Patent ID: 6597705
Filing Date: 2003-07-22
Classification: H04W

Abstract:
In a communication system having at least first and second base stations, the base stations having communication resources for exchanging communication signals with at least first and second user stations, respectively, a method for allocating the resources in the communication system, comprising:at each of the first and second user stations, transmitting a request for an allocation of resources for transmitting a type of data by the user station; at the first and second base stations, receiving the requests from the first and second user stations, respectively, and other user stations, and allocating resources at the first and second base stations in response to the requests, wherein the first base station optimizes the allocation of resources independently of the allocation of resources of the second base station and minimizes interference in accordance with system stability and throughput with the second base station, while the second base station optimizes the allocation of resources independently of the allocation of resources of the first base station and minimizes interference with the first base station in accordance with system stability and throughput; at the first and second base stations, transmitting first and second assignment signals to the first and second user stations, respectively, wherein each assignment signal specifies a transmission rate; and at the first and second user stations, transmitting the type of data at a rate specified in the first and second assignment signals, respectively; wherein the allocation of resources includes optimizing transmission powers for N number of user stations for the first base station by optimizing: maxP&it;&Sum;Ni=1&it;hi&it;Pi,subject to:AminP&gE;(Ioc+N0)W1AmaxP&lE;(Ioc+N0)W1Pi&lE;Pmaxi, i=1, . . . , N, and where 1 is a vector of all ones of size N, IocW is the interference that the base station receives from other base stations, W is a bandwidth of the communication system, No is an Additive White Gaussian Noise (AWGN) density, hi is a channel gain from an ith user station to the base station, Amin and Amax are NÃ—N matrices defined by: Am&it;â€ƒ&it;i&it;â€ƒ&it;n=[W&it;â€ƒ&it;h1Rm&it;â€ƒ&it;i&it;â€ƒ&it;n1&it;Î³1-h2&ctdot;-hN-h1W&it;â€ƒ&it;h2Rm&it;â€ƒ&it;i&it;â€ƒ&it;n2&it;Î³2&ctdot;-hN&vellip;&vellip;&vellip;&vellip;-h1-h2&ctdot;W&it;â€ƒ&it;hNRm&it;â€ƒ&it;i&it;â€ƒ&it;nN&it;Î³N],Am&it;â€ƒ&it;ax=[W&it;â€ƒ&it;h1Rm&it;â€ƒ&it;ax1&it;Î³1-h2&ctdot;-hN-h1W&it;â€ƒ&it;h2Rm&it;â€ƒ&it;ax2&it;Î³2&ctdot;-hN&vellip;&vellip;&vellip;&vellip;-h1-h2&ctdot;W&it;â€ƒ&it;hNRm&it;â€ƒ&it;axN&it;Î³N]where (Eb/I0)i=&ggr;i, i=1, . . . , N, Rmini&lE;Ri&lE;Rmaxi, i=1, . . . , N, and Pi&lE;Pmaxi, i=1, . . . , N.