Interference Mitigation Technique for Coexistence of Pulse-Based UWB and OFDM

Abstract

Ultra-wideband (UWB) is a useful radio technique for sharing frequency bands between radio systems. It uses very short pulses to spread spectrum. However, there is a potential for interference between systems using the same frequency bands at close range. In some regulatory systems, interference detection and avoidance (DAA) techniques are required to prevent interference with existing radio systems. In this paper, the effect of interference on orthogonal frequency division multiplexing (OFDM) signals from pulsebased UWB is discussed, and an interference mitigation technique is proposed. This technique focuses on the pulse repetition cycle of UWB. The pulse repetition interval is set the same or half the period of the OFDM symbol excluding the guard interval to mitigate interference. These proposals are also made for direct sequence (DS)-UWB. Bit error rate (BER) performance is illustrated through both simulation and theoretical approximations.

Review of the State of Art of Tunable Impulse Ultra-Wideband Technology as Integrator for Wireless Sensing and Identifications Short-Range Networks

“…The findings from this conducted research experiments can be explained as the following: In dual case of Narrow-band systems affected by UWB interference it has been found that, the effects of a single UWB node interference are almost negligible, whereas this is not the case as the aggregate effect of many UWB nodes and interference should be taken into account in the system design to allow coexistence. Other researchers [6], proposed an interference mitigation technique for coexistence of Bi-phase UWB and other wideband systems such as Orthogonal Frequency Division Multiplexing (OFDM) and IEEE 802.11a Wireless Local Area Network (LAN) as the interference affect and degrade the system bit error performance. By using multi-carrier type transmission pulse and template Figure 1.…”

A Cooperative Scheme for Spectrum Sensing in Cognitive Radio Systems

“…First, UWB communications are only used for signaling when operations at very low bit rates are acceptable. Secondly, range increase can be ensured either through recourse to multi-finger Rake receivers [12] or adoption of pulse repetition cycle techniques allowing interference minimization while not reducing the UWB average signal power [13]. Thus, UWB is used for signaling since the advantages of reduced interference and relaxed synchronization requirements are considered to outweigh the drawbacks deriving from increased complexity.…”

Analysis of the maximum likelihood channel estimator for OFDM systems in the presence of unknown interference

“…Narrow band interference (NBI) arises in orthogonal frequency-division multiplexing (OFDM) systems in a number of transmission scenarios, such as Wi-Fi communications [1,2] or cognitive radio, where different types of wireless services can use the same frequency band. The NBI can affect several subcarriers.…”