Single sideband suppressed carrier digital communications method and system
OwnerHarold R. Walkerinventor
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Abstract
A method of modulating a phase reversing pulse train including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing. The method includes the steps of: identifying select ones of the input data bits which repeat the data state of a respectively preceding one of the input data bits; identifying select ones of the pulses which correspond to the select bits; and, alternately shortening and lengthening the periods associated with the select ones of the pulses.
Claims34
A method of modulating a phase reversing pulse train including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing, said method comprising the steps of:
- identifying select ones of said input data bits which repeat the data state of a respectively preceding one of said input data bits;
- identifying select ones of said pulses which correspond to said select bits;
- and,
- alternately shortening and lengthening said periods associated with said select ones of said pulses.
A modulator for modulating a bipolar signal including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing, said modulator comprising:
- means for identifying select ones of said input data bits which repeat the data state of a respectively preceding one of said input data bits;
- means for identifying select ones of said pulses which correspond to said select bits;
- and,
- means for shortening and lengthening said periods associated with said select ones of said pulses.
A filter suitable for use in modulating a phase reversing pulse train including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing, said filter comprising:
- a transformer including first and second secondary nodes;
- a first capacitor coupled to said first node;
- a crystal oscillator coupled to said second node;
- and,
- a second capacitor coupled to said second node;
- wherein, when the crystal oscillator is excited by a narrow band rapidly phase reversing signal frequency acts as a reference element only.
A filter suitable for use in modulating a phase reversing pulse train including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing, said filter comprising:
- a reference resonator having a group delay;
- and,
- a signal path that bypasses the resonator, such that the group delay of the resonator does not factor in transmission of said modulated pulses, but determines a bandwidth of the filter by virtue of said resonator being used as an impedance reference only.
A method of digital data encoding a multiplicity of data bits, each having a data state, to cause a phase or polarity reversal each bit period while changing the temporal duration of each bit period to encode the data, the said method comprising the steps of:
- identifying the data state of the last incoming bit;
- alternately shortening and lengthening duration of the phase reversal period if the bit is repeated;
- reversing phase or polarity at exactly one bit period if the data state changes from a one to a zero or vice versa.
A filter suitable for use in modulating a phase reversing pulse train including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing, said filter comprising:
- a reference resonator having a group delay independent of a group delay of the filter operated in a parallel mode having a high impedance at a frequency associated with said temporal duration such that said pulses do not pass through it, and provides negative feedback at frequencies off resonance;
- and,
- a signal path that bypasses the resonator, such that the group delay of the resonator does not factor in transmission of said modulated pulses, but determines a bandwidth of the filter by virtue of said resonator being used as an impedance reference only.
A filter suitable for use in modulating a phase reversing pulse train including a plurality of signal pulses each having an associated period of a given temporal duration to encode a multiplicity of input data bits each having a data state, and prevent losses of clock timing, said filter comprising:
- a reference resonator having a group delay having a group delay independent of a group delay of the filter operated in a series mode, providing positive feedback that accentuates the gain of the filter at a resonant frequency, and is not in a signal of said modulated pulses;
- and
- a signal path that bypasses the resonator, such that the group delay of the resonator does not factor in transmission of said modulated pulses, but determines a bandwidth of the filter by virtue of said resonator being used as an impedance reference only.
A digital communication system comprising:
- a means for modulating a pulse train wherein a Fourier frequency components bearing abrupt changes of phase, each of said Fourier frequency components being a single frequency;
- and
- a filtering means operable to pass a selected one of said Fourier frequency components.
Dependencies are inferred from the claim text.