Communication system tonal component maintenance techniques

Details Communication system tonal component maintenance techniques Communication system tonal component maintenance techniques

2008-02-26

2011-10-04

Jamal, Alexander (Department: 2614)

Telephonic communications

Repeater

Pulse or tone repeater

Reexamination Certificate

active

08031861

ABSTRACT:
An apparatus and method for suppressing noise is presented. The apparatus may utilize a filter bank of bandpass filters to split the input noisy speech-containing signal into separate frequency bands. To determine whether the input signal contains speech, DTMF tones or silence, a joint voice activity & DTMF activity detector (JVADAD) may be used. The overall average noise-to-signal ratio (NSR) of the input signal is estimated in the overall NSR estimator, which estimates the average noisy signal power in the input signal during speech activity and the average noise power during silence. Two indirect power measures are performed for each band, measuring a short-term power and a long-term power. The power estimation processes are adapted based on the signal activity indicated by the JVADAD. A NSR adapter adapts the NSR for each frequency band based on the long-term and short-term power measures, the overall NSR and the signal activity indicated by the JVADAD. The NSR adaptation may then be performed. The gain computer utilizes these NSR values to determine the gain factors for each frequency band. The gain multiplier may then perform the attenuation of each frequency band. Finally, the processed signals in the separate frequency bands are summed up in the combiner to produce the clean output signal. In another embodiment of the present invention, a method for suppressing noise is presented. An alternative embodiment of the present invention includes a method and apparatus for extending DTMF tones. Yet another embodiment of the present invention includes regenerating DTMF tones.

REFERENCES:
patent: 4351982 (1982-09-01), Miller et al.
patent: 4351983 (1982-09-01), Crouse
patent: 4423289 (1983-12-01), Swinbanks
patent: 4454609 (1984-06-01), Kates
patent: 4628529 (1986-12-01), Borth et al.
patent: 4630304 (1986-12-01), Borth et al.
patent: 4630305 (1986-12-01), Borth et al.
patent: 4658426 (1987-04-01), Chabries et al.
patent: 4658435 (1987-04-01), Childress et al.
patent: 4769847 (1988-09-01), Taguchi
patent: 5012519 (1991-04-01), Adlersberg et al.
patent: 5285165 (1994-02-01), Renfors et al.
patent: 5351271 (1994-09-01), Coquerel
patent: 5400409 (1995-03-01), Linhard
patent: 5425105 (1995-06-01), Lo et al.
patent: 5432859 (1995-07-01), Yang et al.
patent: 5485524 (1996-01-01), Kuusama et al.
patent: 5533118 (1996-07-01), Cesaro et al.
patent: 5610991 (1997-03-01), Janse
patent: 5619524 (1997-04-01), Ling et al.
patent: 5632003 (1997-05-01), Davidson et al.
patent: 5706395 (1998-01-01), Arslan et al.
patent: 5748725 (1998-05-01), Kubo
patent: 5806025 (1998-09-01), Vis et al.
patent: 6263307 (2001-07-01), Arslan et al.
patent: 6377919 (2002-04-01), Burnett et al.
patent: 0856833 (1999-02-01), None
patent: WO 89/03141 (1989-04-01), None
patent: WO 96/24128 (1996-08-01), None
Special Mobile Group Technical Committee of ETSI: “Digital Cellular Telecommunications System (Phase 2) Full Rate Speech; Part 6: Voice Activity Detection (VAD) for Full Rate Speech Traffic Channels,”Draft ETS300 580-6 (Nov. 1997).
J.S. Lim & A.V. Oppenheim: “Enhancement and Bandwidth Compression of Noisy Speech,”Proceedings of the IEEE, vol. 67, No. 12, pp. 7-25 (Dec. 1979).
M. Berouti, R. Schwartz & J. Makhoul: “Enhancement of Speech Corrupted by Acoustic Noise,”Proceedings of the IEEE Conference on Acoustics, Speech, and Sig. Proc., pp. 208-211 (Apr. 1971).
J.R. Deller et al., “Discrete-Time Processing of Speech Signals,” chapter 7. Prentice Hall Inc. (1987).
Saeed V. Vaseghi, “Advanced Signal Processing and Digital Noise Reduction,” Chapter 9, pp. 242-260, ISBN WILEY 0471958751 (1996).
Kondoz et al., “A High Quality Voice Coder with Integrated Echo Canceller and Voice Activity Detector for VSAT Systems,”3rdEuropean Conference on Satellite Communications-ECSC-3, pp. 196-200 (1993).
Gagnon et al., “Speech Processing Using Resonator Filterbanks,”Proc. IEEE International Conference on Accoustics, Speech&Signal Processing, pp. 981-984 (May 14-17, 1991).
Little, et al, “Speech Recognition for the Siemens EWSD Public Exchange,”Proc. of 1998 IEEE 4thworkshop; Interactive Voice Technology for Telecommunications Applications, IVT, pp. 175-178 (1998).
Mcaulay et al, “Speech Enhancement Using a Soft-Decision Noise Suppression Filter,”IEEE Transactions on ASSP, vol ASP-28, No. 2, pp. 137-145 (Apr. 1980).
Texas Instruments Application Report, “DTMF Tone Generation and Detection: An Implementation Using the TMS320C54x,” pp. 5-12, 20. A-1,. A-2, B-1, B2 (1997).
Roman Kuc:Introduction to Digital Signal Processing, Chapter 9.5, pp. 361-379 (ISBN 0070355703), (1988).

Affiliated with

Also associated with

Rating

Communication system tonal component maintenance techniques does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Communication system tonal component maintenance techniques, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Communication system tonal component maintenance techniques will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4273883