of the MI, we are able to reproduce the (practically relevant) SNR values above which DP MIMO systems outperform SP MIMO systems.Comment: submitted to the IEEE Transactions on Communication