Guo, Yan

Thumbnail Image
Preferred name
Guo, Yan
Official Name
Guo, Yan

Research Output

Filters

2
2
Reset filters

Settings

Now showing 1 - 2 of 2
  • Publication
    Power Adaptive Digital Predistortion for Wideband RF Power Amplifiers With Dynamic Power Transmission
    (IEEE, 2015-10-05)
    Guo, Yan 
    ;
    Yu, Chao 
    ;
    Zhu, Anding 
    To reduce power consumption of wireless transmitters, the transmission power level of RF power amplifiers (PAs) may dynamically change according to real-time data traffic. This leads that the existing digital predistortion (DPD) techniques cannot be directly employed because they are mainly suitable for eliminating distortion induced by the PAs operated at a relatively stable condition, e.g., at a constant average power level. To resolve this problem, a power adaptive DPD is proposed in this paper. By accurately modeling the behavior change pattern of the PA with the input power adjustments and embedding it into the DPD model, the proposed DPD system is able to adjust its coefficients to adapt to the behavior variation of the PA induced by the power adjustments without real-time recalibration. A low-complexity online coefficients updating method is also proposed to track the behavior change of the PA caused by other factors, such as bias shifting or temperature variation, during real-time operation. Measurements with a high power LDMOS Doherty PA have been used to validate the proposed approach. Results show that the proposed DPD and its coefficients updating approach can produce excellent performance with very low complexity compared to the conventional approaches.
      471Scopus© Citations 45
  • Publication
    Digital Compensation for Transmitter Leakage in Non-Contiguous Carrier Aggregation Applications With FPGA Implementation
    (IEEE, 2015-11-11)
    Yu, Chao 
    ;
    Cao, Wenhui 
    ;
    Guo, Yan 
    ;
    Zhu, Anding 
    In this paper, a generalized dual-basis envelope-dependent sideband (GDES) distortion model structure is proposed to compensate the distortion induced by transmitter leakage in concurrent multi-band transceivers with non-contiguous carrier aggregation. This model has a generalized structure that is constructed via first generating a nonlinear basis function that maps the inputs to the target frequency band where the distortion is to be cancelled, and then multiplying with a second basis function that generates envelope-dependent nonlinearities. By combining these two bases, the model keeps in a relatively compact form that can be flexibly implemented in digital circuits such as field programmable gate array (FPGA). Experimental results demonstrated that excellent suppression performance can be achieved with very low implementation complexity by employing the proposed model.
      597Scopus© Citations 16