| Author | Eakapong Tungsrisaguan |
| Call Number | AIT Thesis no.TC-99-12 |
| Subject(s) | Cable television
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. School of Advanced Technologies |
| Publisher | Asian Institute of Technology |
| Abstract | The effect of cross-phase modulation (XPM) on the novel system configuration for
optical CATV/HDTV distribution is studied. In this system configuration, the head-end
transmits a discrete number of optically FSK modulated HDTV signals together with a
corresponding number of optical local oscillator (LO) signals to the receiver. The signals are
then frequency down-converted to microwave frequencies followed by channel selection in
an electrical heterodyne receiver with a tunable electrical local oscillator. The signal of the
selected channel is then demodulated by a dual filter FSK receiver. Since the FSK signal is
achieved by the use of direct frequency modulation of the DFB laser, the signal power is not
constant but depends on the symbol sent. The random bit pattern of each channel results in
the fluctuation in signal power. XPM then transforms these amplitude fluctuations into phase
fluctuations which interfere with the receiver operation.
The results of the analysis show that XPM causes the bit error rate to be worse than
the analysis in the previous study. This poses various limits on important system parameters,
i.e., number of channel, fiber distance, bit rate, FM conversion efficiency and DC modulation
gain of the laser, number of passive splitter branches, and maximum number of subscribers. |
| Year | 1999 |
| Type | Thesis |
| School | School of Advanced Technologies |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Sharma, A. B.; |
| Examination Committee(s) | Makelainen, Kimmo ;Teerapat Sa-nguankotchakom ; |
| Scholarship Donor(s) | Asian Institute of Technology;John F. Kennedy Foundation; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |