I'm trying to find the name of a book I read a long time ago. The basic plot is that science/technology has been outlawed and some guy is illegally listening to the skies. He receives a signal from space and is killed after relaying it to a colleague. This kicks off a cross-generational story of decrypting the message, rebuilding our science and technology education programs and building a spaceship to meet the coming aliens.
Some tidbits I remember:
the alien ship which they meet towards the end had one person on it, a human, and I think that ship used nuclear pulse propulsion. The ship the people of Earth made traveled a lot faster (I think using a bussard ramjet?). The Earthlings travel on to the alien home world which it turns out is full of humans as well.