A technique to determine the optimal design of an FDM-FM communications link considering both dollar cost and system performance is established. The four major items of a communications system, transmitter, receiver, transmitting antenna, and receiving antenna, are considered to be stages of a serial-multistage system with the signal-to-noise power ratio as a final boundary value and threshold as a constraint. For eyery combination of the four equipment items, an rms channel modulation index is computed, which for median performance and the system constraint minimizes the required received carrier power. The cost of those combinations of equipment meeting or exceeding the system requirements are computed and compared. Single variable search optimization techniques are used. Rigorous rapid design of analog communications systems is provided. The least cost system and other selected qualifying systems are explicitly determined.