PCM-FDM System for Existing Microwave Radio Baseband

Digital transmission over the empty lower baseband of an existing microwave radio system has the advantages of economical and easy construction. A 1.544 Mbit/s PCM-FDM converter (PF-B1) has been developed. Field test results show that the error-rate per bit is less than 10
^-8
over 840 km with 3 basebands.