IEEE 802.15.4a -- Understanding the protocol and Reducing Multi-User Interference

Experimental results from various studies have proved that the 2.4 GHz ISM band has become increasingly congested. Widespread use of Wi-Fi (802.11) along with incumbent technologies already utilizing this band have made it difficult to provide other wireless services within the same band without an increase in bit error rate and a drop in throughput. The 802.15.4 protocol which has been defined for low data rate networks is currently also being deployed in the 2.4 GHz band.;This paper suggests the use of Ultra Wide Band (UWB) as a feasible alternative to deploying a Zigbee based Home Area Network (HAN) on the 2.4 GHz spectrum using Direct Spread Spectrum (DSSS). The FCC has approved the 802.15.4a standard for an UWB PHY layer for a sensor based networks. This study gives an analysis of the standard. The performance evaluation for this standard leads our focus to multi-user interference effects on preamble detection which affects synchronization and timing acquisition in a non-coherent energy detector receiver. The paper also considers two approaches that can be taken up to overcome multi-user interference so that, the inherent robustness of UWB is not overcome by inaccuracy in data reception introduced by interference.