I always get confused in the terminology of modulation level (M) and number of bits per symbol (N). Please correct me if I am wrong. Because with these values, my question extends to polarization multiplexed versions of the same.
For BPSK, N=1 and M=2
For QPSK, N=2 and M=4
For 8QAM, N=3 and M=8
For 64QAM, N=6 and M=64
Then, how the N and M values change if they all are polarization multiplexed? I.e. PM-BPSK,PM-QPSK,PM-8QAM,PM-64QAM? I think we can send more bits in PM format now but for will the N,M values change? I need to substitute these in some formula for my work and so I need clarity on this.