Central Carrier-Assisted Phase Retrieval Scheme Based on Parallel Alternative Projections GS Algorithm

In this paper, based on parallel alternative projections Gerchberg-Saxton (GS) algorithm, we propose a central carrier-assisted phase retrieval scheme (PAP-CCA-PR). This scheme constructs a PR receiver with multiple parallel dispersive elements for the first time and implements the fusion of parallel alternative projections and central carrier-assisted techniques in the GS algorithm, which improves the convergence speed of the algorithm and reduces the system carrier-to-signal power ratio (CSPR) requirement. Compared to the existing scheme, for a 30 GBaud 16-quadrature amplitude modulation (16-QAM) signal, transmitting 80 km of standard single-mode fiber (SSMF), and meeting the 7% forward error correction (FEC) threshold condition, the CSPR and number of iterations (NOI) of PAP- CCA-PR scheme can be reduced to − dB and 4, respectively, with the guard band reduced to 2.6 GHz.