Method for setting cyclic shift considering frequency offset

A method for setting cyclic shift to be applied to a given sequence, the method comprising:

• (a) acquiring a variable of du as a cyclic shift corresponding to a Doppler shift of one subcarrier spacing by using a root index (u) of the given sequence;
• (b) acquiring variables of G, S, P and R by equations of,
• P=└du/NCS┘
• S=2·du+P·NCS
• G=└NZC/S┘
• R=max(└(NZC−2·du−G·S)/NCS┘,0)
• when a range of the variable (du) is Ncs≦du<(Nzc/3), and acquiring the variables of G, S, P and R by equations of,
• P=└(NZC−2·du)/NCS┘
• S=NZC−2·du+P·NCS
• G=└du/S┘
• R=min(max(└(du−G·S)/NCS┘,0),P)
• when the range of the variable (du) is (Nzc/3)≦du≦(Nzc−Ncs)/2, wherein “Ncs” is a predetermined cyclic shift parameter, “Nzc” corresponds to a length of the given sequence, “G” is a number of groups generated by grouping the given sequence, “S” is a length of the each group of the groups, “P” is a number of applicable cyclic shift values for each group of the groups, and “R” is a number of additional cyclic shift values which are applicable to the given sequence not based on the groups;
• (c) setting the cyclic shift value (Cv) by an equation of,
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• wherein the restricted sets are cyclic shift sets restricted due to a Doppler shift, and the unrestricted sets are cyclic shift sets not restricted due to the Doppler shift.

A method for transmitting a random access preamble using cyclic shift, the method comprising:

• acquiring a root index (u) of a sequence for the random access preamble from system information;
• setting a cyclic shift value to be applied to the sequence, wherein the cyclic shift value is determined to be set according to restricted sets restricted due to a Doppler shift, and the cyclic shift value to be applied to the sequence is set by considering a cyclic shift corresponding to a Doppler shift of one subcarrier spacing;
• generating the sequence having the root index (u) with the set cyclic shift value;
• and
• transmitting the generated sequence as the random access preamble;
• wherein said setting the cyclic shift value to be applied to the sequence comprises:
• acquiring a first variable (du) indicating the cyclic shift value corresponding to the Doppler shift of one subcarrier spacing by using the root index (u) of the sequence;
• acquiring secondary variables comprising a number (G) of a group of groups within the sequence, a length (S) of each group of the groups of the each group (S), a number (P) of applicable cyclic shift values for each group of the groups, and a number (R) of additional cyclic shift values which are applicable to the sequence not based on the groups, using the first variable (du), and
• setting the cyclic shift value to be applied to the sequence according to the secondary variables.