16-QAM

• See QAM (Quadrature Amplitude Modulation)
• The 16-QAM is a specific case of M-ary QAM scheme in which a carrier wave of fixed frequency can exist in one of sixteen different states in the constellation plot.
• Each symbol consists of four bits out of 16 different possible combinations ranging from 0000 to 1111.
• The total number of bits that can be accomodated in a symbol for 16-QAM is 4.
• Since, this scheme uses binary data to perform modulation and demodulation, the number of combinations possible with four bits is 24 i.e. 16.
• Or equivalently, the number of bits that can be accomodated as per equation 2 is log2 16 = 4.1