Methods, systems, and devices for contention-based transmissions using differential coding techniques in mobile communication technology are described. An exemplary method for wireless communication includes transmitting, by a wireless device, a payload including a first portion that is modulated using a differential coding technique and a second portion that is modulated using an amplitude-shift keying (ASK) or phase-shift keying (PSK) modulation, and where the payload includes an identity of the wireless device and at least one of a user plane data or a control plane data.