Remote transmitter control system

• US 4,606,049 A
• Filed: 12/03/1984
• Issued: 08/12/1986
• Est. Priority Date: 12/03/1984
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Daniel, Richard A.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Chin, Stephen
• Application Number:
  US06/677,434
• Time in Patent Office: 617 Days
• Field of Search: 375/3, 375/4, 375/7, 375/8, 375/45, 375/62, 375/88, 455/7, 455/9, 455/14, 455/20, 455/23, 370/75, 179/170 R, 179/170 J, 340/825.05, 340/870.18
• US Class Current: 375/272
• CPC Class Codes: H04L 25/02 Details ; arrangements for supplying electrical power along data transmission lines systems for transmitting signals via power distribution lines H04B3/54
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence

Abstract

A remote transmitter system including a control station and a remote trantter station. The control station includes a variable frequency oscillator, a modulator, a parallel to series digital data converter and a DC power supply. The remote transmitter station comprises a power storage circuit, a phase-locked-loop demodulator, a local oscillator, a modulator and a power amplifier. The variable frequency oscillator provides two signals f_o and f₁ that are harmonics of each other and are in-phase. These signals modulate the 0'"'"'s and 1'"'"'s of digital data that is transmitted along a coaxial cable to the phase-locked-loop demodulator that provides a control signal to the local oscillator and the modulated digital data signal (f_o, f₁) to the modulator. The local oscillator generates two signals f_A and f_B, that have a predetermined phase and/or frequency relationship to f_o and f₁. The f_o and f₁ signals are detected and applied to the modulator as a control signal (D_o, D₁) that generates a serial input signal (f_A, f_B) to the power amplifier and represents the binary data. The invention may be used with either phase modulation, or frequency modulation depending upon the design of the local oscillator. The two outputs f_A and f_B of the modulator can be designed to have any relationship of frequency for frequency modulation or phase for phase modulation.

Claims

1. A remote transmitter control system comprising:

(a) a control station for generating a frequency modulated control signal that represents binary digital data, said control station including

(1) a variable frequency oscillator, said variable frequency oscillator providing two frequencies f₀ and f₁ that are harmonically related, in phase and f₀ is greater that f₁ ;

(2) a source of binary digital data;

(3) a first modulator, said first modulator being responsive to said f₀ and f₁ frequencies and to said source of binary digital data for generating a frequency modulated control signal wherein f₀ and f₁ respectively represent the two states of said binary data; and

(b) a remote transmitter station including a control signal responsive means for receiving said frequency modulated control signal and independently generating a modulated transmission signal that represents said binary digital data, and a transmitter means, said control signal responsive means including

(1) a local oscillator, the output of said local oscillator being transmit frequencies f_A and f_B ;

(2) a second modulator, said second modulator receiving the transmit frequencies f_A and f_B from said local oscillator, the output of said second modulator being applied to the input of said transmitter means; and

(3) a phase-locked-loop demodulator, said phased-locked-loop demoulator being responsive to said frequency modulated control signal for providing frequency f₀ to said local oscillator, providing control signals representing the digital data to said second modulator, and providing a power control signal to said transmitter when transmit frequencies f_A and f_B are present.

2. The system of claim 1 wherein:

(a) said source of binary digital data is responsive to signal f₀ and provides binary signals that are in phase with f₀ and f₁ when modulating said first modulator.

3. The system of claim 2 wherein:

(a) said local oscillator is phase locked to f_o.

4. The system of claim 3 wherein:

(a) the outputs f_A and f_B of said local oscillator are in phase and f_B is an integer frequency multiple of f_A.

5. The system of claim 4 wherein:

(a) the outputs f_A and f_B of said local oscillator are 180°

out of phase with respect to each other and f_A is in phase with f_o.