NLOS identification and ranging methods in indoor IR-UWB systems
Date of Issue2016-06-01
School of Electrical and Electronic Engineering
Impulse radio ultra-wideband (IR-UWB) is a promising communication technology. With the advantages of high accuracy, great anti-interference performance, high data rates, and low power consumption, it is drawing more and more attention and is becoming a hot research area for future communication and position estimation applications. In this dissertation, we mainly focus on the IR-UWB ranging techniques which appears to be the basis o f further UWB positioning. A detailed introduction of UWB signals and widely-adopted UWB channel models are provided. Moreover, as NLOS propagation poses a threat to the accuracy o f ranging estimates, we also address the NLOS identification problem. Parametric-based as well as non-parametric-based method for identification are compared by simulations. It is found that both of them work well, and non-parametric-based method can better simplify the receiver since it merely depends on the statistics o f the received signal without the need to extract the channel statistics. To correctly identify the channel condition will no doubt benefit the range estimation, which is also discussed in the dissertation. Two main ranging techniques, namely Received Signal Strength (RSS) and Time of Arrival(TOA) based algorithms are presented. For the latter, in order to reduce the influence o f noise and multipath effects and improve the ranging accuracy, we also propose an energy-detection-based based TOA which uses a threshold to search for the first direct path. Extensive simulations of RSS and TOA ranging methods are conducted, which implies that in most cases, TOA outperforms RSS as expected.
DRNTU::Engineering::Electrical and electronic engineering