What happens to the data throughput when transitioning from quadrature phase shift keying (QPSK) to 16-QAM (quadrature amplitude modulation) in a channel of the same bandwidth?

When transitioning from quadrature phase shift keying (QPSK) to 16-QAM in a channel with the same bandwidth, the data throughput increases significantly due to the higher efficiency of 16-QAM.

QPSK encodes 2 bits per symbol, as it uses four distinct phases for signal transmission. In contrast, 16-QAM utilizes both amplitude and phase to represent 4 bits per symbol, effectively allowing the transmission of more information in the same symbol duration. As a result, the data throughput, which is a measure of how much information can be sent over a channel within a given period, can effectively double when switching from QPSK to 16-QAM, assuming the same channel conditions and bandwidth.

This increase in bits per symbol directly correlates with the doubling of data throughput, making it a key advantage of using 16-QAM over QPSK for applications requiring higher data rates without changing the bandwidth of the channel.