A wireless device is configured to produce a signal in a time slot of a frame, wherein the time slots have variable lengths. The signal having a first portion and a second portion, wherein the first portion and the second portion are located in defined time regions in the slot. Further, the first portion having data and a multiplexed first pilot, wherein the multiplexed first pilot is derived from a pseudo random sequence, the second portion having a pilot sequence and a cyclic prefix. The wireless device transmits the produced signal in the time slot.

A wireless device is configured to produce a signal in a time slot of a frame, wherein the time slots have variable lengths. The signal having a first portion and a second portion, wherein the first portion and the second portion are located in defined time regions in the slot. Further, the first portion having data and a multiplexed first pilot, wherein the multiplexed first pilot is derived from a pseudo random sequence, the second portion having a pilot sequence and a cyclic prefix. The wireless device transmits the produced signal in the time slot.