An enhanced dual carrier modulation for performance improvement in WiMedia UWB systems

In this paper, we propose an enhanced dual carrier modulation algorithm to improve performance in WiMedia ultra-wideband (UWB) systems. The proposed algorithm, which is named as double dual carrier modulation (DDCM), uses additional precoding to the conventional DCM to transmit symbols over different subbands. By using DCM and additional precoding, the proposed algorithm exploits not only frequency diversity in one subband, but also frequency diversity between uncorrelated subbands, resulting in more diversity and better performance than DCM. We also propose the detection method of the proposed algorithm by sharing the modified dual carrier modulation (MDCM) detection block which is included in WiMedia UWB systems. The proposed detection method reduces hardware complexity by combining the MDCM detection and the proposed algorithm detection. Simulation results of applying the proposed algorithm to WiMedia UWB systems show that the performance was improved by 1.5 dB and transmission range increased by 0.5 m in CM1 at a PER of 1%, compared to DCM.