Method and apparatus to support scalability in a multicarrier network

• US 20070258525A1
• Filed: 05/05/2006
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: Guangdong OPPO Mobile Telecommunications Corporation Limited
• Original Assignee: Intel Corporation
• Inventors: Jacobsen, Eric, Foerster, Jeff, Dahle, Dan
• Granted Patent: US 8,023,574 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

A multicarrier communication device can vary the number of subcarriers being used to carry on multicarrier communication within a network, based on a predetermined criterion (e.g., traffic load, etc.).

Claims

1. An apparatus comprising:

a discrete Fourier transform (DFT) engine to perform a DFT on orthogonal frequency division multiplexing (OFDM) symbols received from a communication medium, said DFT engine having a variable DFT size; and

a controller to;

(a) vary a number of subcarriers (N) being used by said apparatus to communicate with other devices, based on a predetermined criterion, and (b) cause said DFT size of said DFT engine to change in accordance with said number of subcarriers.

2. The apparatus of claim 1, wherein:

said predetermined criterion includes a communication traffic load level within a corresponding network.

3. The apparatus of claim 2, wherein:

said communication traffic load level is a load level within a cell of a cellular wireless communication network.

4. The apparatus of claim 1, wherein:

said controller includes logic to check for bandwidth availability when a decision to increase said number of subcarriers has been made.

5. The apparatus of claim 4, wherein:

said logic to check for bandwidth availability includes logic to determine whether a license has been acquired to use spectrum associated with said increased number of subcarriers, when a license is required.

6. The apparatus of claim 1, wherein:

said apparatus has a core set of subcarriers that are always used regardless of variations made by said controller in said number of subcarriers, wherein said core set of subcarriers includes at least one control subcarrier to carry MAP data.

7. The apparatus of claim 6, wherein:

said controller defines at least one new control subcarrier to carry MAP data when said controller increases said number of subcarriers above a predetermined quantity.

8. The apparatus of claim 1, wherein:

said controller includes logic to collect capability information about said other devices and logic to use said capability information to determine whether to change the number of subcarriers used by said apparatus.

9. The apparatus of claim 8, wherein:

said capability information identifies which subcarriers each of said other devices are capable of using.

10. The apparatus of claim 8, wherein:

said controller includes logic to use said capability information to allocate subcarriers to said other devices.

11. The apparatus of claim 1, further comprising:

a demodulator/demapper to demodulate symbols associated with subcarriers of received OFDM symbols and to demap resulting data, wherein said controller is to cause said demodulator/demapper to be reconfigured when said number of subcarriers is changed.

12. The apparatus of claim 1, further comprising:

an inverse discrete Fourier transform (IDFT) engine to perform an IDFT on modulated subcarriers to generate an OFDM symbol for transmission, said IDFT engine having a variable IDFT size, wherein said controller causes the IDFT size of said IDFT engine to be the same as the DFT size of said DFT engine.

13. The apparatus of claim 12, further comprising:

a mapper/modulator to map input data bits to data symbols associated with subcarriers of an OFDM symbol to be generated and to modulate said subcarriers using said data symbols, wherein said controller is to cause said mapper/modulator to be reconfigured when said number of subcarriers is changed.

14. A method comprising:

estimating a network parameter; and

determining whether to change a number of subcarriers (N) being used by a multicarrier device based, at least in part, on said estimated network parameter.

15. The method of claim 14, wherein:

said multicarrier device is a wireless base station providing network access services within a cell of a network; and

said network parameter is a communication traffic load within said cell.

16. The method of claim 14, wherein:

determining whether to change a number of subcarriers being used includes deciding to increase said number of subcarriers when an estimated communication traffic load is greater than a predetermined level.

17. The method of claim 14, wherein:

determining whether to change a number of subcarriers being used includes deciding to decrease said number of subcarriers when an estimated communication traffic load is less than a predetermined level.

18. The method of claim 14, further comprising:

changing a discrete Fourier transform (DFT) size of a DFT engine within said multicarrier device when said number of subcarriers is changed.

19. The method of claim 18, further comprising:

changing an inverse discrete Fourier transform (IDFT) size of an IDFT engine within said multicarrier device when said number of subcarriers is changed.

20. The method of claim 14, further comprising:

reconfiguring a mapper/modulator within said multicarrier device when said number of subcarriers is changed.

21. The method of claim 20, further comprising:

reconfiguring a demodulator/demapper within said multicarrier device when said number of subcarriers is changed.

22. The method of claim 14, further comprising:

when a decision to increase said number of subcarriers is made, checking for bandwidth availability before increasing said number of subcarriers.

23. The method of claim 22, wherein:

checking for bandwidth availability includes determining whether any FCC licensing requirements associated with increasing said number of subcarriers have not been met.

24. The method of claim 14, further comprising:

collecting capability information for user devices communicating with said multicarrier device, wherein determining whether to change a number of subcarriers includes using said capability information in addition to said estimated network parameter to determine whether to change said number of subcarriers.

25. A system comprising:

a dipole antenna to receive orthogonal frequency division multiplexing (OFDM) symbols from a wireless communication medium;

a discrete Fourier transform (DFT) engine to perform a DFT on OFDM symbols received by said dipole antenna, said DFT engine having a variable DFT size; and

a controller to;

(a) vary a number of subcarriers (N) being used by said system to communicate with other devices, based on a predetermined criterion, and (b) cause said DFT size of said DFT engine to change in accordance with said number of subcarriers.

26. The system of claim 25, wherein:

said predetermined criterion includes a communication traffic load level within a corresponding network.

27. The system of claim 26, wherein:

said communication traffic load level is a load level within a cell of a cellular wireless communication network.

28. An article comprising a storage medium having instructions stored thereon that, when executed by a computing platform, operate to:

estimate a network parameter; and

determine whether to change a number of subcarriers (N) being used by a multicarrier device based, at least in part, on said estimated network parameter.

29. The article of claim 28, wherein:

said multicarrier device is a wireless base station providing network access services within a cell of a network; and

said network parameter is a communication traffic load within said cell.

30. The article of claim 28, wherein said instructions further operate to:

change a discrete Fourier transform (DFT) size of a DFT engine within said multicarrier device when said number of subcarriers is changed.