A Survey of Periodic Binary Nearly Perfect Signals with Lengths N≡1mod4

The binary phase manipulated radio signals, which auto - correlation functions have small side-lobes, are named perfect, as they have a critical role for many types of radio communication systems. With regard to this situation, in the paper we suggest several necessary conditions for existence of periodic binary nearly perfect PM signals with lengths N=1mod4. On their base an exhaustive computer search has been conducted. As a result, several unknown up to now periodic binary nearly perfect signals with lengths N≡1mod4 have been found.