A method of processing a digitally encoded radio signal (102) comprising a bit to be determined is disclosed. The method comprises correlating a first bit sequence (103) comprising the bit with a plurality of predetermined filters (104a-h) to create a first set of filter coefficients (110a-h); calculating (120) a first likelihood data set (124) comprising a likelihood of said bit having a given value for each bit position from the first set of filter coefficients. A second bit sequence (103) comprising the bit at a different position is then correlated with the filters to create a second set of filter coefficients (10a-h), from which a second likelihood data set (124) is calculated. A soft output bit (26) comprising a probability weighted bit value from data corresponding to the bit at a first and second bit positions from the first and second likelihood data sets respectively is then calculated.