DOPPLER CHANGE GENERATING DEVICE

摘要

PURPOSE:To simulate the Doppler change of reciprocating between an earth station and a satellite in the digital satellite communication by using one side of two pairs of the Doppler change generating devices and two clock generating devices as the transmitting system Doppler change generating means and other side as the receiving system Doppler change generating means. CONSTITUTION:Transmitting data 201 are written through a flip flop 211 for retiming and a two-directional buffer 212 to a triple memory 214. A writing address to the memory is executed by a counter 217 for the memory writing address which is operated at a transmitting clock 202. The data written in the memory 214 are addressed and read by a counter 216 for the memory reading address which is operated by a Doppler clock 203, and outputted through a buffer 212 and a flip flop 213 for retiming together with the clock 203. The frequency of a reading clock 203 is suitably changed, the frequency difference of DELTAf is given between the frequency of a writing clock 202 and the frequency of a reading clock 203. The symbol DELTAf is changed as well as the frequency change by the action of a satellite and the Doppler change is obtained.