Behavioral Modeling and Digital Predistortion of 2x2 MIMO Wireless Transmitters with Enhanced Multivariable Polynomials

In this paper we propose a novel concept named Enhanced Multivariable Memory Polynomials (EMVP) for the behavioral modeling and linearization of Multiple Input Multiple Output (MIMO) transmitters in the presence of linear (LC) and nonlinear (NLC) coupling effects. The proposed model improves the linearization performance of the conventional Multivariable Memory Polynomials (MVP) model. Its performance is experimentally compared with the ones of three popular polynomial models. EMVP model has succeeded in offering better linearization of MIMO transmitters, with fewer coefficients, compared to the conventional models. Experimental results showed improvement in Adjacent Channel Power Ratio (ACPR

FPGA Implementation of the Generalized Parallel Two-Box Model-based Digital Predistorter for Wireless Transmitters

In this paper, the FPGA implementation of the generalized parallel two-box (GPTB) model is proposed. The blocks such as multipliers, complex magnitude calculator, and magnitude powers calculator have been utilized to implement the GPTB model. In the implementation of the proposed model, a total of 30 complex multipliers, 56 noncomplex multipliers and 56 adders were used. The GPTB DPD model has been implemented by using System Generator and Vivado software. The FPGA with a part number of xc7vx690t-3 from Xilinx has been employed to implement the model. The simulation results demonstrate the correctness of the implemented model in Vivado. Also, the verification of the GPTB model is accomplished by means of the simulation of the transmitter excited by QAM signals in the ADS software. The measure of an adjacent channel power ratio (ACPR) decreased by about 16[Formula: see text]dB as a result of the simulation.

Linealización mediante Predistorsión Digital de un Sistema Radio sobre Fibra de Doble Banda

En este artículo se propone la linealización de un sistema Radio-over-Fiber (RoF) de doble banda mediante predistorsión digital. Los resultados han sido evaluados experimentalmente con señales LTE en un sistema RoF, obteniendo mejores resultados que con el predistorsionador clásico de una banda en términos de Adjacent Channel Power Ratio (ACPR), pérdidas de potencia y Error Vector Magnitude (EVM).

A 280 W LDMOS broadband Doherty PA with 52% of fractional bandwidth based on a multi-line impedance inverter for DVB-T applications

We introduce a new technique for the design of an output combiner for Doherty power amplifier (DPA) and its effective exploitation for the development of a wideband laterally diffused metal oxide semiconductor (LDMOS) DPA. The design is enabled by a two-line impedance inverter for the DPA back-off operation, which is capable of 52% of fractional bandwidth. The technique is validated by the development of a DPA prototype for Ultra high frequency terrestrial digital video broadcast (DVB-T) applications, with optimized peak power and efficiency over 470–806 MHz. The prototype delivers between 40 and 53% of average efficiency across the band, at 49 dBm output power in average across the bandwidth, and supporting DVB-T signals with 8 MHz bandwidth and a peak-to-average power ratio of 10.5 dB. It achieves the target adjacent channel power ratio of −52 dBc at 750 MHz if digital pre-distortion is applied, and provides 47.8 dBm of output power with a drain efficiency of 44.3%.