###### Abstract  
Radio frequency interference (RFI) constitutes a significant problem in achieving a good quality of service in radio links. Several techniques have been proposed to identify and mitigate RFI in wireless networks. However, most of these techniques are not generalized for all propagation environments due to varying geographical features from one environment to another. The need for extensive frequency scan measurements on the links to identify the available channels, evaluate the performances of the links, and detect RFI in the channels becomes imperative. This study presents a performance evaluation of frequency scan measurements from active microwave links comprising eighteen base stations. The measurements equipment included a spectrum analyzer and a 0.6 m antenna dish. The frequency scans were taken at 6 GHz, 7 GHz, and 8 GHz with full azimuth coverage of the horizontal and vertical polarization. Measured data were processed to determine the available frequencies and RFI in the channels. The histogram and probability density function of the frequency scans were computed. The cumulative distribution functions were determined, and the statistical error characteristics of the frequency scans for the estimated normal distribution and the estimated fitness curve were derived. The short-time Fourier transform of the noisy signal was obtained, and the signal without noise was recovered using the inverse short-time Fourier transform. Analysis of the scanned signals before and after the noise removal is demonstrated. The denoised signals compare favorably with related results in the preliminary literature. Overall, these frequency scans would be beneficial in evaluating RFI measurements and spectrum planning and hold great promise for designing robust RFI detection algorithms for future wireless systems. c 2021  
of dynamic wireless propagation environments due to differences in the geographical terrains. In recent times, reconfigurable intelligent surfaces (RIS) have been implemented to tackle this problem [10, 11]. RIS is currently being designed to enable the envisioned 6G wireless networks just as massive MIMO is being utilized in the ubiquitous 5G wireless networks [12, 13]. However, real-time control of the reflection amplitude and phase shift of RIS is achievable at a high design cost [14]. Moreover, the computational complexity of RIS-enabled signal processing systems remains an issue that needs to be resolved. Additionally, the available literature on RIS only presents the theoretical and simulation analysis of the system. There has been no detailed study on the practical deployment of RIS as an enabling technology to address the vast RFI issues in microwave radio links to the best of the authors' knowledge. Thus, the need to conduct comprehensive frequency scan measurements on active microwave links to evaluate the performances of the links and to detect and mitigate RFI in the channels is worthy of investigation. To this end, elaborate frequency scan measurements were conducted on three active microwave links at 6 GHz, 7 GHz, and 8 GHz by considering the horizontal and vertical polarization. The links comprised eighteen base transceiver stations. Several network parameters were measured with a spectrum analyzer and a 0.6 m antenna dish, covering the full azimuth with the vertical and horizontal polarization. The experimental data were processed and analyzed in MATLAB. The results are presented and discussed in Section 4 of this paper. The primary focus of this paper is to evaluate the performance of microwave links using the radio frequency interference measurements obtained from the active links located in dense urban cities. These frequency scan measurements would provide reliable information for the detection and mitigation of RFI in the microwave links that were tested. The measured data will provide information on the best microwave link deployment techniques for optimum performance in dense urban environments.