Constantine V. Skidanenko - Menlo Park CA Gregor D. McGibbon - San Carlos CA
Assignee:
GTE Communication Systems Corporation - Phoenix AZ
International Classification:
H04M 322
US Classification:
179 18FA
Abstract:
A floating battery feed circuit employs a single primary winding, a pulse width control circuit and a peak detector for providing a controlled current to a subscriber loop. The amplitude of the controlled current is determined by the loop resistance. A comparator circuit has one input connected to the output of a peak detector via a breakdown diode. The second comparator input is connected to a reference voltage. When the voltage from the breakdown diode exceeds a predetermined value the comparator provides an 0 output to indicate an on-hook state. For a peak detector output voltage below said predetermined value, the comparator provides a +5 volt output indicating an off-hook state.
Apparatus For Isolating The Voice Frequency Path From The Floating Battery Feed During Signalling
Constantine V. Skidanenko - Menlo Park CA Gregor D. McGibbon - San Carlos CA
Assignee:
GTE Lenkurt Incorporated Communication Systems - Phoenix AZ
International Classification:
H04M 700
US Classification:
179 16AA
Abstract:
In a floating battery feed circuit, the voice frequency is normally connected on the subscriber loop side of the blocking capacitor which is used to prevent the DC loop current from flowing in the winding of the associated voice frequency transformer. This capacitor adversely offsets the dial pulse signals. An optical isolator is responsive to the answer control signal from a dial pulse originating (DPO) channel unit and provides a control signal to a switching circuit, which connects the voice frequency circuit to the loop during answer periods and disconnects the voice frequency circuit from the loop during dial pulse signaling.
System And Method For Reducing Tandeming Effects In A Communication System
- Burlington MA, US Victor Zeyliger - Redwood City CA, US Constantine V. Skidanenko - San Jose CA, US
International Classification:
G10L 19/12 G10L 19/08 H04W 76/04
Abstract:
The present disclosure is directed towards a system and method for reducing tandeming effects in a communications system. The method may include receiving, at a speech decoder, an input bitstream associated with an incoming initial speech signal from a speech encoder. The method may further include determining whether or not coding is required and if coding is required, modifying an excitation signal associated with the bitstream. The method may also include providing the modified excitation signal to an adaptive encoder.