Hands-free telephone

Details Hands-free telephone Hands-free telephone

1997-10-17

1999-03-16

To, Doris H.

Telecommunications

Transmitter and receiver at same station

Radiotelephone equipment detail

455563, 455550, 370289, 379410, H04M 908

Patent

active

058841946

ABSTRACT:
The present invention provides a hands-free telephone wherein near-end caller voice detection information is provided with little error, and wherein electric power saving effects are improved, and also wherein the far-end caller does not receive an unnatural impression. An echo canceller comprises: level calculating unit 1, 2, and 3 for calculating the level of reception signals, input transmission signals, and residual signals; and adaptive filter 4 for inputting the reception signals and transmission input signals and outputting residual signals; echo cancellation amount calculation unit 5 for calculating the echo cancellation amount from the input transmission signal level and residual signal level; voice detection threshold value control unit 6 for controlling the voice detection threshold value according to the reception signal level and the echo cancellation amount; voice detection unit 7 for outputting a voice detection flag using the residual signal level and the voice detection threshold value; attenuator control unit 9 for controlling the suppression amount based on the reception signal level, and attenuator 10 for performing suppression according to the suppression amount.

REFERENCES:
patent: 4852161 (1989-07-01), Hagiwara
patent: 5400399 (1995-03-01), Umemoto et al.
patent: 5668865 (1997-09-01), Duttweiler et al.
"TMS320WP010 Digital Signal Processor for AEC/LEC/ANS," Texas Instruments, SPRS040-Oct. 1995, pp. 1-17.
Ryoichi Miyamoto et al.; "ECHO Canceller Type Hands-Free Mobile Telephone"; (Oki Denki Kenkyu Kaihatsu, Jan. 1989; #141; vol. 56, No. 1, pp. 34-40).

Affiliated with

Also associated with

Rating

Hands-free telephone does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Hands-free telephone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hands-free telephone will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-826697