Selection and performance evaluation of time hopping codes for UWB communication systems

Abstract

Ultra-Wideband (UWB) is a promising technology with its attractive and unique features newlinemotivating major advances in wireless communication system development. In the past four newlinedecades, it has been used for short range radar systems, military communications and remote newlinesensing applications. In 2002, the Federal Communications Commission (FCC) in the United newlineStates issued a ruling that UWB could be used for data communications, radar and safety newlineapplications with bandwidth allocation of (3.1-10.6 GHz) so that UWB radios, with low-power newlineultra-short information bearing pulses, can coexist with existing services such as the IEEE newline802.11 a/b/g WLANs and GPS which operate in the lower band of UWB allocations. The very newlinelarge bandwidth of UWB systems is the biggest allocation to any communication system, and newlineso has the vide potential to offer data rates of the order of Gbps. Due to low transmitted power newlineUWB systems are limited to short range communication for high data rates or long distance newlinecommunication at low data rates. It also has low probability of interception and detection, low newlinecost, small size equipment and can pass through buildings. However, UWB systems face newlinemultiple challenges in terms of pulse design, antenna, modulation, interference reduction, newlinefading, multipath multiuser interference. newlineThe problem of Multiuser Interference (MUI) reduction and spectrum shaping in UWB newlinecommunication systems, using Frequency Hopping (FH) codes as Time Hopping (TH) codes is newlineundertaken as no code construction method was available for TH codes. Now it is possible to newlinegenerate TH codes with better correlation properties and have also shown that better correlation newlineproperties have direct impact on BER performance of the system, which motivated the current newlinework. Coexistence of UWB communication with other existing or upcoming narrowband newlinecommunication systems have been analyzed by providing methods to create spectrum null newlineusing mathematical modification in TH codes without compromising their correlation newlineproperties. Following objectives have