1. A turbo decoding iteration count control method comprising: a step of detecting that a value of a positive/negative bit included in a current soft decision result for each bit of a received codeword matches a value of a positive/negative bit included in a previous soft decision result; a step of deciding whether a tendency of said positive/negative bit can be recognized in all bits of said received codeword or not; and a step of deciding whether iterations of soft decision decoding should be terminated or not based on said decision result.