JPS6481557A - Automobile telephone set - Google Patents
Automobile telephone setInfo
- Publication number
- JPS6481557A JPS6481557A JP23754687A JP23754687A JPS6481557A JP S6481557 A JPS6481557 A JP S6481557A JP 23754687 A JP23754687 A JP 23754687A JP 23754687 A JP23754687 A JP 23754687A JP S6481557 A JPS6481557 A JP S6481557A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- ring tone
- digital signal
- digital
- converter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
PURPOSE:To offer an automobile telephone set preventing production of a ring tone itself by providing a digital signal processing means setting a pseudo signal of an opposite phase cancelling a ring tone based on the characteristic of a transmission signal or a reception signal and a ring tone path. CONSTITUTION:A caller voice entering a microphone 1 is amplified by an amplifier 2, converted into a digital signal by an A/D converter 13a and given to one input terminal of a digital signal processing unit 14. The digital signal processor 14, based on the reception signal, applies the digital processing such as echo canceller to estimate the pseudo signal of an opposite phase corresponding to the ring tone and cancelling it with respect to the inputted voice signal. The voice signal processed by the digital signal processor 14 is given to a D/A converter 15a from one output terminal and supplied to a radio equipment from the transmission output terminal 5 via switches 16, 17.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23754687A JPS6481557A (en) | 1987-09-24 | 1987-09-24 | Automobile telephone set |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23754687A JPS6481557A (en) | 1987-09-24 | 1987-09-24 | Automobile telephone set |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6481557A true JPS6481557A (en) | 1989-03-27 |
Family
ID=17016932
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP23754687A Pending JPS6481557A (en) | 1987-09-24 | 1987-09-24 | Automobile telephone set |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6481557A (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5742250A (en) * | 1980-08-28 | 1982-03-09 | Nec Corp | Data transfer system between plural processors |
JPS6038958A (en) * | 1983-08-12 | 1985-02-28 | Nec Corp | Loudspeaker telephone set |
JPS60200676A (en) * | 1984-03-26 | 1985-10-11 | Nippon Telegr & Teleph Corp <Ntt> | Telephone set circuit having holding tone sending function |
-
1987
- 1987-09-24 JP JP23754687A patent/JPS6481557A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5742250A (en) * | 1980-08-28 | 1982-03-09 | Nec Corp | Data transfer system between plural processors |
JPS6038958A (en) * | 1983-08-12 | 1985-02-28 | Nec Corp | Loudspeaker telephone set |
JPS60200676A (en) * | 1984-03-26 | 1985-10-11 | Nippon Telegr & Teleph Corp <Ntt> | Telephone set circuit having holding tone sending function |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR0158465B1 (en) | Noise cancellation apparatus & telephone sender/receiver apparatus | |
MY122083A (en) | Echo canceler for non-linear circuits | |
CA2056516A1 (en) | Dual mode cellular radio communication apparatus having an echo canceller employed in both analog and digital modes | |
DK385486A (en) | DUPLEX SPEAKER PHONE FOR RADIO AND WIRELESS BASED PHONES | |
GB1458663A (en) | Microphone circuits | |
EP0717547A3 (en) | Automaticaly variable circuit of sound level of received voice signal in telephone | |
AU2215192A (en) | Digital control circuit | |
EP0129208A3 (en) | Handsfree circuit for telephone instrument | |
JPS56143751A (en) | Transceiver with interphone | |
JPS6481557A (en) | Automobile telephone set | |
TW355889B (en) | Circuit arrangement for line adaptation and echo suppression | |
KR200241677Y1 (en) | Handfree device of the mobile communication system having a echo preventing function | |
KR0121115Y1 (en) | Telephone circuit | |
JPS645250A (en) | Howling prevention circuit for loudspeaker system telephone set | |
JPS6424667A (en) | Voice conference equipment | |
JPH0758828A (en) | Echo reduction device for telephone set | |
GB2273630B (en) | Telecommunications | |
KR0116754Y1 (en) | Signal to noise improving circuit in microphone | |
JPS57104312A (en) | Control device for sound volume of acoustic device | |
JPS5717258A (en) | Button telephone set | |
GB2010642A (en) | Circuit arrangements for a calling, door speaking and door opening installation | |
TW344184B (en) | A compact telephone device | |
JPS6449363A (en) | Microphone system for conference call | |
JPH09326733A (en) | Echo cancellation device | |
JPS5567267A (en) | Hand-free telephone set |