Modular receiver for signals having multiple channels and multiple formats

• US 5,058,138 A
• Filed: 01/16/1990
• Issued: 10/15/1991
• Est. Priority Date: 01/16/1990
• Status: Expired due to Term

• Current Assignee: Neeco-Tron, Inc. (Major Custom Assemblies, Inc.)
• Original Assignee: Pacesetter Electronics Incorporated
• Inventors: Figura, John A., Eidelman, Harry
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): Tse, Young
• Application Number:
  US07/464,968
• Time in Patent Office: 637 Days
• Field of Search: 375/75, 375/87, 375/97, 375/88, 375/8, 370/69.1, 370/70, 370/50, 370/85.9, 370/120, 370/122, 370/123, 455/17, 455/53, 455/182, 455/183, 455/260, 455/265, 455/316, 455/349, 361/380, 361/390, 361/392, 361/393, 361/394, 361/395, 361/422, 329/300, 329/301, 329/304, 329/311, 329/315
• US Class Current: 375/334
• CPC Class Codes: H03J 1/005 in a loop
• CPC Class Codes: H04J 1/045 Filters applied to frequency transposition

Abstract

Disclosed is an apparatus for receiving a selected channel of a signal having a plurality of channels, each channel having a plurality of subchannels. A parabolic reflector, low noise amplifier and block converter receive the signal. A tuner detects the selected channel in the received signal and provides a detected signal corresponding to the selected channel. A demodulator demodulates the detected signal into a baseband signal corresponding to the selected channel, the baseband signal being modulated with the subchannels of the selected channel. An analog bus is connected to the demodulating means for providing the baseband signal. A first demodulator connected to the analog bus demodulates a first subchannel of the subchannels of the baseband signal and provides a signal representative of the first subchannel. A second demodulator connected to the analog bus demodulates a second subchannel of the subchannels of the baseband signal and provides a signal representative of the second subchannel. A digital bus is connected to the first and second demodulators. A power supply is connected to the analog bus and so that the analog bus carries power supply signals to the demodulators. The digital bus carries data in, data out, clock and enable signals to the demodulators.

Claims

1. An apparatus for receiving a selected channel of a signal having a plurality of channels, each channel having a plurality of subchannels, the apparatus comprising:

means for receiving the signal;

means for detecting the selected channel in the received signal and providing a detected signal corresponding to the selected channel;

means for demodulating the detected signal into a baseband signal corresponding to the selected channel, the baseband signal being modulated with the subchannel of the selected channel;

an analog bus connected to the demodulating means for providing the baseband signal;

a first demodulator connected to the analog bus for demodulating a first subchannel of the subchannels of the baseband signal and providing a signal representative of the first subchannel;

a second demodulator connected to the analog bus for demodulating a second subchannel of the subchannels of the baseband signal and providing a signal representative of the second subchannel; and

a digital bus connected to the first and second demodulators.

2. The apparatus of claim 1 further comprising a power supply connected to the analog bus and wherein the analog bus carries power supply signals to the demodulating means and wherein the digital bus carries data in, data out, clock and enable signals to the demodulating means.

3. The apparatus of claim 1 wherein the first demodulator includes a first register, connected to the digital bus, for controlling the first demodulator and wherein the second demodulator includes a second register, connected to the digital bus, for controlling the second demodulator.

4. The apparatus of claim 3 further comprising a controller connected to the digital bus for addressing the first and second registers via the digital bus and for providing control data to the first and second registers via the digital bus, and a demodulating circuit connected to the analog bus for providing to the controller control signals modulated on the baseband signal.

5. The apparatus of claim 1 further comprising a controller connected to the digital bus for addressing the first and second demodulators via the digital bus and for providing control data to the first and second demodulators via the digital bus, and a demodulating circuit connected to the analog bus for providing to the controller control signals modulated on the baseband signal.

6. The apparatus of claim 1 further comprising a chassis connected to the analog and digital buses having a plurality of slots adapted to receive modules and wherein the first and second demodulators each comprises a module positioned in a slot in the chassis.

7. The apparatus of claim 1 wherein said means for detecting comprises a band-pass filter having at least two different selectable bandwidths and means, connected to the digital bus, for controlling the bandwidth of the band-pass filter;

and further comprising a controller connected to the digital bus for addressing the bandwidth controlling means via the digital bus and for providing control data to the bandwidth controlling means via the digital bus, and a demodulating circuit connected to the analog bus for providing to the controller control signals modulated on the baseband signal.

8. The apparatus of claim 1 wherein said means for detecting comprises a band-pass filter having at least two different selectable bandwidths, said filter being preset to pass to the demodulating means only signals within a frequency range of the detected signal corresponding to the selected channel.

9. The apparatus of claim 1 wherein said means for detecting comprises a local oscillator generating a local oscillator signal for demodulating the received signal, a first reference oscillator generating a first reference signal, a first phase lock loop for adjusting the frequency of the local oscillator signal with respect to a phase difference between the first reference signal and the local oscillator signal, a second reference oscillator generating a second reference signal, and a second phase lock loop for adjusting the frequency of the first reference signal with respect to a phase difference between the second reference signal and the baseband signal.

10. The apparatus of claim 1 wherein the first signal representative of the first subchannel provided by the first demodulator comprises a data signal and the second signal representative of the second subchannel provided by the second demodulator comprises an audio signal.

11. The apparatus of claim 1 wherein said first demodulator further comprises a controller, responsive to the signal representative of the first subchannel, for controlling the operation of the second demodulator .

12. The apparatus of claim 11 wherein the controller controls baud rate and demodulating frequency of the second demodulator.

13. The apparatus of claim 1 wherein the first demodulator comprises a selectable band-pass filter connected to the analog bus and receiving the baseband signal, an FM demodulator for demodulating the signal provided by the bandpass filter, and a selectable low-pass filter for providing the demodulated signal as an output signal.

14. The apparatus of claim 13 further comprising a digital bus connected to the first and second demodulators and a register, connected to the digital bus, controlling the selectable band-pass filter, the selectable low-pass filter and demodulating frequency of the FM demodulator.

15. The apparatus of claim 1 wherein the digital bus connected to the first and second demodulators is integral with the analog bus.

16. An apparatus for receiving a selected channel of a signal having a plurality of channels, each channel having a plurality of subchannels, the apparatus comprising:

means for receiving the signal;

means for detecting the selected channel in the received signal and providing a detected signal corresponding to the selected channel;

means for demodulating the detected signal into a baseband signal corresponding to the selected channel, the baseband signal being modulated with the subchannels of the selected channel;

an analog bus connected to the demodulating means for providing the baseband signal; and

a chassis connected to the analog bus and having a plurality of slots, each slot for receiving a module to which the baseband signal is supplied, each module for demodulating a subchannel of the baseband signal and providing a signal representative of the subchannel.

17. The apparatus of claim 16 further comprising an audio module positioned in one of the slots for demodulating a first subchannel of the baseband signal and providing an audio signal representative thereof.

18. The apparatus of claim 16 further comprising a data module positioned in one of the slots for demodulating a first subchannel of the baseband signal and providing a data signal representative thereof.

19. The apparatus of claim 18 further comprising an audio module positioned in one of the slots for demodulating a first subchannel of the baseband signal and providing an audio signal representative thereof.

20. The apparatus of claim 16 further comprising a controller for controlling operation of the means for detecting the selected channel and a demodulating circuit demodulating the baseband signal to provide to the controller control signals modulated on the baseband signal.

21. The apparatus of claim 16 further comprising a digital bus connected to the chassis and each of the modules located therein.

22. The apparatus of claim 21 further comprising a controller module positioned in one of the slots and at least one other module positioned in the other slots, said controller module for addressing the other modules via the digital bus and for providing control data to the other modules via the digital bus, and a demodulating circuit demodulating the baseband signal to provide to the controller module control signals modulated on the baseband signal.

23. The apparatus of claim 21 further comprising an audio module positioned in one of the slots for demodulating a first subchannel of the baseband signal and providing an audio signal representative thereof.

24. The apparatus of claim 21 further comprising a data module positioned in one of the slots for demodulating a first subchannel of the baseband signal and providing a data signal representative thereof.

25. The apparatus of claim 24 further comprising an audio module positioned in one of the slots for demodulating a first subchannel of the baseband signal and providing an audio signal representative thereof.

26. A module for use in combination with a receiver having a chassis connected to a digital bus for providing control information and connected to an analog bus providing baseband signal with a plurality of subchannels modulated thereon, said chassis having a plurality of slots, each slot for receiving one of the modules and for supplying a connection to the analog and digital buses, said module comprising:

means for demodulating the baseband signal including means, responsive to the control information, for selectively controlling a bandwidth of the baseband signal being demodulated;

means for engaging the analog bus via the slot and for providing the demodulated baseband signal to the demodulating means;

means for engaging the digital bus via the slot; and

means for supporting the demodulating means, the analog bus engaging means and the digital bus engaging means.

27. The module of claim 26 wherein the digital bus engaging means provides the control information to the means for controlling.

28. The module of claim 27 wherein the means for controlling controls the baud rate and demodulating frequency of the demodulating means.

29. The apparatus of claim 27 wherein the demodulating means comprises a band-pass filter, having selectable bandwidths, connected to the analog bus and receiving the baseband signal.

30. The apparatus of claim 29 wherein the means for controlling further comprises a register, connected to the digital bus, controlling the band-pass filter.

31. The apparatus of claim 27 wherein the demodulating means comprises a low-pass filter, having selectable bandwidths, connected to the analog bus and receiving the baseband signal, and wherein the means for controlling selects the bandwidth of the low-pass filter in response to the control information.

32. The apparatus of claim 31 wherein the means for controlling further comprises a register, connected to the digital bus, controlling the low-pass filter.

33. The apparatus of claim 27 wherein the demodulating means comprises a frequency synthesizer connected to the analog bus and providing a local oscillator signal of selectable frequency for demodulating the baseband signal, and wherein the means for controlling selects the frequency of the local oscillator signal in response to the control information.

34. The apparatus of claim 33 wherein the means for controlling further comprises a register, connected to the digital bus, controlling the frequency synthesizer.