IP Library Granted Patent US 8,036,199
Granted Patent B2
US 8,036,199 · App. 12/748,781 · Granted Oct 11, 2011

OFDMA with adaptive subcarrier-cluster configuration and selective loading

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,036,199
App. No.
12/748,781
Granted
Oct 11, 2011
Kind
B2
Abstract

A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.

Claims (52)

1. A method for estimating interference using received pilot symbols, said method comprising:

receiving, at a subscriber station, pilot symbols from at least two base stations;

estimating, at said subscriber station, a channel response based, at least on, said received pilot symbols; and

estimating, at said subscriber station, a first interference level in a data period using said estimated channel response.

2. The method of claim 1 further comprising:

calculating a second interference level in a pilot period based, at least on, said received pilot symbols;

determining an order for two or more clusters of subcarriers using at least said first interference level and said second interference level; and

selecting at least one cluster based, at least, on said determined order and one or more predetermined performance criteria.

3. The method of claim 2 further comprising:

predicting an available data rate for said ordered clusters.

4. The method of claim 3 wherein said predicting comprises:

obtaining said data rate information from a table, wherein said table stores a desired transmission rate associated with an interference level.

5. A method for determining subcarrier energy levels based on received pilot symbols, said method comprising:

receiving pilot symbols from at least two base stations;

determining a first energy level of one or more clusters of subcarriers by performing energy detection for said one or more clusters based, at least, on said received pilot symbols;

determining a second energy level of said one or more clusters of subcarriers by performing energy detection for said one or more clusters during a data period; and calculating an energy difference between the first energy level and the second energy level.

6. The method of claim 5 further comprising:

determining an order for two or more clusters using at least said calculated energy difference between the first and second energy levels; and

selecting at least one cluster based, at least, on said determined order and one or more predetermined performance criteria.

7. The method of claim 5 wherein calculating said energy difference between the first and second energy levels comprises:

comparing the signal power of a cluster based on said received pilot symbols with the signal power of the cluster during the data period.

8. The method of claim 5 wherein calculating said difference in the first and second energy levels comprises:

comparing the energy of one or more observed samples based on said received pilot symbols with the energy of said one or more observed samples during the data period, wherein said comparing is performed for subcarriers in said one or more clusters; and

summing the comparison results for each subcarrier.

9. A subscriber station comprising:

a processor for determining a first energy level of one or more clusters of subcarriers by performing energy detection for the one or more clusters based on received pilot symbols from at least two base stations;

determining a second energy level of said one or more clusters by performing energy detection for said one or more clusters during a data period; and

calculating a difference in the first energy level and the second energy level.

10. The subscriber station of claim 9 wherein said processor:

further determines an order for two or more clusters using at least said calculated energy difference between the first and second energy levels; and

wherein said processor selects at least one cluster based, at least, on said determined order and one or more predetermined performance criteria.

11. The subscriber station of claim 9 wherein said processor compares the signal power of a cluster based on said received pilot symbols with the signal power of the cluster during the data period.

12. The subscriber station of claim 9 wherein said processor compares the energy of one or more observed samples based on said received pilot symbols with the energy of said one or more observed samples during the data period, wherein said comparing is performed for subcarriers in said one or more clusters; and

sums the comparison results for each subcarrier.

13. A subscriber station comprising:

a processor estimating a channel response based, at least on, received pilot symbols from at least two base stations; and

estimating a first interference level in a data period using said estimated channel response.

14. The subscriber station of claim 13 wherein said processor:

calculates a second interference level in a pilot period based, at least on, said received pilot symbols;

determines an order for two or more clusters using at least said first interference level and said second interference level; and

selects at least one cluster based, at least, on said determined order and one or more predetermined performance criteria.

15. The subscriber station of claim 14 wherein said processor:

predicts an available data rate for said ordered clusters.

16. The subscriber station of claim 15 wherein said processor obtains said data rate information from a table, wherein said table stores a desired transmission rate associated with an interference level.

17. A subscriber station comprising:

a processor determining a first energy level of one or more clusters of subcarriers by performing energy detection for the one or more clusters based on received pilot symbols from at least two base stations; determining a second energy level of said one or more clusters by performing energy detection for said one or more clusters during a data period; and

calculating a difference in the first energy level and the second energy level.

18. The subscriber station of claim 17 further comprising wherein said processor further:

determines an order for two or more clusters using at least said calculated energy difference between the first and second energy levels; and wherein said processor selects at least one cluster based, at least, on said determined order and one or more predetermined performance criteria.

19. The subscriber station of claim 17 wherein said processor compares the signal power of a cluster based on said received pilot symbols with the signal power of the cluster during the data period.

20. The subscriber station of claim 17 wherein said processor compares the energy of one or more observed samples based on said received pilot symbols with the energy of said one or more observed samples during the data period, wherein said comparing is performed for subcarriers in said one or more clusters; and

sums the comparison results for each subcarrier.

Assignments (9)
RELEASE OF SECURITY INTEREST Recorded Jan 12, 2012
From: BAKER COMMUNICATIONS FUND II, L.P.; BAKER COMMUNICATIONS FUND II (QP), L.P.
To: ADAPTIX, INC.
Reel/Frame 027531/0093 →
SECURITY AGREEMENT Recorded Oct 13, 2011
From: ADAPTIX, INC.
To: BAKER COMMUNICATIONS FUND II, L.P.; BAKER COMMUNICATIONS FUND II (QP), L.P.
Reel/Frame 027060/0222 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 12, 2011
From: LI, KEMIN
To: BROADSTORM TELECOMMUNICATIONS, INC.
Reel/Frame 026116/0981 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2010
From: J & K SERVICES L.L.C.
To: SDR HOLDINGS, L.L.C.
Reel/Frame 024296/0098 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2010
From: SDR HOLDINGS, LLC
To: KAON SYSTEMS, INC.
Reel/Frame 024296/0346 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2010
From: SDR HOLDINGS, L.L.C.
To: KAON SYSTEMS, INC.
Reel/Frame 024296/0489 →
CHANGE OF NAME Recorded Apr 27, 2010
From: KAON SYSTEMS, INC.
To: ADAPTIX INC., A DELAWARE CORPORATION
Reel/Frame 024296/0594 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2010
From: LI, XIAODONG; LIU, HUI; ZHANG, WENZHONG
To: BROADSTORM TELECOMMUNICATIONS, INC.
Reel/Frame 024295/0995 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2010
From: BROADSTORM TELECOMMUNICATIONS, INC.
To: J & K SERVICES L.L.C.
Reel/Frame 024296/0051 →