Stmicroelectronics S.a.

St-ericsson Sa

Telefonaktiebolaget Lm Ericsson (publ)

Fabrice Belveze

Olivier Isson

Luc Garcia

Fatima Aourik

Robin Gerzaguet

Thomas Morel

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

A receiver () has an ln-phase path (l-path) () that delivers a digital l-path signal x(t) and a Quadrature path (Q-path) () that delivers a digital Q-path signal x(t). The receiver () includes a compensation stage () arranged to compensate for gain error g and phase error &#x3c6; between the digital l-path signal x(t) and the digital Q-path signal x(t). The compensation stage () has a compensation coefficient generation stage (), a compensation coefficient application stage (), a gain control stage (), a relative gradient generation stage () and a step parameter generation stage (). Compensation coefficients W, W, W, Wapplied to the digital l-path signal x(t) and the digital Q-path signal x(t) are generated by iteratively updating them using a relative gradient of the compensated digital in-phase signal y(t) and a compensated digital quadrature signal y(t), and a step parameter &#x3bc;, the magnitude of which is adjusted based on a rate of change of the compensation coefficients W, W, W, W.

IQ mismatch compensation

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

A filter intended to receive a discrete time signal at a sampling clock frequency, comprising a determined number, greater than 2, of filtering units, each filtering unit comprising head capacitors in a number equal to the determined number, assembled in parallel between an input terminal and the terminal of an integration capacitor, and means for connecting, in successive clock cycles in a number equal to the determined number, successively each head capacitor to the input terminal, and for then simultaneously connecting the head capacitors to the integration capacitor, and in which the successive clock cycles during which the head capacitors of a filtering unit are connected to the input terminal are offset by one clock cycle from one filtering unit to the next one.

Analog filter with passive components for discrete time signals

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 filter intended to receive a discrete time signal at a sampling clock frequency, comprising a determined number, greater than 2, of filtering units, each filtering unit comprising head capacitors in a number equal to the determined number, assembled in parallel between an input terminal and the terminal of an integration capacitor; and means for connecting, in successive clock cycles in a number equal to the determined number, successively each head capacitor to the input terminal, and for then simultaneously connecting the head capacitors to the integration capacitor, and in which the successive clock cycles during which the head capacitors of a filtering unit are connected to the input terminal are offset by one clock cycle from one filtering unit to the next one.

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Fontanil-Cornillon, France

Fabrice Belveze