Impact of Squashing Function’ s Slope on ANN based Channel Estimation in SFBC-OFDM System

This correspondence emphasises on the usage of softsign squashing function in the ANN based channel estimation (in frequency-domain) for SFBC-OFDM system. The softsign based approach outperforms the hyperbolic tangent squashing function by providing smoother asymptotes while using feedforward neural networks for the estimation of slowly time-varying channels. By exploiting the lower saturation tendency of softsign function, the efficiency of channel estimator can be enhanced, which in turn improves the symbol error rate performance of SFBC-OFDM system.