METHOD FOR OPERATING AN ULTRA WIDE-BAND DEVICE, ULTRA WIDE-BAND DEVICE, AND VEHICLE COMPRISING AN ULTRA WIDE-BAND DEVICE
An ultra-wideband sensor transmits impulse radio signals at different times and generates respective channel impulse responses that describe a respective reflected signal as a function of a path delay. The channel impulse responses are used to generate a time-variant channel impulse response in which the channel impulse responses are arranged according to the times of transmission of the respective associated impulse radio signals. At least one respective local maximum of the scatter function quantity, characterized by a respective Doppler frequency and a respective path delay, is detected in scatter functions of respective time windows. A predetermined selection method is used to select at least one local maximum as the respective observation maximum to be tracked for motion detection. A signal characteristic of the channel impulse response is generated for the respective observation maximum to be tracked and a predetermined motion detection method detects at least one predetermined movement.
1 . A method for operating an ultra-wideband device comprising:
at an ultra-wideband sensor:
transmitting impulse radio signals at different times and generating respective channel impulse responses that describe a respective reflected signal as a function of a path delay,
using the channel impulse responses to generate a time-variant channel impulse response in which the channel impulse responses are arranged according to times of transmission of respective associated impulse radio signals,
transforming predetermined time windows of the time-variant channel impulse response to produce respective scatter functions of the Doppler frequency,
detecting in the scatter functions of the respective time windows at least one respective local maximum of a scatter function quantity, characterized by a respective Doppler frequency and a respective path delay,
using a predetermined selection method to select at least one local maximum as a respective observation maximum to be tracked for motion detection,
generating a signal characteristic of the channel impulse response for the respective observation maximum to be tracked, and
detecting using a predetermined motion detection method at least one predetermined movement of the observation maximum to be tracked in the signal characteristic of the channel impulse response.
2 . The method as claimed in claim 1 , wherein a periodic movement is detected as the predetermined movement ( 7 ) by the predetermined motion detection method.
3 . The method as claimed in claim 1 , wherein a non-periodic movement is detected as the predetermined movement by the predetermined motion detection method.
4 . The method as claimed in claim 1 , wherein the channel impulse responses are filtered by a DC component filter.
5 . The method as claimed in claim 1 , wherein a low-pass filter is applied to Doppler frequency domain.
6 . The method as claimed in claim 1 , wherein the detecting of the predetermined movement results in a control signal being provided on an interface of the ultra-wideband device.
7 . The method as claimed in claim 1 , wherein a low-pass filter is applied to a frequency domain of the signal characteristic ϕ(t).
8 . The method as claimed in claim 1 , wherein before the motion detection method is carried out, a temporal sampling rate of the signal characteristic is reduced by a decimator.
9 . An ultra-wideband device configured to:
transmit impulse radio signals at different times by way of an ultra-wideband sensor and to generate respective channel impulse responses that describe a respective reflected signal as a function of a path delay,
use the channel impulse responses to generate a time-variant channel impulse response in which the channel impulse responses are arranged according to the times of transmission of respective associated impulse radio signals,
transform predetermined time windows of the time-variant channel impulse response to produce respective scatter functions of a Doppler frequency,
detect at least one respective local maximum of scatter function quantity, characterized by a respective Doppler frequency and a respective path delay, in the scatter functions of the respective time windows,
use a predetermined selection method to select at least one local maximum as a respective observation maximum to be tracked for motion detection,
generate a signal characteristic of the channel impulse response for the respective observation maximum to be tracked, and
use a predetermined motion detection method to detect at least one predetermined movement of the observation maximum to be tracked in the signal characteristic of the channel impulse response.
10 . A vehicle comprising an ultra-wideband device as claimed in claim 9 .