Abstract: Correlation analysis (CA) in PCM format is often used in signal recognition. Signals representation in PCM format allows for calculate correlation functions (CF) with assign accuracy, however at the same time causes a large number of multi-bit operations and leads to insufficient resolution and fast-acting of CA. Therefore, in such tasks it is expedient to use small-bit differential methods. However, the known approaches to differential CA are not enough studied. This paper purpose is the resolution and fast-acting increase of noisy signals CA in real time on base of modified differential PCM (DPCM) algorithms.