Linear Combination of Pulses for Coexistence in the IEEE 802.15.4a Standard
The low data rate accurate location ranging Wireless Personal Area Network zWPAN standard IEEE which is based on ultra wideband zUWBg impulse radios suggests using linear combination of pulses to reduce interference to coexisting primary systems. In this paper we consider possible implementations of linear combination of pulses as suggested in the standard and study the generated notches in the resulting code spectrum. Using the zy transform approach we show that the number of these notches is limited and the notch locations are not flexible due to the limited number of pulses allowed by the standard. We also make some suggestions for increasing the number of notches at desired frequencies.