Devices and methods for ultra-wideband communications

• US 20060039448A1
• Filed: 08/22/2005
• Published: 02/23/2006
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: Mcdonnell Boehnen Hulbert & Berghoff LLP
• Original Assignee: Interuniversitair Micro-Electronica Centrum VZW (IMEC International)
• Inventors: Ryckaert, Julien
• Granted Patent: US 7,822,097 B2
• Time in Patent Office: Days
• US Class Current: 375/130
• CPC Class Codes: H04B 1/7172 Pulse shape in general H04L25/03834
• CPC Class Codes: H04B 1/7174 Pulse generation in general H04L25/03834
• CPC Class Codes: H04B 1/719 Interference-related aspects

Abstract

A method for generating an ultra-wideband communications signal is described. The method includes generating a piecewise linear ultra-wideband baseband signal comprising at least one pulse, based on an inputted data signal; generating a carrier tone having a carrier frequency suitable for wireless transmission; and upconverting the baseband signal with the carrier tone to the carrier frequency. A method for interpreting a received ultra-wideband communications signal, the signal having a center frequency in the RF domain, is also described. The method includes generating at least one local signal template, synchronized with the received ultra-wideband communications signal and having substantially the same center frequency; correlating the received ultra-wideband communications signal with each of the local signal templates in the analog domain, obtaining at least one ultra-wideband baseband signal; and interpreting the at least one ultra-wideband baseband signal to generate a data signal. Devices for implementing these methods are also described.

Claims

1. A method for generating an ultra-wideband communications signal, comprising in combination:

generating a piecewise linear ultra-wideband baseband signal having at least one pulse, wherein the baseband signal is generated based on an inputted data signal;

generating a carrier tone having a carrier frequency suitable for wireless transmission; and

upconverting the baseband signal with the carrier tone to the carrier frequency, thereby generating the ultra-wideband communications signal.

2. The method of claim 1, wherein the at least one pulse has a duration and the carrier tone has a period, and wherein the duration is longer than the period.

3. The method of claim 1, wherein the ultra-wideband baseband signal comprises a plurality of pulses separated from each other in time.

4. The method of claim 1, wherein the ultra-wideband communications signal has a bandwidth of at least one of at least 500 MHz and at least 20% of the carrier frequency.

5. The method of claim 1, wherein the ultra-wideband communications signal has a center frequency within one of a first range of 3-5 GHz and a second range of 6-10 GHz.

6. The method of claim 5, wherein the ultra-wideband communications signal has a bandwidth of maximum 2 GHz if the center frequency is within the first range and maximum 4 GHz if the center frequency is within the second range.

7. The method of claim 1, further comprising tuning at least one of shape and bandwidth of the at least one pulse.

8. The method of claim 1, further comprising tuning the carrier tone frequency.

9. The method of claim 1, wherein generating a carrier tone includes switching an oscillator off between two pulses.

10. The method of claim 9, wherein the oscillator is a ring oscillator.

11. The method of claim 1, wherein the at least one pulse is a triangular pulse.

12. A method for interpreting a received ultra-wideband communications signal, the signal having a center frequency in a radio frequency domain, comprising in combination:

generating a plurality of local signal templates, wherein the plurality of local signal templates are phase-shifted with respect to each other, are synchronized with the received ultra-wideband communications signal, and have substantially the same center frequency;

correlating the received ultra-wideband communications signal with each of the local signal templates in an analog domain, thereby obtaining an ultra-wideband baseband signal for each correlation; and

interpreting the ultra-wideband baseband signals to generate a data signal.

13. The method of claim 12, wherein correlating the received ultra-wideband communications signal with each of the local signal templates in an analog domain comprises:

mixing the received ultra-wideband communications signal with each of the local signal templates to obtain mixed signals; and

integrating each of the mixed signals to obtain the ultra-wideband baseband signals.

14. The method of claim 12, wherein generating a plurality of local signal templates includes switching a ring oscillator on and off.

15. The method of claim 12, wherein generating a plurality of local signal templates comprises for each signal template:

generating a piecewise linear ultra-wideband baseband signal comprising at least one pulse, wherein the baseband signal is generated based on the received ultra-wideband communications signal;

generating an upconversion tone having an upconversion frequency substantially equal to the center frequency of the received ultra-wideband communications signal; and

upconverting the baseband signal with the upconversion tone, thereby generating the signal template.

16. The method of claim 12, wherein generating a plurality of local signal templates includes generating two phase-shifted local signal templates, wherein a first local signal template is shifted substantially 90°

from a second local signal template.

17. The method of claim 12, wherein generating a plurality of local signal templates includes generating three local signal templates having a phase shift of approximately 120°

between each other.

18. A device for generating an ultra-wideband communications signal, comprising in combination:

a signal generator for generating a piecewise linear ultra-wideband baseband signal having at least one pulse, wherein the baseband signal is generated based on an inputted data signal;

an oscillator for generating a carrier tone having a frequency in the RF domain; and

a mixer for upconverting the baseband signal with the carrier tone to the RF domain, thereby generating the ultra-wideband communications signal.

19. The device of claim 18, wherein the signal generator has a pulse position modulator and a pulse shaping circuit.

20. The device of claim 18, wherein the oscillator is a ring oscillator.

21. The device of claim 18, further comprising a timing circuit for switching off at least one of the signal generator and the oscillator between two pulses.

22. A device for interpreting a received ultra-wideband communications signal, the signal having a center frequency in the RF domain, comprising in combination:

a signal generator for generating a plurality of phase-shifted local signal templates having substantially a same center frequency as the received ultra-wideband communications signal;

a timing circuit for synchronizing the local signal templates with the received ultra-wideband communications signal;

an analog correlator for each local signal template, wherein the analog correlator correlates the received ultra-wideband communications signal with each local signal template, thereby obtaining an ultra-wideband baseband signal per correlator; and

interpretation means for deriving a data signal from the received ultra-wideband baseband signal.

23. The device of claim 22, wherein each of the analog correlators includes a mixer and an analog integrator downstream of the mixer, wherein the received ultra-wideband communications signal and one of the local signal templates provide inputs to the mixer.

24. The device of claim 22, wherein the signal generator has a ring oscillator, and wherein the timing circuit switches the ring oscillator on and off in synchronization with the received ultra-wideband communications signal.

25. The device of claim 22, wherein the device includes two analog correlators, and wherein the signal generator includes a phase shifter for generating a second local signal template that is shifted substantially 90°

from a first local signal template.

26. The device of claim 22, wherein the device includes three analog correlators, and wherein the signal generator maintains a phase shift of approximately 120°

between the signal templates supplied to each of the analog correlators.

27. The device of claim 22, wherein the interpretation means includes a baseband detection circuit for detecting pulses in the ultra-wideband baseband signal.

28. The device of claim 22, wherein the timing circuit includes at least one capacitor, a current source for supplying current to the at least one capacitor, and a comparator for comparing voltage on the at least one capacitor with a reference voltage, and wherein the comparator provides an output which forms a timing signal.

29. The device of claim 28, wherein the device includes a first capacitor and a second capacitor parallel to the first capacitor, and wherein the device includes a data signal controlled switch that is operable to connect and disconnect the first capacitor from the comparator.

30. The device of claim 28, wherein the timing circuit further includes a reset node for resetting the timing circuit by discharging the at least one capacitor.

31. The device of claim 28, wherein the timing circuit further includes a feedback of the output of the comparator, wherein the feedback is used for discharging the at least one capacitor.