Link scheduling and power control for OFDMA uplink systems
- This thesis aims at tackling the problem of optimum joint power allocation and resource scheduling while maintaining certain QoS constraints. In particular, the uplink of an OFDMA (orthogonal frequency division multiple access) system is investigated for which a detailed model for the signal-to-interference-plus-noise (SINR) is developed. This model includes multiple access interference (MAI) due to frequency synchronization errors and Doppler shifts as well as CCI due to the reuse of radio frequency resources in neighboring cells. The developed SINR model serves as the basis for the optimization problem which makes use of a heuristic relaxation to simplify the NP hard problem of the joint power and user scheduling optimization. The chosen power controlled random access (PCRA) problem formulation incorporates the power v/s delay dilemma prevalent in wireless multiple access networks. The PCRA problem is transformed into a convex optimization problem through the technique of geometric programming. The final contribution of this thesis is the improvement of an existing link scheduling algorithm for non-perfect channel estimation information at the transmitter.
