OPTICAL MULTIPLEX COMMUNICATION EQUIPMENT

PURPOSE:To secure an optimum S/N for each line even when the number of lines is changed by correcting a signal level of an information signal based on the result of detection of the lines. CONSTITUTION:The equipment is provided with information signal generating circuits 10A-10D, 28, 32A-32C, 34 which set freely the line number of an input signal as required, convert the input signal into modulation signals S5, S6, multiplex them and generate an information signals S1 and with line number detection circuits 50A-50D, 54A-54C detecting number of the line of the input signal and output line number detection results K1, K2. Thus, the amplitude of the information signal S1 resulting from multiplexing the input signal is kept to a prescribed value by correcting the signal level of the information signal S1 based on the line number detection results K1, K2 in the signal level compensating circuit 28 and 34.