Equivalent Baseband Models and Corresponding Digital Predistortion for Compensating Dynamic Passband Nonlinearities in Phase-Amplitude Modulation-Demodulation Schemes
| Autor: | Alexandre Megretski, Omer Tanovic, Yan Li, Vladimir Stojanovic, Mitra M. Osqui |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Computer science
Amplifier 020208 electrical & electronic engineering Bandwidth (signal processing) Volterra series 020206 networking & telecommunications 02 engineering and technology Topology Predistortion Amplitude modulation LTI system theory Nonlinear system Modulation Signal Processing 0202 electrical engineering electronic engineering information engineering Baseband Demodulation Electrical and Electronic Engineering Passband |
| Zdroj: | MIT web domain |
| Popis: | We consider equivalent baseband representation of transmission circuits in the form of a nonlinear dynamical system $\mathbf S$ in discrete time (DT) defined by a series interconnection of a phase-amplitude modulator, a nonlinear dynamical system $\mathbf F$ in continuous time (CT), and an ideal demodulator. We show that when $\mathbf F$ is a CT Volterra series model, the resulting $\mathbf S$ is a series interconnection of a DT Volterra series model of the same degree and equivalent memory depth, and an LTI system with special properties. The result suggests a new, nonobvious, analytically motivated structure of digital precompensation of analog nonlinear distortions such as those caused by power amplifiers in digital communication systems. The baseband model and the corresponding digital compensation structure readily extend to OFDM modulation. MATLAB simulation is used to verify the preposed equivalent baseband model and demonstrate the effectiveness of the new compensation scheme, as compared to the standard Volterra series approach. |
| Databáze: | OpenAIRE |
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