Abstract: A device reduces the dynamic range of a signal at a first point along a signal processing direction in a transmitter of a communication system. The device includes an input to which an input signal is applied, a correction prediction device, a delay device, an addition device, and an output. The correction prediction device generates a predictive signal based on the input signal which represents the prediction of the signal at the first point, and generates a correction signal from the predictive signal. The delay device generates an input signal delayed by a delay from the input signal, the delay taking into consideration the processing time in the correction prediction device. The addition device subtracts the correction signal from the delayed input signal in order to generate a corrected signal. The output provides the corrected signal at a second point in front of the first point.

Abstract: A DC-offset correction circuit includes an analog circuit to generate a plurality of analog offset-correction signal values, each of which are assigned to a hop band. The analog circuit is coupled to a tap of an analog receiver chain and includes a first analog selector to select an analog offset-correction signal value, the selected analog offset correcting signal value being assigned to a current hop band. Further, the DC-offset correction circuit includes a combiner to combine a received signal with the selected analog offset-correction signal value and feed the analog receiver chain.

Abstract: A mixer circuit includes a first oscillator, a second oscillator, an up-conversion mixer, a down-conversion mixer, and a detect and control unit. The up-conversion mixer has a first input terminal coupled to the first oscillator and an output terminal. The down-conversion mixer has a first input terminal coupled to the output terminal of the up-conversion mixer and a second input terminal coupled to the second oscillator. The detect and control unit is coupled to the down-conversion mixer.

Abstract: A mixer circuit includes a mixer having input terminals and an output terminal, to provide an output signal by mixing input signals, wherein the mixer exhibits leakage. The circuit also includes a signal generator coupled to one of the input terminals of the mixer to provide a correction signal, an up-conversion mixer coupled to the mixer to provide an up-converted signal by mixing a test signal with the output signal of the mixer, and a down-conversion mixer coupled to the up-conversion mixer to provide a down-converted signal by down-converting the up-converted signal. A signal detector is coupled to the down-conversion mixer and detects a spurious signal in the down-converted signal, the spurious signal indicating the leakage, and a control unit is coupled to the signal detector and the signal generator to control generation of the correction signal depending on the detected spurious signal to compensate the leakage.

Abstract: A circuit arrangement for generating local oscillator signals is supplied with a reference frequency signal by means of a signal input. A frequency divider is used to derive a second signal from the reference frequency signal. The reference frequency signal and the second signal are supplied to a selection device, where one of the signals is output on the basis of a first selection signal. In an auxiliary signal generator, a single auxiliary signal at an auxiliary frequency is generated on the basis of a second selection signal. In a frequency conversion device, a local oscillator signal which can be tapped off on the signal output is derived from the output signals from the selection device and the auxiliary signal generator.

Abstract: To reduce the crest factor of a total signal, the signal dynamic range is corrected in baseband upstream of the interpolation filters. To this end, provision is made for the input of a correction device to be coupled to at least two signal sources which are designed to provide digital signals on different frequency bands. The correction device is designed to determine correction factors from the digital signals applied to the input and use them to alter the respective digital signals. The output of the correction device is coupled to a first and at least one second interpolation filter. This allows reduction of the signal dynamic range in baseband, which reduces the crest factor without having to accept substantial losses in signal quality.

Abstract: A simplified compensation matrix is set up for the compensation of phase errors between the I and the Q component in data transmission systems with quadrature modulation or demodulation. This simplified compensation matrix permits a previously determined phase error ?? to be used as the basis for replacing two of the multipliers required in the conventional circuit configurations by relatively simple shift registers (4, 5) for a multiplication by 1 or by a constant.

Abstract: A fast frequency-hopping transceiver comprises a RF-unit arranged on a first chip, a base-band unit on a second chip, a bidirectional operable data and control interface arranged between said first and said second chip having at least one data line for data communication, at least one control line for controlling the data communication and at least one clock line for providing a clock signal, memory means implemented within said RF-unit containing all the required chip settings which are specific to a certain frequency of received and/or transmitted data being part of the intended hopping sequence. The transceiver also includes control means for programming said memory means during an initialization phase during a set-up of a communication link of said data communication.

Abstract: The method is used for limiting the power of a transmission-end signal (xn) compiled from a plurality of differently spread-coded signals. In this context, it is assumed that the quantity of spread codes used for the differently spread-coded signals is known as code engagement information (Cch,SF,k; 80). First, correction spread codes are selected by virtue of the engagement information (Cch,SF,k; 80) being evaluated. On the basis of the selected correction codes, a spread-coded correction signal (y?n) is formed which is overlaid with the compiled signal (xn).

Abstract: A device reduces the dynamic range of a signal at a first point along a signal processing direction in a transmitter of a communication system. The device includes an input to which an input signal is applied, a correction prediction device, a delay device, an addition device, and an output. The correction prediction device generates a predictive signal based on the input signal which represents the prediction of the signal at the first point, and generates a correction signal from the predictive signal. The delay device generates an input signal delayed by a delay from the input signal, the delay taking into consideration the processing time in the correction prediction device. The addition device subtracts the correction signal from the delayed input signal in order to generate a corrected signal. The output provides the corrected signal at a second point in front of the first point.

Abstract: In a method for reducing the dynamic range of a multicarrier transmission signal (12?) which is formed in a transmitter and is composed of two or more carriers, the various signal structure timings of the carriers are determined. A delay unit (100; D0, D1, . . . , DN?1) is then used to set a delay profile between the signal structure timings of various carriers, in such a manner that the signal structures of different carriers or substructures of them are not aligned in time with respect to one another.

Abstract: The device for detecting a useful signal comprises an autocorrelation unit (AK) for autocorrelating a signal (s(t)) which can contain a periodic signal, and a cross correlation unit (CK) for cross correlating the signal s(t) with a known signal (b(t)). Furthermore, the device comprises a logic unit (VE) for logically combining outputs of the autocorrelation unit (AK) and of the cross correlation unit (CK) which outputs a combinatorial signal (d(t)) which specifies whether the useful signal has been detected.

Abstract: A device for detecting a useful signal by detecting a periodic signal contained in the useful signal exhibits a correlation unit (24) for correlating the signal with the sign of the signal, taking into consideration a time delay. It also comprises an amplitude estimating unit (21) for estimating the amplitude of the signal and a decision unit (14) which is connected downstream of the amplitude estimating unit (21) and the correlation unit (24), for deciding about the presence of the periodic signal.

Abstract: A method for synchronizing a receiver for a convolutionally coded reception signal having a sequence of received data symbols includes decoding the convolutionally coded reception signal by means of a Viterbi decoder that calculates a minimum metric signal sequence. The metric signal sequence is then compared with an adjustable threshold value. If metric signal exceeds the threshold value too frequently during a predetermined time period, at least one received data symbol is discarded.

Abstract: An electronic transmitter device has a puncturing device with two data outputs and/or an interleaver with two data inputs. An electronic receiver device has a de-interleaver with two data outputs and/or a depuncturing device with two data inputs.

Abstract: Each burst of an OFDM signal which is transmitted, for example, on the basis of the IEEE 802.11a/g WLAN Standard contains a preamble with a sequence of ten short training signals. The DC offset is derived from the mean value of the signal over a measurement section of the training signal sequence, with a first subsection of the measurement section in time being weighted with a rising weighting function, and a last subsection of the measurement section in time being weighted with a falling weighting function. A central subsection, which is not weighted, may be located between the two. The signal is accumulated in this way over the measurement section, and the result is divided by the sum of the weights of the subsections. Using this procedure, the averaging process has better filter characteristics than the noise contribution from the actual signal.

Abstract: A simplified compensation matrix is set up for the compensation of phase errors between the I and the Q component in data transmission systems with quadrature modulation or demodulation. This simplified compensation matrix permits a previously determined phase error ?? to be used as the basis for replacing two of the multipliers required in the conventional circuit configurations by relatively simple shift registers (4, 5) for a multiplication by 1 or by a constant.

Abstract: A method for synchronizing a receiver for a convolutionally coded reception signal having a sequence of received data symbols includes decoding the convolutionally coded reception signal by means of a Viterbi decoder that calculates a minimum metric signal sequence. The metric signal sequence is then compared with an adjustable threshold value. If metric signal exceeds the threshold value too frequently during a predetermined time period, at least one received data symbol is discarded.