An Interference-Aware Cognitive Radio UWB (IA-CR-UWB) system using Eigen pulse shaping

Abstract

To protect the performance of the UWB system against undesired interference and to avoid deterioration of the coexisting systems, special transmit and receive (T-R) pulses are designed. In this paper, we propose a Interference Aware Cognitive) Radio (IA-CR) Ultra Wide-Band (UWB) system which will have superior performance over noncognitive ultra wide band systems. A modified Eigen-analysis method is used to design the UWB pulse shapes and the T-R filters. This method allows the imposing of sharp spectrum nulls at the frequency bands of the interferers. In practical scenarios, when the interference activity is not static, static transmit and receive filters will have degraded performance. With our proposed IA-CR capability, the UWB system performs spectrum sensing to pick the most suitable transmit and receive filters that will minimize its error rate performance. The coexistence of a practical UWB system with other narrow band systems as IEEE 802.11 wireless LAN systems operating at 5.2 GHz and radio location services operating at 8.5 GHz is considered in this paper. The proposed IA-CR UWB system is shown to outperform static interference rejection systems. The simulations are performed using the system parameters and channel models for the IEEE 802.15.4a UWB system.