Efficient-BER-computation-of-LDPC-coded-SC_MRC-sy

  Abstract—Selection combining cascaded with maximum-ratio combining (SC/MRC), which is particularly useful when site diversity is available, combined with low-density parity-check (LDPC) codes is able to combat the effects of fading. The biterror rate (BER) expressions of uncoded SC/MRC and SC/MRC with LDPC codes over an independent and identically distributed Rayleigh-fading channel are derived based on the Gaussian approximation approach. These expressions are also applicable to the selection combining and maximum-ratio combining as special cases. The derived expressions are in good agreement with simulation results and approach the density evolution (DE) thresholds. These expressions are able to achieve a significant reduction in computational time with a reasonable accuracy for analyzing the BER performance as compared to simulations and DE.