  In this paper, we present a low-complexity joint detection-decoding algorithm
for nonbinary LDPC codedmodulation systems. The algorithm combines
hard-decision decoding using the message-passing strategy with the signal
detector in an iterative manner. It requires low computational complexity,
offers good system performance and has a fast rate of decoding convergence.
Compared to the q-ary sum-product algorithm (QSPA), it provides an attractive
candidate for practical applications of q-ary LDPC codes.
