ROF LINK APPARATUS OF SELECTING IF BANDWIDTH THROUGTH MMF AND ITS IF SELECTING METHOD

摘要

An ROF(Radio Over Fiber) link system for selecting an IF(Intermediate Frequency) band to process various service signals through a multi-mode optical fiber and a method thereof are provided to offer uniform performance, regardless of the types, length, and connection states of multimode optical fibers, by obtaining a proper IF band out of a bandwidth of 3dB in order to accept various service signals at the same time. An ROF link system comprises ROF transmitting blocks(31-1-31-N) and ROF receiving blocks(38-1-38-N). Each of the ROF transmitting blocks(31-1-31-N) comprises a Seep OSC(Oscillator)(301-1-301-N), a multiplier(302-1-302-N), and a BPF(Band Pass Filter)(303-1-303-N). The Seep OSCs(301-1-301-N) receive information on an IF band established through the first control part(33) and provide frequency components of the IF band for IF modulation respectively. The multipliers(302-1-302-N) respectively combine input service signals(1-N) with the IF frequency components of the Seep OSCs(301-1-301-N) and execute IF modulation. The BPFs(303-1-303-N) execute filtering for the IF-modulated IF-band signals respectively. Each of the ROF receiving blocks(38-1-38-N) comprises a BPF(304-1-304-N), a Seep OSC(305-1-305-N), and a multiplier(306-1-306-N). The BPFs(304-1-304-N) respectively execute filtering for the IF-modulated IF-band signals transferred from the ROF transmitting blocks(31-1-31-N). The Seep OSCs(301-1-301-N) receive information on an IF band established through the second control part(37) and provide RF-IF frequency components for IF-to-RF modulation respectively. The multipliers(302-1-302-N) respectively combine the IF-band signals transferred through the BPFs(304-1-304-N) with RF-IF frequency components of the Seep OSCs(305-1-305-N) and execute RF modulation.