Method for Generating Random Access Channel ZC Sequence, and Apparatus

摘要

Embodiments provide a method for generating a random access channel ZC sequence, and an apparatus. A method for generating a random access channel ZC sequence includes: generating, by a base station, notification signaling, where the notification signaling instructs user equipment UE to generate a random access ZC sequence by using a second restricted set in a random access set; and sending, by the base station, the notification signaling to the UE, so that the UE generates the random access ZC sequence by using the second restricted set, where the random access set includes an unrestricted set, a first restricted set, and the second restricted set; and the second restricted set is a random access set that the UE needs to use when a Doppler frequency shift of the UE is greater than or equal to a first predetermined value.

主权项

1. A method, comprising:
selecting, by a base station, a shift serial number v from a range of 0 to (nshiftRAngroupRA+nshiftRA−1), wherein v is a positive integer, nshiftRA is a quantity of candidate sequence shifts of user equipment (UE) in one group, ngroupRA is a quantity of groups, and nshiftRA is a quantity of candidate sequence shifts of UE within a last length that is insufficient for one group; and obtaining, by the base station, a cyclic shift value Cv according to the shift serial number v by using the following formula (1):
Cv=doffset+dstart└v/nshiftRA┘+(v mod nshiftRA)NCS  (1); wherein doffset is a shift offset, dstart is a cyclic shift distance between neighboring groups, nshiftRA is the quantity of candidate sequence shifts of UE in one group, and NCS is a quantity of cyclic shifts occupied by one user; wherein nshiftRA, dstart, ngroupRA, and nshiftRA meet formulas (2) to (5); or nshiftRA, dstart, ngroupRA, and nshiftRA meet formulas (6) to (9); or nshiftRA, dstart, ngroupRA, and nshiftRA meet formulas (10) to (13):
nshiftRA=└du/NCS┘  (2);dstart=4du+nshiftRANCS  (3);ngroupRA=└NZC/dstart┘  (4);nshiftRA=max(└(NZC−4du−ngroupRAdstart)/NCS┘,0)  (5);nshiftRA=└(NZC−4du)/NCS┘  (6);dstart=NZC−4du+nshiftRANCS  (7);ngroupRA=└du/dstart┘  (8);nshiftRA=min(max(└(du−ngroupRAdstart)/NCS┘,0),nshiftRA)  (9);nshiftRA=└(NZC−3du)/NCS┘  (10);dstart=NZC−3du+nshiftRANCS  (11);ngroupRA=└du/dstart┘  (12); andnshiftRA=0  (13); wherein du is a cyclic shift to which a ZC sequence corresponds when a Doppler frequency shift is one time a physical random access channel (PRACH) subcarrier spacing.