Abstract: The invention features a filter arrangement for filtering an input signal that includes a transmitter signal having a predetermined pulse shape at a receiving end to transmit the input signal, a decimation filter to decimate the input signal that includes a passband frequency range and a wide transition frequency range with an amplitude attenuation, and a matching filter to match the input signal to the pulse shape of the transmitter signal. Such filter arrangements also feature passband frequency ranges for decimation filters which are smaller than the ranges for matching filters.

Abstract: An analogue frontend, such as is used, for example, in receivers for communications equipment, comprises a plurality of analogue components (1-3) which are connected upstream of an analogue/digital converter (4). In order to control the drive level of the individual analogue components (1-3) precisely, the input of the analogue/digital converter (4) can optionally be connected via a switch-over device (8) to the output of any one of the analogue components (1-3) and a drive level control signal for the respective analogue component (1-3) can be generated by a digital control device (5) by evaluating the sampled value which is then supplied by the analogue/digital converter (4).

Abstract: A method for processing signals composed of data symbols that are each separated from one another by a guard interval. Such signals are used for digital television transmission, for example. The guard intervals results in that gaps in the flow of recovered data are produced at the reception end. These gaps are prevented by extending evaluation of the symbols to the duration of the guard interval. This allows an additional buffer store to be dispensed with.

Abstract: The nonrecursive digital filter has variable coefficients for the purpose of shifting the frequency response from one characteristic frequency fc1 to another characteristic frequency fc2. The method enables calculating the coefficients of the nonrecursive digital filter for shifting the frequency response of the filter from one characteristic frequency fc1 to another characteristic frequency fc2. The coefficients of a prototype of the filter are prescribed or calculated for a given sampling frequency, the continuous time impulse response associated with this prototype is calculated and the impulse response is sampled at the sampling frequency fa2=fa1* fc1/fc2. The new coefficients are thereby produced. The filter can then be operated with the new coefficients at the old sampling frequency. As an alternative, the new coefficients can be calculated from the coefficients of the prototype of the filter by interpolating the values of the continuous time impulse response at an interval of 1/fa2.

Abstract: A method for digital clock recovery and selective filtering includes prescribing or calculating first coefficients of a prototype of a selective filter at a characteristic frequency fc for a given sampling frequency fa. Second coefficients of a selective filter are calculated at the characteristic frequency fc2 from the first coefficients at points tk=&Dgr;t+k*d, where k is an integer greater than or equal to 0, by interpolating values of a continuous-time impulse response at points tk, where d = fc2 * fa fc * fa 1 . The selective filter is operated with the second coefficients at fa1.

Abstract: A circuit for demodulating two-dimensional data symbols transmitted by carrier-based data transmission. The circuit has a tuner and a quadrature demodulator. The tuner has a first intermediate frequency stage for converting a carrier frequency of an input signal containing the two-dimensional data symbols to a first intermediate frequency f1, a surface wave filter, and a second intermediate frequency stage connected downstream of the surface wave filter for converting the carrier frequency of the input signal to a second intermediate frequency f2. The second intermediate frequency f2 is lower than the first intermediate frequency f1. The demodulator converts the input signal at the second carrier intermediate frequency f2 to a baseband and splits it into in-phase and quadrature components.

Abstract: A method for digital clock recovery and selective filtering includes prescribing or calculating first coefficients of a prototype of a selective filter at a characteristic frequency fc for a given sampling frequency fa. Second coefficients of a selective filter are calculated at the characteristic frequency fc2 from the first coefficients at points tk=?t+k*d, where k is an integer greater than or equal to 0, by interpolating values of a continuous-time impulse response at points tk, where d = fc2 * fa fc * fa 1 The selective filter is operated with the second coefficients at fa1.