Patent ID: 7839830

Claim:
A method comprising the steps of: constraining total power received from cellular users accessing a base station through any one of a TDMA access, CDMA access, and a derivation of a TDMA/CDMA access, and scheduling users for access to the base station within the constrained total power in response to an optimization that for each time slot determines a group of time critical cellular users and their transmission power factoring in instantaneous location-dependent channel states and long term quality of service performance, wherein the optimization includes the following steps: i) ∀i (backlogged users), letting l i ⁡ ( t ) = l i RoT ⁡ ( t ) ≡ ( 1 - L * ⁡ ( t ) ) ⁢ ( 1 + f ) ⁢ G dv ⁢ G a ⁢ p _ i max ⁢ h i ⁡ ( t ) N 0 ⁢ W ; ii) sorting i's into a list U with decreasing u i RoT ⁡ ( t ) = w i ⁡ ( t ) B i ⁡ ( t ) a ⁢ W ⁢ ⁢ log 2 ⁡ ( 1 + 1 G dv ⁢ G a ⁢ l i RoT ⁡ ( t ) ( 1 + f ) - ( 1 + f - ϕ ) ⁢ l i RoT ⁡ ( t ) ) ; iii) moving the first user i from U into I(t), calculating i's (interference-free) SINR s i (t,I) (see below for the equation) and utility increment u i (t,I) (see below); iv) removing the next user k from U and letting I′(t)=I(t)+{k}, then proceeding to check whether I′(t) offers better utility than I(t) below under RoT and s i min (∀iεI′(t)) constraints; v) calculating I′(t)-defined SINR as follows: s i ⁡ ( t , I ′ ) = p _ i max ⁢ h i ⁡ ( t ) N 0 ⁢ W + ( 1 + f ) ⁢ G d ⁢ ⁢ v ⁢ G a ⁢ ∑ k ∈ I ′ ⁡ ( t ) , k ≠ i ⁢ ⁢ p _ k max ⁢ h k ⁡ ( t ) + ϕ ⁢ ⁢ G d ⁢ ⁢ v ⁢ G a ⁢ p _ i max ⁢ h i ⁡ ( t ) , ∀ i ∈ I ′ ⁡ ( t ) ; vi) checking if ∃iεI′(t), s i (t, I′)<s i min , and if yes, going back to the previous step, otherwise proceeding to the next step; vii) ∀iεI′(t), calculating I′(t)-defined per-user load and utility increment as follows l i ⁡ ( t , I ′ ) = ⁢ ( 1 + f ) ⁢ G d ⁢ ⁢ v ⁢ G a ⁢ s i ⁡ ( t , I ′ ) 1 + ( 1 + f - ϕ ) ⁢ G d ⁢ ⁢ v ⁢ G a ⁢ s i ⁡ ( t , I ′ ) , ⁢ u i ⁡ ( t , I ′ ) = ⁢ w i ⁡ ( t ) B i ⁡ ( t ) α ⁢ W ⁢ ⁢ log 2 ( 1 + s i ( t , I ) ) ; viii) calculating L ⁡ ( t ) = 1 - 1 ( 1 + δ ) ⁢ Z t ⁢ ⁢ h - ∑ ∀ i ∈ I ′ ⁡ ( t ) ⁢ ⁢ l i ⁡ ( t , I ′ ) ; If L(t)<0 or ∑ ∀ i ∈ I ′ ⁡ ( t ) ⁢ ⁢ u i ⁡ ( t , I ′ ) < ∑ ∀ i ∈ I ⁡ ( t ) ⁢ u i ⁡ ( t , I ) , and if U≠NULL, then going back to step iv); ix) adding k to I(t): I(t)=I′(t), L*(t)=L(t); If U=NULL, stop with scheduling decision as {p i (t)= p i max 1 (iεI(t)) , ∀iεK}; otherwise, going back to Step iv).