Patent ID: 6985521

Claim:
An apparatus for channel estimation in a communication device having a transmit path and a receive path both coupled to a communication medium, and the apparatus comprising: a pseudo-random noise generator (PRN) coupled to the transmit path to inject a codeword consisting of ‘+1’s together with ‘−1’s or ‘0’s together with ‘1’s into the transmit path; a correlator coupled to the receive path to generate an ordered set of correlation coefficients corresponding with successive phasings of the codeword with respect to a received signal, and the correlator including: a detector to detect peaks within the ordered set of correlation coefficients including both a peak corresponding with a leakage signal together with at least one other peak corresponding to a reflection of the injected codeword by the communication medium, and the detector determining at least one of the offset between peaks or a relative magnitude of the peaks, thereby estimating the channel characteristics across the communication medium; a plurality of XOR gates each with an output and a pair of inputs a first of which pair of inputs couples to a corresponding bit of the codeword and a second of which pair of inputs couples to a corresponding sample of the received signal; a shifter to shift the codeword with respect to the corresponding samples of the received signal or vice-versa; and a summer coupled to the outputs of each bit of the plurality of XOR gates to sum the outputs of the plurality of the plurality of XOR gates codeword on each shift of the shifter, thereby generating successive ones of the ordered set of correlation coefficients.