Cognitive radio (CR) is a promising technique for future wireless communication systems. In CR networks, dynamic spectrum access (DSA) of frequency is implemented to mitigate spectrum scarcity. Specifically, a secondary (unlicensed) user may be allowed to access the temporarily unused frequency bands granted to a primary (licensed) user. DSA has to be implemented so that the quality of service ...

Relativistic shock models of gamma-ray bursts may be tested by comparison of their predicted low energy asymptotic spectral indices s to observations. Synchrotron radiation theory predicts that the instantaneous spectrum has s = −1/3 and the spectrum integrated over the radiative decay of the electrons’ energies has s = 1/2, with other cases lying between these limits. We examine the spectra of...

In this work, we perform a spectral analysis of flipped multilevel Toeplitz sequences, i.e., study the asymptotic behavior $\{Y_{{n}} T_{{n}} (f)\}_{{n}}$, where $T_{{n}}(f)$ is real, square matrix generated by function $f\in L^1([-\pi,\pi]^d)$ and $Y_n$ exchange matrix, which has 1's on main antidiagonal. line with what have shown for unilevel spectrum determined 2 x matrix-valued whose eigenv...