Mid-Term frequency domain scheduler for resource allocation in wireless mobile communications systems

Abstract

This article approaches the dynamic resource allocation problem for the downlink of a wireless mobile communication system (WMCS). The article defines the architecture and functions of the global resource scheduler, as well as the quality index for scheduling, the signal to interference-plus-noise ratio (SINR). The proposed approach divides the scheduling task into two components: a distributed one, with local, short-term scope; and a centralized one, with global, medium-term scope. The optimization model considers a set of slack variables for guaranteeing feasibility. This allows the service provider to fully satisfy the users' service demands. The model type is mixed, non-linear, which demands large computational power for an exact solution. So an approximate strategy is used, in order to decouple the search space

Convergence of derivative-free nonmonotone Direct Search Methods for unconstrained and box-constrained mixed-integer optimization

“…A local solution will hopefully require the evaluation of g(x i ; z) at points in a small discrete set. In some applications the subproblem (37a) reduces to a linear model and z i is chosen with heuristics linked to the structure of the problem [39]. It is advisable to use known efficient techniques whenever possible.…”

The Channel Estimation and Modeling in High Altitude Platform Station Wireless Communication Dynamic Network

“…It can use CAZAC (Constant Amplitude Zero Autocorrelation) sequence [12][13][14][15] as training sequence for channel estimation with fast moving system environment. This sequence will ensure the independence of each transmit antenna pilot frequency which can eliminate the interference of the pilot frequency when doing the channel estimation [10,16,17]. Transmitting antenna can send pilot frequency alternately which will avoid aliasing, namely, when transmitting pilot frequency information by one antenna while other antennas remain idle.…”