Martin Mittelbach

Learn More
The optimal transmit strategies of single-user multiantenna systems with respect to average capacity maximization are well understood. However, the performance measure does neglect delay aspects which are important for higher layer design. Therefore, we consider the maximization of the effective capacity in a single-user multi-antenna system with covariance(More)
In this paper, feedback with carry shift registers (FCSRs) are analyzed with main focus on the general case of FCSRs with arbitrary connection integer and on maximum-period FCSRs. Moreover, a keystream generator that employs the structure of the linear feedback shift register (LFSR)-based Geffegenerator is studied in connection with FCSRs as a special(More)
We derive a parameterization of positive definite matrices using the Cholesky decomposition in combination with hyperspherical coordinates. Based on the parameterization we develop a simple and efficient method to randomly generate positive definite matrices with constant or bounded trace according to a uniform distribution. Further, we present an efficient(More)
In this paper a highly flexible and scaleable multiband impulse radio UWB architecture for high data rates is described and evaluated. The investigations are mainly focused on on-off-keying modulation combined with a low-complexity non-coherent energy detection receiver. Various representative system configurations are defined and examined by simulation,(More)
We study the ergodic capacity of a frequency-selective Rayleigh fading channel with correlated scattering, which finds application in the area of UWB. Under an average power constraint, we consider a single-user, single-antenna transmission. Coherent reception is assumed with full CSI at the receiver and no CSI at the transmitter. We distinguish between a(More)
A coding theorem and converse are proved for abstract channels with time structure that contain continuous-time continuous-valued channels and the result by Kadota and Wyner (1972) as special cases. As main contribution the coding theorem is proved for a significantly weaker condition on the channel output memory and without imposing extra measurability(More)
In this paper, we study the ergodic capacity of a frequency-selective Rayleigh fading channel with correlated scattering. Under an average power constraint, we consider a single-user, single-antenna transmission. Coherent reception is assumed with full CSI at the receiver and no CSI at the transmitter. We distinct between a continuousand a discrete-time(More)
We consider a discrete-time frequencyselective block-fading channel with Rayleigh fading and correlated scattering. This is relevant in the area of UWB and if transceiver filters are included in the capacity analysis. Under an average power constraint, we assume a single-user, single-antenna transmission with full CSI at the receiver and no CSI at the(More)
A coding theorem and converse are proved for abstract channels with time structure that contain continuous-time continuous-valued channels and the result by Kadota and Wyner from 1972 as special cases. As main contribution the coding theorem is proved for a significantly weaker condition on the channel output memory and without imposing extra measurability(More)