Coding assisted iterative channel estimation for impulse radio ultra-wide band communication systems

In this paper, we consider a coded ultra-wide band (UWB) impulse radio system. At the receiver, to estimate multipath delays and amplitudes, the soft information output from a soft-input soft-output (SISO) decoder is used to assist the estimation. The SISO decoder and the channel estimator work in an iterative way and no training sequence is used in the estimation. Compared with the non data-aided channel estimation without using the soft information output from the SISO decoder, the performance of this iterative channel estimation is better. We also explain this iterative method by using the expectation maximization (EM) algorithm, which can be used to prove the convergence of this iterative method.