Infineon Technologies Ag

Intel Mobile Communications Gmbh

Intel Mobile Communications Technology Gmbh

André Neubauer

Markus Hammes

Andreas Schmid

Christian Kranz

Michael Speth

Dieter Brückmann

Michael Madden

Ulrich Boetzel

Frank Gersemsky

Jürgen Niederholz

Stefan Van Waasen

Bernd Schmandt

Dieter Brueckmann

Michael Warmers

Juergen Niederholz

Rüdiger Lorenz

Sönke Mehrgardt

Rüdiger Pott

Ulrich Bötzel

The method is based on a signal interval (DB) which comprises a first part (ET) (which is modulated using a first modulation method (GFSK)) of the signal interval and a second part (which is modulated using a second modulation method (DMPSK)) of the signal interval. The channel parameters (c(i)) relating to the second part (which is modulated using the second modulation method) of the signal interval are determined using a received data signal (a(i); p(i)) from the first part (ET) of the signal interval (DB).

Method for channel estimation when using different modulation methods within one signal interval

A detector for zero crossings and a counter which is connected to it are used to determine the time intervals between the zero crossings of the received signal or of an intermediate-frequency signal which is produced from the received signal, and for detection of the digital signal data. In this case, a sequence of determined zero crossing intervals can be stored in digital form in a shift register chain, and can be compared in a classification device with previously stored interval sequences. Furthermore, a frequency offset can be determined by averaging the zero crossing intervals and can be compensated for by suitable selection or modification of the previously stored interval sequences, in which case the latter can also be used during the synchronization phase. The synchronization process may, furthermore, be assisted by payload data identification.

Demodulation of a digitally frequency-modulated analog received signal by evaluation of the time intervals between the zero crossings

A method for calculating zero-crossing reference sequences ({t}) for the data detection of a sequence of zero crossings ({{circumflex over (t)}}) of a received signal is disclosed. The data detection is determined in a receiver, wherein the received signal is based on a data symbol sequence ({d}) angle-modulated at a transmitter and transmitted to the receiver. The zero-crossing reference sequences ({t}) are calculated in accordance with an equation specifying an output of a finite state machine that describes, at least approximately, the signal generation in the transmitter.

Method and device for calculating zero-croccing reference sequences for signal detection of angle-modulated signals based on zero crossings of the received signal

In a method for estimating a frequency deviation between a received spread-spectrum code signal and a local frequency signal, the received spread-spectrum code signal is despread using a local spread-spectrum code. The despread signal is integrated over a particular integration period. From at least two successively obtained integration values, a phase change value characteristic of the phase change between the two integration values is calculated. From this, the frequency deviation is determined.

Method and device for estimating a frequency in the acquisition of a spread-spectrum code signal

A data transmission system transmits first data bursts from a base station to mobile stations. The first data bursts at least in some cases contain two or more data blocks that are intended for different mobile stations. The data transmission system furthermore transmits second data bursts from at least one of the mobile stations to the base station and produces guard time intervals between successive data bursts.

Data transmission system, frame structure, and method for radio transmission of data

The present invention is directed to a receiver for a wire-free communication system for reception of a received signal which is modulated using a digital modulation method having a first frequency conversion device for production of a frequency-converted received signal by conversion of the received signal to an intermediate frequency. The receiver further includes a pre-filter for production of a filtered received signal from the frequency-converted received signal such that the received signal is band-limited, and an analogue/digital converter for production of a binary received signal from the filtered received signal by comparison of the filtered received signal with a level threshold. In addition, the receiver includes a phase reconstruction device for production of a phase-reconstructed received signal by reproduction of the phase of the received signal from the time intervals between zero crossings of the binary received signal, and a mapping device for production of a bit sequence by mapping symbols from the phase-reconstructed received signal onto this bit sequence using the digital modulation method.

Receiver for a wire-free communication system

In a method for estimating a frequency offset (f, &#x3a9;) of a modulated bandpass signal (s) with an assumed carrier frequency (&#x3a9;) in a mobile radio receiver, times (&#x3c4;) of the zero cross-overs of the bandpass signal are determined in a first step. Using the times (&#x3c4;) of the zero cross-overs and the assumed carrier frequency (&#x3a9;), the required frequency offset (f, &#x3a9;) is estimated in a further step by calculating the DC component of an instantaneous frequency which is given by the frequency of the bandpass signal less the assumed carrier frequency.

Method for estimating a frequency offset of a modulated bandpass signal

A detector () for zero crossings and a counter () which is connected to it are used to determine the time intervals between the zero crossings of the received signal or of an intermediate-frequency signal which is produced from the received signal, and for detection of the digital signal data. In this case, a sequence of determined zero crossing intervals can be stored in digital form in a shift register chain (), and can be compared in a classification device () with previously stored interval sequences. Furthermore, a frequency offset can be determined by averaging the zero crossing intervals and can be compensated for by suitable selection or modification of the previously stored interval sequences, in which case the latter can also be used during the synchronization phase. The synchronization process may, furthermore, be assisted by payload data identification.

Apparatus for demodulation of a signal which is frequency-modulated with a data symbol sequence {d}, having a zero crossing detector (), a generator () for production of a sequence {z}, with zbeing calculated from zero crossings tand t, and having a unit () for reconstruction of the data symbol sequence {d}, which is characterized by a minimum Euclidean distance between the sequence {z} and an auxiliary sequence, with each sequence element in the auxiliary sequence being formed from convolution of the data symbol sequence {d} with a sequence {h} relating to the index k, and with the sequences {h} being functions of the times tand t.

Demodulation of a frequency-modulated received signal by means of a Viterbi algorithm

Method and device for calculating zero-crossing reference sequences for signal detection of angle-modulated signals based on zero crossings of the received signal

When data bursts are transmitted between a base station and a mobile receiver, a changeover is made between a plurality of modulation methods during an existing radio link for modulation of the data. For resynchronization of the receiver in the event of the changeover, synchronization information items are determined from a first part (ET) of the data burst modulated by a first modulation method, and are used for synchronization with a second part (ZT) of the data burst modulated by the second modulation method.

Method for resynchronization of a mobile radio receiver in the event of a changeover between two different modulation methods

A data transmission system has a base station and at least one mobile station. Data packets are interchanged between the base station and the mobile station using a time slot method. In this case, first measures are used for transmission of a first part of a data packet at a predetermined first symbol rate and at a first transmission frequency, and second measures are used for transmission of a second part of the data packet at a second symbol rate and at a second transmission frequency.

Data transmission system having a high data transmission rate and method of transmitting the data

In order to improve the reliability and the accuracy of a position-finding method such as the GPS method, the quality of a radio link which is used for the position-finding method is determined by estimating a parameter, in particular the Rice factor of the amplitude distribution density, which is characteristic of the ratio of the strength of a signal transmitted via a line-of-sight path, with respect to the strength of the signals transmitted via non-line-of-sight paths.

Reliability and the accuracy of position-finding methods by estimation of the Rice factor of a radio link

A receiver () of a position-finding system comprises a calculation unit () for calculation of a statistical value (&#x39b;) on the basis of a received signal, and a detector unit () for comparison of the statistical value (&#x39b;) with a threshold value (&#x3ba;) and for determining whether the received signal is a synchronized location signal, an estimation unit () for estimation of the Rice factor (K) of the radio link via which the received signal has been transmitted, and a determination unit for calculation of the threshold value (&#x3ba;) on the basis of the Rice factor (K).

Receiver for a position-finding system with improved sensitivity

In a method for avoiding transients during switching processes in integrated circuits, a module of the integrated circuit is switched from a first operating state to a second operating state, a load change occurring thereby. In this case, it is ensured that the occurring quotient of load change and time duration for the transition from the first operating state to the second operating state does not exceed a predetermined limit value, thereby reducing or avoiding transients associated with such switching.

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Krefeld, Germany

André Neubauer