  By presenting an approximated performance-complexity tradeoff (PCT)
algorithm,a low-complexity non-binary low density parity check (LDPC) code over
q-ary-input symmetric-output channel is designed in this manuscript which
converges faster than the threshold-optimized non-binary LDPC codes in the low
error rate regime. We examine our algorithm by both hard and soft decision
decoders.Moreover, simulation shows that the approximated PCT algorithm has
accelerated the convergence process by 30% regarding the number of the decoding
iterations.
