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Cell search method in UMTS

  • US 7,324,479 B2
  • Filed: 10/28/2002
  • Issued: 01/29/2008
  • Est. Priority Date: 10/27/2001
  • Status: Expired due to Fees
First Claim
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1. 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 the neighbor cells as a candidate sector group, from which the UE receives valid signals by the asynchronous cell search by obtaining N1 slot peaks higher than a first threshold among slot peaks measured using PSCH (Primary Synchronization Channel) signals from the neighbor cells, acquiring code groups and frame timings using SCCH (Secondary Synchronization Channel) signals received from the neighbor cells corresponding to the N1 slot peaks, and selecting N1×

    N2 code groups and frame timings higher than a second threshold, and selecting N3 correlations higher than a third threshold among correlations between a CPCH (Common Pilot Channel) signal received in correspondence with each of the N1×

    N2 code groups and frame timings and the codes of the N1×

    N2 code groups, and designating codes corresponding to N1×

    N2×

    N3 correlations as the candidate sector group; and

    measuring the power levels of signals with the codes designated as the candidate sector group by a window cell search.

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