An Energy Efficient Sub-Band Based UWB Receiver and Its Performance Improvement by Interference Rejection Filtering

Abstract

A sub-band based ultra wideband (SUWB) system is proposed for energy efficient short range wireless communications. The proposed technique divides the bandwidth of 500 MHz into number of sub-bands that may be utilized for higher data rate or higher reliability or multi user access depending on system requirements. The energy efficiency is achieved by reducing the sampling rate requirements and also by the use of an orthogonal code based interference rejection and multi-path cancellation receiver. An interference rejection method is also proposed to further enhance the performance of the system for high data rate and/or high delay spread channels. This results in a low power and low complex alternative to improve performance in comparison to the conventional equalization methods. The simulation results in terms of the BER performance of the method for the IEEE 802.15.4a channel models are presented. A significant improvement in SNR of 5-7 dB is reported with the incorporation of the interference rejection filter for low and medium delay spread channels.