Digital Predistortion Utilizing Over-the-Air Feedback for Phased Arrays

Kalman Filter Algorithm for Adaptive Digital Predistortion

This paper introduces a recursive algorithm of Kalman filter for digital predistorter parameters extraction based on memory polynomials predistorter model. The predistorter model is firstly formulated as linear regression expression. Then we derive the state-space equation of the model and attain the steps of the algorithm. Finally, the accuracy and stability of the algorithm is proved by simul...

Digital Electronic Predistortion for Optical Communications

RF PA Linearization: Open-loop Digital Predistortion Using Cartesian Feedback for Adaptive PA Characterization

This work combines the advantages of two different RF power amplifier (PA) linearization techniques: digital predistortion (DPD) and Cartesian feedback (CFB). Cartesian feedback, an extension of classical continuoustime feedback, is limited by the bandwidth of its loop transfer function; this bandwidth, in turn, puts an upper limit on the bandwidth of the data input. However, this limitation gi...

Optically Interconnected Phased Arrays

Phased-array antennas are required for many of NASA's future missions. They will provide agile electronic beam forming for communications and tracking in the range of 1 to 100 GHz. Such phased arrays are expected to use several hundred GaAs monolithic microwave integrated circuits (MMIC's) as transmitting and receiving elements. However, the interLn CO connections of these elements by conventio...

GCMAC-based predistortion for digital modulations

The subject of this paper is the compensation for nonlinearities in digital communication systems by means of predistortion. In this work, we apply the Generalized Cerebellar Model Articulation Controller (GCMAC) to simplify and accelerate the predistorter convergence. The range of analyzed predistorters includes: 1) a symbol-rate data predistorter that, for a given time span, achieves a simila...