Method and mobile station to perform the initial cell search in time slotted systems

摘要: A method is disclosed that a Mobile Station MS performs at switch-on to search the most favorable target cell in UMTS systems like 3GPP CDMA LCR (Low Chip Rate) option (1.28) Mcps TDD (Time Division Duplex) mode and equivalent TD-SCDMA Synchronous CDMA). Signal antenna sum of different RF downlink frames coming from carriers assigned frequency ranges. DL synchronization timeslot BCCH TS0 are both transmitted with full power frames, first one includes out (32) SYNC codes on basis. Following conventional approach absence common pilot without prior knowledge used frequencies would force MS, for all channel raster stored SIM card, correlation received frame sYNCs order detect BSIC which associate measures. two-step invention measures performed towo-step scan PLMN band interleaved steps; once final selected respective only correlated one. At least duration about (5) ms long whole (15) MHz bandwidth acquired, IF converted, A/D converted digital set stored. rough multiplying by tuned steps wide as (1.6 MHz) along band, filtering baseband signal Root Raise Cosine low-pass filter. The subdivided into blocks half (337.5νs) each block measured. strongest indicates priority frequency. values put Spectral Table together load indicators. indicators percentage timeslots almost equally loaded block. three successive scan. second step but now (200) kHz cover (1.6) spectrum around step. Then error reference oscillator corrected data-aided techniques calibration value connections.