A new weighted proportional fair scheduling algorithm for SDMA/OFDMA systems

A new and efficient radio resource allocation and scheduling algorithm for SDMA/OFDMA systems with downlink zero-forcing beamforming is proposed to support the diverse quality of service (QoS) requirements of heterogeneous services. In particular, a unified urgent weight is given by taking into account QoS requirements (i.e., delay deadline, minimum data rate), queue length and user fairness. The subcarrier is dynamically allocated to the user with the highest priority. Then the remaining users on the same carrier are selected based on the semi-orthogonal user selection scheme. Finally, allocating the transmit power with a greedy method to the spatial subchannels is implemented. The goal of the algorithm is to maximize the system throughput by fully exploiting multiuser diversity gain in space, time, and frequency domain while guaranteeing the QoS for real time (NT) services with delay deadline requirement and non-real time (NRT) services with minimum data rate requirement.