A channel encoding system and a channel decoding system for use in transmitting
multiple high definition television programs in a single satellite channel. The
channel encoding system may comprise a frame formatter that may be configured to
format a transport stream to produce a block stream. An error correction encoder
may be configured to encode the block stream to produce an error protected block
stream. An interleave module may be configured to interleave the error protected
block stream to produce a data stream. A turbo encoder may be configured to encode
the data stream to produce an encoded stream. A bit-to-symbol mapper may be configured
to map the encoded stream to produce a symbol stream capable of at least eight
different symbols. Finally, a modulator may be configured to modulate the symbol stream.