Signal Generators N5171B Analog & N5172B Vector - Data Sheet Custom modulation real-time mode (Option 431) (Does not require Option 660) Modulation PSK BPSK, QPSK, OQPSK, π/4DQPSK, gray coded and unbalanced QPSK, 8PSK, 16PSK, D8PSK, IS95 QPSK, IS95 OQPSK, EDGE, HDQPSK, SOQPSK ...