Adaptive predicting circuit using a lattice filter and a corresponding differential PCM coding or decoding apparatus
US4389726A · kind A · utility
Inventors
Key dates
| Filing date | Apr 10, 1981 |
| Grant date | Jun 21, 1983 |
| Priority date | — |
| Expiry date | Apr 10, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/042
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An adaptive predicting circuit comprises a lattice filter with N identical cells each having four accesses. The first and second accesses of a cell are respectively connected to the third and fourth accesses of the preceding cell. Each cell comprises a circuit with a delay of one sampling time and two multipliers each having two inputs, one receiving a signal and the other a multiplication coefficient k.sub.m (t). The coefficient k.sub.m (t) is supplied to the multipliers. The adaptive predicting circuit also comprises an adder having N inputs respectively connected to the N cells and one output supplying a prediction signal. The coefficient k.sub.m (t) is supplied by a circuit for the sequential adaptation of the coefficient k.sub.m (t) inherent to each cell. The adaptation circuit has four inputs respectively connected to the first access of the cell, to the output of the delay circuit, and to the third and fourth accesses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.