Onboard baseband processing (OBP) can play distinguish role in enhancing the robustness, increasing the capacity and simplifying the earth stations for satellite communication systems. OBP usually needs demodulating and decoding many digital modulation signals, so as to support baseband switching and multiplexing, as well as regenerating the signals to reduce the noises accumulation, but it also brings two fatal disadvantages--too high complexity and less flexibility of its channels in applications. Non-regenerating OBP, without onboard demodulation and decoding, can play similar roles as the regenerating OBP while overcome its drawbacks. However, there was a serious obstruction to obstruct it from applications, i.e., there was no effective method to transmit many waveform signals without demodulated via the downlink. Our two inventions about continuous wave time division multiplexing (CWTDM) have broken through the obstruction, and opened the way for its wide applications.