Analog processor for digital satellites

• US 6,408,164 B1
• Filed: 06/09/1999
• Issued: 06/18/2002
• Est. Priority Date: 01/17/1997
• Status: Expired due to Term

• Current Assignee: Com Dev Limited (Honeywell International Inc.)
• Original Assignee: Com Dev Limited (Honeywell International Inc.)
• Inventors: Tailor, Bharat, Lazaris-Brunner, Ken, Beauchamp, Gary
• Primary Examiner(s): Kincaid, Lester G.
• Application Number:
  US09/328,479
• Time in Patent Office: 1,105 Days
• Field of Search: 455/12.1, 455/13.1, 455/427, 455/428, 455/20, 455/21, 455/22, 455/13.3, 455/266, 455/275, 370/316, 370/323, 375/216
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An analog processor for use with digital satellites is disclosed. The analog processor is connected between the receiving circuitry of the satellite and a pool of digital on-board processors, and segments the bandwidth of uplink RF beams into sub-bands that can be processed more readily with standard, low-risk, low-power digital processors. Using the present invention, the risk of employing a particular digital processor technology can be managed and optimized. The present invention also provides for the dynamic allocation and reallocation of the available on-board digital processing bandwidth based on the anticipated traffic pattern and changes in the traffic pattern. In addition, the present invention facilitates the use of standard and non-standard redundancy schemes at minimal hardware expense.

Claims

1. A satellite communications processor for processing information transmitted to a satellite in a plurality of uplink beams, comprising:

a plurality of digital processors; and

an analog sub-band processor coupled between the uplink beams and the plurality of digital processors, wherein the analog sub-band processor includes a switch matrix for switching the uplink beams to form a set of switched uplink beams, and a plurality of sub-band processing chains coupled to the set of switched uplink beams, wherein each sub-band processing chain includes variable translation circuitry for extracting a sub-band of information from an uplink beam and for routing the sub-band of information to one of the plurality of digital processors.

2. The satellite communications processor of claim 1, wherein the variable translation circuitry includes:

a mixer having two inputs and one output, wherein one of the inputs is coupled to one of the switched uplink beams;

a variable local oscillator coupled to the other input of the mixer; and

a bandpass filter coupled to the output of the mixer,

wherein the variable local oscillator generates a translation frequency that causes the mixer to translate a sub-band of information from the uplink beam to an extraction frequency for filtering by the bandpass filter.

3. The satellite communications processor of claim 2, wherein the translation frequency is selectable.

4. The satellite communications processor of claim 2, wherein the bandpass filter is a surface-acoustic wave device.

5. The satellite communications processor of claim 2, wherein the sub-band processing chains further include a downconverter coupled to the bandpass filter that converts the sub-band of information to a baseband signal.

6. The satellite communications processor of claim 2, wherein the downconverter performs a real downconversion.

7. The satellite communications processor of claim 2, wherein the downconverter performs a complex downconversion.

8. The satellite communications processor of claim 1, wherein the switch matrix and the sub-band processing chains can be reconfigured to accommodate changing traffic patterns of the uplink beams.

9. The satellite communications processor of claim 1, further including at least one summer circuit coupled between one or more of the plurality of sub-band processing chains and at least one of the digital processors, wherein the at least one summer circuit combines the sub-bands of information from the one or more sub-band processing chains prior to digital processing.

10. A digital satellite for processing a plurality of uplink beams, comprising:

a switch matrix for switching the uplink beams to a plurality of switched outputs;

a plurality of sub-band processing chains coupled to the plurality of switched outputs for extracting a plurality of carrier signals from the uplink beams, each sub-band processing chain including variable translation circuitry for translating the frequency of the switched uplink beam and a bandpass filter for extracting the carrier signals from the switched uplink beam; and

a plurality of digital processors coupled to the sub-band processing chains for digitizing and processing the extracted carrier signals.

11. A multi-beam satellite apparatus for processing a plurality of uplink beams, each uplink beam including a plurality of carrier signals, comprising:

an N×

M uplink beam switch matrix for switching N of the uplink beams to one or more of M outputs of the N×

M uplink beam switch matrix;

at least M sub-band extraction circuits coupled to the M outputs of the N×

M uplink beam switch matrix, each sub-band extraction circuit including a selectable local oscillator for generating a frequency translation signal, a mixer coupled to one of the M outputs and to the frequency translation signal, and a bandpass extraction filter coupled to the output of the mixer, wherein the frequency translation signal causes the mixer to translate a sub-band of carrier signals from the uplink beam to an extraction frequency that is within the passband of the bandpass extraction filter; and

a plurality of digital processors coupled to the M sub-band extraction circuits for processing the carrier signals in each of the extracted sub-bands.

12. A communications satellite, comprising:

a plurality of receivers for receiving a plurality of uplink beams, each uplink beam including a plurality of carrier signals;

a switch matrix coupled to the receivers for switching the uplink beams;

a plurality of variable sub-band extraction circuits coupled to the switched uplink beams, wherein each variable sub-band extraction circuit extracts one or more carrier signals from an uplink beam in response to a variable translation signal; and

a plurality of digital processors coupled to the variable sub-band extraction circuits for processing the extracted carrier signals.

13. A satellite processor, comprising:

a switch matrix coupled to a plurality of uplink beams for switching the uplink beams to form a set of switched uplink beams; and

a plurality of sub-band processing chains coupled to the set of switched uplink beams, wherein each sub-band processing chain includes variable translation circuitry for extracting a sub-band of information from an uplink beam, wherein the variable translation circuitry includes;

a mixer having two inputs and one output, wherein one of the inputs is coupled to one of the switched uplink beams;

a variable local oscillator coupled to the other input of the mixer; and

a bandpass filter coupled to the output of the mixer,

wherein the variable local oscillator generates a translation frequency that causes the mixer to translate a sub-band of information from the uplink beam to an extraction frequency for filtering by the bandpass filter.