SYSTEM AND METHOD FOR RESOURCE ALLOCATION OF A LTE NETWORK INTEGRATED WITH FEMTOCELLS

• US 20110183678A1
• Filed: 01/28/2010
• Published: 07/28/2011
• Est. Priority Date: 01/28/2010
• Status: Active Grant

• Current Assignee: Nytell Software LLC (Intellectual Ventures LLC)
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Kerpez, Kenneth J., Lan, Tian, Sinkar, Kaustubh, Kant, Latha
• Granted Patent: US 8,509,166 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04W 24/06 Testing, supervising or monitoring using simulated traffic
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

A resource scheduling and power allocation technique is provided for a LTE radio network integrated with femtocells. The technique utilizes a tri-phase approach that includes a stochastic geometric model of an exemplary radio network that generates a channel attenuation matrix for each channel at each PRB. A resource scheduling and power allocation procedure determines a near optimal assignment of mobile user to PRBs based on the channel attenuations, potential data rates, and transmit power subject to maximizing the data rates in accordance with a fairness objective. A discrete-event simulation procedure simulates the end-to-end transmission of the data packets in a packet-switch network in accordance with the assignments to analyze the behavior of the overall network.

Claims

1. A method for allocating resources in a radio network, comprising the steps of:

providing a radio network model of the radio network based on the LTE specifications, the radio network model having a plurality of PRBs, each PRB comprising a plurality of time units, t, and a plurality of subcarriers f, PRB (t, f), a plurality of mobile users i, a plurality of base stations b_i, and a plurality of channels (b_i, i);

determining channel attenuations, H(b_i, i t, f) for all i, t, f; and

assigning each mobile user i, a PRB so that a data rate of mobile user i is maximized in accordance with a fairness objective, the data rate of mobile user i being a function of channel attenuations and a transmit power associated with the mobile user i.

2. The method of claim 1, further comprising the step of:

simulating transmission of data from a first mobile user to a second mobile user using the radio network model with the assigned PRBs in a packet-switched network.

3. The method of claim 1, wherein the assigning step further comprises the steps of:

using a water-filling technique to determine a water level for each mobile user i as a function of channel attenuations and transmit power;

calculating a set of data rates for each mobile user i and for each PRB as a function of the water levels; and

assigning each mobile user i, a select PRB subject to maximizing the data rates over all mobile users and subject to maximizing the fairness objective.

4. The method of claim 1, wherein the fairness objective is a α

-fair utility function.

5. The method of claim 1, wherein a subset of the base stations are femtocells.

6. A computer program product having a computer readable storage medium comprising:

a radio air interface model including a plurality of mobile users, a plurality of base stations, a subset of base stations including femtocells, a plurality of resource units, each resource unit having a plurality of time slots and subcarrier frequencies, and a plurality of channels;

a radio air interface model procedure to generate the radio air interface model based on LTE specifications; and

a resource scheduling and power allocation procedure that generates resource unit assignments, each resource unit assignment assigns each mobile user to a resource unit while maximizing data rates for each mobile user in accordance with a fairness objective.

7. The computer readable storage medium of claim 6, further comprising:

a discrete simulation procedure that simulates the transmission of data through a packet-switched network including the radio air interference model in accordance with the resource unit assignments.

8. The computer readable storage medium of claim 6, wherein the resource scheduling and power allocation procedure

determines channel attenuations for each channel and resource unit,

allocates power allocations for each mobile user as a function of the channel attenuations, a power budget for the mobile user and without assigning a mobile user to a resource unit,

computes data rates for each mobile user as a function of the power allocations, and

assigns each mobile user a resource unit in accordance with maximizing a fairness objective.

9. The computer readable storage medium of claim 6 wherein the fairness objective is a α

-fair utility function.

10. The computer readable storage medium of claim 6 wherein the resource unit is a PRB.

11. A system for allocating resources in a radio network, comprising:

a plurality of mobile users, each mobile user associated with a transmit power constraints and a power budget maximum;

a plurality of channels, each channel associated with a base station and a mobile user;

a plurality of resource units, each resource unit comprising a set of time units and subcarriers;

a power allocation mechanism to determine a maximum data rate for each mobile user as a function channel attenuations associated with each channel for each resource unit, transmit power constraints, and independent of assignments of a mobile user to a select PRB; and

a resource scheduling mechanism to determine an assignment of a mobile user to a PRB, utilizing the data rates, subject to maximizing a fairness constraint overall the mobile users and subject to assigning each mobile user to a select PRB.

12. The system of claim 11, further comprising:

a simulation mechanism to simulate data packet transmissions from a first mobile user to a second mobile user in a packet-switch network in accordance with the assignments, wherein the first mobile user transmits through a femtocell base station and the second mobile user transmits through an LTE-based base station.

13. The system of claim 11, wherein the fairness objective is a α

-fair utility function.

14. The system of claim 11, wherein the resource unit is a PRB.