  Unique word OFDM is a novel technique for constructing OFDM symbols, that has
many advantages over cyclic prefix OFDM. In this paper we investigate two
different approaches for the generation of an OFDM symbol containing a unique
word in its time domain representation. The two-step and the direct approach
seem very similar at first sight, but actually produce completely different
OFDM symbols. Also the overall system's bit error ratio differs significantly
for the two approaches. We will prove these propositions analytically, and we
will give simulation results for further illustration.
