A non-uniform filter bank is created by joining sections of oversampled
uniform filter bands that are based on complex exponential modulation (as
opposed to cosine modulation). Each filter bank handles a given,
non-overlapping frequency band. The bands are not of uniform bandwidth,
and the filters of different banks have different bandwidths. The
frequency bands of the different filter banks cover the frequency of
interest with gaps in the neighborhoods of the filter band edges. A set
of transition filters fills those gaps.