All good broths start with a good boil up. The traditional ramen has beef marrowbones and usually a number of pig's trotters. Of course it needs the usual aromatics such as onions, carrots, celery, etc. I am on holidays so cannot provide a precise recipe now. If you enjoy a laugh and can cope with subtitles the movie Tampopo is the best food movie ever (my opinion). It is all about how to make a ramen broth with lots of amusing distractions. It is available on DVD. I have watched it so many times I do not read the subtitle!
When you stop horsing around it is time to fire up the BBQ & Smoker