Telephonic communications – Having light wave or ultrasonic link for speech or paging... – Including fiber optic link within telephone network
Patent
1988-04-18
1989-06-27
Ng, Jin F.
Telephonic communications
Having light wave or ultrasonic link for speech or paging...
Including fiber optic link within telephone network
379 63, 379390, 370 32, H04Q 704, H04M 100, H04M 1100
Patent
active
048436216
ABSTRACT:
A mobile radiotelephone (120) includes a microcomputer (220), speakerphone control circuitry (106) and mobile radio (112). In the transmit voice path, speakerphone control circuitry (106) includes switch (201), variable gain amplifier (202), compressor amplifier (203), switch (204), variable gain amplifier (205), and two registers (212-213). In the receive voice path, speakerphone control circuitry (106) includes variable gain amplifier (232), expander amplifier (233), switch (234), variable gain amplifier (235), switch (236) and two registers (216-217). Speakerphone control circuitry (106) also includes rectifier/filter (224), a companding analog-to-digital (A/D) converter (225), two latches (218-219), rectifier/filter (226) and two registers (214-215). Microcomputer (220) accesses registers (212-217) by means of a data bus (222) including address, control and data lines. Microcomputer (220) utilizes digital samples from A/D converter (225) to dynamically detect acoustic feedback and to continuously generate and store in its memory an envelope signal and a valley signal for the transmit and receive voice paths for controlling voice path gain switching. In order to determine when to switch gain between the voice paths, microcomputer (220) compares the envelope signal to the valley signal to detect the presence of voice signals and, if the voice signals are detected for a pre-selected time, the gain of the path in which voice signals have been detected is increased and the gain of the other path is decreased.
REFERENCES:
patent: 4081622 (1978-03-01), Clark et al.
patent: 4122304 (1978-10-01), Mallien, II
patent: 4123711 (1978-10-01), Chow
patent: 4220820 (1980-09-01), Mallien, II
patent: 4378603 (1983-03-01), Eastmond
patent: 4400584 (1983-08-01), Vilmur
patent: 4550426 (1985-10-01), Gilling et al.
patent: 4560840 (1985-12-01), Hansen
patent: 4629829 (1986-12-01), Puhl et al.
patent: 4677645 (1987-06-01), Kahiwa et al.
patent: 4741018 (1988-04-01), Potratz et al.
Hackbart Rolland R.
Kim David H.
Motorola Inc.
Ng Jin F.
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