Estimation of channel parameters using iterative least squares approach for W-CDMA and UWB systems

This paper proposes a new blind method to estimate the channel parameters such as the direction-of-arrival (DOA) and multipath time-of-arrival (TOA) for a communication system. We employ mathematical inverse problem techniques to find the solution. We specify an appropriate physical model to explain the received signal and reformulate the nonlinear estimation problem into a linear least squares problem. We then apply conjugate gradients (CG) iterations on the resulting normal equations (NE) to obtain the solution. We demonstrate our method for a W-CDMA system and extend the methods to an ultra-wideband (UWB) system. We also present a method for multiuser detection (MUD).