A phase estimation algorithm based on quasi-QPSK circle-splitting

Abstract

The synchronous carrier is extracted from the received signal, the bit synchronous clock is extracted from the signal code, and the carrier is extracted from the 2DPSK signal by the square loop circuit. In coherent optical communication system, laser phase noise signal in the complex plane rotation, so need to signal at the receiving end is used to estimate the carrier phase and recovery: this paper mainly a comparative study on characteristics of the current carrier phase estimation algorithm, this paper introduces the two classical algorithms Viterbi&Viterbi algorithm and blind search (BPS) algorithm, the basic principle of phase summarizes six kinds of two class league phase noise estimation algorithm. The hardware complexity and line-width tolerance of eight carrier phase estimation algorithms are compared, and the performance of these eight carrier phase estimation algorithms in 16QAM system is evaluated.The simulation results show that compared with the traditional QPSK circlet algorithm, the proposed quasi-QPSK circlet algorithm improves 85% of the line width and symbol cycle product at 1dB SNR cost when the bit error rate is 1*10-2. Combined with the multistage phase estimation algorithm, the total tolerable linewidth of the improved algorithm and the symbol periodic product reach 5.1* 10^-5, which means that the laser linewidth that can be tolerated reaches 1.63mhz for the 32Gbaud system.