Throughput Improvement through Precoding in OFDMA Systems with Limited Feedback

In this paper, we study the possibility of throughput improvement through precoding in OFDMA based wireless systems with limited channel feedback. Precoding can increase the overall system throughput by selecting the use of higher modulation and coding schemes (if there are any) in each physical resource unit (PRU) under a maximum bit error rate constraint. For a specific form of precoding that we proposed in, we analytically derive a formula for the maximum PRU throughput. Sufficient conditions guaranteeing that our proposed technique outperforms the conventional technique are derived. Finally, numerical results show the amount of throughput gain achieved by our proposed technique.