Going from 128 to 256 QAM and keeping the bandwidth constant will provide a small increase in data rate but will require a higher Carrier to Noise Ratio.thickglass14 said:Hi guys, I set HDMI Modulator recently, but here is one question - it has QAM 16/32/64/128/256. What is the practical difference between 128 and 256 for example if I keep resolution and bitrate the same?
QAM (Quadrature Amplitude Modulation) is a type of digital modulation used in communications systems to transmit data. QAM 256 and QAM 128 are two different types of QAM modulation schemes with varying levels of complexity.
The main difference between QAM 256 and QAM 128 is the number of points on the constellation diagram used to represent the digital signal. QAM 256 has 256 points, while QAM 128 has 128 points. This means that QAM 256 can transmit more data compared to QAM 128.
The difference in points on the constellation diagram affects the complexity and accuracy of the signal. With more points, QAM 256 can transmit more data and is less prone to errors compared to QAM 128.
This depends on the specific application and the trade-off between data rate and error rate. QAM 256 is more efficient for transmitting large amounts of data, but QAM 128 may be better for applications with lower data rates but more stringent requirements for error rate.
Aside from the number of points on the constellation diagram, the two modulation schemes also have different signal-to-noise ratio requirements. QAM 256 requires a higher signal-to-noise ratio for accurate data transmission compared to QAM 128.