Narrowband Interference Suppression Performance of Multi-Correlation Differential Detection

Radio frequency interference (RFI) is one of the foremost concerns in safety critical applications that utilize GPS. RFI sources either intentional or unintentional at the vicinity of the victim receiver can potentially mask the weak GPS signals. Most commercial receivers are equipped with no or basic level of protection against in-band RFI. Acquisition under strong RFI is more difficult as the GPS receiver has no prior knowledge of both signal and interference parameters. This paper proposes the use of multi-correlation differential detection (MCDD) technique over traditional noncoherent technique for enhanced acquisition under strong RFI. More importantly, the developed MCDD technique provides an efficient means to detect and mitigate narrowband interference for GPS acquisition. A simple CW interference detection/suppression scheme utilizing thee inherent operation of MCDD is proposed. The interference detection/suppression performance of the developed scheme is validated using hardware simulated GPS signals. The paper further extends by demonstrating the advantages of augmenting GPS signal acquisition with interference excision methods. Preliminary analysis using hardware simulated GPS data corrupted with continuous wave (CW) and narrowband interference (NBI) substantiate the superior detection performance of the MCDD technique over traditional noncoherent scheme for GPS acquisition under strong RFI.