Differential coding

In digital communications, differential coding is a technique used to provide unambiguous signal reception when using some types of modulation. It makes data to be transmitted to depend not only on the current signal state (or symbol), but also on the previous one. In digital communications, differential coding is a technique used to provide unambiguous signal reception when using some types of modulation. It makes data to be transmitted to depend not only on the current signal state (or symbol), but also on the previous one. The common types of modulation that require differential coding include phase shift keying and quadrature amplitude modulation.