Patent ID: 8170031

Claim:
A method of scheduling transmission resources in a wireless communication system comprising: configuring a base station for serving a plurality of mobile devices distributed within an extended cell radius served by said base station and a set of relay stations, said relay stations communicating with said base station and said mobile devices operable for communicating with said relay stations or with said base station directly; and determining a transmission schedule for communications between said base station and said mobile devices directly or through any of said relay stations by first formulating said transmission schedule as an integer process where an objective function of maximizing the aggregate two-hop net data flow of the set of users comprises a relationship: max ⁢ ∑ k ∈ U ⁢ ⁢ a k , subject ⁢ ⁢ to : ∑ k ∈ U ⁢ x mk ≤ 1 , ∀ m ∈ C r , ∑ k ∈ U ⁢ y nk ≤ 1 , ∀ n ∈ C a , ∑ m ∈ C r ⁢ w mk r ⁢ x mk = a k , ∀ k ∈ U , ∑ n ∈ C a ⁢ w nk a ⁢ y nk = a k , ∀ k ∈ U , a k ≤ β k ⁢ B k r _ k ⁢ T , ∀ k ∈ U , where ⁢ ⁢ x mk , y mk ∈ { 0 , 1 } ; a k ≥ 0 ; w mk r , w nk a ∈ [ 0 , 1 ] , ∀ m , n , k ; with a k being net data flow for user (or mobile device) ‘k’; x mk being indicator variable for user ‘k’ on relay channel ‘m’; y nk being indicator variable for user ‘k’ on access channel ‘n’; w mk r being weight when relay channel ‘m’ is assigned to user ‘k’ (the weight or marginal utility of a user on a channel is the ratio of its instantaneous throughput on that channel to its average throughput); w nk a being weight (marginal utility) when access channel ‘n’ is assigned to user ‘k’; C a being the set of channels on the access hop; C r : the set of channels on the relay hop; U being the set of users (or mobile devices); B k being buffer size for user ‘k’; β k being quality of service (QoS) weight for user ‘k’; r k being average throughput of user ‘k’; and T being the scheduling period (i.e., duration of OFDMA frame).