Patent ID: 8964659
Filing Date: 2015-02-24
Classification: H04L,H04W

Abstract:
1. A method of configuring random access resources for random access transmission, the method comprising: determining, at a base station, a number n of preamble signatures that can be used for random access transmission, wherein the n preamble signatures are generated by using Zadoff-Chu Zero Correlation Zone (ZC-ZCZ) sequences; grouping the n preamble signatures into K groups, each of the K groups being named group j where j=1, 2 . . . K, wherein K corresponds to a number of downlink component carriers and K is an integer that is greater than or equal to 2, wherein the number n of preamble signatures increases by multiples of the number of downlink component carriers per cell; assigning each group j to a corresponding downlink component carrier; assigning configuration data to each group j; transmitting, from the base station, the configuration data for each group j on the corresponding downlink component carrier, wherein the configuration data include a threshold value for selecting one of several sub-groups of preamble signatures related to contention based access, and the threshold value is configured to be selected from a specific sub-group having a last preamble signature number; receiving, at the base station, an uplink component carrier including a random access preamble with a specific preamble signature selected based on information size of a contention resolution message and a radio condition; determining, at the base station, to which downlink component carrier or group j the specific preamble signature corresponds; and transmitting, from the base station, a random access response on the determined downlink component carrier.