Method and apparatus for differentially decoding signals

The present invention relates to a method and apparatus in which a differentially coded signal having forward error correction added to the encoded data can be decoded with an improved bit error rate performance Apparatus for decoding a differentially encoded input signal having forward error correction added to the encoded data, the apparatus comprising: a differential decoder to receive the input signal and to decode the data in each differentially encoded signal interval thereof by reference to the data in a previous differentially encoded signal interval; error correcting means to correct errors in the decoded signal form the decoder; and means for supplying to the decoder the corrected data from each signal interval to act as a reference for decoding the data in a following signal interval.