Abstract
This paper presents a theoretical analysis and derives the amplifier output noise power spectral density result in a closed form when the input to the amplifier is a band limited Gaussian noise. From the computed power spectral density the NPR is evaluated by a simple subtraction. The method can be applied to any amplifier with known input-output characteristics. The method may be applied to analyze various other important characteristics of the nonlinear amplifier such as spectral regrowth that refers to the spreading of the signal bandwidth when a band limited signal is inputted to the nonlinear amplifier. The paper presents numerical results on the NPR as a function of the noise bandwidth, depth level of the notch, and the output power back-off obtained from the analysis presented in the paper.
Highlights
The power amplifier is one of the most important subsystems of modern communication systems [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
The paper presents numerical results on the noise power ratio (NPR) as a function of the noise bandwidth, depth level of the notch, and the output power back-off obtained from the analysis presented in the paper
The analytical results have been encoded in the form of a relatively simple MATLAB program that can provide the result for any specified amplifier input-output characteristics, notch bandwidth and depth, and the output power back-off
Summary
The power amplifier is one of the most important subsystems of modern communication systems [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]. In case of digitally modulated signals at the amplifier input in the digital communication systems, one of the most important performance measures is in terms of the bit error rate (BER) achieved in the presence of both the distortion introduced by the amplifier and any channel interference plus noise Both these measures are functions of the detailed modulation techniques, multiple accessing or multiplexing techniques, and the number of user signals at the amplifier input in addition to the amplifier input-output characteristics and the output power backoff. A performance characterization of the nonlinear power amplifiers that is independent of the specifics of the amplifier input signal, such as the multiple accessing and modulation techniques used, the number of users, and the relative power level of the various user signals, is commonly used in the practice This measure is termed the noise power ratio (NPR). The paper presents numerical results on the NPR as a function of the noise bandwidth, depth level of the notch, and the output power back-off obtained from the analysis presented in the paper
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
