Cell search method in UMTS
AssigneeSamsung Electronics Co., Ltd.
InventorSeong-Ho Hur
Life of this patent
Estimating the term…
Abstract
A cell search method in an asynchronous mobile communication system. For cell search, a UE searches signals received from Node Bs in a slot synchronization step, calculates the timing offset of each of the Node Bs by comparing signals having slot peaks higher than a first threshold with each other among the searched signals in a frame synchronization and code group identification step, and detects the timing offsets of neighbor Node Bs by comparing the timing offsets of signals higher than a second threshold with each other in a code identification step. In addition, Node Bs that transmit signals higher than the second threshold in the code identification step are included in a candidate set and are subject to a cell search periodically.
Claims5
A method of searching a plurality of neighbor cells that transmit signals using unique codes in a UE (User Equipment) that exchanges data with a reference cell in an asynchronous CDMA (Code Division Multiple Access) mobile communication system, the method comprising the steps of:
- performing an asynchronous cell search on each of signals received from the neighbor cells and designating codes corresponding to neighbor cells as a candidate sector group, from which the UE receives valid signals by the asynchronous cell search;
- and
- measuring the power levels of signals with the codes designated as the candidate sector group by a window cell search.
A method of searching at least one neighbor cell in a UE (User Equipment) that exchanges data with a reference cell in an asynchronous CDMA (Code Division Multiple Access) mobile communication system, the method comprising the steps of:
- obtaining N1 slot peaks satisfying a first threshold among slot peaks measured using a PSCH (Primary Synchronization Channel) signal from the neighbor cell;
- acquiring code groups and frame timings for each of the N1 slot peaks using an SCCH (Secondary Synchronization Channel) signal from the neighbor cell, and selecting N2 code groups and frame timings satisfying a second threshold;
- selecting N3 correlations for each of (N1×N2) code groups and frame timings, which satisfies a third threshold among correlations between a CPCH (Common Pilot Channel) signal received from the neighbor cell and the codes of the code group, and designating codes corresponding to (N1×N2×N3) correlations as a candidate sector group;
- and
- measuring the power levels of signals received from the sectors in the candidate sector group by a window cell search.
Dependencies are inferred from the claim text.