Abstract: The invention relates to a method of preparing signals (X and Y) to be compared to establish predistortion at the input of an amplifier (12), the signals comprising a signal (X) before amplification and a signal (Y) after amplification by said amplifier. Preparation includes time aligning (22) the signal before amplification (X) with the signal after amplification (Y) before using them to establish said predistortion. The invention preferably operates in two stages, namely a stage of coarse time alignment, in which the signal before amplification (X) is subjected to a time delay comprising an integer number of first time units, and a stage of fine time alignment, in which a delay or advance value of a fraction of the first time unit is determined.

Abstract: The invention relates to a method of transmitting calls in a cellular type telecommunications system using a plurality adjacent carrier frequency bands and in which a first cell or a first site uses only a fraction of said frequency bands, the transmitted signals being subjected to peak clipping prior to application to an amplifier of a transmitter system in order to optimize the efficiency of the amplifier. Prior to being applied to the input of the amplifier, the signals (32) to be transmitted for the first cell (or first site) are subjected to filtering (28) so that the power density of the peak-clipping noise is not eliminated in adjacent frequency bands (f2, f3) that are unused by said first cell.

Abstract: In a method of transmitting more than one carrier using the same power amplifier associated with a linearization arrangement, a composite signal comprising the carriers is clipped before it is applied to the input of the amplifier in order to limit the ratio of the peak power to the average power of the signal to be transmitted. Each carrier is clipped individually and the clipping power density for each carrier is a function of its power.

Abstract: A method of transmitting telecommunication signals uses a power amplifier associated with linearization means for amplifying simultaneously a plurality of signals modulating different carriers. The composite signal consisting of the carriers is clipped on the upstream side of the amplifier. The clipping threshold depends on the sum of the powers of the various signals to be transmitted and an operating parameter of the amplifier depends on the sum of the powers in order to maintain an optimum efficiency of the amplifier and/or to minimize the power margin, i.e. the difference between the saturation power and the average operating power.

Abstract: A method of optimizing the performance of a mobile radio system transmitter using processing operations including discrete Fourier transform (DFT) computation, filtering in the frequency domain, inverse discrete Fourier transform (IDFT) computation, overlapping of processed sample blocks, and oversampling, wherein, for a given input sampling frequency, a given order of magnitude of the output sampling frequency, and a given order of magnitude of the required frequency resolution, the length of the DFT and the length of the IDFT are chosen in such a manner as to enable the finest possible choice of the percentage overlap and/or the oversampling factor.

Abstract: The invention concerns a transmission equipment for a telecommunication system operating on a wide frequency band, which equipment contains: a signal branch (32) including an analog chain (12′), a power amplifier (14′) associated to a feedforward linearization circuit including: a first subtractor (16′) having a first input (16′2) receiving a signal representing the input of the amplifier and a second input (16′1) representing the output of this amplifier, residual error amplifier (20′) which amplifies the output of the first subtractor, and a second subtractor (22′) which subtracts the output of the residual error amplifier from the output of the power amplifier (14′), the signal branch containing predistortion means (40) which provide correction signals depending on the output signal of the power amplifier.

Abstract: The invention concerns a transmission equipment for a telecommunication system operating on a wide frequency band, which comprises:

Abstract: The invention relates notably to a method for clipping a wideband signal in order to eliminate signal overshots having an amplitude above a predefined threshold before submitting the wideband signal to a power amplifier.

Abstract: In a broadband multicarrier modulator, all processing within a modulator is replaced by a pre-computed table so that a modulated signal can be produced as a function of the modulating signal merely by reading the table. The carrier frequency of the modulator is even programmable. The size of the pre-computed table is reduced by using an automation. With this automation the address for reading the table at a given time depends on preceding values of the modulating signal. By reading the table on a time sharing basis it is even possible, with a single modulator, to perform the work of several modulators. A multicarrier modulator is then easily implemented.

Abstract: The invention concerns a method of transmitting a control signal by a base station of a digital cellular mobile radio system, said base station comprising at least one array of a plurality of antennas for dynamically creating a beam (31) transmitting said control signal, said transmit beam (31) being adapted to assume different angular positions (33) within a predetermined angular range (32). In accordance with the invention, said method includes a step of allocating to said control signal, in at least one of said transmit subsystems, a predetermined specific time shift so that said transmit beam (31), called a vibrating beam (31), assumes in succession at least some (33) of said different angular positions and enables isotropic broadcasting of said control signal in said angular range (32). The invention also concerns a corresponding base station.

Abstract: Fourier transform processing is applied to digital signals obtained by analog-to-digital conversion of signals supplied by two microphones spaced by a fixed distance to produce two series of discrete data each datum of which represents the energy and phase of a spectral frequency band of the received sound. A dominant angle of incidence representing the angle of incidence of a speech signal component of the received sound signal relative to the two microphones is determined from phase differences between the discrete data in the same frequency bands of the two series and is used to combined the two series of discrete data into a single instantaneous spectrum in which any speech signal component is amplified relative to the noise.

Abstract: A device for recovering an original bit stream from a received bit stream by processing the received bit stream in accordance with the Viterbi algorithm comprises an operator to establish the maximal metric of rank r of the state E.sub.j denoted Met.sub.r (E.sub.j) for r greater than n and the (r-n) th bit of the bit stream corresponding to the metric from input values which are maximal metrics of rank r-1 of states E.sub.2k and E.sub.2k+1 denoted Met.sub.r-1 (E.sub.2k) and Met.sub.r-1 (E.sub.2k+1) and the conditional probabilities related to the states E.sub.2k, E.sub.2k+1) that the r-th bit of the bit streams associated with these states has a determined value denoted (Pr(b(r)+0/E.sub.2k) and (Pr(b(r)=0/E.sub.2k+1) for example where k is equal to 2j for any value of j less than 2.sup.n-1 and has the value 2(j-2.sup.n-1) for any value of j greater than or equal to 2.sup.n-1, so that Met.sub.r (E.sub.j) takes the larger of the values of the expressions Met.sub.r (E.sub.j)+(Pr (b (r)=0/E.sub.2k) and Met.sub.

Abstract: A signal processing circuit for the European digital cellular radio system continuously exchanging speech samples with a converter circuit (AD), exchanging baseband digital signals with a radio circuit (R) and exchanging data and signalling information with a control circuit (C) which also transmit control signals to it.

Abstract: In a method of sequencing signal processing in the reduced rate communication mode of a digital cellular radio system for conveying digitized speech communications between a terminal and a base station by means of traffic frames each comprising time slots the terminal has a time slot for sending to the base station and a time slot for receiving from the base station. The communication comprises blocks representing groups of speech samples. Each block is formed of sub-blocks each conveyed during traffic frame time slots. During each traffic frame the following are effected: a configuration process, the processing of a receive time slot, the processing of a send time slot, the processing of a send block during a send period outside the traffic frames, and the processing of a receive block during a receive period, a particular traffic frame.

Abstract: The present invention concerns an integrated circuit (1) comprising a standard cell (4), an application cell (2) and a test cell (3) designed in particular to store or to modify from outside the integrated circuit the value of communication signals passing between the standard cell and the application cell. The standard cell executing instructions provided on an instruction bus (3B4) by a program memory located in the application cell in response to an instruction address carried by an instruction address bus (3A4), the conductors of these buses constituting communication links. The integrated circuit further includes a branching circuit for replacing at least one erroneous instruction from the program memory with a replacement instruction previously stored in the integrated circuit in response to a predetermined state of the communication links.

Abstract: In a method of sequencing signal processing in the communication mode of a digital cellular radio system for conveying digitized speech communications between a terminal and a base station by means of traffic frames each comprising time slots the terminal has a time slot for sending to the base station and a time slot for receiving from the base station. The communication comprises blocks representing groups of speech samples. Each block is formed of sub-blocks each conveyed during traffic frame time slots. During each traffic frame the following are effected: a configuration process, the processing of a receive time slot, the processing of a send time slot, the processing of a send block during a particular send traffic frame, and the processing of a receive block during a particular receive traffic frame.

Abstract: A clock signal generator using fractional frequency division is provided comprising a division circuit that produces a clock signal starting from a timing rhythm signal. The frequencies of the two signals are in a division ratio which is the sum of a whole part and a fractional part. A pulse subtractor is provided for receiving the rhythm signal and transmitting it to the division circuit while deleting at least one pulse from this signal upon a command. An accumulator commands a pulse subtractor on each occasion when the product of the number of pulses of the clock signal counted, starting from a time of origin and of the fractional part, changes by unity.

Abstract: In a multiprocessor machine comprising K channels of different signals, the signals are converted to digital samples by K analog-to-digital converters connected respectively to each channel. N monolithic elementary processors are connected by means of a sample acquisition bus which is common to all of the K analog-to-digital converters. They are also connected by a ring bus which is common to all of the processors so as to permit circulation between processors of the results of computation performed on the samples received by each processor. A control unit and at least one transfer automat synchronized by a common clock signal initiate respectively on the one hand the performance of computations to be carried out by the processors on the samples which they receive as well as on the other hand the transfer of samples on the acquisition bus and the transfer of the results of computation between processors on the ring bus.

Abstract: According to the method, the clock signal is obtained from a phase increment datum .DELTA.P, representing the frequency to be synthesized. It consists in performing a binary number M modulo addition of each phase increment with the modulo M sum of the phase increments already totalized inside a phase accumulating device. After each overflow of capacity of the accumulator device, the remaining residual phase error P.sub.K is read in the accumulating device. Correlatively, 2.sup.Q clock signals with a period T.sub.c, phase-shifted with respect to each other by T.sub.c /2.sup.Q are generated. A temporal error .DELTA.t.sub.K is computed by obtaining the ratio P.sub.K /.DELTA.P between the residual phase error P.sub.K and the phase increment .DELTA.P per period T.sub.c. Finally that clock signal for which the phase shift with respect to the computation clock signal is closest to the computed residual phase is selected.

Abstract: A high frequency digital synthesizer is provided with aperiodic correction optimizing the spectral plurity, including:a generator of reference clock signals of frequency F.sub.C,a computing device, which, from a frequency increment of the signal to be synthesized, delivers, on the one hand, uncorrected pulses of frequency F.sub.Sj shifted in the time with respect to the signal of frequency F.sub.S to be synthesized by an amount .DELTA.t at most equal to 1/F and, on the other hand, a time error signal corresponding to the shift .DELTA.t and a correction circuit which is initiated by each of the frequency pulses F.sub.Sj for delaying the signal F.sub.Sj by a maximum time when the time error signal is zero by an amount equal to the maximum time reduced by the shift .DELTA.t indicated by the time error signal.