Innovative Radiating Systems for Train Localization in Interference Conditions

Table 1

Adaptive antenna nulling versus beam-forming techniques.

𝑁-elements antenna feature	Nulling	Beam-forming
Robustness to interference	Low (low gain along not IF directions)	Medium (adequate gain roll-off shown)
Maximum number of spatial nulls	𝑁−1	𝑁−1
Null depth	<−20 dB	<−20 dB
Directional beam capability	No	Yes
Impact on accuracy measurement	Not compatible with high precision applications	More than 100° on carrier phase meas.; 1 meter on code phase meas.