multiple modem or ethernet backhaul?

so I have a L-shaped home with walls that's almost impossible to get reception. the cable comes in at the one end of the L-shape and my office is in the other end of the L.

I have the cable running to each room of the house but by the time it reaches the other side of the house, the signal speed is 1/8th of the speed. is it possible to connect another cable modems to satellite unit?