Radio Resource Management for the Multi-User Uplink Using DFT-Precoded OFDM

In this paper we investigate resource allocation for an uplink DFT-precoded OFDMA system, a subset of which is agreed on to be used in the Third Generation Partnership Project-Long Term Evolution (3GPP-LTE) uplink. Different from the well studied OFDMA resource allocation problem, each user equipment (UE) is assigned a set of sub-carriers, within which individual power allocation per sub-carrier basis is unfavorable due to the additional added complexity and possibly high peak to average power ratio of the resulting waveform. We assume a widely used linear equalizer at the receiver with multiple antennas and formulate the problem as the sub-carrier allocation problem for OFDMA with equal gain power allocation. Furthermore, we present an optimum resource allocation algorithm for the single user case and a heuristic sub- optimum algorithm for the multi-user case that can efficiently allocate resources for DFT-precoded OFDMA system.