Preliminary Technical Assessment of the Feasibility of Frequency Sharing by Fixed and Mobile Users in the 4-28 MHz Frequency Range

Abstract

The circuit compatibility of fixed and mobile users at HF has been calculated. Interference to the fixed service is at a minimum: (1) for a mobile system with low channel usage; (2) for a radiotelephony fixed system, when SSB modulation is used; and (3) under fading conditions when diversity reception is employed. High circuit com­ patibility also occurs when the interfering transmitter is in the skip zone of the desired receiver and during time periods when either the shared frequency is well above the MUF for the fixed system propa­ gation path or is well below the LUF for the fixed system path.