Methods, devices and systems for encoding and transmitting data in a wireless communications system and, in particular, for unscheduled data transmissions including low data rate transmissions. The method for transmitting data in a wireless network includes mapping data according to a predefined sequence pattern from a group of sequence patterns to provide a spreading sequence that includes multiple non-zero elements and that is enabled to partially collide in the wireless network with other spreading sequences that have been mapped according to other sequence patterns from the group; and transmitting the spreading sequence. Multiple sequences may be received by a network node and decoded using successive interference cancellation (SIC) techniques.