Improved performance of a random OFDMA mobile communication system

In this paper we consider the uplink performance of an OFDMA (orthogonal frequency division multiple access) system for mobile communications. First, we describe the random OFDMA system which is based on MC-FDMA (multicarrier FDMA), and where each user has a set of randomly selected subchannels. We also describe the performance criteria considered for the evaluation of this system and present different system implementations depending on the level of block synchronization assumed. In the last section we describe different methods for improving the system performance, one based on different receiver configurations and another based on different sets of subchannels per user depending on the traffic load. We also show some simulation results for the performance of the system under the different assumptions