Adaptive frequency reuse method of radio resources management and allocation

• US 8,068,459 B2
• Filed: 03/31/2009
• Issued: 11/29/2011
• Est. Priority Date: 03/31/2009
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yang, Hua, Lomnitz, Yuval, Li, Li, Kravtsov, Vladimir, Chen, Clark, Sun, Homgmei, Himayat, Nageen, Talwar, Shilpa
• Primary Examiner(s): Chang; Kent
• Assistant Examiner(s): FANG, PAKEE
• Application Number:
  US12/415,957
• Publication Number:
  US 20100246538A1
• Time in Patent Office: 973 Days
• Field of Search: 370336-337, 370329-331, 370319-326, 370/314, 370343-345, 455/450, 455/464, 455/446, 455/447, 455/453
• US Class Current: 370/329
• CPC Class Codes: H04W 28/0861 between base stations
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

A method for managing and allocating radio resources (RRMA method) of multiple radio resource types to subscriber stations is disclosed. The RRMA method includes bandwidth partitioning, into parts comprising “slots” with a given reuse pattern, a selection rule, to select a “cell, reuse pattern” pair serving each user, and an allocation rule, for distributing to each user an appropriate number of bandwidth slots from the selected “cell, reuse pattern” pair. After an adaptation period, the method reaches a desired fairness, while simultaneously reaching a maximal mean throughput, possible under this fairness. For big networks, the method provides basically decentralized radio resource management. The RRMA method is useful to cellular networks having a single set of orthogonal sub-channels (frequency/time slots) being reused by all network cells, such as time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), or OFDMA/TDMA cellular systems. Particularly, the method is applicable in fractional frequency reuse cellular networks.

Claims

1. A method comprising:

generating a weight list vector comprising a plurality of weights, each weight being associated with a distinct radio resource type in a cellular network, each radio resource type comprising a pair consisting of a base station and a reuse pattern of a slot, the slot being an equally divided portion of a frame used to transmit data over sub-channels in the cellular network, the reuse pattern being a vector comprising the transmit powers of all base stations in the slot;

broadcasting the weight list vector to a plurality of users in the cellular network;

receiving a radio resource type from a user, wherein the radio resource type is selected according to a predefined selection rule;

allocating a radio resource to a user in the cellular network such that the instant throughput to the user is proportional to its instant fair relative throughput over all users selecting the same radio resource type.

2. The method of claim 1, receiving the radio resource type according to the predefined selection rule further comprising:

receiving the radio resource type selected by the user as one having a maximum ratio of spectral efficiency to weight, wherein the ratio is a normalized spectral efficiency.

3. The method of claim 1, receiving the radio resource type according to the predefined selection rule further comprising:

receiving a sub-channel index selected by the user as one having a sub-channel with a maximum normalized spectral efficiency.

4. The method of claim 1, further comprising:

updating the weight list vector such that the following are true;

the load factors of radio resource types converge to be even; and

the total weight of the radio resources of the entire cellular network is not changed.

5. The method of claim 2, further comprising:

assigning an instant fair relative throughput to currently active users of the cellular network, wherein the assignment is based on the following;

a last reported normalized spectral efficiency of a user;

a cumulative distribution function of normalized spectral efficiency over all users connected to the network; and

a desired fairness of the throughput distribution to the users.

6. The method of claim 5, further comprising:

allocating to each currently active user a number of radio resource units, the number of radio resource units to provide instant throughput to the allocated user, wherein the allocation is based on the following;

a last reported spectral efficiency of all active users;

the proportionality of a user'"'"'s allocated instant throughput to its assigned instant fair relative throughput, inside a set of all active users which have last reported a given resource type; and

an allocation of each radio resource unit to some active user, wherein a last reported resource type is equal to the radio resource type of the allocated unit.

7. The method of claim 6, further comprising:

computing an aggregate fair relative throughput and an aggregate throughput of each radio resource type in each weight list update cycle, wherein the aggregate fair relative throughput comprises a sum of instant fair relative throughputs to all users selecting the resource type, during this update cycle, divided by the number of frames forming the cycle, and the aggregate throughput comprises a sum of instant throughputs to all users selecting the resource type, during this update cycle, divided by the number of frames forming the cycle.

8. The method of claim 7, further comprising:

computing a load factor of each radio resource type, wherein the load factor is a ratio of the aggregate fair relative throughput of the radio resource type to the aggregate throughput of the radio resource type.

9. The method of claim 8, further comprising:

computing a base station load factor, wherein the base station load factor is the mean value of load factors of all radio resource types local to this base station; and

transmitting the base station load factor and a local weight list vector to a resource management unit over a backhaul of the cellular network.

10. The method of claim 5, further comprising:

computing a local cumulative distribution function of normalized spectral efficiency;

reporting the cumulative distribution function to a resource management unit; and

receiving a united cumulative function of normalized spectral efficiency from the resource management unit;

wherein the resource management unit unites local cumulative distribution functions and broadcasts the united cumulative distribution function to all base stations in the cellular network.

11. The method of claim 10, further comprising:

receiving a base station weight from the resource management unit, wherein the computation of the base station weight is based on base station load factors received from a plurality of base stations in the cellular network.

12. The method of claim 4, further comprising:

updating a local weight list vector in such a way that the following are true;

the load factors of local radio resource types converge to be even;

but

the overall weight of the local radio resources divided by the frame size is equal to the last received value of the base station weight, wherein the last received value is received from a resource management unit.

13. The method of claim 9, further comprising:

computing a weight of each frame partition by the resource management unit, wherein the partition weight is equal to a mean value, of weights of radio resource types being a pair of any base station and this frame partition, wherein the computation is based on the reported local weight list vectors from all base stations in the cellular network.

14. The method of claim 13, further comprising:

computing a new partition vector by the resource management unit, the computation being based on computed weights of frame partitions in which the following are true;

the weights of frame partitions converge to be even;

but

the sum of all partitions is equal to the frame size.

15. The method of claim 11, further comprising:

receiving a new partition vector from the resource management unit over the backhaul of the cellular network.