Performance Analysis of the Iterative Turbo Decoding Stopping Criteria in AWGN Channel

The variances in the channel estimates errors is the factor that affected the channel reliability factor in iterative turbo decoding, due to the flawed in the estimates of the signal-to-noise ratio (SNR). However, most of the stopping criteria approaches in turbo decoding assumed the channel reliability at the receiver is known with respect to the threshold. Under additive white Gaussian noise (AWGN) channel, three stopping criteria for iterative decoding are analyzed in this paper. The Cross-entropy (CE), Hard Decision Aided (HDA) and Sign-Change Ratio (SCR) are utilized for the simulation process by comparing the reliability channel stopping criteria. It is further enhanced by expanding puncturing method the rate of the system for AIN. At high SNR, the scaled received data results in the stopping criteria to stop iteration sooner while keeping up the BER performance, however more regrettable at certain frame size. Consequently, the different frame size does not influence the BER performance either in unscaled or scale condition.