A detection circuit performs a turbo detection process to recover a frame of data symbols from a received signal, the data symbols of the frame having been effected, during transmission, by a Markov process with the effect that the data symbols of the frame in the received signal are dependent one or more preceding data symbols which can be represented as a trellis having a plurality of trellis stages. The detection circuit comprises a plurality of processing elements, each of the processing elements is associated with one of the trellis stages representing the dependency of the data symbols of the frame according to the Markov process and each of the processing elements is configured to receive one or more soft decision values corresponding to one or more data symbols associated with the trellis stage, and each of one or more of the processing elements is configured, in one clock cycle to receive fixed point data representing a priori forward state metrics a priori backward state metrics, and fixed point data representing a priori soft decision values for the one or more data symbols being detected for the trellis stage. For each of a plurality of clock cycles of the turbo detection process, the detection circuit is configured to process, for each of the processing elements representing the trellis stages, the a priori information for the one or more data symbols being detected for the trellis stage associated with the processing element, and to provide the extrinsic soft decision values corresponding to the one or more data symbols for a next clock cycle of the turbo detection process.