Enhancing MB-OFDM throughput with dual circular 32-QAM

Quadrature phase shift keying (QPSK) and dual carrier modulation (DCM) are currently used as the modulation schemes for multiband orthogonal frequency division multiplexing (MB-OFDM) in the ECMA-368 defined ultra-wideband (UWB) radio platform. ECMA-368 has been chosen as the physical radio platform for many systems including wireless USB (W-USB), Bluetooth 3.0 and wireless HDMI; hence ECMA-368 is an important issue to consumer electronics and the user´s experience of these products. To enable the transport of high-rate USB, ECMA-368 offers up to 480 Mb/s instantaneous bit rate to the medium access control (MAC) layer, but depending on radio channel conditions dropped packets unfortunately result in a lower throughput. This paper presents an alternative high data rate modulation scheme that fits within the configuration of the current standard increasing system throughput by achieving 600 Mb/s (reliable to 3.1 meters) thus maintaining the high rate USB throughput even with a moderate level of dropped packets. The modulation system is termed dual circular 32-QAM (DC 32-QAM). The system performance for DC 32-QAM modulation is presented and compared with 16-QAM and DCM.