It looks like an uneven log cabin quilt. With pieced sections. It was probably an original someone designed and made. If you want to make something like it get a pad of graph paper, some colored pencils and start in the center drawing it out.
Many quilters create quilts without commercial patterns. I use graph paper and colored pencils a lot. I always start with a ( frame) lines determining the size I want the finished quilt to be then determine what size each little square represents. From there I can start designing