FCC authorizes IBOC for LPFM
The FCC has issued the long awaited 74 page Report and Order on Digital Audio Broadacsting (DAB) and specifically confirms that the FCC's choice for DAB standard is the iBiquity In Band On Channel (IBOC) system that is marketed under the name HD Radio. LPFM starts at paragraph #56.
While iBiquity supports LPFM stations having the option of going digital, they do note that it may not be efficient for LP-10 stations to convert as they will produce a signal that will be under the noise floor and would be difficult for the DAB receiver to detect. However, according to iBiquity, would not be the case with LP-100 stations.