Hello,

I am trying to simulate a 3/5 LDPC code. I have encoded it using the Systemic approximate Lower Triangular Encoding system and I am using Sum-Product and Min Sum for Decoding. I have modulated the signal using BPSK and I am passing the signal through the AWGN channel. My error rates only work for negative SNR(dB) values. Occasionally, it does work for positive values (but not more than 1). See images 4, 5, and 9 for what I am telling. But mostly it works for negative values only (Like image 6). Is this right? I don't know why it happens like this. Can anyone help me with this? Please comment if you need further information. I thank all who takes the time to help me with this.