By implementing Pulse Amplitude Modulation (PAM) transmission technology, next-generation 200 and 400-Gbits/s transmission methods defined by IEEE802.3bs and IEEE802.3cd increase transmission capacity compared to the conventional NRZ method without increasing the symbol rate.  In PAM4 signaling, instead of transferring 1 bit at one of two levels of 0 or 1 in one time slot as in NRZ signaling, 2 bits of data are transferred at four levels in one time slot. Learn how to generate 32 and 64 Gbaud PAM signals for evaluation as well as BER measurement methods and measuring instrument requirements.