A receiver comprising: a receive antenna and receive filter for receiving and filtering a radio signal; a channel response estimator for estimating channel responses using training symbols in the received radio signal; said receiver being characterized in that it further comprises: a pre-filter and noise-whitening filter estimator for estimating net channel responses using the estimated channel responses and the received radio signal; a pre-filter and noise-whitening filter for filtering the received radio signal using the estimated net channel responses; a set partition selector for selecting a best set partition from a group of given partitions by using the estimated net channel responses and the filtered radio signal, where said selected best set partition describes which signal states of a joint signal set associated with the filtered radio signal are to be combined together to determine a reduced-state joint trellis; and a reduced-state demodulator for jointly demodulating multiple data symbols in the filtered radio signal using the reduced-state joint trellis determined by the selected best set partition, wherein the multiple data symbols in said filtered radio signal have been received from at least two transmitters and. a receive antenna and receive filter for receiving and filtering a radio signal; a channel response estimator for estimating channel responses using training symbols in the received radio signal; said receiver being characterized in that it further comprises: a pre-filter and noise-whitening filter estimator for estimating net channel responses using the estimated channel responses and the received radio signal; a pre-filter and noise-whitening filter for filtering the received radio signal using the estimated net channel responses; a set partition selector for selecting a best set partition from a group of given partitions by using the estimated net channel responses and the filtered radio signal, where said selected best set partition describes which signal states of a joint signal set associated with the filtered radio signal are to be combined together to determine a reduced-state joint trellis; and a reduced-state demodulator for jointly demodulating multiple data symbols in the filtered radio signal using the reduced-state joint trellis determined by the selected best set partition, wherein the multiple data symbols in said filtered radio signal have been received from at least two transmitters and. a pre-filter and noise-whitening filter estimator for estimating net channel responses using the estimated channel responses and the received radio signal; a pre-filter and noise-whitening filter for filtering the received radio signal using the estimated net channel responses; a set partition selector for selecting a best set partition from a group of given partitions by using the estimated net channel responses and the filtered radio signal, where said selected best set partition describes which signal states of a joint signal set associated with the filtered radio signal are to be combined together to determine a reduced-state joint trellis; and a reduced-state demodulator for jointly demodulating multiple data symbols in the filtered radio signal using the reduced-state joint trellis determined by the selected best set partition, wherein the multiple data symbols in said filtered radio signal have been received from at least two transmitters and.