Application of Distance Spectrum Analysis to Turbo Code Performance Improvement
نویسنده
چکیده
We present a simple method to improve the performance of turbo codes. Distance spectrum analysis is used to identify information bit positions a ected by low-distance error events, which are few in number due to the sparseness of the spectrum. A modi ed encoder inserts dummy bits in these positions, resulting in a lower and steeper error oor in the bit-error-rate (BER) performance curve. For su ciently large interleaver size, the only cost is a very slight reduction in the code rate. We illustrate the method using a rate 1/2 turbo code, with interleaver length N = 10000: The proposed method improves the BER by an order of magnitude at Eb=N0 = 2:5 dB, with a rate loss of only 0.4%.
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