Telefonaktiebolaget Lm Ericsson (publ)

U.S. Philips Corporation

Sharp Kabushiki Kaisha Corporation

Bayerische Motoren Werke Aktiengesellschaft

Peter Schramm

Udo Wachsmann

Fabian Wenger

Mathias Pauli

Uwe Dettmar

Johannes B Huber

Carl Magnus Frodigh

H&aring;kan Gunnar Olofsson

Jamshid Khun-Jush

Frank Muller

Robert Fischer

Johan Skold

Wolfgang Gerstacker

Gerd Zimmermann

Raimund Meyer

Johan Sk&ouml;ld

Frank M&uuml;ller

Stefan Rommer

Peter Larsson

Hui Li

Jan Lindskog

Stefan Mueller-Weinfurtner

Johan Sköld

Georg Frank

Mikael Höök

G&ouml;ran Malmgren

Mikael H{umlaut Over (oo)}k

Stefan Davidsson

Fredrik Johansson

J&ouml;rn Thielecke

Anders Ranheim

Richard Rau

Martin Arend

Göran Malmgren

Henrik Andreasson

Roger Walther

Lennart Gafvels

Henrik Anders Andreasson

Håkan Gunnar Olofsson

Frank Mueller

A motor vehicle hands-free device includes a communication interface designed so that at least one first mobile telephone and one second mobile telephone can be connected to the motor vehicle hands-free device, in particular in parallel or simultaneously, a control device designed so that mobile telephone address book entries from the first mobile telephone and mobile telephone address book entries from the second mobile telephone can be transferred to the motor vehicle hands-free device via the radio interface, and a common address book that can be generated on the basis of the mobile telephone address book entries of the first mobile telephone and the mobile telephone address book entries of the second mobile telephone.

Hands-free telephone device of a motor vehicle

The present invention concerns a method for estimating the time-dispersion of a channel comprising D subchannels, wherein one computes from a received signal a set of estimated Channel Transfer Factors (CTF's) &#x124;[&#x3bd;], where &#x3bd;(0&#x2266;&#x3bd;&#x2266;D) is the subchannel number, said method comprising a step of calculating, for a predetermined strictly positive integer d, a correlation factor Crepresenting the correlations, both in amplitude and in phase, between pairs &#x124;[&#x3bd;] and &#x124;[&#x3bd;+d] of said computed CTF estimates. By an appropriate choice of d, the time-dispersion resolution can be adapted to most prevalent channels. The correlation is optionally corrected according to the mean channel estimation signal-to-noise ratio. This method can be used for many applications where knowing the time-dispersion characteristics of a channel is required, and is, for example, particularly suitable for designing a channel estimation filter, and for link adaptation. Application to devices and apparatus implementing these methods.

Correlation method for channel estimation for OFDM

A method and a device of providing timing information within a wireless communication system is described. The timing information is extracted from a received transmit signal. The inventive method comprises the steps of providing a training signal on the receiver side relating to a known signal portion of the transmit signal, scaling the training signal, quantizing the scaled training signal, correlating one or more parts of the received transmit signal with the scaled training signal to obtain one or more correlation results, and determining the timing information on the basis of the correlation results.

Method and device for providing timing information in a wireless communication system

The invention relates to a method and a device for controlling frequency selection within a wireless communication system in response to radar-like interference signals. The method comprises continuously or quasi-continuously monitoring and assessing a plurality of frequencies with respect to a radar-like interference signal and allocating a quality parameter to each assessed frequency, the quality parameter indicating the probability that the frequency is occupied. The method further comprises selecting one or more frequencies in dependence on the allocated quality parameters and subsequent frequency monitoring.

Method and device for controlling frequency selection within a wireless communication system

In order to correct frequency deviations of signals in a multicarrier system, such as a OFDM-system, the present invention provides a frequency tracker and a method to operate the same. The frequency tracker is based on a decision directed digital phase locked loop exhibiting a predictive character. On the basis of an estimated phase offset for a received signal (signal component, signal symbol) a predicted phase offset is calculated and applied to the signal (signal component, signal symbol). Further, received signals (signal components, signal symbols) are sampled and for each sample a sample phase offset to be corrected is calculated in dependence to the related estimated phase offset to incorporate the predictive character. In particular, the predicted sample phase offsets are calculated as a function of a corresponding predicted phase offset and a measure being indicative of a distance, in the time domain, between a corresponding phase reference point for the predicted phase offset and a phase reference point defined for a specific part of the received signal, preferably for a preceding preamble signal.

Frequency correction for a multicarrier system

The present invention relates to a link quality determination unit (LQ-DET) for determining a link quality (LQ) of a transmission link (TL) between an OFDM transmitter (TR) and an OFDM receiver (RC) of an OFDM transmission system (SYS). A first link quality measure determination unit (Q-DET) determines a first link quality measure (Q) on the basis of a signal power variation or a signal-to-noise variation determined by a variation determination unit (VS-DET). A second link quality determination unit (Q-DET) calculates a second link quality measure (Q) on the basis of an average signal-to-noise ratio based on the noise power (P) and the signal power (P). To perform a link adaptation (LA) an overall link quality determination unit (Q-DET) combines the first and second link quality measures (Q, Q) into an overall link quality measure (Q).

Link quality determination of a transmission link in an OFDM transmission system

A radio receiver system () comprises a radio receiver (), a receiver sample clock (), which is used for sampling a modulated base-band signal; and a timing correction unit (). The timing correction unit () performs, in the frequency domain, a timing drift compensation between a transmitter sample clock () and the receiver sample clock (). In one example context of implementation, the plural modulated radio frequency carriers have been modulated using Orthogonal Frequency Division Multiplexing (OFDM).

Timing drift compensation in wireless packet-based systems

The invention discloses a method for use in a wireless communications system with a plurality of broadcasting nodes, comprising the step of enabling one node in the system to function as a central node in said system and letting said node enable measurements on at least one frequency in a frequency band used by the system. Said measurements are carried out to detect if said at least one frequency is being utilized by a transmitter foreign to the system. Preferably, the measurement is enabled by means of the node transmitting a message to other nodes in the system, said message being a message pre-defined within the system as a message prohibiting all nodes from transmitting during a certain interval, said message being transmitted after the system has been detected by the node to be silent during a predefined interval between frame transmissions from the nodes in the system.

Wireless communications system with detection of foreign radiation sources

A TDMA/TDD link adaptation method determines radio link quality at a base station. The radio link quality is used to update and broadcast a physical layer parameter indicator (10-16) from the base station on a broadcast control channel having a common physical layer parameter indicator for all uplink and downlink channels.

Link and radio cell adaptation in TDD systems

A bit rate indicator for use in the mobile station of a radiotelephone system which provides an indication to the user of the maximal bit rate available in the current cell and the predicted bit rate the user can expect to achieve if a session were initiated in his present location. In calculating the maximal bit rate, the mobile station receives a message from the base station indicating the base station's capabilities, such as support for multi-slot operations and coding/modulation schemes. The mobile station then uses the base station's capabilities along with its own capabilities to determine the maximal bit rate. In calculating predicted bit rate, the mobile station measures the link quality of at least one channel and based on, at least one of, the measured link quality and mobile's capabilities, determines a predicted bit rate the user would achieve in his present location. Both the maximal and predicted bit rates can be outputted on the mobile station for comparison by the user. This information can be used to effectively direct the user to the location in a cell with the best link quality. The present invention may be especially useful when using a mobile station to interface with the Internet.

Terminal bitrate indicator

In wireless telecommunications systems, such as wireless local area networks, a flexible, less complex, and bandwidth efficient forward error correction method can be achieved by applying a first convolutional coding scheme to the bits in a first portion of a data block and a second convolutional coding scheme to the bits in a second portion of the data block, wherein the second portion of the data block may encompass a remaining portion of the data block, excluding the first portion, or the entire data block, including the first portion. While the first coding scheme employs a first code rate, the second coding scheme employs a second code rate that is higher than the first code rate. The higher rate makes it possible to incorporate the one or more tail bits into the second portion of the data block, and therefore, avoid generating any additional symbols, such as orthogonal frequency division multiplexing symbols, to exclusively modulate the tail bits.

Efficient system and method for forward error correction

The present invention relates generally to the problem of cell selection, for e.g. cell handover, in mobile telecommunication systems, and more particularly to the problem of selecting the optimum cell among cells with differing capabilities due to different air interface modes. Known algorithms for cell selection and handover are extended by applying additional criteria that take into account the capabilities, due to different modulation and coding schemes, of the mobile station and the base stations that are possible candidates. The quality of service (&ldquo;QoS&rdquo;) is predicted for the different cell candidates based on a combination of signal strength or C/I, different cell capabilities, multislot capability, etc. Then the cell is selected for which the predicted QoS is maximum. In another embodiment the invention is extended by taking into account further criteria which are suitable from a system point of view, e.g. to avoid a significant increase of average outage probability or interference level. The present invention increases the use of base stations supporting high data rates. The result is an increase in overall system throughput.

Cell selection in mobile radio systems

A method of communicating control information in systems that support multiple modulation schemes for communicating voice or data and control information. To provide backward compatibility dedicated control channels use the modulation scheme used in current systems, for example GMSK modulation scheme. Traffic channels and associated control channels use linear modulation schemes that have the same symbol rate. The modulation scheme of the associated control channel uses a reduced signal set of the modulation scheme used for traffic channels. Also, an in-band signalling procedure is used to indicate to a receiving station the modulation type, channel coding and speech coding used for a transmitted burst.

Method for communicating information in a communication system that supports multiple modulation schemes

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Eching, Germany

Peter Schramm