Telephonic communications – Subscriber line or transmission line interface – Network interface device
Patent
1984-10-11
1988-04-05
Ng, Jin F.
Telephonic communications
Subscriber line or transmission line interface
Network interface device
370 321, 364724, H04B 323
Patent
active
047364149
ABSTRACT:
The method provides the use, for the determination of the estimation echo-channel pulse response, of digital filtering techniques of the transversal adaptive type, and the subdivision of the pulse-response of the equivalent echo channel into three intervals, the second of which consists of the significant portion of the pulse response and is determined by the iterative search for the value and the position of the coefficient of maximum absolute value; the first interval corresponds to a pure delay and the third corresponds to the contribution given by the lowest frequencies of the base band. To copy the echo-signal, there are only considered the pulse-response coefficients whose indexes are comprised in the second interval, and the samples of the signals to be copied belonging to preceding sampling instants, whose indexes are also comprised in the second interval.
REFERENCES:
patent: 3535473 (1970-10-01), Flanagan et al.
patent: 3721777 (1973-03-01), Thomas
patent: 3860768 (1975-01-01), Wehrmann
patent: 4024357 (1977-05-01), Sourgens et al.
patent: 4282411 (1981-08-01), Stewart
patent: 4360712 (1982-11-01), Horna
patent: 4546216 (1985-10-01), Tegethoff
patent: 4558187 (1985-12-01), Billi et al.
patent: 4562312 (1985-12-01), Duttweiler
patent: 4577309 (1986-03-01), Barazeche et al.
patent: 4582963 (1986-04-01), Danstrom
patent: 4587382 (1986-05-01), Yang
AMI Preliminary Disclosure, AMI SZ816, Echo Canceller Processor, Jul. 1981, "Simultaneous Two-Way Data Transmission Over a Two-Wire Circuit", V. G. Koll et al., IEEE Transactions on Communications, Feb. 1973, Concise Papers, pp. 143-147.
"Echo Cancellation on Time-Variant Circuits", N. Demytko et al., Proceedings of the IEEE, vol. 65, No. 3, Mar. 1977, pp. 444-453.
Montagna Roberto
Nebbia Luciano
Cselt Centro Studi e Laboratori Telecomunicazioni SpA
Dubno Herbert
Ng Jin F.
Ross Karl F.
Telespazio Spa per le Comunicazioni Spaziali
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