— We propose to apply a technique called time-reversal to UWB communications. In time-reversal a signal is precoded such that it focuses both in time and in space at a particular receiver. Spatial focusing reduces interference to other co-existing systems. Due to temporal focusing, the received power is concentrated within a few taps and the task of… (More)
— We study the possibility to transmit data over channels with large delay spreads under the constraint of a very simple receiver which has only one tap. Such a scheme is of interest when a cost-efficient way to transmit potentially high data rates are sought after. We investigate the performance of the optimal pre-filter for this scheme, and compare it to… (More)
Political stock markets (PSM) are sometimes seen as substitutes for opinion polls. On the bases of a behavioural model, specific preconditions were drawn out under which manipulation in PSM can weaken this argument. Evidence for manipulation is reported from the data of two separate PSM during the Berlin 1999 state elections.
We investigate the high-SNR probability density function of the mutual information of the Ricean MIMO channel for Gaussian code books and the case where the channel's fixed component has rank 1. The purpose of this paper is threefold: 1) We propose an illustrative geometrical technique characterizing the mutual information as the log of the random volume of… (More)
The extension of multiple-input multiple-output (MIMO) sphere decoding from the narrowband case to wideband systems based on orthogonal frequency division multiplex-ing (OFDM) requires the computation of a QR decomposition for each of the data-carrying OFDM tones. Since the number of data-carrying tones ranges from 48 (as in the IEEE 802.11a/g standards) to… (More)