Figure - available from: International Journal of Numerical Modelling Electronic Networks Devices and Fields
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Block diagram of (A) baseband harmonic injection, (B) feed‐forward harmonic cancelation, and (C) HC‐DPD techniques
Source publication
High frequency (HF) transmitters implemented with the multi‐octave power amplifier (PA) are always faced with the problem of interfering harmonics because of the nonlinearity of the PA. In this paper, the harmonic cancelation digital predistortion (HC‐DPD) scheme is proposed and well discussed to cancel the in‐band intermodulation distortion (IMD)...
Citations
... The power amplifier (PA) is a crucial and energy-intensive constituent of the RF chain. 2 A PA typically operates with a nonlinear dynamic range, resulting in in-band and out-of-band nonlinear distortion. The in-band distortion reduces the error vector magnitude (EVM) and degrades the link performance, while the out-of-band distortion breaks the spectral masks and interferes with other users of adjacent channels. ...
Using a large number of power amplifiers brings serious nonlinear distortion to 5G communication systems, which becomes a challenging problem for conventional digital predistortion (DPD) to linearize signals. To address this challenge, we propose a digitally assisted nonlinearity suppression architecture for applications in multiple antenna arrays. In this architecture, we use an auxiliary array to generate a nonlinear cancelation signal to cancel with the main beam at the receiving end. We explore a two‐step method to model the nonlinear signal and combine neural network to complete the modeling. In addition, we introduce a novel method for estimating and tracking the channel to update the model coefficients. To verify the proposed methods, we design a scene and compare the performance of our architecture with that of conventional DPD. Our experiments demonstrate that our proposed methods can significantly enhance the adjacent channel power leakage ratio performance by 12 dB while also optimizing in‐band distortion. Moreover, our architecture outperforms conventional DPD approaches even with enhanced distortion.
