Abstract: A method and device for graphically representing the I and/or Q components of digitally modulated high frequency signal are described, in which the I or Q components measured in a temporally successive manner are graphically represented side-by-side on a display device.

Abstract: A method and a device for determining an unabbreviated channel-impulse response in an OFDM transmission system, of which the duration is greater than the length of the guard interval, estimates the channel-transmission factor at frequency-time positions of a relatively-coarse frequency-time raster, interpolates the channel-transmission factor at frequency-time positions of a relatively-fine frequency-time raster and calculates the unabbreviated channel-impulse response by means of inverse Fourier transform from the estimated or interpolated values of the channel-transmission factor at the frequency-time positions of the relatively-fine frequency-time raster. In this context, estimated values of the channel-transmission factor optimized at the individual frequency-time positions of the relatively-fine frequency-time raster are determined from received symbols and from transmitted symbols estimated by means of decision from the received symbols.

Abstract: A method and a device for determining an unabbreviated channel-impulse response in an OFDM transmission system, of which the duration is greater than the length of the guard interval, estimates the channel-transmission factor at frequency-time positions of a relatively-coarse frequency-time raster, interpolates the channel-transmission factor at frequency-time positions of a relatively-fine frequency-time raster and calculates the unabbreviated channel-impulse response by means of inverse Fourier transform from the estimated or interpolated values of the channel-transmission factor at the frequency-time positions of the relatively-fine frequency-time raster. In this context, estimated values of the channel-transmission factor optimized at the individual frequency-time positions of the relatively-fine frequency-time raster are determined from received symbols and from transmitted symbols estimated by means of decision from the received symbols.

Abstract: The method for monitoring the stability of the carrier frequency (?i) of identical transmitted signals (si(t)) of several transmitters Si of a single-frequency network is based upon a calculation of a carrier-frequency displacement ??i of a carrier frequency ?i of a transmitter Si relative to a carrier frequency ?0 of a reference transmitter S0. For this purpose, the phase-displacement difference (???i(tB2?tB1)) caused by the carrier-frequency displacement ??i between a phase displacement ??i(tB1) at a first observation time tB1 and a phase displacement ??i(tB2) at a second observation time tB2 of a received signal (ei(t)) of the transmitter Si associated with the respective transmitted signal (si(t)) is determined relative to a received signal e0(t) of the reference transmitter S0 associated with the reference transmitted signal s0(t).

Abstract: In order to display the amplitude distortions of a transmission channel, the amplitude distribution of a measurement signal of a known amplitude distribution is measured at the output of the transmission channel. Based on a given multitude of amplitude measured values that are measured and digitized in succession, the frequency of occurrence of the amplitude distribution is then determined and displayed in adjacently connected amplitude windows.

Abstract: A method and device evaluating the quality of a signal by virtue of the deviation of at least one measured characteristic variable of the signal in relation to an associated reference value. The quality is calculated by averaging all of the deviations which are determined and standardized in relation to said characteristic variables.

Abstract: A method for monitoring the time synchronization of a total of n transmitters in a common wave network is described in which a reference total pulse response is compared with a measured total pulse response belonging to the transmission channels of the n transmitters of the common wave network. A reference pulse response is fixed in the reference total pulse response in relation to the pilot pulse response, on the basis of which the remaining reference pulse responses are references to classify synchronization errors in the common wave network in various synchronization error categories.

Abstract: The method for monitoring the stability of the carrier frequency (?i) of identical transmitted signals (si(t)) of several transmitters Si of a single-frequency network is based upon a calculation of a carrier-frequency displacement ??i of a carrier frequency ?i of a transmitter Si relative to a carrier frequency ?0 of a reference transmitter S0. For this purpose, the phase-displacement difference (???i(tB2?tB1)) caused by the carrier-frequency displacement ??i between a phase displacement ??i(tB1) at a first observation time tB1 and a phase displacement ??i(tB2) at a second observation time tB2 of a received signal (ei(t)) of the transmitter Si associated with the respective transmitted signal (si(t)) is determined relative to a received signal e0(t) of the reference transmitter S0 associated with the reference transmitted signal s0(t).

Abstract: The aim of the invention is to detect the remaining carrier power on a multi-carrier signal that is QAM-modulated in the 8K mode according to the DVB-T-standard. Said signal is provided with a central carrier which is situated in the center of the individual carriers and, at times, is a continual and, at times, a scattered pilot. The influence of the remaining carrier power on a carrier that is adjacent to the central carrier is detected and then converted to the central carrier.

Abstract: The aim of the invention is to process OFDM signals which are simultaneously received via a multiple antenna system having a plurality of separate receive channels. To this end, the channel correction values or the confidence values are determined in the receive channels for each carrier of the OFDM signal while using known techniques. In addition, the I/Q values of each individual carrier of the OFDM signal which are obtained in the OFDM demodulator are weighted with these channel correction values or confidence values. Afterwards, the I/Q values weighted in such a manner are totaled.

Abstract: The aim of the invention is to determine the user data constellation of a multi-carrier signal at the receiving end. Said signal is QAM modulated in the 2K mode according to the DVB-T standard and is provided with a central carrier that is situated I the centre of the individual carriers and is temporarily modulated with user data and temporarily represents a distributed pilot. To resolve the aim of the invention, the appearance frequency of all I/Q values pertaining to the portion of user data belonging to the central carrier is detected and the centre of said user data constellation is then detected.

Abstract: The invention relates to a method for displaying the mean modulation error MERRMS of a multiple carrier (OFDM) signal in which: a) The square of the error vector is calculated according to the relation (I) for each actual modulation symbol I of each individual carrier k of the multiple carrier signal; b) this value mk is offset with the content of a storage location of a memory, said storage location being assigned to the same carrier k, which comprises the same number of storage locations as the OFDM signal carrier, according to relation (II) (iteration formula) with A2k,1+1: new measured value (instant 1+1) which should be filed in storage location k of the memory A2; A2k,l+l: previous measured value (instant 1) from storage location k of memory A2; mk: Actual measured error square for carrier k; k: Carrier number within the OFDM spectrum, grows with the frequency, k=0 . . .

Abstract: A method for determining the phase and/or amplitude noise spectrum of a digitally modulated input signal. The method for determining a phase-noise spectrum comprises generating real complex samples, by digitally sampling a phase component and phase quadrature component of the input signal in baseband, determining ideal complex samples from generated real samples, establishing complex quotients from the real and ideal complex samples, generating modified complex quotients by assigning the value 1 to the complex quotients, and subjecting the modified complex quotients to a Fourier transform. The invention also concerns a similar method for determining the amplitude noise spectrum of the digitally modulated input signal.

Abstract: For measuring and evaluating multi-carrier signals the I and/or Q components obtained by demodulation are integrated across several values and are graphically shown for every single carrier or combined carrier groups of the multi-carrier signal on the screen display unit. To this end, the individual carriers or carrier groups are applied side by side on the horizontal axis of a diagram and the I and/or Q components that pertain to the carriers or carrier groups are recorded along a vertical line.

Abstract: The invention relates to a method for measuring the receiver-side bit error rate of the transmission path of a DVB transmission system in which the data stream to be transmitted is channel-coded on the transmitter side by a Reed-Solomon coder and on the receiver side channel-decoder by a corresponding Reed-Solomon decoder. According to the method, a test data stream is fed in on the transmitter side and the Reed-Solomon coder is switched off so that the receiver-side decoder recognizes a data stream with non-correctable errors and allows the same to reach the output uncorrected. The bit error rate is then determined from the uncorrected test data stream.

Abstract: A method and device for graphically representing the I and/or Q components of digitally modulated high frequency signal are described, in which the I or Q components measured in a temporally successive manner are graphically represented side-by-side on a display device.

Abstract: In order to display the amplitude distortions of a transmission channel, the amplitude distribution of a measurement signal of a known amplitude distribution is measured at the output of the transmission channel. Based on a given multitude of amplitude measured values that are measured and digitized in succession, the frequency of occurrence of the amplitude distribution is then determined and displayed in adjacently connected amplitude windows.

Abstract: In an arrangement for graphic display, in the IQ plane on the screen of a display device, of IQ values emitted at an output of a demodulator for quadrature-amplitude-modulated signals, an address of the data memory is allocated to each individual IQ value and a pixel of the display device is allocated to each address of the data memory. Information allocated to the respective IQ value, e.g. a predetermined pixel hold time, is stored under each address of this data memory. A processor is directly connected to the IQ output of the demodulator, and determines the associated IQ value address in the data memory for each IQ value.