Communications and NetworksPublished 19 September 2025A DSP-free carrier phase recovery system using 16-offset-QAM laser forwarded links for 400 Gb/s and beyondMarziyeh Rezaei · Dan Sturm · Pengyu Zeng · Sajjad MoazeniFrontiers in Communications and Networksdoi 10.3389/frcmn.2025.1642672