Comments on "The Cramer-Rao Bounds of Hybrid TOA/RSS and TDOA/RSS Location Estimation Schemes"

It is shown that in the above letter by Catovic and Sahinoglu the Cramer-Rao Bound (CRB) for the time difference of arrival/received signal strength (TDOA/RSS) based location estimation was derived incorrectly. The correct version of the CRB for the TDOA/RSS is provided, and the corresponding simulation results are given.