A sample assessment of the constellation form influence on noise immunity for reception of the QAM-8 radio signal in the Matlab environment
... satellite communication system and the Sirius satellite. The paper presents the results of a study, when an experimental facility was assembled to assess the probability of receiving bit error for a QAM-8 radio signal, depending on the type of signal constellation for different SNRs in the MathLAB + Simulink simulation environment. The results of the research, as well as the developed experimental facility, will be used in the comparative assessment of noise stability of the radio communication channel ...
On the history of graph theory. Origin
... not always a tree in the mathematical sense and may include cycles. Another ancient unscientific use of graphs is the image of the starry sky:
— just a drawing of stars — a graph without edges;
— asterisms and arrangements of stars of constellations can be both “minimal“ trees and graphs with cycles;
— figures and regions of constellations in the starry sky are hypergraphs.
The authors proposed the year 1542 as the year of the probable appearance of the Konigsberg bridges ...