Stmicroelectronics S.a.

Stmicroelectronics N.v.

Telefonaktiebolaget Lm Ericsson (publ)

Commissariat a L'energie Atomique

St-ericsson Sa

Telia Ab

Olivier Isson

Fabrice Belveze

Daniel Bengtsson

Tomas Nordstrom

Fatima Aourik

Thierry Lenez

Tomas Nordström

Jean-Benoit Pierrot

Thomas Morel

Patrice Lenez, Legal Representative

The invention concerns receive circuitry for demodulating an input signal received from a transmission channel, the receive circuitry including a frequency interpolation filter arranged to provide channel estimations (&#x124;n) of the entire channel, the frequency interpolation filter having at least one filter receiving the pilot frequency channel estimations and performing filtering based on a plurality (Q) of the pilot channel estimations at a time; and a memory arranged to store the filter coefficients for the at least one filter, the coefficients being based on a frequency-domain autocorrelation of a model of the transmission channel, the model representing the time distribution of the channel power of the transmission channel determined independently of the pilot frequency channel estimations, wherein said model is based on a &#x3c7;distribution.

Receiver with channel estimation circuitry

The invention concerns receive circuitry for demodulating an input signal received from a transmission channel, the receive circuitry having a decision feedback equalizer including an inter-carrier interference estimation block arranged to provide an estimation of inter-carrier interference (ICI) noise based on at least a channel estimation determined for a previous symbol, a channel estimation determined for the next symbol, and on a previous estimation of the symbol data for the current symbol, the previous estimation being provided by a feedback path comprising a demapping block; and correction circuitry arranged to determine the estimation of the original data signal based on the estimation of ICI noise subtracted from the input signal.

Receiver with ICI noise estimation

Detection method and device for a receiver in a digital communication system designed to process a frame comprising a periodic sub-set of length n, said method comprising the following steps:&#x2014;determining a first vector u having a length n;&#x2014;determining a second shifted vector v;&#x2014;calculating a correlation function between said first and second vectors;&#x2014;calculating a quadratic error function between said first and second vectors;&#x2014;calculating a first cost function that is a linear combination of both preceding functions and, according to the sign of the result,&#x2014;calculating a second cost function of frame beginning estimate; and&#x2014;starting the communication system receiver.

Method and system for controlling a receiver in a digital communication system

A method of COFDM demodulation of symbols, each including first carriers conveying data and pilots having their frequency positions varying at least partly from one symbol to the next symbol. The method includes, for each symbol, a step of determining a first estimate of the transfer function of the channel for each carrier in a set of the first carriers of the symbol such that, for the frequency positions of the considered carriers, symbols different from the symbol include pilots, corresponding to a linear combination of second estimates determined for pilots at the frequency of said carrier. The coefficients of the linear combination are determined in iterative fashion, a new coefficient value being equal to the sum of the last value of the coefficient and of a term including the product between an iteration step and an error term, the iteration step being determined in iterative fashion.

Method and device for estimating the transfer function of the transmission channel for a COFDM demodulator

A method of COFDM demodulation of successive symbols, each symbol comprising data carriers and pilots. The method includes, for each symbol, the determination of estimates of the transfer function of the channel for the symbol carriers, including the steps of determining, for first carriers such that, for the frequency positions of the considered carriers, symbols different from the symbol include pilots, a first estimate based on second estimates obtained for pilots having the frequency of the carrier; and determining, for second carriers, a third estimate based on the first estimates. For at least one first carrier, the first estimate is further determined based on at least the third estimate determined for a carrier of a symbol received before the symbol at the same frequency as the carrier.

A method for MC-CDMA transmission of data between nodes of a network, including assigning to each node at least one spreading matrix, a set of data of at least one datum to be transmitted by a node being multiplied by the spreading matrix which is associated therewith and the product being then transmitted on a group of carriers in at least one predetermined set of samples forming at least one OFDM symbol; forming symbols to be transmitted all having the same duration, whatever the transmit node; and adding to each transmitted symbol a cyclic prefix and a cyclic suffix representing a predetermined number of samples, respectively of the end and of the beginning of the symbol.

MC/CDMA data transmission method

A digital subscriber line transmission system comprising an IFFT circuit generating successive outgoing time domain symbols on a subscriber line from respective groups of digital frequency domain coefficients; an FFT circuit generating groups of digital frequency domain coefficients from respective incoming time domain symbols received on the subscriber line, a current incoming symbol being delayed with respect to a current outgoing symbol by a predetermined time interval; and circuitry for, during an end portion of a current incoming symbol, subtracting from the signal received on the subscriber line an estimated echo obtained by a filter from a signal portion following the end of the current outgoing symbol, and adding thereto, through said filter, a beginning portion of the current outgoing symbol, wherein said portions have a duration at least equal to said predetermined time interval.

DSL transmission system with means for ensuring local echo orthogonality

The invention relates to a far-end crosstalk canceling circuit for a digital subscriber line transmission system, the transmission system including a plurality of line termination modems transmitting discrete multitone symbols Si to corresponding network termination modems over n transmission channels. The invention multiplies the vector S=(Si) i=1 to n, before transmission, by a precompensation matrix M such that the matrix product H*M is diagonal, H being the transfer matrix of the plurality of downstream transmission channels defined by R=H*S where R=(Ri), i=1 to n, is the vector of the discrete multitone symbols Ri respectively received by the modems.

DSL transmission system with far-end crosstalk compensation

The invention relates to a far-end crosstalk canceling circuit for a digital subscriber line transmission system, the transmission system including a plurality of line termination modems receiving discrete multitone symbols from corresponding network termination modems over a plurality of transmission channels. The invention estimates the modulated data actually transmitted by the network termination modems from the frequency components of the discrete multitone symbols received by the line termination modems and to evaluate the far-end crosstalk as a linear combination of these estimates. Far-end crosstalk cancellation for all the line termination modems is also provided in a centralized manner.

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La Tronche, France

Olivier Isson