Quadrature OFDMA systems based on layered FFT structure
IEEE Transactions on Communications
Chunk-based resource allocation in OFDMA systems: part I: chunk allocation
IEEE Transactions on Communications
BER-based chunk allocation in multiuser OFDM wireless systems
GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
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This paper studies traffic channel design tradeoffs for downlink orthogonal frequency division multiple access (OFDMA) systems. For fixed and portable users where the propagation channels are quasistatic, we show that the aggregated rate can be maximized by exploiting "multiuser diversity" through intelligent channel allocation. In this case, the traffic channel should be configured so that its corresponding achievable data rate has the highest variance among users. The capacity upper and lower bounds are derived to quantify the impact of different traffic channel configurations. For mobile services where multiuser diversity cannot be efficiently exploited due to the signaling overhead, we show that the system outage capacity is maximized when the traffic channels are configured with maximum frequency diversity. Using the results presented, designers of OFDMA system can determine the optimum traffic channel configuration based on the types of services supported by the network.