  This paper investigates the estimation of radio channel parameters from
receiver data, whereby the transmitter is fully unknown. We use a multipath
model to describe the radio channel between transmitter and receiver. According
to this model, we discuss the accessibility of parameters for estimation. Based
on the Maximum-Likelihood principle, we derive a cost function. A second cost
function is derived from the cross relation between the receiver channels. To
estimate the parameters, we seek for the minimum of these cost functions. The
performance of the presented cost functions are compared in simulations.
