  Filter bank multicarrier (FBMC) systems that are based on offset quadrature
amplitude modulation (OQAM), namely, FBMC-OQAM, have been criticized for their
inefficiency in the use of spectral resources, because of the long ramp-up and
ramp-down tails at the beginning and the end of each data packet, respectively.
We propose a novel method for shortening these tails. By appending a set of
virtual (i.e., none data carrying) symbols to the beginning and the end of each
packet, and clever selection of these symbols, we show that the ramp-up and
rampdown tails in FMBC-OQAM can be suppressed to an extent that they deem as
negligible and thus may be ignored. This shortens the length of signal burst in
each FBMC-OQAM packet, hence, improves on its bandwidth efficiency, viz., the
same data is transmitted over a shorter period of time. We develop an
optimization method that allows computation of virtual symbols, for each data
packet. Simulation results show that, compared to existing methods, the
proposed tail-shortening approach leads to a superior out-of-band (OOB)
emission performance and a much lower error vector magnitude (EVM) for the
demodulated symbols.
