Throughput Enhancement for IEEE 802.11a Wireless LANs

Orthogonal Frequency Division Multiplexing (OFDM) in combination with bit-interleaved coded modulation (BICM) is efficient and robust high-speed transmission technique used in IEEE 802.11a standard. In this paper, using Request To Send (RTS)/ Clear To Send (CTS) mechanism, we present a method to improve throughput performance by adaptively changing constellation size and power distribution across the sub-carriers without sacrificing throughput due to explicit feedback. Based on the theoretical analysis, this complex maximization problem can be approximately solved by a simple iterative algorithm. Simulation results show that the proposed method can significantly improves throughput performance and the performance gain is robust to channel estimation and synchronization error.