Ultra Wideband Impulse Radio Systems with Multiple Pulse Types

TL;DR

This paper explores the use of multiple pulse types in ultra wideband impulse radio systems, demonstrating improved robustness against interference and deriving analytical performance expressions.

Contribution

It introduces multi-pulse IR systems with spectral analysis and closed-form BER expressions, enhancing interference resilience over traditional single-pulse systems.

Findings

Multi-pulse IR systems have spectral properties as the average of individual pulses.

Closed-form BER expressions for multi-pulse SR-IR systems are derived.

Multi-pulse IR systems show improved robustness against interference.

Abstract

In an ultra wideband (UWB) impulse radio (IR) system, a number of pulses, each transmitted in an interval called a "frame", is employed to represent one information symbol. Conventionally, a single type of UWB pulse is used in all frames of all users. In this paper, IR systems with multiple types of UWB pulses are considered, where different types of pulses can be used in different frames by different users. Both stored-reference (SR) and transmitted-reference (TR) systems are considered. First, the spectral properties of a multi-pulse IR system with polarity randomization is investigated. It is shown that the average power spectral density is the average of the spectral contents of different pulse shapes. Then, approximate closed-form expressions for the bit error probability of a multi-pulse SR-IR system are derived for RAKE receivers in asynchronous multiuser environments. The effects of both inter-frame interference (IFI) and multiple-access interference (MAI) are analyzed. The theoretical and simulation results indicate that SR-IR systems that are more robust against IFI and MAI than a "conventional" SR-IR system can be designed with multiple types of ultra-wideband pulses. Finally, extensions to multi-pulse TR-IR systems are briefly described.