g parser 2 the frequency interleaver 210 comprises first permutation functions 302 and second permutation functions 304 for the i th encoder output there are m i output streams after the interleaver operations the frequency interleaver 210 further includes frequency rotation units 306 three stages of operations are involved with interleaver operation 1 first permutation operations by first permutation functions 302 2 second permutation operations by second permutation functions 304 and 3 frequency rotations by frequency rotation units 306 in order to fully explore the diversity gains when multiple encoders e g encoders 206 fig1 are present bit circulation operation is followed after the interleaving functions for each spatial stream processed within the interleaver 210 the first two stages of interleaving i e first and second permutation operations are identical among the different spatial streams which in this example are the same as in a conventional ieee 802 11a interleaving alternatively instead of the ieee 802 11a interleaving other interleaving examples are possible and anticipated by the present invention however for the third operation i e frequency rotations the amount of frequency rotation by the frequency rotation units 306 varies among the spatial streams in general the frequency rotation amount can be a variable in each.