iPhone won't activate after resetting everything and it says "No Service" when it had service before

i deleted everything (apps,photos,emails,contacts,music) to make room for ios 7 and there still wasn't enough space so i decided to reset EVERYTHING and after it did it onned again and I went through the welcome thing again and it won't let me activate my iphone. i plugged it into itunes and itunes said it can't recognize the device. My phone has never been jailbroken and is almost 14 months old. I have the 8GB iPhone 4.