World-first demonstration of most frequency band -effective 64 APSK modulation for earth observation satellites. - World fastest communication speed of 505 M bit per second for a small satellite-


Prof. Hirobumi Saito (Electrical and Electronics Course, Deprtment of Engineering, University Tokyo, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency ) and his team have developed transmitting and receiving communication technologies with 64 Amplitude and Phase Shift Keying, 64APSK  modulation from an earth orbiting satellite to a ground station.  For the first time in the world his group demonstrated these technologies at X band radio frequencyband in orbit with Hodoyoshi 4 small satellite launched by Tokyo University.  The communication speed is 505 M bit per second, which is the highest speed for small satellites. These technologies is very useful to increase communication speed under constraint of radio frequency bands. One can realize 3G bit per second communications in X band for earth observation satellites  with these technologies.