D.A. Tkachenko1, Yu.V. Batov2, D.A. Puzko3, A.L. Gelgor4

1–4 Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia)

Formulation of the problem. Second generation digital satellite television systems DVB-S2 and DVB-S2X include different modes with Amplitude and Phase Shift Keying (APSK) modulation that implies modulation of signal amplitude. These modes have high spectral efficiency and they may be used for transmission of High Definition TV (HDTV) and Ultra High Definition TV (UHDTV) services, but they require good linearity of high power amplifier (HPA) characteristics for uplink earth stations and for satellite transponders. Application of digital predistortion is an effective tool to improve the linearity of HPA characteristics.

Objective. To make the evaluation of effectiveness for application of HPA digital predistortion in satellite broadcasting systems DVB-S2 and DVB-S2X based on simulation modeling including estimation of possible decrease for polynomial degree of the predistortion algorithm.

Results. The simulation model for DVB-S2X is developed including main stages of signal processing in transmitter and receiver devices, taking into account characteristics of satellite channels including digital predistortion based on Volterra model and different HPA models. Calculation of threshold values for signal-to-noise ratio at the receiver input is done for different DVB-S2/S2X modulation and coding modes for different HPA models. It is shown that application of HPA digital predistortion may significantly decrease threshold values of signal-to-noise ratio (for 2 – 9 dB) and it allows obtaining practically the same performance results for different types of travelling wave tube and solid state amplifiers that are close to the Hard-Limiter channel signal-to-noise threshold values provided in DVB standard documentation. The investigation also shows that decrease of polynomial degree in predistortion algorithm from 10 to 3 almost does not change the system performance (for APSK modes the threshold values increase up to 0,5 – 1,0 dB depending on HPA model and the mode of modulation and coding).

Practical significance. Obtained results shows that application of HPA digital predistortion is feasible for satellite broadcasting systems DVB-S2 and DVB-S2X, however, the selection of predistortion system parameters should be a compromise between providing proper system performance and complexity of predistortion algorithm implementation.

Tkachenko D.A., Batov Yu.V., Puzko D.A., Gelgor A.L. Estimation of effectiveness for application of digital predistortion in high power amplifiers of DVB-S2/S2X satellite systems. Radiotekhnika. 2022. V. 86. № 12. P. 47−57. DOI: https://doi.org/10.18127/j00338486-202212-04 (In Russian)

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