| Popis: |
The aim of this work is to develop a system for suppression of the narrowband interferences in GNSS receiver designed for consumer market. High demands on power consumption and cost are typical for receivers of that type. A relatively simple system for suppression of the narrowband interferences in GPS / GLONASS receiver is presented in this paper. The effectiveness of the suggested method is achieved by combining of the pre- and post-correlation interference suppression techniques. The first method is based on the use of adaptive IIR notch filters. The feature of the suggested approach is that the single module of interference detection is used for all filters. This module is implemented on the basis of 64-point FFT. The tuning of filters and the analysis of FFT results are performed by the DSP. The second method is implemented in software. For interference suppression it uses power accumulations at the correlator output by averaging them in time-frequency domain. Simulation and experimental results are provided. The results demonstrate that the suggested method is of practical use because it is simple in implementation, flexible and easily adaptable to, for example, power of the interference source and frequency scanning rate. |
