This paper is devoted to the feasibility study of a wireless sensing system, mainly based on passive surface acoustic wave sensors, for remote measurement of temperature aboard space platforms. The use of passive sensors is particularly attractive since they need no battery and are robust in extreme environments, as they contain no active electronic circuits. The main objective of this paper is the complete characterization of the wireless system environment, in order to determine the main fundamental limits of this technology from a communication theory point of view. Preliminary experimental measurements are used for defining the main environment parameters, validating some of the theoretical limit computations, and proving the space application feasibility

The IEEE.802.15.4a standard has recently attracted much attention as an indoor short-range highspeed wireless communication. One of the most exciting characteristics of the IEEE.802.15.4a standard is that its bandwidth is over 500MHz which can satisfy an extensive range of space applications. Moreover due to its low power spectral density emission and its resistance to multipath, the UWB technology seems adapted for an intra-spacecraft application with hard electromagnetic compatibility constraints and presence of reflective spacecraft internal cavities. This paper presents an overview of the different BER simulations in presence of multipath and narrowband interference due to the spacecraft environment. This paper presents part of the work performed in the first phase of the activity covered by the UWB4SAT project (ESTEC/Contract No. 4000107142/12/NL/AK) with the objective to demonstrate the feasibility of an intraspacecraft UWB communication.

ESA is investigating wireless cable replacement for intra-spacecraft (IS) applications to reduce cable weight, and add flexibility to the subsystem layout. The low emission limit and robustness to highly reflective environments make UWB a potential candidate for cable replacement. Therefore, to validate these assumptions, channel measurements have been conducted in a representative spacecraft; the ESA Venus Express mockup, which is divided in separate compartments/cavities connected by openings. Channel measurements that cover the entire 3 to 10 GHz UWB spectrum, are conducted for all cavity combinations of the Venus Express. Channel statistics are derived from the measurements. Moreover, the raw channel measurements are used in a hardware-true physical layer (PHY) simulator, based on current Holst Centre -IMEC UWB hardware platform supporting IEEE 802.15.4a standard. The used hardware specification are from the non-coherent setting, employing power detection and integrate and dump in RX for easy synchronization in a highly reflective environment, insensitivity to clock jitter, and robustness against clock offsets at cost of reduced sensitivity. The PHY results correspond well to the outage probability derived from the channel measurements when taking the actual noncoherent setting receiver hardware sensitivity into account. Since most power is in the scattered power, the most dominating factor in IS UWB communication is not the actual position or distance between the antennas, but the minimum number of openings between the cavities. The low mean loss of the measured radio channel combined with the immunity of the UWB air-interface to small-scale-fading, ensures that the signal is always well above the noise floor of the non-coherent setting of the current Holst Centre -IMEC hardware.

This work is devoted to the feasibility study of a wireless sensing system, mainly based on passive surface acoustic wave (SAW) sensors, for remote measurement of temperature aboard space platforms. The use of passive sensors is particularly attractive since they need no battery and are robust in extreme environments, as they contain no active electronic circuits. The main objective of this study is the complete characterization of the wireless system environment, in order to determine the main fundamental limits of this technology from a communication theory point of view. Preliminary experimental measurements are used for both defining the main environment parameters, validating some of the theoretical limit computations and proving the space application feasibility. WiSEE 2013 1569816775

No abstract