OFDMA with adaptive subcarrier-cluster configuration and selective loading

• US 7,715,358 B2
• Filed: 10/31/2007
• Issued: 05/11/2010
• Est. Priority Date: 12/15/2000
• Status: Expired due to Fees

• Current Assignee: Adaptix, Inc. (Acacia Research Corporation)
• Original Assignee: Adaptix, Inc. (Acacia Research Corporation)
• Inventors: Li, Xiaodong, Liu, Hui, Zhang, Wenzhong, Li, Kemin
• Primary Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US11/931,926
• Publication Number:
  US 20080137551A1
• Time in Patent Office: 923 Days
• Field of Search: 370242-246, 370/252, 370319-322, 370328-330, 370/338, 370/341, 370343-345, 370/431, 370/445, 370/310, 370/313, 370/332, 370/430, 370/465, 370/913, 370/500, 455/41.2, 455 61- 62, 455/63.1, 455/67.11, 455418-420, 455/422.1, 455/443, 455447-448, 455/450, 455/452.2, 455/550.1, 455/556.2, 455/561, 455423-425, 455/434, 455/501, 455/513, 455525-526, 375/144, 375147-148, 375346-348
• US Class Current: 370/344
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04J 11/003 at the transmitter transmission to multiple receive units in multiple input multiple output [MIMO] H04B7/0452; transmit antenna weighting H04B7/0615
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0005 applied to payload information
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0011 applied to payload information
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0079 Formats for control data H04L1/16 takes precedence; training sequences H04L25/00 and H04L27/00
• CPC Class Codes: H04L 1/04 using frequency diversity
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• 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 5/0035 : Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0037 : Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0042 : intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0046 : Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0048 : Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 : of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/006 : Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0064 : Rate requirement of the data, e.g. scalable bandwidth, data priority
• 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: H04L 5/0082 : at predetermined intervals
• CPC Class Codes: H04L 5/0094 : Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 5/023 : Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 24/08 : Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/04 : Wireless resource allocation
• CPC Class Codes: H04W 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/20 : Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/541 : using the level of interference
• CPC Class Codes: H04W 72/542 : using measured or perceived quality
• CPC Class Codes: H04W 74/04 : Scheduled access hybrid access H04W74/02

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

1. A method comprising:

measuring collisions between OFDMA pilot symbols broadcast from at least two base stations during a pilot period;

determining a first interference level between the at least two base stations based on the measured pilot symbol collisions;

calculating an SINR estimate based at least partially on the determined first interference level; and

wherein the method comprises a subscriber unit configured for performing the above steps.

2. The method of claim 1, comprising:

measuring, by the subscriber unit, collisions between non-pilot OFDMA traffic broadcast from at least two base stations during a traffic period; and

determining, by said subscriber unit, a second interference level between the at least two base stations based on the non-pilot collisions.

3. The method of claim 2, comprising calculating a power difference between the pilot period and the traffic period.

4. The method of claim 3, comprising selecting one or more clusters for transmission to a subscriber based on the calculated power difference.

5. The method of claim 4, wherein the selecting comprises selecting the one or more clusters based on a weighted average of the calculated power difference and the calculated SINR estimate.

6. The method of claim 5, wherein the determining comprises determining the first interference level between the at least two base stations located in neighboring cells.

7. A subscriber unit configured to communicate using OFDMA, the subscriber unit comprising:

a first processing logic configured to determine a first interference level based on collisions between pilot symbols received from at least a first base station and a second base station; and

a second processing logic configured to calculate an SINR estimate based on the first interference level,

wherein the subscriber unit is configured to transmit the calculated SINR estimate to both the first base station and the second base station.

8. The subscriber unit of claim 7, comprising third processing logic configured to determine a second interference level between the at least two base stations based on collisions between non-pilot traffic from at least the first and second base stations.

9. The subscriber unit of claim 8, wherein the subscriber unit is configured to transmit a modulation rate to both the first base station and the second base station based on the calculated SINR estimate.

10. The subscriber unit of claim 7, wherein the first processing logic is configured to determine the first interference level based on collisions between pilot symbols received from the first base station, the second base station, and a third base station.

11. The subscriber unit of claim 7, wherein the first processing logic comprises hardware logic.

12. A method comprising:

receiving first OFDMA pilot symbols broadcast from a first base station;

receiving second OFDMA pilot symbols broadcast from a second base station;

estimating a channel condition for the first base station based on the first and second OFDMA pilot symbols;

estimating a channel condition for the second base station based on the first and second OFDMA pilot symbols; and

wherein the method comprises a subscriber unit configured for performing the above steps.

13. The method of claim 12, comprising requesting communication with the first base station.