A method for identifying a leading edge time period of a received radio signal includes identifying a greatest energy time period in a sequence of time periods. The received radio signal has a greatest average energy in the greatest energy time period. The method also includes identifying a least energy time period in the sequence of time periods. The received radio signal has a least average energy in the least energy time period. Further, the method includes setting a threshold energy based on the greatest average energy and the least average energy, determining a number of window time periods based on a characteristic of a radio channel used by the received radio signal, and identifying as a leading edge time period an earliest time period that precedes the greatest energy time period within the number of window time periods. The received radio signal in the leading edge time period has an average energy greater than or equal to the threshold energy.