Abstract: The invention relates to a method of formation of one or more mixed signals (Sout) on the basis of at least two digital source signals (S1, S2), in particular audio signals, in which the mixed signal or signals (Sout) are formed by mixing the source signals (S1, S2). In particular, a quantity characteristic of a source signal or of the mixing is determined and the value (W1, W2) of the said characteristic quantity is watermarked on at least one of the signals (S1, S2, Sout). The invention also relates to a method of separation intended to separate, at least partially, at least one digital source signal contained in one or more mixed signals comprising a watermarked value of a quantity characteristic of a source signal or of the mixing.

Abstract: A method for estimating the phase in a digital communication system, comprising the steps of: receiving and storing a block of observations Yk; executing at least one phase locked loop (PLL) on a predetermined sequence of observations extracted from said block. Each PLL provides an intermediate value, combining both intermediate values makes it possible to provide a sharpened phase estimate. The method allows realization of an improved phase estimator based on the simplicity of phase locked loops.

Abstract: A turbocode receiver system of a signal emitted by a turbo-coded modulated transmitter system, includes: a soft demapper (1) the output of which is connected to a turbodecoder (2), and an adaptive locked loop including: a measurement generator (3) the input of which is connected to the turbodecoder output to receive the reliability vector (LLRout) of the result and adapted to transform the vector into a reliability measurement (M(I)), equal to the average of the lowest reliability values of word bits, transmitted to a phase shift estimator (4) the output of which is connected to a phase compensator (5) positioned upstream of the soft demapper and adapted to correct the incoming signal of the phase value ?.

Abstract: The invention concerns a method for estimating the gain and/or the phase of observation data (yk) transmitted in QAM modulation. The method includes (A) iteratively estimating the phase and/or gain parameters based on a specific phase and/or gain law and (B) executing an adaptive procedure for estimating the phase and/or gain parameters, the adaptive procedure including at least one function for estimating the parameters based on the value of likelihood probability, expressed in terms of log-likelihood, of each observation data (yk) with respect to the set of bits constituting the symbols of the QAM modulation. The invention is applicable to single-carrier or multicarrier digital transmissions.

Abstract: Each received word is subjected to SISO turbodecoding consisting in generating decoded test words using an iterative algorithm, calculating the analog weight of the decoded test word, which weight is the half-sum of the products of the value of each bit mapped to ±1 of this decoded test word and the log-likelihood of this bit, classifying the analog weight values of the concurrent words according to a first analog weight vector and a second analog weight vector formed by the analog weight components of the decoded test words, the bit of rank j of which is at a first value, and a second analog weight vector formed by the analog weight components of the decoded test words, the bit of rank j of which is at a second value, and calculating the SISO decoding soft-decision output value as being the difference between the analog weight components of the first and second vectors.

Abstract: A receiver for a digital data transmission device for receiving a digital signal and comprising a free sampler physically taking samples rk of a received signal r(t) at a frequency at least equal to twice the received signal spectrum maximum frequency. A digital interpolator allows to derive a sequence of samples Xk calculated from said physical samples, according to a tuning parameter ?. An equalizer adjustable to a set of equalization parameters e allows to process said interpolator output samples Xk. A computing unit simultaneously provides, in a single processing, values of ? to the digital interpolator and values of the equalization parameters e to the digital equalizer. The invention also provides a method for digitally processing a received signal in a digital transmission device.

Abstract: A modulation process for a digital transmission system having an error correcting code and determination of the number of bits to load on a transmission channel. The process judiciously associates a coder for introducing redundancy to the binary information, an interleaver for suppression the correlation to the encoded information and a labeling of the same based on a GRAY type coding in order to associate the said binary information with points of a constellation which is selected among a predetermined set of constellations. The process achieves a precise determination of the order and size of the constellation to utilize and, therefore, the computation of the bit loading as a function of the signal to noise ratio measured in reception and as a function of the bit error rate Pbit at the output of the receiver. The process is well adapted to the Multi Tone transmission system, and to the use of turbo codes.

Abstract: A method for estimating the phase in a digital communication system, comprising the steps of: receiving and storing a block of observations Yk; executing at least one phase locked loop (PLL) on a predetermined sequence of observations extracted from said block. Each PLL provides an intermediate value, combining both intermediate values makes it possible to provide a sharpened phase estimate. The method allows realization of an improved phase estimator based on the simplicity of phase locked loops.

Abstract: A modulation process for a digital transmission system having an error correcting code and determination of the number of bits to load on a transmission channel. The process judiciously associates a coder for introducing redundancy to the binary information, an interleaver for suppression the correlation to the encoded information and a labeling of the same based on a GRAY type coding in order to associate the said binary information with points of a constellation which is selected among a predetermined set of constellations. The process achieves a precise determination of the order and size of the constellation to utilize and, therefore, the computation of the bit loading as a function of the signal to noise ratio measured in reception and as a function of the bit error rate Pbit at the output of the receiver. The process is well adapted to the Multi Tone transmission system, and to the use of turbo codes.

Abstract: A receiver for a digital data transmission device for receiving a digital signal and comprising a free sampler physically taking samples rk of a received signal r(t) at a frequency at least equal to twice the received signal spectrum maximum frequency. A digital interpolator allows to derive a sequence of samples Xk calculated from said physical samples, according to a tuning parameter &tgr;. An equalizer adjustable to a set of equalization parameters e allows to process said interpolator output samples Xk. A computing unit simultaneously provides, in a single processing, values of &tgr; to the digital interpolator and values of the equalization parameters e to the digital equalizer. The invention also provides a method for digitally processing a received signal in a digital transmission device.