Estimating Optimal Linear Regression Filter Length for Channel Estimation

A receiver circuit comprising

• a channel response measurement circuit configured to perform a plurality of channel response measurements corresponding to a path delay or to a signal frequency, to obtain ordered channel measurement samples for a current estimation interval, and
• a processing circuit configured to:
• estimate a short-term slope value for each of a plurality of sequential observation time intervals, each observation time interval comprising a plurality of the ordered channel measurement samples and having a uniform length;
• for each of a plurality of candidate filter lengths, where each candidate filter length is an integer multiple of the uniform length, compute a distortion metric value based on the short-term slope values for observation time intervals falling within the candidate filter length, the distortion metric value characterizing an extent to which the candidate filter length will introduce a tracking bias in filtering the ordered channel measurement samples;
• and
• select a filter length for use in demodulating a received signal from at least among the candidate filter lengths, based on the distortion metric values, such that the longest filter length meeting a pre-determined distortion criterion is selected.