Frequency division multiplex single-sideband modulation system

Claim 2

A modulation system for a plurality of applied analog channel signals comprising: means for sampling and converting each analog channel signal into a digital signal; means for selectively commutating each of said digital signals at a frequency equal to the frequency of said sampling; means for selectively modulating each commutated signal with one of a plurality of sampled sinusoidal signals of diverse frequencies, the maximum sinusoidal signal frequency being no greater than one-half said frequency of sampling; digital filter means, having a variable signal passband characteristic, for selectively processing said modulated signals; means for varying said digital filter means signal passband characteristic in synchronization with said modulating means to select predetermined spectral components of said modulated signals; and means for converting each of said processed signals into a corresponding analog signal to develop a plurality of a frequency division multiplex single-sideband signals.

Claim 3

A frequency division multiplex single-sideband modulation system for a plurality of applied analog channel signals comprising: means for converting each analog channel signal into a corresponding digital coded signal; means for selectively sampling each of said digital coded signals at a predetermined rate; means for selectively modulating each sampled digital coded signal with one of a plurality of sampled sinusoidal signals of predetermined frequencies; digital filter means, having a variable signal passband characteristic, for processing said modulated signals; means for varying said digital filter means signal passband characteristic in synchronization with said modulating means; and means for converting each of said processed signals into an analog signal to develop a plurality of a frequency division multiplex single-sideband signals.

Claim 4

A frequency division multiplex single-sideband modulation system for a plurality of applied analog channel signals comprising: means for converting each analog channel signal into a corresponding digital coded signal; means for selectively sampling each of said digital coded signals at a predetermined rate; means for selectively modulating each sampled digital coded signal with one of a plurality of sampled sinusoidal signals of predetermined frequencies; digital filter means, having a variable signal passband characteristic, for processing said modulated signals; means for varying said digital filter means signal passband characteristic in synchronization with said modulating means; and means for converting each of said processed signals into an analog signal to develop a plurality of a frequency division multiplex single-sideband signals.

Claim 5

Apparatus for frequency division multiplexing a plurality of applied analog channel signals comprising: means for converting each analog channel signal into a corresponding digital channel signal; means for multiplexing said digital channel signals to develop a plurality of channel signals separated by predetermined intervals of time; means for selectively modulating each multiplexed channel signal with a sinusoidal signal; digital filter means, having a variable signal passband characteristic, for processing said modulated signals; means for varying said digital filter means signal passband characteristic such that the passband of the filter is selectively shifted from one modulated channel signal to the next in synchronization with said modulating means; and means for converting each of said processed signals into a corresponding analog signal to develop a plurality of a frequency division multiplex single-sideband channel signals.

Claim 6

Apparatus for frequency division multiplexing a plurality of applied analog channel signals comprising: means for converting each analog channel signal into a corresponding digital channel signal; means for multiplexing said digital channel signals to develop a plurality of channel signals separated by predetermined intervals of time; means for selectively modulating each multiplexed channel signal with a sinusoidal signal; digital filter means, having a variable signal passband characteristic, for processing said modulated signals; means for varying said digital filter means signal passband characteristic such that the passband of the filter is selectively shifted from one modulated channel signal to the next in synchronization with said modulating means; and means for converting each of said processed signals into a corresponding analog signal to develop a plurality of a frequency division multiplex single-sideband channel signals.

Claim 7

Apparatus for converting a plurality of space division channel signals into a plurality of frequency division multiplex signals comprising: modulator means; first means for successively applying each of said channel signals to the input terminal of said modulator means; a plurality of sinusoidal signal sources having diverse signal frequencies, each signal frequency associated with one of said plurality of channel signals; second means, in synchronization with said first means, for successively applying said sinusoidal signal frequencies to said modulator means; digital filter means having a selectively alterable passband for processing the signal output of said modulator means; and third means, in synchronization with said second means, for selectively altering the passband of said digital filter means to successively pass predetermined spectral components of the signal output of said modulator means.

Claim 8

Apparatus for converting a plurality of space division channel signals into a plurality of frequency division multiplex signals comprising: modulator means; first means for successively applying each of said channel signals to the input terminal of said modulator means; a plurality of sinusoidal signal sources having diverse signal frequencies, each signal frequency associated with one of said plurality of channel signals; second means, in synchronization with said first means, for successively applying said sinusoidal signal frequencies to said modulator means; digital filter means having a selectively alterable passband for processing the signal output of said modulator means; and third means, in synchronization with said second means, for selectively altering the passband of said digital filter means to successively pass predetermined spectral components of the signal output of said modulator means.

Claim 9

A single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for converting applied analog signals into digital signals and means for storing said digital signals for a first predetermined interval of time; means for selectively applying said stored digital signals to a terminal in an interval of time which is a predetermined fraction of said first predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said selectively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; means for arithmetically combining the output signals of said first and second circuit paths; means for converting said combined signals to analog output signals; and means for filtering said analog output signals.

Claim 10

A single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for converting applied analog signals into digital signals and means for storing said digital signals for a first predetermined interval of time; means for selectively applying said stored digital signals to a terminal in an interval of time which is a predetermined fraction of said first predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said selectively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; means for arithmetically combining the output signals of said first and second circuit paths; means for converting said combined signals to analog output signals; and means for filtering said analog output signals.

Claim 11

The multiplex system as defined in claim 5 wherein said digital filter means has a low-pass signal characteristic.

Claim 12

The multiplex system as defined in claim 5 wherein said digital filter means has a high-pass signal characteristic.

Claim 13

A single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for sampling applied signals and means for storing said sampled signals for a first predetermined interval of time equal to the reciprocal of the sampling rate; first means for successively applying to a terminal said stored channel signals in an interval of time which is a predetermined fraction of said first predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said successively applied signals with a signal of predetermined frequency, filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of signals of diverse frequencies; and means for arithmetically combining the output signals of said first and second circuit paths.

Claim 14

A single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for sampling applied signals and means for storing said sampled signals for a first predetermined interval of time equal to the reciprocal of the sampling rate; first means for successively applying to a terminal said stored channel signals in an interval of time which is a predetermined fraction of said first predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said successively applied signals with a signal of predetermined frequency, filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of signals of diverse frequencies; and means for arithmetically combining the output signals of said first and second circuit paths.

Claim 15

A single-sideband frequency division multiplex system comprising: means for storing a plurality of applied digital signals for a first predetermined interval of time; means for selectively applying to a terminal said stored digital signals for a second predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said repetitively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; and means for arithmetically combining the output signals of said first and second circuit paths.

Claim 16

A single-sideband frequency division multiplex system comprising: means for storing a plurality of applied digital signals for a first predetermined interval of time; means for selectively applying to a terminal said stored digital signals for a second predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said repetitively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; and means for arithmetically combining the output signals of said first and second circuit paths.

Claim 17

The multiplex system as defined in claim 9 wherein said digital filter means has a low-pass signal characteristic.

Claim 18

The multiplex system as defined in claim 9 wherein said digital filter means has a high-pass signal characteristic.

Claim 19

A single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for sampling and converting applieD analog signals into digital signals and means for storing said digital signals for a first predetermined interval of time equal to the reciprocal of the channel sampling rate; means for selectively applying said stored digital signals to a terminal at a rate which is a predetermined multiple of said sampling rate; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said selectively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating each of said processed signals with one of a plurality of sampled sinusoidal signals of diverse frequencies; means for arithmetically combining the output signals of said first and second circuit paths; and means for converting said combined signals to analog output signals.

Claim 20

A single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for sampling and converting applieD analog signals into digital signals and means for storing said digital signals for a first predetermined interval of time equal to the reciprocal of the channel sampling rate; means for selectively applying said stored digital signals to a terminal at a rate which is a predetermined multiple of said sampling rate; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said selectively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating each of said processed signals with one of a plurality of sampled sinusoidal signals of diverse frequencies; means for arithmetically combining the output signals of said first and second circuit paths; and means for converting said combined signals to analog output signals.

Claim 21

The multiplex system as defined in claim 12 wherein said digital filter means has a low-pass signal characteristic.

Claim 22

The multiplex system as defined in claim 12 wherein said digital filter means has a high-pass signal characteristic.

Claim 23

A single-sideband frequency division multiplex system comprising: means for converting a plurality of applied analog signals into digital signals; means for storing said converted signals for a first predetermined interval of time; means for commutating said stored converted signals at a rate which is a predetermined multiple of the reciprocal of said first predetermined interval of time; first and second circuit paths responsive to said commutated signals, each circuit path including first means for modulating said commutated signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; means for arithmetically combining the output signals of said first and second circuit paths; and means for converting said combined signals to analog output signals to develop a plurality of frequency division multiplex single-sideband signals.

Claim 24

A single-sideband frequency division multiplex system comprising: means for converting a plurality of applied analog signals into digital signals; means for storing said converted signals for a first predetermined interval of time; means for commutating said stored converted signals at a rate which is a predetermined multiple of the reciprocal of said first predetermined interval of time; first and second circuit paths responsive to said commutated signals, each circuit path including first means for modulating said commutated signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; means for arithmetically combining the output signals of said first and second circuit paths; and means for converting said combined signals to analog output signals to develop a plurality of frequency division multiplex single-sideband signals.

Claim 25

A single-sideband frequency division multiplex system comprising: means for storing a plurality of applied digital signals for a first predetermined interval of time; means for alternately inverting the sign of each of said stored signals; means for repetitively applying to a terminal said inverted stored signals for a second predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said repetitively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; and means for arithmetically combining the output signals of said first and second circuit paths.

Claim 26

A single-sideband frequency division multiplex system comprising: means for storing a plurality of applied digital signals for a first predetermined interval of time; means for alternately inverting the sign of each of said stored signals; means for repetitively applying to a terminal said inverted stored signals for a second predetermined interval of time; first and second circuit paths connected to said terminal, each circuit path including first means for modulating said repetitively applied signals with a sampled sinusoidal signal of predetermined frequency, digital filter means for processing said modulated signals, and second means for modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; and means for arithmetically combining the output signals of said first and second circuit paths.

Claim 27

a single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for storing applied signals for a first predetermined interval of time; means for selectively commutating said stored signals at a rate which is a predetermined multiple of the reciprocal of said first predetermined interval of time; first means for selectively modulating each of said commutated signals with a sampled sinusoidal signal of predetermined frequency; digital filter means for processing said modulated signals; second means for selectively modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; and third means for selectively combining the modulated signals of said second means.

Claim 28

a single-sideband frequency division multiplex system comprising: a plurality of input signal channels, each including means for storing applied signals for a first predetermined interval of time; means for selectively commutating said stored signals at a rate which is a predetermined multiple of the reciprocal of said first predetermined interval of time; first means for selectively modulating each of said commutated signals with a sampled sinusoidal signal of predetermined frequency; digital filter means for processing said modulated signals; second means for selectively modulating said processed signals with a plurality of sampled sinusoidal signals of diverse frequencies; and third means for selectively combining the modulated signals of said second means.

Claim 29

The multiplex system as defined in claim 17 wherein said digital filter means has a low-pass signal characteristic.

Claim 30

The multiplex system as defined in claim 17 wherein said digital filter means has a high-pass signal characteristic.