System and method for utilizing spectral resources in wireless communications

• US 20090257480A1
• Filed: 04/09/2008
• Published: 10/15/2009
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Wi-LAN Inc.
• Inventors: Wu, Shiquan, Yee, Jung
• Granted Patent: US 8,411,766 B2
• Time in Patent Office: Days
• US Class Current: 375/211
• CPC Class Codes: H04L 27/0004 using wavelets
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0062 Avoidance of ingress interference, e.g. ham radio channels
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks

Abstract

A wireless communication system comprises a wavelet analyzer and a wavelet signal generator. The wavelet analyzer is operable to analyze wireless signals within a frequency and time map of a communications spectrum, whereby the wavelet analyzer is adapted to determine one or more available cells within the frequency and time map. The wavelet signal generator is operable to generate one or more wavelet signals for transmission within the determined one or more available cells of the frequency and time map based on the analyzed wireless signals within the frequency and time map.

Claims

1. A wireless communication system comprising:

a wavelet analyzer operable to analyze wireless signals within a frequency and time map of a communications spectrum, the wavelet analyzer adapted to determine one or more available cells within the frequency and time map; and

a wavelet signal generator operable to generate one or more wavelet signals for transmission within the determined one or more available cells of the frequency and time map based on the analyzed wireless signals.

2. The system according to claim 1, further comprising a transmitter including:

a modulator operable to modulate the one or more wavelet signals with data;

a digital-to-analog converter operable to convert the modulated one or more wavelet signals from a digital format to an analog format;

an amplifier operable to amplify the one or more wavelet signals that are in analog format; and

an antenna operable to radiate the one or more wavelet signals that are amplified.

3. The system according to claim 2, further comprising a band pass filter operable to filter the one or more wavelet signals that are amplified.

4. The system according to claim 2, further comprising an up converter operable to shift the one or more wavelet signals in analog format from an intermediate microwave frequency to a millimetre wave carrier frequency prior to amplification by the power amplifier.

5. The system according to claim 2, wherein the data comprises one of the group consisting of binary phase shift key (BPSK) data, phase shift key (PSK) data, quadrature phase shift key (QPSK) data, and quadrature amplitude modulation (QAM) data.

6. The system according to claim 2, further comprising an error correction unit operable to encode the data prior to modulation of the one or more wavelet signals.

7. The system according to claim 2, further comprising a receiver including:

an antenna operable to receive the wireless signals; and

an amplifier operable to amplify the filtered wireless signals.

8. The system according to claim 7, further comprising a band pass filter operable to filter the received wireless signals.

9. The system according to claim 7, further comprising a down converter operable to shift the amplified wireless signals from a millimetre wave carrier frequency to an intermediate microwave frequency.

10. A wireless communication system comprising:

a receiver portion operable to receive wireless signals associated with a frequency and time map within a communications spectrum, wherein using wavelet analysis the receiver portion is adapted to analyze the wireless signals for determining one or more available cells within the frequency and time map; and

a transmitter portion coupled to the receiver and operable to modulate one or more wavelet signals with data for transmission within the determined one or more available cells of the frequency and time map.

11. The system according to claim 10, wherein the receiver portion comprises a wavelet analyzer operable to analyze the wireless signals.

12. The system according to claim 11, wherein the transmitter portion comprises a wavelet generator operable to generate one or more modulated wavelet signals based on the analyzed wireless signals.

13. A wavelet signal generation device for wireless transmission, comprising:

an analog to digital converter device operable to convert received wireless signals into digitized signals; and

a digital signal processor device operable to perform wavelet analysis on the digitized signals for determining one or more available cells within a frequency and time map of a communications spectrum, wherein the digital signal processor device generates one or more wavelet signals for transmission within the determined one or more available cells within the frequency and time map of the communications spectrum.

14. The device according to claim 13, wherein the digital signal processor comprises:

a first module operable to calculate wavelet coefficients for each of the digitized signals;

a second module operable to calculate a magnitude value for each of the digitized signals based on the wavelet coefficients, wherein the magnitude value for each of the digitized signals is compared to a threshold value for determining the one or more available portions of the communications spectrum; and

a third module operable to select the one or more wavelet signals for transmission within the determined one or more available portions of the communications spectrum, wherein upon selection, the third module combines data information with the one or more wavelet signals.

15. The device according to claim 14, wherein the digital signal processor comprises a programmable device programmed to include the first, the second, and the third module.

16. A method of utilizing a wireless communication spectrum, comprising:

receiving one or more wireless signals associated with a frequency and time map within the wireless communication spectrum;

determining signal strength for the received wireless signals using wavelet analysis, wherein the signal strength is determined for at least one cell within the frequency and time map; and

allocating the at least one cell for wireless transmission based on a threshold value exceeding the determined signal strength.

17. The method according to claim 16, further comprising wirelessly transmitting a wavelet carrier signal within the allocated at least one cell.

18. The method according to claim 17, further comprising exchanging control information between a transmitter and receiver, wherein prior to transmitting the wavelet carrier signal from the transmitter to the receiver, the transmitter sends the control information to the receiver via a rendezvous channel.

19. The method according to claim 18, wherein the control information comprises transmission center frequency information, transmission time slot information, and information associated with the wavelet carrier signal prior to wirelessly transmitting the carrier wavelet signal.

20. The method according to claim 17, wherein the wavelet carrier signal is generated based on a scaling and a shift parameter.

21. The method according to claim 20, wherein the scaling parameter dilates the wavelet signal in time and reduces the wavelet signal frequency band based on the dilation in time.

22. The method according to claim 20, wherein the scaling parameter compresses the wavelet signal in time and increases the wavelet signal frequency band based on the compression in time.

23. The method according to claim 20, wherein the shift parameter repositions the wavelet signal to one of a plurality of cells within the frequency and time map.

24. The method according to claim 16, wherein determining the signal strength comprises:

determining a plurality of wavelet coefficients corresponding to the received wireless signal; and

determining an average energy from the determined plurality of wavelet coefficients.

25. The method according to claim 24, wherein determining the average energy comprises averaging a squared modulus for each of the determined plurality of wavelet coefficients.

26. The method according to claim 16, wherein the at least one cell comprises a finite frequency band and a finite time slot.

27. The method according to claim 16, wherein allocating at least one cell comprises allocating a plurality of adjacent cells within the frequency and time map based on the threshold value exceeding the determined signal strength of the plurality of adjacent cells.

28. A method of utilizing a wireless communication spectrum, comprising:

allocating a plurality of frequency and time cells associated with the wireless communication spectrum, wherein each of the plurality of frequency and time cells are scalable in time and frequency;

measuring wireless signal strength within each of the plurality of frequency and time cells using wavelet analysis;

determining one or more of the plurality of frequency and time cells based on the measured wireless signal strength; and

transmitting one or more wavelet signals within the determined one or more of the plurality of frequency and time cells.

29. The method according to claim 28, wherein each of the plurality of frequency and time cells comprises a wireless channel within the wireless communication spectrum.

30. The method according to claim 28, wherein the signal strength detection comprises:

monitoring each of the plurality of frequency and time cells for a received wireless signal;

determining a plurality of wavelet coefficients corresponding to the received wireless signal;

determining an average energy based on the determined plurality of wavelet coefficients; and

determining one or more of the plurality of frequency and time cells based on a threshold value exceeding the determined average energy.

31. The method according to claim 28, wherein the signal strength detection comprises detecting an absence of wireless signal.

32. A method of utilizing a wireless communication spectrum, comprising:

scanning a frequency and time map having a plurality of cells for detecting at least one wireless signal, wherein each of the plurality of cells is scalable in time and frequency; and

generating a wavelet signal for wireless transmission within any one of the plurality of cells if;

the at least one wireless signal is undetected within the any one of the plurality;

or

using wavelet analysis the detected at least one wireless signal within the any one of the plurality of cells comprises a signal strength below a threshold value.

33. The method according to claim 32, wherein scanning the plurality of cells comprises:

scanning at least one first frequency and time cell including a first bandwidth and first time interval; and

scanning at least one second frequency and time cell including a second bandwidth and second time interval, wherein the second time interval is a multiple of the first time interval and the second bandwidth is fraction of the first bandwidth.

34. The method according to claim 32, wherein each of the at least one first and second frequency and time cell comprises a channel within the wireless communication spectrum.

35. The method according to claim 32, wherein the using of wavelet analysis to detect at least one wireless signal comprising a signal strength below a threshold value comprises:

determining a plurality of wavelet coefficients corresponding to the detected at least one wireless signal; and

determining the signal strength by calculating an average energy based on the determined plurality of wavelet coefficients.

36. The method according to claim 35, wherein the average energy is calculated by averaging a squared modulus for each of the determined plurality of wavelet coefficients.

37. A wireless communication system comprising:

a wavelet analyzer operable to analyze wireless signals within a frequency and time map of a communications spectrum, the wavelet analyzer adapted to determine one or more available cells within the frequency and time map; and

a wavelet signal generator for generating daughter wavelets from a selected mother wavelet, wherein the wavelet signal generator generates one or more daughter wavelets for transmitting data information within the determined one or more available cells.

38. The system according to claim 37, further comprising a memory operable to store mother wavelets associated with each cell within the frequency and time map.