Patent ID: 9118531
Filing Date: 2015-08-25
Classification: H04J,H04L

Abstract:
1. A method of performing a random access procedure, the method performed by a user equipment (UE) and comprising: receiving, at a radio frequency (RF) unit of the UE, a first logical index, wherein the first logical index is one of consecutive logical indexes mapped to physical root indexes of a root Zadoff-Chu (ZC) sequence, the physical root indexes are divided into subgroups according to cyclic shift parameters, and each of the subgroups includes at least one physical root index; receiving, at the RF unit of the UE, information on a cyclic shift parameter; and transmitting, at the RF unit of the UE, a random access preamble based on a preamble sequence, which is one of a predetermined number of available preamble sequences, wherein the predetermined number of available preamble sequences are found, at a processor of the UE, by including preamble sequences in the order of increasing cyclic shift from a first root ZC sequence with a first physical root index mapped to the first logical index in a memory of the UE and by further including preamble sequences in the order of increasing cyclic shift from a second root ZC sequence with a second physical root index mapped to a second logical index in the memory of the UE when the predetermined number of available preamble sequences cannot be found from the first root ZC sequence, wherein the second logical index is consecutive to the first logical index, wherein a sum of the first physical root index and the second physical root index is equal to a length of the root ZC sequence, wherein a value of the cyclic shift is obtained from the cyclic shift parameter.