Patent ID: 6519276
Filing Date: 2003-02-11
Classification: H04B

Abstract:
A sequential path searching method in a mobile telecommunication system supporting a variable data rate transmission and having a sequential searcher which selects a path from among a plurality of paths using a predetermined high threshold value and a predetermined low threshold value, and wherein the plurality of paths have different delay times, said method comprising the steps of:(i) despreading along a time axis in units of walsh symbols, signals received through the plurality of paths; (ii) dividing the despread signals into a plurality of power control groups (PCGs) each of which comprises a plurality of Walsh symbols; (iii) selecting a PCG from among the plurality of PCGs and reading a first Walsh symbol of the plurality of walsh symbols belonging to the selected PCG; (iv) selecting a first searcher position that is located on the time axis, and calculating a correlation energy value of the first Walsh symbol at the first searcher position; (v) determining whether or not a path has been detected at the first searcher position by comparing said calculated correlation energy value of the first Walsh symbol with the predetermined high threshold value and the predetermined low threshold value; (vi) reading a second Walsh symbol at a second searcher position, next to the first searcher position on the time axis and calculating a correlation energy value of the second Walsh symbol at the second searcher position, if it is possible to determine that the path has been detected or has not been detected at the first searcher position; (vii) checking whether the first Walsh symbol is located at the last position of the PCG, if it is impossible to determine that the path has been detected or has not been detected at the first searcher position; (viii) reading the second walsh symbol and calculating the correlation energy value of the second walsh symbol at the first searcher position, if the first walsh symbol is not located at the last position of the PCG; and (ix) reading the second walsh symbol and calculating the correlation energy value of the second walsh symbol at the second searcher position, if the first walsh symbol is located at the last position of the PCG.