Abstract: A device which enables different spreading factors while preserving a comnmon scrambling code, in particular for transmission in a code division multiple access cellular mobile radio system. The device including a grouper for grouping the various data symbols of a kth incoming sequence (k=1, . . . , K) into different blocks of QMAX/QK symbols, and a spreader for spreading K incoming sequences with K respective spreading codes of respective length Qk (k=1, . . . , K) which is a sub-multiple of a maximum length QMAX, wherein the spreader spreads the blocks from the kth incoming sequence (k=1, . . . , K) with the corresponding code of length Qk to obtain a spread sequence including different spread blocks of length QMAX. The device further includes a scrambler for scrambling each of the K spread sequences obtained in this way using a scrambling code of length QMAX.

Abstract: During allocation of time slots of a UMTS frame to a terminal, the UMTS network provides a continuous gap having a duration at least equal to 5 ms in a UMTS frame to enable the receiver of the terminal to measure the power of any GSM signals received and to prepare for possible handover by pre-synchronizing to an adjoining GSM cell.

Abstract: Method of allocating orthogonal codes in a code division multiple access mobile radio system using codes of variable length which are generated in such a way that they can be represented in the form of a tree, said method including, in response to a code allocation request, a first step of determining, in accordance with the tree capacity used, corresponding to codes already allocated, and the tree capacity required, corresponding to the code allocation requested, if such allocation is possible.

Abstract: A base station of a space division multiple access digital cellular mobile radio system includes an array of active antennas dynamically creating receive and/or transmit beams in the direction of mobile stations present in the current cell associated with the base station. The array of active antennas is driven by receive and/or transmit systems. At least one of the mobile stations present in the current cell is a calibration transponder-station used, in addition to its conventional function, as a calibration transponder for receiving and/or transmitting at least one test signal enabling calibration of the receive and/or transmit systems.

Abstract: The invention relates to a method of digitally linearizing an amplifier having non-linearity, the method being of the type comprising: a prior stage in which correction parameters for correcting said non-linearity are determined, and a linear amplification stage performed by applying predistortion followed by amplification. In the invention, stage in which the correction parameters are determined comprises the following steps: acquiring said amplified test signal in the form of samples in baseband; defining a modelled amplifier, by computing parameters of a predetermined amplifier model on the basis of said samples of the amplified test signal; and computing said correction parameters on the basis of said modelled amplifier so that they make it possible to linearize said modelled amplifier. The invention also relates to a corresponding system for digitally linearizing an amplifier.

Abstract: A device for linearizing transmitter amplifiers for transmitter equipment including a plurality of transmitters (11, 12, . . . 1n), each including a transmitter amplifier (4) and not totally decoupled from each other, said device including means for controlling the transmission of linearization signals relative to each amplifier and means (6) for analyzing the corresponding amplified linearization signals to determine the non-linearities of said amplifier and applying to wanted signals a pre-correction (5) to compensate said non-linearities, said device being essentially characterized in that it includes central control means (8, 8′, 10-20) for commanding the transmission of linearization signals relating to different transmitter amplifiers at different times.

Abstract: A source sequence including N data elements is interleaved to deliver an interleaved sequence according to a method which includes at least one interleaving step associating a data element of index j in the interleaved sequence with a data element of index i in the source sequence, where:j=(a.multidot.i+b) (modulo N)+1, 1.ltoreq.i.ltoreq.N and 1.ltoreq.j.ltoreq.N;a is a predetermined integer relatively prime with N and such that 2.ltoreq.a.ltoreq.N-1; andb is a predetermined integer such that 0.ltoreq.b.ltoreq.N-1.

Abstract: A device for controlling the biasing of an amplifier receives an input signal to be amplified and a bias signal and supplies an amplified output signal. The amplifier has at least two separate possible power output values and the amplified output signal is principally in a predetermined frequency band. The device includes a circuit for controlling the biasing of the amplifier which receives linearity control information and generates the bias signal in accordance with the linearity control information so that an actual out-band send level is substantially equal to the required out-band send level. The actual out-band send level is defined as a send level of the amplified output signal outside the predetermined frequency band. The required out-band send level is defined as a predetermined maximal out-band send threshold level for any of the separate possible output power values.

Abstract: A digital receiver includes an antenna for picking up signals, a converter for converting an incoming signal to a predetermined intermediate frequency, and baseband processor. The receiver further includes an analog/digital converter using oversampling relative to the bandwidth of the signal and receiving the intermediate frequency signal at its input, and decimation filters receiving the output signal from the analog/digital converter and having their outputs connected to the baseband processor.

Abstract: In a digital half-duplex frequency division multiple access radio system a mobile station is either sending or receiving. For each call between a mobile station and a base station, a first frequency is allocated for the up link direction (from the mobile station to the base station) and a second frequency is allocated for the down link direction (from the base station to the mobile station). The signals exchanged by the stations are organized in frames of predetermined fixed duration grouped into multiframes comprising a predetermined number of frames including at least one control frame. At least some of the control frames are listening frames during which the sending mobile station interrupts sending, switches to receive mode and (if appropriate) reverts to send mode.

Abstract: The present invention relates to a dummy burst structure used in a cellular digital radio-communications system operating on the principle of time division multiple access, each cell in the system being associated with a beacon frequency subdivided into periodically-repeated frames, each of which comprises at least one signalling channel or beacon path for transmitting signalling messages to mobile stations, the other channels serving in particular to transmit useful data, the burst being transmitted over those channels of the beacon frequency which are not assigned to transmitting useful data, or over certain time slots of the signalling channel when there is no signalling data to be transmitted over the certain time slots, wherein the burst contains a signalling message.

Abstract: The analog-to-digital converter receives an analog input signal (x(t)) to produce a digital error signal (y(t)).It comprises a subtractor (1) to calculate the difference between the input signal and a reference signal (Ur(t)), a converter subsystem (2, 3, 4) to produce the error signal from said difference and a feedback loop to produce the reference signal by means of a digital-to-analog converter (5) which delivers a comparison signal (Uc(t)) in response to the error signal.In accordance with the invention, the input signal (x(t)) is assigned a center frequency (f.sub.0), the feedback loop comprises a displacement unit (7) for displacing the frequency response of the digital-to-analog converter (5) from the null frequency towards the center frequency (f.sub.0), said displacement unit producing the reference signal (Ur(t)) from the comparison signal (Uc(t)).

Abstract: In a method of controlling the power at which an access packet is transmitted by a mobile on an access channel to a base transceiver station of a mobile radio system, the base transceiver station transmitting a broadcast channel regularly, the base transceiver station transmits on the broadcast channel a power indication representing the transmit power of the broadcast channel. At the mobile the power received on the broadcast channel is measured and the measured power is compared with the transmit power indicated by the transmit power indication on the broadcast channel to deduce an estimated propagation loss from the mobile to the base transceiver station. An optimal transmit power for the access packet is determined on the basis of the estimated propagation loss and parameters of the mobile radio system.

Abstract: In a method of determining, in a cellular mobile radio system with more than one type of cell, which type of cell a mobile station is accessing, the management network of the system sends to the mobile station a signalling message (recognition message) in the form of a sinusoid whose frequency (recognition frequency) differs from a reference frequency known to or determinable by the mobile station. The difference, optionally a null difference, between the reference frequency and the recognition frequency is characteristic of the cell type. The mobile station determines the recognition frequency. The mobile station then determines the difference between the reference frequency and the recognition frequency. The mobile station then determines the cell type from this difference.

Abstract: The present invention relates to a device for correcting a frequency shift due to the Doppler effect in a transmission system. The device for correcting a frequency shift due to the Doppler effect is applicable to a transmission system in which a signal is transmitted in a transmission lobe between a transmitter and a receiver that are in relative motion. The frequency shift which is the difference between the frequency of the transmitted signal as measured at the receiver and as measured at the transmitter is presented as the sum of a center frequency characteristic of the transmission lobe plus a position frequency which is a function of the position of the receiver in the transmission lobe. The device includes means for tuning the receiver which has a tuning frequency such that said tuning frequency is equal to the sum of the transmitted frequency plus the center frequency.