Yogesh BEEHARRY, Tulsi Pawan FOWDUR, Krishnaraj M. S SOYJAUDAH

Performance of Bit Level Decoding Algorithms for Binary LTE Turbo Codes with Early Stopping

Turbo codes apply an iterative message passing mechanism between two concatenated decoders. Their astounding performance has led to their widespread adoption in several communication standards such as Long Term Evolution (LTE), and Code Division for Multiple Access (CDMA) 2000. This paper gives an overview of three bit-level decoding Max-Log-MAP algorithms with Sign Difference Ratio (SDR)-based early stopping that can be used in LTE Turbo Codes. A detailed computational complexity analysis is given for the three methods. It is observed that the complexity of the decoding methods decrease significantly as the Eb/N0 increases when SDR is used. Moreover, the Bit Error Rate (BER) performance of the methods was also assessed and compared for different modulation schemes. Results show that the different methods perform differently in the waterfall and error-floor regions with different modulation schemes. Moreover, the computational complexity analysis show that Method 2 requires fewer overall number of computations compared to Methods 1 and 3.

Keywords:

LTE Turbo Codes, Max-Log-MAP Turbo Decoding, Computational Complexity Analysis.,

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