Patent ID: 8547903

Claim:
A method of performing a ranging procedure at a terminal in a wireless communication system that supports a legacy scheme and a normal scheme, the method comprising: selecting a specific ranging structure from a first ranging structure that supports the legacy scheme and a second ranging structure that supports the normal scheme based on probabilities; and transmitting a ranging signal through the specific ranging structure, wherein code resources for the first ranging structure are generated using a pseudo random noise code generation equation 1+X 1 +X 4 +X 7 +X 15 , wherein code resources for the second ranging structure are generated using a pseudo random noise code generation equation 1+X 8 +X 11 +X 14 +X 15 , wherein, for a normal communication, a probability for the first ranging structure is given as P A1 (0<P A1 <1) and a probability for the second ranging structure is given as P A2 (P A1 +P A2 =1) in consideration of a ranging load, wherein, for an emergency communication, the probability for the first ranging structure is given as P B1 (0<P B1 <1) and the probability for the second ranging structure is P B2 (P B1 +P B2 =1) such that P B1 =(P A2 −offset), P B2 =(P A1 +offset) and P B1 <P B2 , and wherein the offset is a positive real number.