High performance coherent demodulator for wireless ATM systems-offset-QPSK simultaneous carrier and bit-timing recovery scheme

This paper proposes a novel OQPSK coherent demodulator suitable for wireless ATM systems. The evaluation results show that the proposed demodulator achieves a bit error rate performance close to the theoretical performance over an AWGN channel with a preamble of less than ten symbols. Moreover, the proposed demodulator surpasses differential detection (evaluated for QPSK with a hard-wired clock) over Rician fading channels typical of wireless ATM (WATM) systems with directional antennas or LOS paths achieving agile synchronization. The proposed demodulator is a strong candidate for receivers of wireless ATM systems.