A fluid flow meter system comprising: a sensor, secured to a structure defining a lumen , the sensor including: (i) a first transducer configured to transmit consecutively a plurality of copies of an ultrasonic transmit (TX) signal through a fluid flowing through the lumen ; (ii) a second transducer to receive a plurality of ultrasonic (RX) signals corresponding to the plurality of transmitted copies of the ultrasonic TX signal, an analog-to-digital converter configured to sample, at a first frequency, the plurality of ultrasonic RX signals received by the second transducer , the plurality of copies of the ultrasonic TX signal transmitted with distinct time delays with respect to periods of a clock signal of the analog-to-digital converter ; and a processor configured to: generate a fine resolution signal using sampled versions of the plurality of ultrasonic RX signals generated by the analog-to-digital converter , the fine resolution signal associated with a second sampling rate higher than the first sampling rate; compute a cross-correlation signal indicative of cross-correlation between the fine resolution signal and a reference waveform; and determine an estimate of a fluid flow parameter of the fluid based on the computed cross-correlation signal. a sensor, secured to a structure defining a lumen , the sensor including: (i) a first transducer configured to transmit consecutively a plurality of copies of an ultrasonic transmit (TX) signal through a fluid flowing through the lumen ; (ii) a second transducer to receive a plurality of ultrasonic (RX) signals corresponding to the plurality of transmitted copies of the ultrasonic TX signal, an analog-to-digital converter configured to sample, at a first frequency, the plurality of ultrasonic RX signals received by the second transducer , the plurality of copies of the ultrasonic TX signal transmitted with distinct time delays with respect to periods of a clock signal of the analog-to-digital converter ; and (i) a first transducer configured to transmit consecutively a plurality of copies of an ultrasonic transmit (TX) signal through a fluid flowing through the lumen ; (ii) a second transducer to receive a plurality of ultrasonic (RX) signals corresponding to the plurality of transmitted copies of the ultrasonic TX signal, an analog-to-digital converter configured to sample, at a first frequency, the plurality of ultrasonic RX signals received by the second transducer , the plurality of copies of the ultrasonic TX signal transmitted with distinct time delays with respect to periods of a clock signal of the analog-to-digital converter ; and a processor configured to: generate a fine resolution signal using sampled versions of the plurality of ultrasonic RX signals generated by the analog-to-digital converter , the fine resolution signal associated with a second sampling rate higher than the first sampling rate; compute a cross-correlation signal indicative of cross-correlation between the fine resolution signal and a reference waveform; and determine an estimate of a fluid flow parameter of the fluid based on the computed cross-correlation signal. generate a fine resolution signal using sampled versions of the plurality of ultrasonic RX signals generated by the analog-to-digital converter , the fine resolution signal associated with a second sampling rate higher than the first sampling rate; compute a cross-correlation signal indicative of cross-correlation between the fine resolution signal and a reference waveform; and determine an estimate of a fluid flow parameter of the fluid based on the computed cross-correlation signal. <EOS>