Abstract: In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.

Abstract: In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.

Abstract: In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.

Abstract: In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.

Abstract: In one embodiment, an apparatus includes: a baseband processor having a preamble generation circuit to generate a preamble for an orthogonal frequency division multiplexing (OFDM) transmission, the preamble generation circuit to generate the preamble having a first portion comprising a first plurality of symbols, each of the first plurality of symbols having a plurality of carriers, where a subset of the plurality of carriers have non-zero values, the preamble generation circuit to generate the non-zero values using a sequence of complex values selected to optimize a peak-to-average power ratio (PAPR); a digital-to-analog converter (DAC) coupled to the baseband processor to convert the first plurality of symbols to analog signals; a mixer coupled to the DAC to upconvert the analog signals to radio frequency (RF) signals; and a power amplifier coupled to the mixer to amplify the RF signals.

Abstract: In one embodiment, an apparatus comprises: a baseband processor having a preamble generation circuit to generate a preamble for an orthogonal frequency division multiplexing (OFDM) transmission, the preamble generation circuit to generate the preamble having a first portion comprising a first plurality of symbols and a second portion comprising a second plurality of symbols, where the preamble generation circuit is to generate at least some of the second plurality of symbols having at least one frequency disruption between successive symbols of the second portion; a digital-to-analog converter (DAC) coupled to the baseband processor to convert the first plurality of symbols and the second plurality of symbols to analog signals; a mixer coupled to the DAC to upconvert the analog signals to radio frequency (RF) signals; and a power amplifier coupled to the mixer to amplify the RF signals.

Abstract: A method for correction of an impulse response of a multipath propagation channel. Such a method includes at least one iteration of the following acts: obtaining a current impulse response of the propagation channel; estimating a temporal shift between the current impulse response and a reference impulse response of the propagation channel; and correcting the current impulse response based on at least the temporal shift, delivering a corrected impulse response.

Abstract: A method of selecting a data signal implementing the following acts: a first act of modulating a first data signal carrying at least one content to be broadcast, called a first candidate signal, the first candidate signal carrying payload data and additional data associated with a communications layer; at least one second act of modulating a second data signal carrying the at least one content to be broadcast, called a second candidate signal, the second candidate signal carrying the payload data and additional data associated with the communications layer, the additional data being distributed differently in the second candidate signal, relative to the additional data of the first candidate signal; and an act of selecting from amongst the candidate signals, the candidate signal for which the modulation delivers a modulated signal having a peak-to-average power ratio (PAPR) meeting a predetermined criterion.

Abstract: A system and method provide adaptive filtering of radio frequency (RF) signals. Multiple signals are received in a predetermined RF spectrum, the signals including a desired signal and multiple potentially interfering signals. A first signal of the potentially interfering signals is down-converted to a baseband signal, and a power of the baseband signal is determined. When the power exceeds a predetermined threshold power, a first notch filter, corresponding to a frequency of the first signal, is activated.

Abstract: A method to discriminate a real echo peak from an aliased echo peak comprises: computing ‘a correlation between N samples of a digital data and a copy of the same N samples delayed by a time delay ?1,0 to obtain a first correlation result, time delay ?1,0 being equal to a time interval T between a first and a second distinct power peaks of an estimated channel impulse response, the first peak being the highest power peak within the temporal window, and/or computing—a correlation between the N samples and a copy of the same N samples delayed by a time delay TIFFT-?1,0 to obtain a second correlation result, and deciding whether the second peak is a real echo peak or an aliased echo peak based on the first and/or second correlation results.

Abstract: A system and method provide adaptive filtering of radio frequency (RF) signals. Multiple signals are received in a predetermined RF spectrum, the signals including a desired signal and multiple potentially interfering signals. A first signal of the potentially interfering signals is down-converted to a baseband signal, and a power of the baseband signal is determined. When the power exceeds a predetermined threshold power, a first notch filter, corresponding to a frequency of the first signal, is activated.

Abstract: A method to discriminate a real echo peak from an aliased echo peak comprises: computing ‘a correlation between N samples of a digital data and a copy of the same N samples delayed by a time delay ?1,0 to obtain a first correlation result, time delay ?1,0 being equal to a time interval T between a first and a second distinct power peaks of an estimated channel impulse response, the first peak being the highest power peak within the temporal window, and/or computing—a correlation between the N samples and a copy of the same N samples delayed by a time delay TIFFT-?1,0 to obtain a second correlation result, and deciding whether the second peak is a real echo peak or an aliased echo peak based on the first and/or second correlation results.

Abstract: In an OFDM mobile communications system, an algorithm for forming a preliminary estimate of the channel on pilot subcarriers is carried out. Based on this preliminary estimate, a channel property is estimated. This channel property is then used to decide whether to enter a mobile receiver mode or a stationary receiver mode. For example, in the mobile mode channel estimation is performed using only pilot symbols from the current symbol period, while in the static mode channel estimation is performed using pilot symbols from the current symbol period and pilot symbols from other symbol periods.

Abstract: A fine OFDM symbol synchronization method comprising the steps of: estimating (in 36) a channel impulse response (CIR) from received predetermined pilots present in OFDM symbols, the pre-determined pilots being arranged within the OFDM symbol at frequency intervals corresponding to n carrier frequencies, and their positions being shifted by k carrier frequencies from one OFDM symbol to the next, so that it is sent on the same frequency earner every m OFDM symbols, and thus m*k=n, m, n and k being integer numbers greater than one, and fine-tuning (in 60) the position of a time-domain-to-frequency-domain window used for receiving OFDM symbols, according to the position of at least one power peak in the estimated channel impulse response, wherein, if there are channel impulse response replicas in the estimated channel impulse response, the positions of correlated power peaks spaced apart by a multiple of Formula (I) is used for finding the position of the at least one power peak used n for fine-tuning, where Tu