Signal-to-Quantization Noise Ratio (SQNR)
November 6, 2019
Back to: Sampling & Reconstruction
Signal power and quantization noise should be discussed in unison. Most importantly, the signal power should be sufficiently more than the power of the quantization noise. The signal-to-quantization noise ratio (SNQR) is used to equate this ratio.
As discussed in the previous lesson, quantization noise is added when quantization is used to digitize a signal. Some level of error is introduced with this method of analog-to-digital conversion. The SQNR is used as a quick error metric in regard to quantization noise.
Let Ps be the signal power and Pn be the quantization noise. The SQNR and its decibel version, SQNRdB, are defined as:
Increasing the Signal-to-Quantization Noise Ratio
A higher SQNR value indicates a lower value of quantization noise. The SQNR value can be increased in several ways, two of which are discussed in the following lessons.