Noise power ratio (NPR) by zrk787
Noise-to-power ratio (NPR)—a 65-year-old telephone system parameter regains in modern wireless applications...
Noise-to-power ratio (NPR)—a 65-year-old telephone system parameter that regains the nascent noise-to-power ratio (NPR) in modern wireless applications. The concept of a frequency-division-multiplexed (FDM) telephone system has emerged since its inception. In simple terms, NPR is used to measure the "quietness" of an idle channel in a multi-channel system when there is random activity on other channels. Noise and intermodulation distortion products enter the idle channel, reducing performance. Originally used to examine 4 kHz wide voice channels in FDM links, the concept is now also useful in determining the characteristics of multi-channel broadband communication systems – but there are some important differences in modern measurement techniques.