A MIMO-based multiuser OFDM multiband of UWB communications is presented to meet FCC emission limitations for indoor UWB operations. The present UWB system divides a single UWB frequency band of 7.5 GHz into eleven frequency bands as a multiband. Each frequency band has 650-MHz frequency bandwidth, uses an OFDM with multicarrier, and employs different modulations. The present UWB system can be programmable not only to transmit different data rates in a relatively longer distance but also to avoid interference with other devices by controlling the multiband and/or some of the multicarrier within each of the OFDM. The present UWB system can transmit a very high data rate up to 11 Gbps approximately.