Cell Search Method Using RSSI Sorting and Frequency Exclusion

The patent applies preliminary action by performing RSSI measurements and sorting frequencies before the actual cell search. The terminal pre-processes the frequency list by measuring signal strength and arranging frequencies in descending order of RSSI values. This preliminary sorting ensures that the most promising frequencies are searched first, improving detection reliability while reducing overall search time by avoiding exhaustive scanning of low-probability frequencies.

The patent segments the frequency search space by dividing candidate frequencies into groups based on RSSI thresholds. Instead of treating all frequencies equally, the method creates segments (high RSSI, medium RSSI, low RSSI) and applies different search strategies to each segment. This segmentation allows the terminal to focus computational resources on high-probability segments while quickly dismissing low-probability segments, resolving the contradiction between comprehensive search and time efficiency.

The patent performs preliminary RSSI-based filtering and sorting before the cell search process. By measuring received signal strength indication for all candidate frequencies in advance and sorting them in descending order, the terminal creates a prioritized search list. This preliminary action ensures that frequencies with stronger signals are examined first, maintaining detection completeness for strong signals while enabling early termination when a suitable cell is found, thus reducing startup time.

The patent applies partial action by searching only a subset of candidate frequencies in detail rather than all frequencies exhaustively. After sorting by RSSI, the terminal focuses its search efforts on the top-ranked frequencies that are most likely to contain a valid cell. This partial search approach maintains completeness for high-probability frequencies while avoiding unnecessary searching of low-probability frequencies, thereby reducing overall startup time.