Patent ID: 8693573

Claim:
A method for transmitting a random access preamble to a base station, the method performed by a user equipment and comprising: generating the random access preamble from a Zadoff-Chu (ZC) sequence having a length N ZC , wherein the random access preamble is defined by cyclic shift (C v ) of the ZC sequence; and transmitting the random access preamble to the base station, wherein the C v satisfies the following Equation 1: C v =S·└v/P ┘+( v mod P )· N CS , v= 0, 1, . . . , ( P·G+R− 1), [Equation 1] where ‘G’ represents a number of groups defined from the ZC sequence, ‘S’ represents a length of each of the groups, ‘P’ represents a number of cyclic shift opportunities for each of the groups, and ‘R’ represents a number of additional cyclic shifts, and wherein parameters of Equation 1 are given under condition of N CS ≦d u <(N ZC /3) by: P=└d u /N CS ┘, S= 2 ·d u +P·N CS , G=└N ZC /S ┘, and R =max(└( N ZC −2· d u −G·S )/ N CS ┘,0), where ‘N CS ’ is a cyclic shift unit and ‘d u ’ is a variable corresponding to a Doppler shift of one subcarrier spacing.