Abstract: The present invention relates to a method of switching from a first mobile radio mode to a second mobile radio mode in a multimode mobile radio terminal having a first part and a second part respectively operating in compliance with first and second radio access technologies and respectively provided with first and second clocks, the method including the following steps: locking the first part of the mobile terminal to a first mobile radio mode associated with an first clock; the mobile terminal calculating the time shift between the clocks of the two mobile radio modes; correcting the time of a second part of the terminal using the calculated time shift; and switching a second part of the mobile terminal to a second mobile radio mode associated with the second clock.

Abstract: In a method of estimating the relative frequency uncertainty between two parts of a mobile radio system able to communicate via two mobile radio networks at first and second particular frequencies, each part of the mobile radio system has a clock from which the particular frequency is derived and the uncertainty is estimated by measuring the number of pulses of each of the clocks during a time window of duration T starting at a time t. The method includes the following steps, with the time window T sliding: a) measuring the number of pulses of each of the clocks at n intermediate times t+(T/n), t+(2T/n), . . . , t+(nT/n), where n is a positive integer, b) storing the numbers of clock pulses thereby obtained in memory, c) calculating the relative frequency uncertainty at time t+T from the numbers of clock pulses stored in memory.

Abstract: The present invention relates to a receiving system (R) including an adaptive first equalizer (E1) associated with a first threshold detector (S1), and a device (TR) which enables the timing (TR) of a transmitting system to be recovered for said receiving system (R) from an equalized signal (yn) and a signal obtained by thresholding (sn). The receiving system (R) also includes a fixed second equalizer (E2) associated with a second threshold detector (S2). The receiving system finally includes a device (SW) by means of which it is possible to switch between a first mode of operation (position 1) in which the equalized signal (yn) and the signal (sn) obtained by thresholding are supplied by the second equalizer (E2) and the second threshold detector (S2), respectively, and a second mode of operation (position 2) in which the said signals (yn and sn) are supplied by the first equalizer (E1) and the first threshold detector (S1), respectively.

Abstract: A method of detecting blocking artifacts in digital video pictures, includes a step of filtering (GF) a digital input signal (x) using a gradient filter for providing at least one filtered signal, and a step of calculating (CALC) a block level metric (BM) for processing the filtered signal(s) to identify and count blocking artifacts as a function of their position in a grid. If the block level metric (BM) is lower than a threshold, the picture has either not been encoded using a block-based processing, or has been encoded in a seamless way. In the opposite case, the picture has been encoded using a block-based processing in a non-seamless way and corrective actions, such as a post-processing (PP), can be taken.

Abstract: Method for recovering an unknown frequency and frequency drift by iterative correlation in multicarrier radio communications applications, particularly in third/second generation mobile communication systems co-existence environments. The invention detects a correlation peak between a known sequence (28) of bits sent by the base station to the mobile and the received signal (26) by the mobile. The frequency recovering process comprises the correction in frequency of a local oscillator (28) in the mobile till the best correlation result between the received burst (26) and the known pattern (28) is achieved.

Abstract: In a method of estimating the relative frequency uncertainty between two parts of a mobile radio system able to communicate via two mobile radio networks at first and second particular frequencies, each part of the mobile radio system has a clock from which the particular frequency is derived and the uncertainty is estimated by measuring the number of pulses of each of the clocks during a time window of duration T starting at a time t.

Abstract: The present invention relates to a method of switching from a first mobile radio mode to a second mobile radio mode in a multimode mobile radio terminal having a first part and a second part respectively operating in compliance with first and second radio access technologies and respectively provided with first and second clocks, the method including the following steps:

Abstract: The invention enables to estimate the frequency offset introduced by a transmission medium based on the transmission of a known sinusoidal-frequency signal. Two samples out of phase by Π/2+p.2Π where p is an integer are multiplied to obtain a trigonometric function of said frequency offset. The estimate thus obtained is advantageously applied for correcting test signals received during a learning period preceding a transmission period between a transmitter and receiver. The estimate is also applicable for initializing adaptive algorithms for recovering the timing or echo cancellation at the level of the receiver. Any transmission system that utilizes one or various carriers and enables to transmit a sinusoidal signal at a given instant, notably Recommendation V34 of the CCITT.