Nokia Corporation

Nokia Mobile Phones Limited

Snaptrack Incorporated

Marko Alanen

Timo Rantalainen

Ville Ruutu

Gudni Gunnarsson

Sami Vilhonen

Pasi Tikka

Jorma Matero

Jussi Vepsäläinen

Ari Vilander

Pekka Ikonen

Matti Vilppula

Pasi Lehtonen

Jaako Maunuksela

Olli Hyvärinen

Gudni Gunnarson

Maiana Savu

Olli Hyv&auml;rinen

Harri Pellikka

Ruutu Ville

Sami Kalajo

Gundi Gunnarsson

A circuit arrangement includes a transceiver unit, a switching device coupled to the transceiver unit with a terminal and a control device coupled to the switching device. The control device is configured to operate in a first and in a second mode of operation. In the first mode of operation, the switching device is configured by the control device such that a first signal is routed from the transceiver unit via the switching device back to the transceiver unit in a feedback loop. In the second mode of operation, the switching device is configured by the control device such that a second signal is routed from the transceiver unit via the switching device to the terminal or the second signal is routed from the terminal via the switching device to the transceiver unit.

Circuit arrangement for RF loopback

A filtering method, a transceiver and a transmitter are provided. The transmitter comprises a power amplifier amplifying an RF signal and having multiple stages, and a local oscillator, the power amplifier comprising between at least two stages of the power amplifier an impedance circuitry for forming an impedance at a frequency related to the frequency of the local oscillator, and a switch for switching the impedance of the impedance circuitry means to RF frequency.

Transmitter, power amplifier and filtering method

A transmission signal to be transmitted from a radio transmitter is predistorted in order to compensate for the signal distortion caused by a power amplifier. The transmission signal and a signal modeling a power supply voltage applied to the power amplifier are compared with distortion properties of the power amplifier using these signals. The distortion information is comprised in an amplitude distortion lookup table and a phase distortion lookup table. Transmission signal and power supply signal values are associated with envelope and phase predistortion information comprised in the respective lookup tables and the envelope and the phase of the transmission signal is predistorted accordingly.

Signal predistortion in radio transmitter

The present invention relates to estimation of the distance between stations that communicate in a communication system over a radio interface. In the system at least one of the stations transmits signal bursts in time slots in accordance with a timing structure and at least one station receives the signal bursts. The method comprises determination of a first timing of a signal burst received at the receiving station, the first timing being associated with the first component of the received signal burst that meets a predefined condition. A second timing of the received signal burst is also determined for use in adjustment of internal timing of the receiving station for receiving and/or transmitting further signal bursts from and/or to the transmitting station. A timing offset is also determined between the stations. The distance between the stations is estimated based on the timing offset and the first timing of the received signal burst.

Distance estimation in a communication system

A cellular radio network based positioning system for determining the position of a mobile station (). For each base transceiver station (to) or cell of the network, a fixed list of base transceiver stations is stored by a Mobile Positioning Centre (). Each list identifies those base transceiver stations which enable the position of a mobile station served by the corresponding base transceiver station () to be optimally determined. The list is transmitted to the mobile station () via the serving base transceiver station () and the mobile station determines an observed time difference for each of the listed base transceiver stations, relative to the serving base transceiver station (), from signals broadcast by the listed base transceiver stations. The observed time differences are transmitted from the mobile station () to the serving base transceiver station () and are used by the network to compute the position of the mobile station ().

Cellular radio locator system

The invention relates to a method for locating a mobile station (,) by means of the mobile station (,) and a location service center (LSC) (,) in the mobile network by dynamically distributing the computing between these two. Preferably the mobile station (,) measures impulse responses of received bursts to determine time differences, and preprocesses measurement results. The location service center (,) performs the final processing. According to the invention, dummy bursts are also used in the locating process. The method also includes an automatic locating procedure activated in conjunction with an emergency call.

Method for locating mobile station in distributed manner

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Espoo, Finland

Marko Alanen