| 摘要 |
PROBLEM TO BE SOLVED: To perform suitable search processing according to reception environment of a broadcast wave of a reproduced channel. SOLUTION: First determination concerning whether an SNR of the broadcast wave of the reproduced channel is less than a predetermined value is performed based on the SNR (S12), when a first determination result is affirmative, decreasing rate of the SNR is calculated (S13). Second determination concerning whether the decreasing rate is equal to or less than a predetermined threshold is continuously performed (S14), when a second determination result is affirmative, it is determined that a vehicle moves away from a relay station which is utilized at present, and the search processing is performed (S15). Meanwhile, when the second determination result is negative, third determination concerning whether the SNR is recovered more than the predetermined value within predetermined time is performed (S18, S19). Then, when a determination result is negative, it is determined that the vehicle is out of an area of a relay station which is received before when the vehicle passes through a shelter section such as a long tunnel, and the search processing is performed (S15). COPYRIGHT: (C)2010,JPO&INPIT
|
