System and method of communicating signals

• US 20070002961A1
• Filed: 06/29/2005
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Zinser, Richard, Grubis, Matthew, Seidl, Neal, Hoctor, Ralph
• Granted Patent: US 7,573,398 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]

Abstract

A communication system is presented. The system includes one or more transmitters configured to transmit a signal, where each of the signals generated by the one or more transmitters corresponds to a respective frequency. Further, the system includes a plurality of receiver front-ends configured to receive the signal transmitted by each of the one or more transmitters. The system also includes a plurality of remodulator modules configured to translate each of the received signals to a signal having a respective intermediate frequency. In addition, the system includes a combining module configured to combine each of the signals having respective intermediate frequencies to generate a single composite signal. Also, the system includes a single analog-to-digital converter configured to process the composite signal and generate a digital output. Additionally, the system includes a digital signal processor module configured to extract the signal transmitted by each of the one or more transmitters.

Claims

1. A system comprising:

one or more transmitters, wherein each of the one or more transmitters is configured to transmit a signal, and wherein each of the signals generated by the one or more transmitters corresponds to a respective frequency;

a plurality of receiver front-ends configured to receive the signal transmitted by each of the one or more transmitters;

a plurality of remodulator modules configured to translate each of the received signals to a signal having a respective intermediate frequency;

a combining module configured to combine each of the signals having respective intermediate frequencies to generate a single composite signal;

a single analog-to-digital converter configured to process the composite signal and generate a digital output; and

a digital signal processor module configured to extract the signal transmitted by each of the one or more transmitters.

2. The system of claim 1, further comprising a data source configured to generate a data signal.

3. The system of claim 2, wherein the, data signal comprises electrocardiogram data, blood pressure data, blood oxygen level data, or combinations thereof.

4. The system of claim 1, wherein the system comprises a telemetry system.

5. The system of claim 4, wherein the telemetry system comprises a medical telemetry system.

6. The system of claim 1, wherein each of the one or more transmitters is configured to transmit a data signal at a predetermined frequency range, wherein the predetermined frequency range varies from about 608 MHz to about 614 MHz, from about 1395 MHz to about 1400 MHz, from about 1427 MHz to about 1432 MHz, or combinations thereof.

7. The system of claim 6, wherein each of the one or more transmitters is configured to modulate the data signal using a modulation technique, wherein the modulation technique comprises one of a minimum shift keying, Gaussian minimum shift keying, frequency shift keying, differential frequency shift keying or Gaussian frequency shift keying.

8. The system of claim 1, wherein the digital signal processor module comprises a software defined radio configured to extract individual copies of the signal transmitted by each of the one or more of transmitters.

9. A method of communicating signals, the method comprising:

transmitting a signal via one or more transmitters, wherein each of the one or more transmitters is configured to transmit the signal at a respective frequency;

receiving the transmitted signal via a plurality of receiver front-ends;

converting each of the received signals to a respective signal having a respective intermediate frequency;

combining each of the signals having respective intermediate frequencies to generate a single composite analog signal;

processing the composite analog signal via an analog-to-digital converter to generate a digital output signal;

processing the digital signal via a digital signal processor module to extract the signal transmitted by each of the one or more transmitters; and

combining the individual copies of each of the transmitted signals to reconstruct the transmitted signal.

10. The method of claim 9, further comprising generating a data signal via a data source for transmittal via the one or more transmitters.

11. The method of claim 9, wherein the step of receiving comprises:

filtering and amplifying the received signals; and

estimating a signal-to-noise ratio and relative power of each of the received signals.

12. The method of claim 9, wherein the step of converting comprises:

translating each of the received signals to a signal having an intermediate frequency by mixing each of the received signals with a respective radio frequency signal generated by a local oscillator; and

processing each of the translated signals via a first bandpass filter, a variable gain amplifier and a second bandpass filter.

13. The method of claim 9, wherein the step of combining each of the signals having respective intermediate frequencies to generate a single composite analog signal comprises combining each of translated signals via an adder.

14. The method of claim 9, wherein the step of processing the digital signal via a digital signal processor module comprises processing the digital signal via a software defined radio, wherein the software defined radio is configured to extract the signal transmitted by each of the one or more transmitters.

15. The method of claim 14, wherein processing the digital signal via the software defined radio comprises:

extracting individual copies of the signal transmitted by each of the one or more transmitters;

translating each of the individual copies to baseband via a numerically controlled oscillator and a mixer;

reducing sampling frequency of each of the individual copies via one or more stages of decimation filtering; and

resampling each of the decimation filtered individual copies to align each of the individual copies in time.

16. The method of claim 9, wherein the step of combining the individual copies of each of the transmitted signals comprises combining time-aligned individual copies of the transmitted signal based upon respective relative powers or respective signal-to-noise ratios of the received signals.

17. The method of claim 9, wherein the step of combining the individual copies of each of the transmitted signals comprises coherently combining time-aligned individual copies of the transmitted signal via a maximal ratio combiner.

18. The method of claim 9, further comprising processing time-aligned copies of each of the transmitted signals via a detector to generate a single digital output signal.

19. A method of communicating signals, the method comprising:

receiving a transmitted signal at a plurality of receiving antennas;

processing each of the received signals via a bandpass filter;

amplifying each of the filtered signals via a low noise amplifier;

translating each of the filtered signals to a respective signal having a respective intermediate frequency;

processing each of the signals having a respective intermediate frequency; and

combining each of the processed received signals to generate a single composite signal.

20. The method of claim 19, wherein the step of translating comprises mixing each of the received signals with a respective radio frequency signal from a local oscillator to generate a respective signal having a respective intermediate frequency.

21. The method of claim 19, wherein the step of processing each of the signals having a respective intermediate frequency comprises:

processing each of the signals having a respective intermediate frequency via a first bandpass filter;

processing each of the signals having a respective intermediate frequency via a variable gain amplifier; and

processing each of the signals having a respective intermediate frequency via a second bandpass filter.

22. The method of claim 19, wherein the combining step comprises combining each of the plurality of signals having respective intermediate frequencies via an adder to generate the composite signal, wherein the composite signal comprises a remodulated spectrum of each of the plurality of translated signals.

23. A method of communicating signals, the method comprising:

receiving a digital signal having a remodulated signal spectrum of a signal transmitted via one or more transmitters;

extracting individual copies of the transmitted signal;

translating each of the individual copies to baseband via a numerically controlled oscillator and a mixer;

reducing sampling frequency of each of the individual copies via one or more stages of decimation filtering;

resampling each of the individual copies to align each of the individual copies in time;

combining the time-aligned copies; and

processing the combined time-aligned copies via a detector to generate a single digital output signal.

24. The method of claim 23, wherein the step of translating comprises translating each of the individual copies to baseband in-phase and quadrature signals via the numerically controlled oscillator and the mixer.

25. The method of claim 23, wherein the step of resampling comprises shifting in time each of the individual copies, wherein the time shift is less than one sample period.

26. The method of claim 23, wherein the step of combining comprises combining time-aligned individual copies of the transmitted signal based upon respective relative powers or respective signal-to-noise ratios of the received signals.

27. The method of claim 23, wherein the step of combining comprises coherently combining time-aligned individual copies of the transmitted signal via a maximal ratio combiner.