TRANSMISSION OF CDMA SIGNALS OVER AN ANALOG OPTICAL LINK

摘要

A transmission system for backhauling CDMA signals from remote antennas to the centralized base station of a wireless communication system includes a laser transmitter and an optical receiver coupled to an optical fiber. Wireless signals are backhauled to the central base station without degrading signal quality, and with minimal signal processing performed at the remote antenna site. The RF drive current driving the laser transmitter is kept above a predetermined level to prevent noise caused by optical feedback into the laser transmitter caused by Rayleigh backscatter in the optical fiber. A method of testing the optical link is presented which avoids the expense of using a real CDMA system to test each link. The testing method enables the dynamic range of inexpensive, unisolated, uncooled lasers in the optical link to be increased so the optical link can cost-effectively backhaul the CDMA signals.