Signaling Transmission for OFDM-TDD Open Loop AM

An orthogonal frequency division multiplexing-time division duplex (OFDM-TDD) open-loop adaptive modulation (AM) system is proposed. In this system signaling symbols modulated with binary phase shift keying (BPSK) are put on the best sub-carriers in adaptive blocks. In the receiver, signaling can be recovered after the sub-carriers carrying signaling are detected utilizing the specialty of BPSK. Theoretical analysis and simulation results indicate that, the proposed method can enhance reliability of signaling transmission greatly and improve system throughput.