###### Abstract
It can be concluded that the main effective parameter in interference detection is JSR, thus the accuracy and precision of a detection algorithm must be based on the input JSR of designed detector. This study proposes a novel detector and mitigation mechanism for the protection of the narrowband-modulated signal. Digital receiver blocks and their performance are sensitive to the low power interferences. Thus, this study tries to extract a high quality power spectrum and utilize it to estimate the important characteristics of multi-interferences with high resolution and precision. One of the most important targets of this research is to propose a design that can fit in small and common receivers. Thus, all designs are based on simple and basic logical elements that can be found in the field-programmable get array (FPGA) design libraries. Such practical design can be implemented in almost all software environments or embedded in small area of FPGAs with a very low complexity. The proposed design is based on simple blocks, but it is smart and efficient to extract several interference parameters and utilize them for adaptive adjustment of mitigation block. In the heart of the detector, the simplified Welch method is employed for smooth and flexible power spectral density (PSD) estimation. The simplified Welch method [16] gives a smooth PSD where its SNR is enhanced with the help of weighted averaging. Based on the current situation demand, by simply changing one feedback parameter and without any hardware change, the detector can change its mode from a very low power interference detection to hopping center frequency detection. Proposed detector can detect several multi narrowband interferences and estimate their center frequency, bandwidth, power, start, and end of each interference individually. To remove multiple interferences, a chain of several IIR notch filters [13] with multiplexers is proposed. The detector can employ notch filters as much as required, which is equal to the number of observed interferences. Figure 1: Clarity of Continues Wave Interference (CWI) on a modulated signal in different conditions: (**a**) different Jamming to Signal Ratio (JSR) and (**b**) different Signal to Noise Ratio (SNR). Because a narrowband modulated signal carries a lot of information in a dense bandwidth, interference mitigation must be fulfilled with minimum damage to the original signal. The bandwidth of each notch is adjusted in a way that maximizes the received SNR by the receiver. MCWI is utilized as a jamming attack to the DVB-S2 receiver and performance of the new detector and mitigation system is investigated and validated in MCWI detection/mitigation with both simulation and practical tests. The structure of the paper is organized as follows: Section 2 reviews the previous research in RFI detection and mitigation. The methodology, detector structure, and mitigation scenario are proposed in Section 3. The demonstrated simulation results are presented in Section 4. Test bench set up for practical and real-time test are presented in Section 5. Moreover, this chapter explains the obtained results from practical tests with the DVB-S2 receiver under the attack of the MCWI jammer.