Hi Alan I did what Bill suggests on the addition of my deck...but a word of caution. The fill pushed up against the basement concrete/cinder block walls cannot be compacted. Thus any weight on this fill will compress it, causing the source of the added weight (posts up against your foundation) to sink......as mine did :-(
You don't mention what kind of joist system you have (in the absence of a rim joist), so I'll assume its engineered wooden I-beams. What I would do is go into your basement and put up a 2X? across the end of the I-beams, securing it there and to the sill...then bolting your ledger to that. I'd do that at least 4 times in 16 feet. This along with posts at your basement wall, should hold your ledger firmly in place.