A new transmitted reference pulse cluster system for UWB communications

To meet the implementation constraint posed by ultra-wideband (UWB) delay lines, a new transmitted reference pulse cluster (TRPC) structure is proposed where a group of reference and data pulses with short uniform spacing is used for transmission. This structure enables a simple, robust, and practical autocorrelation detector to be implemented in the receiver. It overcomes the major hurdle to the practical implementation of conventional transmitted reference (TR) systems, i.e., the long-wideband-delay-line requirement. TRPC is also compatible with the signal format proposed within the IEEE 802.15.4a Working Group for coherent and noncoherent systems. The performance of the proposed TRPC receiver and noncoherent pulse-position modulation (NC-PPM) with energy detection are analyzed and compared. Simulation results show that TRPC outperforms the conventional TR, NC-PPM, the recently proposed dual-pulse scheme, and the frequency-shifted reference system. In particular, it achieves power saving over NC-PPM by about 1.3-1.9 dB for IEEE 802.15.4a channel model 1 and 1.3-2.3 dB for channel model 8.