Analysis of Multipath Effect in the Tracking Stage using Loop Bandwidth Control Algorithm

Multipath severely degrades the tracking performance of global navigation satellite system (GNSS) receivers, creating inaccuracy estimates and possibly causing the loss of lock. Previous research shows multiple methods to detect, suppress, mitigate or correct multipath in various receiver processing stages. However, these methods are implemented at the cost of increased complexity, being challenging to apply in real-time GNSS receivers. This paper evaluates the behavior of the loop-bandwidth control algorithm (LBCA) under controlled multipath scenarios. The proposed technique is a low-complex adaptive tracking architecture using the LBCA. The LBCA is an adaptive tracking technique that adjusts the time of response of the tracking channel based on the discriminator's statistics. This adaptive tracking architecture is implemented in an open software interface GNSS hardware (GOOSE) receiver and is evaluated under simulated controlled multipath scenarios. These scenarios present a non-line-of-sight (NLOS) signal with different time offsets, carrier phase offsets, and frequency offset levels. The results confirm that the LBCA can serve as a multipath suppression technique at fast fading multipath scenarios. Moreover, multipath indicators from the response of the adaptive tracking architecture are found at slow fading multipath scenarios.