A method of improving frequency diversity of a signal that includes a
plurality of orthogonal frequency division multiplexing (OFDM) symbols
comprises receiving an input data sequence, mapping the input data
sequence to a transmission data sequence, wherein the mapping includes
performing a mapping operation and generating an OFDM symbol using the
transmission data sequence. An orthogonal frequency division multiplexing
(OFDM) transmitter comprises an interface configured to receive an input
data sequence, and a processor configured to perform a mapping operation,
to map the input data sequence to a transmission data sequence wherein
the mapping includes performing the mapping operation, and to generate an
OFDM symbol using the transmission data sequence.