As one of the three communication experiments to be performed on the ECP payload of the LEO satellite ROCSAT-l, the direct broadcasting of digital TV signals using Ka-band experiment has been well planned and prepared. In this experiment, suitable compression and protection methods for the digitized video and audio signals in the LEO and Ka-band environments will be studied. The bitrate will be between 6.6 and 3.3 Mbps, depending on the affordable link budget. The carrier frequency of the up- link is 28.25 GHz, while that of the downlink is 18.45GHz. Because of the strong dependence of system performance on the channel characteristics, a realistic Ka-band channel model suitable for the subtropic Taiwan area will also be developed.