Methods and apparatus that achieve good channel estimation without using
unnecessarily complex interpolation filters are described. Adaptive
interpolation filtering of a signal in a receiver includes determining at
least one correlation function parameter of the channel and determining a
filter configuration based on the correlation function parameter.
Interpolation filtering is then performed on the signal using the
determined filter configuration. The interpolation may be performed in
time, where a Doppler frequency shift can serve as the correlation
function parameter, or in frequency, where a root mean square or maximum
delay spread can serve as the correlation function parameter, or both. A
worst case signal-to-noise ratio may be used in determining the filter
configuration, or, optionally, the signal-to-noise ratio can determined
in real time. The filter configuration can be determined in real time or
selected from one of a plurality of predetermined configurations having
different complexities.