Open AccessChannel fading measurement and statistics of the eCall minimum set of data transmission
Author(s) -
Li Yunrui,
Liu John Q.,
Brandenburg Jacob C.
Publication year - 2020
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2018.6022
Subject(s) - fading , fade , signal (programming language) , fading distribution , cumulative distribution function , computer science , transmission (telecommunications) , attenuation , statistics , multipath propagation , range (aeronautics) , channel (broadcasting) , electronic engineering , telecommunications , real time computing , mathematics , probability density function , physics , engineering , rayleigh fading , optics , programming language , aerospace engineering , operating system
This study presents a testbed for the emergency call (eCall) system satisfying the 3GPP TS 26.267/268/269 standard. Experiments are performed with the in‐vehicle system testbed in a laboratory or a car travelling in city, suburb, countryside or freeway. Sufficient data of the emergency communication signal is recorded and processed. Fading statistics of the received signal after power control are found and discussed with cumulative distribution function of the received signal power, level crossing rate and average fade duration. It is found that with probability less or equal to 0.1 % , fading and attenuation can vary from − 19 dB for the continuous wave (CW) signal at 500 Hz to − 9.5 dB for the CW signal at 2000 Hz. It is recommended to move the CW signals at 500 and 800 Hz for detection and synchronisation in the 3GPP standard to be at 1500 and 2000 Hz, respectively. This will give 9.5 dB improvement in detection and synchronisation. The longest fade duration observed is 540 ms. The 64 ms synchronisation signal in the current standard is insufficient to handle the fading. It is shown that fading is minimised in the frequency range [1000, 2500] Hz for the 3GPP TS 26.267 system.