Receiver apparatus for receiving data from a digital television broadcast system, comprising: - means (51, 202) for receiving a time-domain de-mapping input data stream (Q') having a frame structure, and - means for de-mapping a time-domain de-mapping input data stream (Q') having a frame structure of frames into at least two de-mapping output data streams (S1', S2',..., Sn') carrying error correction code encoded time-domain data, each frame comprising a number of frame intervals (F1, F2,..., FM), wherein each frame interval carries sequentially arranged data blocks (D1, D2,..., DN) from various de-mapping output data streams and wherein within a frame data blocks (D1, D2,..., DN) from the various de-mapping output data streams are differently mapped onto frame intervals (F1, F2,..., FM) from frame interval to frame interval, wherein from frame interval to frame interval within a frame: i) the sequence of de-mapping output data streams (S1', S2',..., Sn') into which data blocks (D1, D2,..., DN) from a frame interval are de-mapped, is different from frame interval to frame interval so that the position of a data block of one particular de-mapping output data stream within a frame interval varies from frame interval to frame interval, and/or ii) the size of data blocks (D1, D2,..., DN) that are de-mapped from a frame interval onto said at least two de-mapping output data streams (S1', S2',..., Sn') is different from frame interval to frame interval so that the size of a data block of one particular de-mapping output data stream within a frame interval varies from frame interval to frame interval, and - means for outputting said at least two de-mapping output data streams (S1', S2',..., Sn'). - means (51, 202) for receiving a time-domain de-mapping input data stream (Q') having a frame structure, and - means for de-mapping a time-domain de-mapping input data stream (Q') having a frame structure of frames into at least two de-mapping output data streams (S1', S2',..., Sn') carrying error correction code encoded time-domain data, each frame comprising a number of frame intervals (F1, F2,..., FM), wherein each frame interval carries sequentially arranged data blocks (D1, D2,..., DN) from various de-mapping output data streams and wherein within a frame data blocks (D1, D2,..., DN) from the various de-mapping output data streams are differently mapped onto frame intervals (F1, F2,..., FM) from frame interval to frame interval, wherein from frame interval to frame interval within a frame: i) the sequence of de-mapping output data streams (S1', S2',..., Sn') into which data blocks (D1, D2,..., DN) from a frame interval are de-mapped, is different from frame interval to frame interval so that the position of a data block of one particular de-mapping output data stream within a frame interval varies from frame interval to frame interval, and/or ii) the size of data blocks (D1, D2,..., DN) that are de-mapped from a frame interval onto said at least two de-mapping output data streams (S1', S2',..., Sn') is different from frame interval to frame interval so that the size of a data block of one particular de-mapping output data stream within a frame interval varies from frame interval to frame interval, and i) the sequence of de-mapping output data streams (S1', S2',..., Sn') into which data blocks (D1, D2,..., DN) from a frame interval are de-mapped, is different from frame interval to frame interval so that the position of a data block of one particular de-mapping output data stream within a frame interval varies from frame interval to frame interval, and/or ii) the size of data blocks (D1, D2,..., DN) that are de-mapped from a frame interval onto said at least two de-mapping output data streams (S1', S2',..., Sn') is different from frame interval to frame interval so that the size of a data block of one particular de-mapping output data stream within a frame interval varies from frame interval to frame interval, and - means for outputting said at least two de-mapping output data streams (S1', S2',..., Sn').