Turbo codes and Shannon's condition for reliable communication
Block transmission over noisy communication channels is characterized by two performance criteria: the bit error probability P/sub b/ and the block error probability P/sub B/. If P/sub B/ goes to zero when N/spl rarr//spl infin/ (where N denotes the length of the permutors), P/sub b/ also must go to zero for all symbols in the block but, in general, the reverse is not true. Therefore we formulate
