Channel estimation for frequency hopping systems via multiple invariances

The problem of channel estimation for a frequency hopping system is considered. Under a discrete multipath fading model, the path gains and delays are estimated separately. By exploiting fixed (but unknown) patterns in the data packet, the delay estimation problem is formulated in an ESPRIT-like format by identifying multiple rotational invariance structures in the received data. Since ESPRIT is limited to exploitation of single invariance, the previously proposed SPECC algorithm is employed for the multipath delay estimation. Performance results based on simulations are presented