Development of the Analysis Procedure of the Efficiency of Methods for Digital Filtering of the Incoherent Scatter Signal

The article considers the methodological features of creating procedures that help in the implementation of effective methods of recognition and suppression in the input signal, which are recorded by the incoherent scatter radar, noise and impulse interference. It is known that the frequency band of the input signal depends on the observation period of the ionosphere, as well as on its height above the Earth’s surface. Therefore, approaches to using analog filters with time-controlled characteristics in a radar receiver are being practiced. These filters, however, require a priori information about of the ionosphere state. At the present time, it is possible to obtain digital samples of a signal with a very small sampling step (tens of thousands of samples during a radar range sweep) using high-speed analog-to-digital conversion. It is also possible to record these readings in the computer memory relative to each sweep. This gives the prospect, based on the results of the experiment, to carry out auxiliary adaptive digital filtering of the obtained data. In this case, filter properties are selected for each altitude range in order to obtain the maximum possible signal-to-noise ratio. In order to introduce high-quality digital filtering methods, this development is aimed at creating a special software-algorithmic procedure, which allows you to control the effectiveness of the proposed filtration methods. The essence of this procedure is that according to the amplitude-frequency and phase-frequency spectra set by the researcher, the corresponding model of the scattering signal is synthesized and its autocorrelation function is calculated. These characteristics in the following steps as reference are used for comparison with similar characteristics, but obtained from the distorted scattering signal. The experimenter has the ability to apply noise and impulse interference to the scattered signal and to test the digital filtering method he proposed. All these steps in software implementation are accompanied by a clear graphical visualization of the results obtained.

Research on Channel Estimation of Power Line Communication System under Impulse Interference

<p>The power line communication system is transmitted by the original power line, which has the advantages of low transmission cost and wide range of power line wiring, but it has high research value due to the disadvantages of bad transmission environment and large interference. In this paper, the problem of channel estimation in power line communication system under impulse interference is analyzed objectively, and the improvement measures in its transmission process are put forward.</p>

USE OF AN ACTIVE PHASED ARRAY ANTENNA IN RADAR’S SIDE LOBES CANCELLATION SYSTEM

The paper describes an example of designing the radar’s side lobes cancellation system. It is based on the scheme of one channel interference canceler. The analysis of the antennas, which are ussually used in radar’s side lobes cancellation systems, is done, and active phased array antenna is chosen as an antenna of the radar’s side lobes cancellation system. The array pattern was formed by using antenna synthesis iterative method in order to fulfill the radar’s side lobes cancellation system’s antenna requirements. The antenna modeling results and its’ analysis are presented. The radar’s side lobes cancellation system with active phased array antenna eliminates intentional noise or impulse interference from any side lobe directions of the radar antenna.