Search

Summary: This paper presents the design, testing, and validation of a ultra‐wideband (UWB) wireless solution to replace wired intra‐spacecraft communications with wireless communications. The system requirements are provided in the framework of the Eu:CROPIS mission and the wired intra‐spacecraft communication system is replaced with a two‐segment wireless network. As such, distinct sets of UWB gateways and nodes are prototyped to interface with the on‐board entities and properly handle the data transmission in the resulting spacecraft and payload wireless networks. To accomplish these tasks, a custom radio module integrated into the prototypes was designed to provide the appropriate UWB RF front‐end and run a custom‐built communication stack. The viability of the solution was tested in laboratory conditions. For the test scenarios, sensor data are acquired in the payload network and forwarded as SpaceWire packets over the spacecraft network. Experimental test results indicate the suitability of the proposed solution in terms of delay and data integrity for implementing intra‐spacecraft wireless communications. [ABSTRACT FROM AUTHOR]

Due to the known issue that the ranging in the 802.15.4™-2015 standard is prone to external attacks, the enhanced impulse radio (EiR), a new amendment still under development, advances the secure ranging protocol by encryption of physical layer (PHY) timestamp sequence using the AES-128 encryption algorithm. This new amendment brings many changes and enhancements which affect the impulse-radio ultra-wideband (IR-UWB) ranging procedures. The timestamp detection is the base factor in the accuracy of range estimation and inherently in the localization precision. This paper analyses the key parts of PHY which have a great contribution in timestamp estimation precision, particularly: UWB pulse, channel sounding and timestamp estimation using ciphered sequence and frequency selective fading. Unlike EiR, where the UWB pulse is defined in the time domain, in this article, the UWB pulse is synthesized from the power spectral density mask, and it is shown that the use of the entire allocated spectrum results in a decrease in risetime, an increase in pulse amplitude, and an attenuation of lateral lobes. The paper proposes a random spreading of the scrambled timestamp sequence (STS), resulting in an improvement in timestamp estimation by the attenuation lateral lobes of the correlation. The timestamp estimation in the noisy channels with non-line-of-sight and multipath propagation is achieved by cross-correlation of the received STS with the locally generated replica of STS. The propagation in the UWB channel with frequency selective fading results in small errors in the timestamp detection. [ABSTRACT FROM AUTHOR]