Abstract
Subcarrier multiplexing (SCM) is emerging as a viable technique for lightwave cable television (CATV) systems.1 There are two fundamental impairments that limit the capacity of such systems,2 namely, shot noise within the receiving photodiode and irreducible nonlinear distortion (NLD) within the transmitting laser (or external modulator). As depicted in Fig. 1, the latter impairment is due to signal clipping and can occur even when the light vs current (L-I) relation is perfectly linear. For example, considering these two fundamental impairments alone, to deliver the 55 dB of carrier- to-noise ratio (CNR) that is desired in CATV trunking applications for the standard analog VSB-AM NTSC signaling format, one needs ~1 mW of received optical power per fifty channels. The received power requirement reduces by ~5.5 dB if the CNR is relaxed to 50 dB and by an additional 6 dB for a CNR of 45 dB. The latter CNR is quite acceptable for fiber-home application.
© 1990 Optical Society of America
PDF ArticleMore Like This
C. J. Chung and Ira Jacobs
TuD1 Optical Fiber Communication Conference (OFC) 1992
RICHARD GROSS
CWD1 Conference on Lasers and Electro-Optics (CLEO:S&I) 1990
Keang-Po Ho and Joseph M. Kahn
ThS3 Optical Fiber Communication Conference (OFC) 1994