Trellis encoder for encoding a dual transmission stream

A trellis encoder to the transmission stream trellis encoding is disclosed. The trellis encoder, the first to third first multiplexer to the memory, selectively outputs one of a predetermined first bit and the storage value stored in the first memory in the transport stream in accordance with an external control signal, from the first mux and adding and outputting the storage value stored in the output output value and the first memory, stored in the predetermined second bit and the second memory in the transport stream according to the first adder, an external control signal for storing the addition result in the first memory adding the output value and a stored value stored in the first memory of the second multiplexer and the second multiplexer for selectively outputting one of the stored values, and a second adder for storage in a third memory. This makes it possible to effectively perform the initialization prior to performing the trellis encoding. Initialized, a trellis encoder, the additional reference signals, the dual transport stream