A staggered spread OFCDM scheme is utilized that improves channel estimation.
In
a first embodiment, each chip stream is time shifted by a predetermined amount
and then transmitted on a predetermined subcarrier. This results in time-spread
symbols being staggered (time-offset) on different subcarriers allowing for more
frequent sampling of the channel. In a second embodiment a staggered spreading
approach is applied in the frequency dimension to improve the performance of a
system with spreading in the frequency dimension.