Apparatus for FM-modulation of digital signals
AssigneeNEC Corporation
InventorHiroyuki Shimizu
Life of this patent
Estimating the term…
Abstract
One of a reference phase signal and an orthogonal phase signal is inverted to provide an inverted phase signal. when an arrangement of a local frequency is the same between transmitting and receiving sides, a carrier wave signal is FM-modulated by the reference and orthogonal phase signals. On the other hand, when the above arrangement is different between the transmitting and receiving sides, a carrier wave signal is FM-modulated by the inverted phase signal and the remaining one of the reference and orthogonal phase signals.
Claims4
An apparatus for FM-modulation of digital data signals, comprising:
- means for supplying reference and orthogonal phase signals by receiving an input digital data signal;
- means for inverting said reference phase signal to provide an inverted reference phase signal;
- means for selecting one signal from said reference phase signal and said inverted reference phase signal;
- and
- means for FM-modulating a carrier wave signal by said one signal and said orthogonal phase signal to provide an FM-modulated digital data signal;
- wherein said one signal is said reference phase signal in case where an arrangement of a local frequency is the same between transmitting and receiving sides, and said one signal is said inverter reference phase signal in case where said arrangement is different between said transmitting and receiving sides.
An apparatus for FM-modulation of digital data signals, comprising:
- means for supplying reference and orthogonal phase signals by receiving an input digital data signal;
- means for inverting said orthogonal phase signal to provide an inverted orthogonal phase signal;
- means for selecting one signal from said orthogonal phase signal and said inverted orthogonal phase signal;
- and
- means for FM-modulating a carrier wave signal by said reference phase signal and said one signal to provide an FM-modulated digital data signal;
- wherein said one signal is said orthogonal phase signal in case where an arrangement of a local frequency is the same between transmitting and receiving sides, and said one signal is said inverted orthogonal phase signal in case where said arrangement is different between said transmitting and receiving sides.
Dependencies are inferred from the claim text.