QPSK carrier and bit-timing simultaneous recovery scheme for coherent demodulation

This paper proposes a new carrier and bit-timing simultaneous recovery scheme, which works with quadrature phase shift keying (QPSK) signals. The proposed scheme uses popular preamble words for simultaneous carrier recovery and bit-timing recovery. Simulation results demonstrate that the proposed scheme greatly reduces the required preamble length to about 20 symbols in low Eb/No channels and fading channels. The proposed scheme is very beneficial for time division multiple access (TDMA) systems that works with QPSK signals.