Patent ID: 7145890
Filing Date: 2006-12-05
Classification: H04W

Abstract:
1. A method for carrying out an idle handoff from a macrocell to a microcell (picocell) in a hierarchical cell structure, comprising the steps of: a) providing different frequency assignments (FA) to the macrocell and the microcell in a same service band, to construct the hierarchical cell structure; b) transmitting cell structure information of neighboring base stations and a pseudo noise (PN) code from a base station to a mobile station; c) checking whether the mobile station for receiving a service through the macrocell is in the hierarchical cell by using the cell structure information of the neighboring base station; and d) checking whether a value of the pseudo noise (PN) code is greater than T_ADD and greater than Ec/Io of the macrocell, by periodically searching the pseudo noise (PN) code of the microcell, to carry out the idle handoff to the microcell, wherein the T_ADD represents a value of a base station pilot strength required for the base station of a neighboring set to be included in a candidate set, the Ec represents pilot energy accumulated during one pseudo noise (PN) chip period, and the Io indicates a total power spectrum density within a reception bandwidth of the macrocell.