Allerton Press

In the modern age, wireless communication has taken on a wide range of applications in different aspects of a human life. Ever increasing demand for higher data rates led the interest of research in FBMC (Filter Bank Multi-Carrier) as a new transmission system for the next-generation mobile communication system. FBMC is a multicarrier technique which utilized filters at the transmitting and the receiving side of the system. It is considered as one of the most promising waveform for fifth generation mobile communication system (5G). But, high value of Peak Average Power Ratio (PAPR) is considered to be one of the giant problems in FBMC. The PAPR reduction techniques used in OFDM cannot be utilized in FBMC due to its overlapping structure. Hence, new PAPR reduction techniques for FBMC have diverted the attention of researchers. In this work, dispersive selective mapping (DSLM) PAPR reduction technique is proposed. Further, the proposed technique is compared to selected mapping (SLM) and clipping PAPR reduction techniques. The simulation results show that the proposed DSLM technique gives the better performance in terms of bit error rate (BER), PAPR and complexity as compared to the SLM and clipping PAPR reduction techniques.

The calculations, used for investigating the characteristics of measurement of radar targets’ angular coordinates near the interface between two media, are based on mathematical models set up as superposition (in the observation point) of two waves reflected from the object: the direct wave and the wave reflected by the surface of the interface between two media. These mathematical models are shown to be convenient and efficient for inquiries in characteristics of amplitude algorithms of measurements. The models agree well with the results of target’s elevation measurement, obtained during full-scale tests.

This paper presents a robust digital video-watermarking system for copyright and copy protection. The proposed method applies the combination of discrete wavelet transform (DWT) and scene-change-detector. For better understanding, this approach can be presented in the form of four stages. The first stage is finding the frame where the watermark is to be inserted. The analysis of watermarking using the level-3 decomposition of LL subband withDWTis described in the second stage. Transparency and the robustness have been analyzed under fifteen different attacks in the third stage. Improvement in the robustness and transparency, as compare to watermarking using different levels of LL subband is calculated in terms of the normalized correlation and the structural similarity index in the fourth stage. The experimental result reveal that the proposed method yields the extracted watermark image and watermarked video of good quality and can sustain different image processing, JPEG compression and geometrical attacks. Empirical results prove the improvement in the performance as the decomposition level increases from level-1 to level-3. Comparative analysis with the existing schemes proves the improved robustness, better imperceptibility and the reduced computational time of the proposed scheme.

An algorithm has been developed and implemented for receiving the broadcast data of base stations of GSM networks that allows us to obtain their identification parameters and carry out the analysis of mutual interference effects. Acase study of the analysis of frequency channels in the 900 MHz band at the fixed point of industrial center was also presented.

An equivalent representation of a circuit formed by coupled lines section with cross-symmetrical loads and additional reactive elements is suggested in the form of partial one-port networks with in-phase or antiphase excitation. Analytical relations for the electrical parameters calculation of elements of the circuit, which enables one to implement devices with dual-band operation mode, have been obtained based on the input impedances of these one-port networks. The examples of application of relations obtained for the simulation of dual-band phase shifters with fixed phase difference, impedance transformers and bandpass filters are provided. The simulation results are confirmed by experimental investigations of these devices.

Thesynthesis and analysis of the maximum likelihood algorithm for estimating the amplitude of ultrawideband quasi-radio signal with unknown amplitude and phase have been performed. The duration of the specified signal can amount to several periods or a fraction of the period of harmonic oscillation. The characteristics of the classical maximum likelihood estimate of the amplitude of a narrow-band radio signal were found while receiving an ultrawideband quasi-radio signal. The conditions of applicability of the model of narrow-band radio signal were defined for solving the problem of amplitude estimation with the specified accuracy.

Việc phân rã mô hình đa thức từng đoạn của bộ tiền biến dạng đã được thực hiện với sự xem xét đến động lực thay đổi của độ lớn vùng bao quát phức cho tín hiệu, tín hiệu này được chuyển đổi bởi một bộ khuếch đại. Mô hình phân rã cung cấp độ chính xác cao hơn trong việc bù đắp cho các biến dạng phi tuyến cho tín hiệu trong bộ khuếch đại so với mô hình đa thức từng đoạn của bộ tiền biến dạng. Phân tích so sánh của các mô hình bộ tiền biến dạng đã được thực hiện để tuyến tính hóa mô hình Wiener-Hammerstein của bộ khuếch đại công suất.

It is proposed a rule of total classes of composition systems of discrete frequency signals (CDF-signals) construction in extended Galois fields. It is carried out modeling and research a correlation properties of CDF-signals, and determined their practical attraction.