Algorithm 1: The proposed EEACC pseudo-code

1: Initialization: ${BLER}_{target}=10\%$, $C_{stepup}=0.2$, $C_{stepdown}=C_{stepup}\frac{1-{BLER}_{target}}{{BLER}_{target}}$, $\mathsf{\Delta }$ C=0, $\mathsf{\Delta }{C}_{max}=+5,\mathsf{\Delta }{C}_{min}=-5$, MCS level L and its bounds $L^{max}$, $L^{min}$, repetition number N and its bounds $N^{max},N^{min}$. We empirically initialize the MCS level and repetition number based on the channel condition. 2: if period T expired out then 3:       if $BLER<7\%$ then 4:         $N=N/2$ 5:       else if $7\%<BLER>13\%$ then 6:         $N=N+1$ 7:       else if $BLER>13\%$ then 8:         $N=2N$ 9:       end if 10: end if 11: if $L>L^{min}\&L<L^{max}$ then 12:      if HARQ feedback=ACK then 13.        $\mathsf{\Delta }C=min\mathsf{\Delta }C+C_{stepup},\mathsf{\Delta }{C}_{max}$ 14.      else if HARQ feedback-NACK then 15.        $\mathsf{\Delta }C=max\mathsf{\Delta }C-C_{stepdown},\mathsf{\Delta }{C}_{min}$ 16.      end if 17.      if $\mathsf{\Delta }C=\mathsf{\Delta }{C}_{max}$ then 18.        $L=L+1$ 19.      if $\mathsf{\Delta }C=\mathsf{\Delta }{C}_{min}$ then 20.        $L=L-1$ 21.      end if 22. else if $L=L^{min}$ then 23.      if HARQ feedback=ACK then 24.        if $N=N^{min}$ then 25.           $\mathsf{\Delta }C=min\mathsf{\Delta }C+C_{stepup},\mathsf{\Delta }{C}_{max}$ 26.           if $\mathsf{\Delta }C=\mathsf{\Delta }{C}_{max}$ then 27.              $L=L+1$ 28.           end if 29.        if $N>N^{min}$ then 30.           $N=N/2$ 31.        end if 32.        else if HARQ feedback=NACK then 33.           if $N=N^{max}$ then 34.              the current channel condition is very bad 35.           else if $N<N^{max}$ then 36.              $N=2N$ 37.           end if 38.        end if 39. else if $L=L^{max}$ 40.      if HARQ feedback=ACK then 41.          if $N=N^{min}$ then 42.             the current channel condition is very good. 43.          else if $N>N^{min}$ then 44.             $N=N/2$ 45.          end if 46.      else if HARQ feedback=NACK then 47.             $\mathsf{\Delta }C=max\mathsf{\Delta }C-C_{stepdown},\mathsf{\Delta }{C}_{min}$ 48.             if $\mathsf{\Delta }C=\mathsf{\Delta }{C}_{min}$ then 49.               $L=L-1$ 50.             end if 51.      end if 52. end if