A comprehensive model for ultrawideband propagation channels

Abstract

Abstract-This paper describes a comprehensive statistical model for UWB propagation channels that is valid for a frequency range from 3-10 GHz. It is based on measurements and simulations in the following environments: residential indoor, office indoor, built-up outdoor, industrial indoor, farm environments, and body area networks. The model is independent of the used antennas. [7] developed the concept of time-hopping impulse radio (TH-IR) systems. In 2002, the frequency regulator in the USA allowed unlicensed UWB transmission (subject to the fulfillment of a spectral masks), and other countries are expected to follow suit. One of the most promising applications for UWB are sensor networks, where the good ranging and geolocation capabilities of UWB [8] are particularly useful. The data rates for those applications are typically low (<1 Mbit/s). Recognizing these developments the IEEE has established the standardization group 802.15.4a, which is currently in the process of developing a standard for these applications.The ultimate performance limits of any communications system are determined by the channel it operates in. For a UWB system, this is the UWB propagation channel, which differs from conventional (narrowband) propagation in many respects. The performance of a system thus can only be evaluated when realistic channel models are available. A number of UWB channel models have been proposed in the past: [9] suggested a model for the frequency range below 1 GHz (this model was adopted by the 802.15.4a group for testing of low-frequency UWB systems). The IEEE 802.15.3a group developed a channel model [10] that is valid from 3 − 10 GHz, but is designed only for indoor residential and office environments, and the distance between transmitter and receiver is restricted to < 10 m.

Body Area Network. A perspective to the future, from research

“…Fort [11] define que las contribuciones llegan en grupos de clústers y afirma que la disposición de las amplitudes sigue una distribución lognormal. » Los tiempos de llegada de los modelos de pequeña escala suelen ser descritos mediante distribuciones exponenciales, sin embargo los modelos de canal que presentan clusterización, requieren aproximaciones más complejas, por lo cual se emplean distribuciones exponenciales mezcladas que tratan de explicar el fenómeno de sobrelapamiento de los clúster generados por los difusores [27].…”

On Secure and Precise IR-UWB Ranging

“…The exact values that we obtain are specific to the channel model (the NLOS model number 2 from [3]), but we are interested in the relative performance of different countermeasures.…”

“…The physical layer is simulated with an accuracy of 100ps. We use the (weak) NLOS channel model number 2 from [3] with a channel spread of roughly 60ns. Unless otherwise stated, we assume the parameter values summarized in Table I.…”

“…Essentially, under multipath propagation, a receiver receives a sum of multiple distorted and attenuated copies of the transmitted signal, each shifted in time by the propagation delay of the path it traversed. In typical indoor environments, the channel spread of the time-delays is in the order of tens of nanoseconds [3], which translates to at least a few meters of ranging error.…”

Filter Bank-based Transceiver Design for Ultrawideband

“…The UWB channel has been characterized in IEEE 802.15.4a (Molisch et al, 2004), where several types of channels are described. Among other environments, channel types 3 and 4 model an indoor environment in line of sight (LOS) and non-line of sight (NLOS) configurations respectively.…”