This paper presents a low complexity non-binary LDPC decoding algorithm

whose complexity can be reduced in the following two ways.First

a new truncation scheme is presented to define the processing/non-processing check node subsets.The check nodes with relatively high reliability are not required to be processed

which can reduce the complexity.Second

for the check nodes in the processing subset

we further present a k-order message truncation for the states and branches of the check node Trellis.In the decoding iterations

only those live states/branches are involved in the message updating process

which can further reduce the computational loads at check nodes.Simulation results show that the presented algorithm performs very closely to several existing improved EMS decoding algorithms

but it has the lowest complexity when decoding the non-binary LDPC codes constructed both in low/high order fields.