Getting Surround Sound From Basic Cable Using A Digital Audio Cable For Surround Sound System?

Using a digital audio cable for surround sound system? - getting surround sound from basic cable

I bought a Panasonic surround sound system had with my Christmas bonus this weekend, a question about the use of digital cable. Now I have my TV with the basic audio cable (red and white), from television to the receiver, and use the AUX input of the receiver to work. When I use the digital cable source in the back of the work of digital TV sets? It is an HDTV, but I have HD cable, so do not know if I could function without a high-definition signal or something