Close two constituent trellis of a turbo encoder within the interleave block. The state of a multi-state encoder is forced to a known/predetermined state at the end and beginning of each data frame. Packet based and/or frame based data transmissions benefit greatly when the encoder state of a multi-state encoder is known at the beginning and end of each frame. Appropriately chosen symbols, selected to force the encoder to a known state at the end of a data frame, may be padded to the end of a data frame that is to be encoded; this will force the encoder to "close" at the end of the data frame. These closure symbols may also be padded to the end of the data frame before the data frame in interleaved. Moreover, within encoder embodiments that include multiple constituent encoders, both constituent encoders will be forced to the known/predetermined state.