Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Stefan Lipp

Ernst Eberlein

Albert Heuberger

Heinz Gerhaeuser

Stephan Buchholz

Sabah Badri

Christian Rohde

Carmen Wagner

Marco Breiling

Heinz Gerhauser

Robert Fischer

Holger Stadali

Frank Burkhardt

Thomas Windisch

Nico Peter

Kirsten Schuh

JÜrgen Hupp

Christian Skubich

Jorge Luis Juárez Peña

An electrical circuit, having: an oscillating element configured to provide a clock signal; and a clock synchronization unit configured to adapt the clock signal based on a reference signal; wherein the clock synchronization unit is configured to extract from an alternating signal the reference signal.

Electrical circuit

Receivers, controller units for receivers and related methods are provided. One receiver includes an adjustable sample provider providing samples of an input signal using an adjustable sample timing and a feedback path providing a feedback signal to the adjustable sample provider based on a timing error. The feedback path includes a loop filter providing sample timing information to the adjustable sample provider and a replacement value provider providing a replacement sample timing information replacing the sample timing information when an input signal does not fulfil a predetermined requirement for a feedback-based sample timing adaptation. The replacement value provider provides the replacement sample timing information considering a timing error information over a longer time period when compared to a time period considered by the loop filter for a provision of the sample timing information.

Adaptive timing synchronization for reception for bursty and continuous signals

There are provided examples of receivers, controller units and related methods, wherein one receiver includes: an adjustable sample provider configured to provide samples of an input signal using an adjustable sample timing; a feedback path configured to provide a feedback signal to the adjustable sample provider on the basis of a timing error, wherein the feedback path includes a loop filter configured to provide sample timing information to the adjustable sample provider; and a replacement value provider configured to provide a replacement sample timing information replacing the sample timing information provided by the feedback path when an input signal does not fulfil a predetermined requirement for a feedback-based sample timing adaptation, wherein the replacement value provider is configured to provide the replacement sample timing information considering a timing error information, or a quantity derived from the timing error information, over a longer time period when compared to a time period considered by the loop filter for a provision of the sample timing information.

A two-stage signaling concept for a datastream to be transmitted from a transmitter to a receiver is proposed. At the transmitter side, a plurality of frame headers are generated, each frame header including data transmission parameters for payload data. A super-frame header for a super-frame is generated. The super-frame includes a plurality of frames, each frame including one of the frame headers and payload data. The super-frame header indicates a set of super-frame-constant frame header transmission parameters for the frame headers of the plurality of frames of the super-frame. A receiver evaluates the super-frame header of to obtain the super-frame-constant frame header transmission parameters, which are then used to evaluate the plurality of frame headers PLH to retrieve the data transmission parameters. The proposed concept provides added flexibility, less signaling overhead, and/or an option of improved receiver performance at low SNR levels.

Two-stage signaling for transmission of a datastream

A terrestrial transmitting station for sending out a terrestrial broadcast signal includes a first receiver for receiving a signal to obtain a satellite receive signal, a second receiver for receiving a local signal to obtain a local receive signal and a signal combiner for combining the first receive signal with the local receive signal to form a combination signal. The signal combiner is implemented to generate the combination signal so that the combination signal is formed according to a hierarchical modulation, wherein the first receive signal is contained in a base layer of the hierarchical modulation and wherein the local receive signal is contained in an overlay layer of the hierarchical modulation. A terrestrial transmitting station further includes a transmitter for sending out the combination signal. A broadcast system includes a first transmitter and at least one terrestrial transmitting station. The information emitted from the satellite-based broadcast system may be received using an associated receiver. An inventive broadcast system allows adding a local information to a supraregionally emitted transmit signal in a frequency-efficient way.

Terrestrial transmitting station for transmitting a terrestrial broadcast signal, satellite-aided broadcast system and receiver for a satellite-aided broadcast system

The invention relates to a method and a device for transmitting information symbols using a plurality of carriers, wherein a first transmission symbol is produced () on the basis of an information symbol. A second transmission symbol is also produced () on the basis of the same information symbol, wherein the second transmission symbol differs from the first transmission symbol. The first and second transmission symbols are modulated () on a carrier and transmitted () at different intervals. The invention further relates to a method and a device for receiving information symbols represented by the first and second information symbols, wherein both transmission symbols received are used in order to extract the information symbol contained in both transmission symbols.

Method and device for transmitting information symbols using a plurality of carriers and method and device for receiving information symbols

A method and an apparatus relating to a fine frequency synchronization compensating for a carrier frequency deviation from an oscillator frequency in a multi-carrier demodulation system of the type capable of carrying out a differential phase decoding of multi-carrier modulated signals, the signals comprising a plurality of symbols, each symbol being defined by phase differences between simultaneous carriers having different frequencies. A phase difference between phases of the same carrier in different symbols is determined. Thereafter, a frequency offset is determined by eliminating phase shift uncertainties related to the transmitted information from the phase difference making use of a M-PSK decision device. Finally, a feedback correction of the carrier frequency deviation is performed based on the determined frequency offset. Alternatively, an averaged frequency offset can be determined by averaging determined frequency offsets of a plurality of carriers. Then, the feedback correction of the frequency deviation is performed based on the averaged frequency offset.

Method and apparatus for fine frequency synchronization in multi-carrier demodulation systems

A method for generating a signal having a frame structure, each frame of the frame structure comprising at least one useful symbol, a guard interval associated to the at least one useful symbol and a reference symbol, comprises the steps of performing an amplitude modulation of a bit sequence such that the envelope of the amplitude modulated bit sequence defines a reference pattern of the reference symbol and inserting the amplitude modulated bit sequence into said signal as said reference symbol. A method for frame synchronization of a signal having such a frame structure comprises the steps of receiving the signal, down-converting the received signal, performing an amplitude-demodulation of the down-converted signal in order to generate an envelope, correlating the envelope with a predetermined reference pattern in order to detect a signal reference pattern of the reference symbol in the signal, and performing the frame synchronization based on the detection of the signal reference pattern.

Coarse frequency synchronisation in multicarrier systems

A method and apparatus provide coarse frequency synchronization compensating for a carrier frequency deviation from an oscillator frequency in a demodulation system capable of demodulating a signal having a frame structure with at least one useful symbol and a reference symbol which is an amplitude-modulated sequence. A received and down-converted signal undergoes amplitude-demodulation to generate an envelope that is correlated with a predetermined reference pattern to determine the carrier frequency deviation. Finally, the oscillator frequency is controlled based on the carrier frequency deviation. The reference symbol may comprise two identical sequences. In this case, the envelope obtained by the amplitude-demodulation has two portions which are based on the identical sequences. One of the portions of the envelope is correlated with the other one of the portions in order to determine the carrier frequency deviation. The oscillator frequency is controlled based on the determined carrier frequency deviation.

Coarse frequency synchronization in multicarrier systems

A method of performing an echo phase offset correction in a multi-carrier demodulation system involves the step of differential phase decoding phase shifts based on a phase difference between simultaneous carriers having different frequencies. An echo phase offset is determined for each decoded phase shift by eliminating phase shift uncertainties related to the transmitted information from the decoded phase shift. The echo phase offsets are averaged in order to generate an averaged offset. Finally, each decoded phase shift is corrected based on the averaged offset.

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Erlangen, Germany

Stefan Lipp