US 8,712,462 B2 · Downlink scheduling in fractional frequency reuse (FFR) systems

Abstract

An apparatus and method are disclosed for determining the optimal bandwidth fractions for all the users in each frequency band in a wireless communication system to maximize the net sum of user utilities. User utilities are functions of average rates of users, where different averaging rules can be used for different users. The standard approach of computing an optimal scheduler strategy involves the solution of a convex optimization problem that has a complexity on the order of O(N3) for N flows. This approach is not feasible for online implementation having a large number of flows. The method of the present work employs an efficient computational algorithm that obtains the optimal bandwidth fractions in O(N) time. This feature makes the method suitable for implementation in wideband cellular systems like LTE (Long Term Evolution) and UMB (Ultra Mobile Broadband).

Claims25

Dependent claims

A method for performing spectral allocation for a wireless link in a wireless communication system wherein the method comprises the steps of:

dividing a bandwidth into multiple sub-bands;
determining a value of transmission power for the wireless link;
assigning one or each of the multiple sub-bands of the bandwidth to the wireless link based on the value of the transmission power of the wireless link;
and
wherein a scheduler is used to assign one or each sub-band of the multiple sub-bands of the bandwidth to a wireless link of the plurality of wireless links based on the value of the transmission power for the wireless link to provide efficient fractional frequency reuse.

2 more elements

An apparatus for performing spectral allocation for a wireless link in a wireless communication system wherein the apparatus comprises:

means for dividing a bandwidth into multiple sub-bands;
means for determining a value of transmission power for the wireless link;
means for assigning one or each of the multiple sub-bands of the bandwidth to the wireless link based on the value of the transmission power of the wireless link;
and
scheduling means to assign one or each sub-band of the multiple sub-bands of the bandwidth to a wireless link of the plurality of wireless links based on the value of the transmission power for the wireless link to provide efficient fractional frequency reuse.

2 more elements

A computer program product stored on a non-transitory computer readable medium for performing spectral allocation for a wireless link in a wireless communication system comprising:

a non transitory computer-readable medium comprising:
code for dividing a bandwidth into multiple sub-bands;
code for determining a value transmission power for the wireless link;
and
code for assigning one of the multiple sub-bands of the bandwidth to the wireless link based on the value of the transmission power of the wireless link;
and
code for a scheduler to assign one or each sub-band of the multiple sub-bands of the bandwidth to a wireless link of the plurality of wireless links based on the value of the transmission power for the wireless link to provide efficient fractional frequency reuse.

4 more elements

Dependencies are inferred from the claim text.

Downlink scheduling in fractional frequency reuse (FFR) systems

Life of this patent

Downlink scheduling in fractional frequency reuse (FFR) systems

Life of this patent

Abstract

Claims25