It is well known that turbo decoding always begins from the first component decoder and supposes that the apriori information is “0” at the first iterative decoding. To alternatively start decoding at two component decoders, we can gain two soft output values for the received observation of an input bit. It is obvious that two soft output values comprise more sufficient extrinsic information than only one output value obtained in the conventional scheme since different start points of decoding result in different combinations of the a priori information and the input codewords with different symbol orders due to the permutation of an interleaver. Summarizing two soft output values for erery bit before making hard decisions, we can correct more errors due to their complement. Consequently, turbo codes can achieve better error correcting performance than before in this way. Simulation results show that the performance of turbo codes using the novel proposed decoding scheme can get a growing improvement wi It is well known that turbo decoding always begins from the first component decoder and supposes that the apriori information is “0 ” at the first iterative decoding. To alternatively start decoding at two component decoders, we can gain two soft output values ​​for the received observation of an input bit. It is obvious that two soft output values ​​include more sufficient extrinsic information than only one output value obtained in the conventional scheme since different start points of decoding result in different combinations of the a priori information and the input codewords with different symbol orders due to the permutation of an interleaver. we can correct more errors due to their complement. Simulation results show that the performance of turbo codes using the novel proposed decoding scheme can get a gr owing improvement wi