Title:
【発明の名称】カーナビゲーション装置の受信装置及びその周波数切換方法
Document Type and Number:
Japanese Patent JP3384355
Kind Code:
B2
Abstract:
PURPOSE: To effectively use road traffic information supplied from an information broadcast station by comparing the information sizes of respective reception frequencies and switching the detection frequency of a reception means into the reception frequency of the largest information size. CONSTITUTION: An information size update part 8 and an update history processing part 9 calculate the size of a data block stored in DRAM 5, generate the information size table of respective frequencies and respective mesh codes and store/update it in SRAM 6. When an error rate exceeds a threshold ε for prescribed time in an error rate comparison/switching part 12 and a switching judgment part 13, the detection frequency of a PLL frequency demodulator 3 is switched to the frequency of an FM broadcast station which is adjacent to a selected FM broadcast station and whose error rate is the smallest. An information size comparison switching part 11 and the switching judgment part 13 compare the information sizes of the respective frequencies of a mesh area to which the present position of a self-vehicle belongs and the detection frequency of the PLL frequency demodulator 3 is switched to the frequency of the largest information size.
Inventors:
Hideharu Matsuura
Akiyoshi Masami
Akiyoshi Masami
Application Number:
JP9258999A
Publication Date:
March 10, 2003
Filing Date:
March 31, 1999
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G01C21/00; G08G1/09; G08G1/0968; G08G1/0969; H03J7/18; H04B7/26; (IPC1-7): G08G1/09; G01C21/00; G08G1/0969; H03J7/18; H04B7/26
Domestic Patent References:
| JP10281778A | ||||
| JP9247019A | ||||
| JP10185598A |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)