A receiver includes digital logic for defining a plurality of signal paths for an ingoing digital signal to determine a frame classification. Frames are classified according to a combination of readings of a plurality of correlation block and relative signal (power) strengths. Power detection is specified for frequency bands of interest. The combination of readings and their corresponding pattern may be used to determine whether a frame is being transmitted in a lower bandwidth channel, an upper bandwidth channel or a large bandwidth channel that overlaps the lower and upper bandwidth channels. A transmission type (legacy, mixed mode, Greenfield) may subsequently be determined based upon the identity of the frame channel.