Method and apparatus of algorithm for coherent receivers with M-QAM modulation format

摘要

An improved Eighth-Order Statistics (EOS) blind phase recovery method is proposed for high-order coherent modulation formats. The method combining EOS blind phase estimate with maximum-likelihood (ML) carrier phase estimate uses multi-stage feed-forward carrier phase recovery algorithm. Experimental results show that the proposed new algorithm can reduce the required computational effort by more than a factor of 3 for 16-QAM system.

主权项

1. A method for carrier phase recovery of a carrier wave, the method comprising:
receiving a carrier wave that was modulated at a signaling rate with a plurality of digital signals; generating a first estimate of the carrier wave's phase angle using eighth-order statistics (EOS) comprising
dividing the digital signal into M number of blocks, wherein M does not exceed 10,performing signal decimation on each of the M number of blocks by lowering the symbol sequences by an integer factor N to form a new signal sequence in each of the M number of blocks,performing EOS blind phase recovery estimation on each of the new signal sequences; and generating a second estimate of the carrier wave's phase angle comprising performing a maximum likelihood estimate based at least in part on the first estimate.