Minimizing Energy Consumption in IR-UWB Based Wireless Sensor Networks

Impulse radio ultra-wideband (IR-UWB) communication has proven an important technique for supporting high-rate, short-range, low-power communication. These are necessary criteria for emerging sensor networks, which oftentimes have very short distance communication requirements, necessitate low power operation and may require high data rates (e.g., for supporting the transmission of images or video). In this paper, using detailed models of typical IR-UWB transmitter/receiver structures, we minimize the energy consumption per information bit in a single link of an IR-UWB system, considering packet retransmissions and overhead. This minimization is realized by finding the optimum packet length and the optimum number of RAKE fingers at the receiver for different transmission distances, using differential BPSK (DBPSK) and OOK with coherent and non-coherent detection. Our results show that at very short distances, it is optimum to use OOK with non-coherent detection and large packets, and at longer distances, it is optimum to use DBPSK with coherent detection and small packets.