Filter-bank multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) is considered by recent research projects as a key enabler for the future 5G air interface. It exhibits better spectrum shape and improves mobility support compared to orthogonal frequency-division multiplexing (OFDM). Therefore, the availability of efficient hardware implementations becomes of high interest. In this context, a novel pipelined hardware architecture of the transmitter capable of supporting several filter lengths and targeting low complexity is proposed and compared to typical FBMC/OQAM and OFDM implementations. For a short prototype filter, the proposed architecture provides a complexity reduction of 40 to 50% in terms of computational and memory resources with respect to a typical FBMC/OQAM transmitter. In addition, it greatly reduces the complexity gap to OFDM, making this modulation scheme particularly attractive from performance and implementation perspectives.