| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce load of correlation processing when performing positional relationship estimation by sonic waves between terminals having restrictions in their functions and the like. <P>SOLUTION: After positional estimation start confirmations (1) and (2), a search terminal 10 previously sets sonic pulses to be sent (3), sends a notification to a searched terminal 20 (4), and the searched terminal 20 starts recording (5). The search terminal 10 sends the sonic pulses according to the setting (7), acquires transmission time of each pulse (8), and notifies the searched terminal 20 of transmission completion (10). The searched terminal 20 terminates the recording (11), acquires receipt time from the recording by correlation processing with load processing reduced (12), and notifies the search terminal 10 of the receipt time (13). The search terminal 10 estimates positional relationship on the basis of the receipt time and the transmission time (14). The correlation processing at a first step obtains a temporary position by roughly setting a window size, the number of data bits, and a sampling interval, and then at a second step fixes the position by setting the parameters precisely around the temporary position. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
