We present the design of intensity-modulation direct-detection optical fiber communication systems with erbium-doped fiber amplifiers for CATV/HDTV distributions. Three system configurations: the In-Line Amplifier scheme; the Passive Star Coupler with Optically Preamplified Receivers scheme; and the Hybrid Passive-and-Active Star Coupler scheme; are considered. The receiver sensitivity is calculated for various system parameters. We also compare these three schemes through the number of HDTV subscribers.