Looking for BPSK constellation

This is a very simple question, right? B stands for 2, P stands for phase, and sk is keying, which is the most basic thing of communication modulation. The simplest constellation mapping scheme is to map the bit 1 to the (0, 1) position in the constellation diagram, and map the bit 0 to the (0, 1) position in the constellation diagram. The maximum likelihood ratio function LLR has been forgotten, so let's answer here first.