Sher Ali Cheema, Mike Wolf, Mario Huemer, Martin Haardt,
"Unique Word DMT Schemes using Real-Valued Constellations for IM/DD Optical Systems"
, in IEEE Photonics Technology Letters, Vol. 30, Nummer 10, IEEE, Seite(n) 935-938, 5-2018, ISSN: 1041-1135
Unique Word DMT Schemes using Real-Valued Constellations for IM/DD Optical Systems
Sprache des Titels:
Discrete multitone transmission (DMT) schemes employing real-valued constellations such as PAM (PAM-DMT) are popular multi-carrier transmission schemes for optical systems using intensity modulation and direct detection. PAM-DMT employs a data dependent cyclic prefix (CP) to
maintain cyclicity. In this letter, we propose a novel DMT scheme using real-valued modulation formats where the usual CPs are replaced by a unique word (UW) that is a known deterministic sequence. This is achieved by designing a code generator matrix in the frequency domain that introduces correlation among the data symbols. The proposed PAM UW-DMT scheme shows a superior bit error ratio performance as compared with PAM CP-DMT. Moreover, the UW can be used for other purposes, such as synchronization and channel estimation.