摘要 |
In a system for frequency-diversity transmission, separate and distinct frequency carriers are obtained from the frequency modulation of an oscillator by a pure frequency with an index such that a certain number of Bessel lines thus obtained constitute a corresponding number of separate carriers. All the carriers are subsequently modulated by the information, then power-amplified in a single amplifier having a peak power equal to that of a single signal whose effective power would be the sum of those of the separate carriers. By means of this system, equipment for radio communication by tropospheric or ionospheric scatter propagation can be constructed in a simple manner and at low cost, with a high diversity order. |