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The article compares various digital modulation schemes like BPSK, QPSK, PAM, 16PSK, 32PSK, 16QAM and 64QAM using the following metrics:
(a) Symbol Error Rate vs. Signal to Noise Ratio (SER vs Es/No)
(b) Symbol Error Rate vs. Bit to Noise Ratio (SER vs Eb/No)
(c) Capacity in bits per second per Hertz vs. Bit to Noise Ratio (Capacity vs Eb/No)
(d) Bit Error Rate vs. Bit to Noise Ratio (BER vs Eb/No)
Symbol Error Rate vs. Es/No
Binary Phase Shift Keying (BPSK) Modulation
In Binary Phase Shift Keying, the symbols  are used for transmitting information. From the post, Bit error probability for BPSK modulation, the symbol error rate is given as,
 .
Click here for Matlab simulation of bit error rate (BER) curve with BPSK modulation.
Pulse Amplitude Modulation (4-PAM)
In 4-PAM modulation, the symbols  are used for transmitting information. The symbol error rate for 4-PAM modulation is derived in the post, symbol error rate for 4PAM and is given as,
 .
Click here for Matlab simulation of symbol error probability with 4PAM modulation
4QAM (QPSK)
In 4-QAM modulation, the symbols  are used for transmitting information. The symbol error rate for 4-QAM modulation, derived in the post, symbol error rate for 4-QAM (QPSK) is given as,
Click here for Matlab simulation of symbol error probability with 4QAM (QPSK) modulation
16QAM
In 16QAM modulation, the symbols  are used. The symbol error rate for 16QAM modulation, derived in the post, symbol error rate for 16-QAM, is given as,
Click here for Matlab simulation of symbol error rate curve with 16QAM modulation
16PSK
In 16PSK modulation, the alphabets  is used, where  . The symbol error rate for 16PSK, derived in the post, Symbol Error Rate for 16PSK is given as,
 .
Click here for Matlab simulation of symbol error rate with 16PSK modulation
Note: The formula derived in this post is for a general M-PSK case. For an M-PSK scheme, the symbol error rate is,
 .
M-QAM
In a general M-QAM constellation, where  and  is even, the alphabets used are:
 , where  .
From the article deriving the symbol error rate for M-QAM,
(Click to enlarge).
Click here to download Matlab/Octave script for simulating symbol error rate for M-QAM modulation
Figure: Symbol Error Rate vs Es/No (dB) in AWGN
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