Telefonaktiebolaget Lm Ericsson (publ)

Qualcomm Incorporated

U.S. Philips Corporation

Basf Fuel Cell Gmbh

Georg Frank

Wolfgang Granzow

Christian Pietsch

Pengjun Huang

Christoph A Joetten

Marc W Werner

Christian Sgraja

Thomas Soczka-Guth

Jochen Baurmeister

Rudiger Knauf

Dirk Gerstenberger

Branislav M Popovic

Helmut B Witteler

Henrik Olofsson

Arnold Schneller

Udo Wachsmann

Peter Schramm

Joachim Clauss

Nicola Varanese

Eugene Baik

Mathias Pauli

Matthias Schulist

Bo Gosta Hedberg

Hans Dieter Schotten

Ethan Robert Duni

Fredrik Bengt Ovesj&ouml;

Fredrik Bengt Ovesjo

Maria Gustafsson

Michael Niegel

Roozbeh Atarius

Bo Hermansson

Christian Nystr&ouml;m

Mathias Schulist

Hans-Joachim Gotz

Markus Brachmann

Thomas Eckart

Udo R&ouml;del

Alexander Maurer

Harald Bonsel

Gregor Deckers

Mike Rommler

Michael Heine

Udo Rodel

Jurgen Pawlik

A device may demodulate a set of OFDM data-pilot symbols and select a subset of based at least in part on the position of each data pilot on a constellation map (e.g., how close the data pilot symbol is to an actual constellation point). The device may then perform a data-pilot-based phase estimation based at least in part on the selected subset. The device may also reduce the number of data pilots by partitioning a set of subcarriers into groups and selecting a representative subcarrier from each group. The phase estimation may then be based on the data pilots received on the selected subcarriers. In some cases, the device may also generate a smooth phase signal based on a linear regression algorithm including a phase averaging and a phase offset estimation and perform the phase estimation using the smooth phase signal.

Feed-forward phase tracking

A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request/response protocol provides reliable transfer of data using message redundancy, retransmission, and/or robust modulation modes dependent on the communication channel conditions.

Apparatus and method of obtaining non-speech data embedded in vocoder packet

System and method of an in-band modem for data communications over digital wireless communication networks

The present invention relates to improvements for a fast setup of physical communication channels in a CDMA-based communication system. A Node B of a telecommunication network is permitted to manage and assign a certain share of the downlink transmission resources of a radio network controller without inquiry of said radio network controller. On reception of a resource request message from a user equipment, the node B derives and specifies a certain amount of said resources that can be allocated to the user equipment. In a preferred embodiment of the present invention said resources are only assigned temporarily until the ordinary RL setup procedure, which involves the RNC, has been successfully finished.

Fast setup of physical communication channels

A method, a computer program product and a device for requesting access to a node (BS) of a wireless communications network () are described. In the network () identification codes are used to differentiate access requests of different network components (UE). The method comprises the step of determining information about a transmission path () to e.g. the network node (BS), the step of determining an identification code in dependence on the determined transmission path information, wherein previously an association between identification codes and transmission path information has been established, and the step of modulating the selected identification code onto a signal to generate an access request signal carrying transmission path information.

Requesting and controlling access in a wireless communications network

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

In a synchronization scheme, for example for establishing a channel in a UMTS radio communication system, when a user device (or user equipment, UE) such as a mobile terminal is establishing a channel with a network, the user device transmits signals on the uplink DPCCH, and the power of these signals is ramped up from a calculated initial power level until the transmission is detected by the receiver, i.e. until the receiver has obtained synchronization to the uplink signal.

Method for establishing a radio channel in a wireless CDMA network wherein the preamble signal increases in power during transmission

The invention relates to a multipath propagation delay determining means (STU, FIGS. ) for determining a power delay spectrum (DPS) of a CDMA signal transmission between a CDMA base station (BS) and a CDMA mobile station (MS) on a plurality of propagation paths (P , P ) within a cell (CL) of a CDMA communication system, comprising an A/D conversion means (A/D) for converting an analog CDMA multipath signal (S , S ) received from at least one antenna (Ant , Ant ) within said cell (CL) into a digital CDMA multipath signal (S , S ) consisting of consecutive radio frames (RF . . . RFn) including consecutive time slots (TS . . . TSm) with complex pilot symbols (PSi) and data symbols (Pdi), a demultiplexing means (PI-DEMUX) for extracting complex pilot symbols (PSi) and data symbols (PDi) from at least two consecutive time slots (TSk&minus;1, TSk, TSk&plus;1) of each radio frame (RFn) and for storing them consecutively in a memory means (BUF) thereof; and a searching means (S . . . SL) for determining a power delay profile (DPS, DPS , DPS , FIG. ) of said each antenna (Ant. , Ant. ) on the basis of said extracted and stored complex pilot symbols and said data symbols (PSi, PDi).

Multipath propagation delay determining means using periodically inserted pilot symbols

An uplink common physical channel (random access channel) frame structure with a separate preamble and data portion. The preamble is used by a base station to detect that a mobile station is attempting a random access request. The data portion of the channel includes user data, and pilot symbols that provide energy for channel estimation during reception of the data portion. A guard interval is preferably inserted between the preamble and data portion of the frame, which enables data detection to occur during an idle period. As such, the frame structures for both the common physical (random access) uplink channel and dedicated physical (traffic) uplink channel are compatible.

Random access in a mobile telecommunications system

Apparatus and method for reducing the range of a transmission signal comprising a plurality of digitally represented complex communication signals, including means for estimating the magnitude of each of the plurality of complex communication signals, based on the complex components, means for determining at least one scaling factor based on the plurality of determined amplitudes and means for reducing the amplitude of the respective complex signal components. The system is accommodated to operate at very high frequency and may advantageously be provided with a circuit determining the amplitude of each of the complex signals using the CORDIC algorithm. The system may further be provided with means for scaling the magnitude of each of the complex components in a coarse scaling step and a fine scaling step. The system allows to effectively reduce the amplitude of the transmission signal eliminating the need for larger and more expensive amplifiers.

Amplitude limitation

In a telecommunications network that employs a CDMA scheme, the amplitude associated with each independent CDMA carrier is digitally limited, thereby limiting the peak-to-average power ratio. This, in turn, is accomplished by measuring the instantaneous amplitude for the in-phase and quadrature signals that make up each CDMA carrier, deriving a maximum amplitude based on the instantaneous amplitude measurements, and then deriving one or more scaling factors based, in-part, on maximum amplitude. The one or more scaling factors are then applied to the in-phase and quadrature signals, which are subsequently filtered, combined and modulated by a corresponding CDMA carrier frequency.

Amplitude limitation in CDMA system

In a communication system including at least one transmitter and at least one receiver, a frequency offset between a carrier frequency of the transmitter and a local frequency reference of the receiver is estimated. A phase difference is computed between successively collected samples of a frequency synchronization signal transmitted by the transmitter and detected by the receiver. The phase difference is added to accumulated phase differences. Phase differences of successively collected samples are computed and added to accumulated phase differences until M accumulated phase differences have been added. The sum of the M phase differences is dumped, resulting in zero accumulated phase differences. Phase differences of successively collected samples are computed, the phase differences are added to accumulated phase differences, and the sum of M phase differences is dumped until N sums of M phase differences have been dumped. The N sums of the M phase differences are added to produce the estimated frequency offset.

Method and apparatus for estimating a frequency offset

The invention relates to a transmission system comprising a phase-locked loop (12) which includes a phase comparator (15) for comparing an oscillator signal with a reference signal and for generating a comparison signal, and an oscillator which is provided for receiving a control signal derived from the comparison signal. The oscillator arranged as a ring oscillator (14) comprises at least one delay element (27 to 31) included in a closed circuit. At least one delay element (27 to 30) has at least two different adjustable delay times. A controller (19) is provided for setting the delay times of at least one delay element (27 to 30) in dependence on the comparison signal.

Transmission system

A mobile radio receiver for a digital radio transmission system includes a recognition arrangement (6) for searching a received digital signal for pulses (i) of a frequency correction burst which recurs with a predetermined frequency in the digital signal and for determining the pulse positions (t). A frequency estimation arrangement (7) derives estimates of the predetermined frequency. In order to improve the initial synchronization of the mobile radio receiver with a base station, the recognition arrangement includes an averaging circuit (14) which averages with weight factors (Us) the pulse positions (t) that have been determined in successive observation intervals, the weight factors (Us) being proportional to the individual pulse heights (U). The reliability of recognition of pulses which belong a frequency correction burst is improved by providing evaluation based on the number of pulses of amplitudes above a selected threshold level during a selected interval, and further evaluation based on a phase error quality of the frequency estimates of the predetermined frequency.

Mobile radio receiver for a radio transmission system

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Nuremberg, Germany

Georg Frank