A receiver apparatus receives a transmit signal through a plurality of transmission channels, wherein each transmission channel is described by its channel vector. A sparseness evaluation unit (127) may obtain a sparseness measure containing sparseness information for previously estimated frequency-domain channel vectors. From the plurality of receive signals, an estimator unit (120) estimates updated channel vectors for the transmission channels by applying an iterative blind channel estimation algorithm that may consider a change of the sparseness measure, out-of-band energy information and/or signal-to-noise information and cross-relations between pairs of receive signals. A combining unit (130) may combine the receive signals on the basis of combining coefficients derived from the estimated channel impulse responses for a pre-selected diversity combining scheme to obtain a combined receive signal representing an estimation of the transmit signal. The receiver apparatus employs an improved blind channel estimation approach.