This chapter addresses the practical problem of signal distortions due to hardware imperfections such as power amplifier (PA) nonlinearity, modulator imperfection, cross-modulation and cross-over interference due to the multiple-frequency (multiband) and multiple-input/output transmission schemes proposed for 4G/5G communication. Basically this chapter targets two problems whose system level description have a certain similarity, so that they can be tackled in a similar digital predistortion system (DPD); however, digital level algorithms and implementation challenges will differ from each other.

Chapter Contents:

• 9.1 Distortion inducing elements in multichannel transmission Multichannel transmission
• 9.2 Distortion in multiband transmission
• 9.3 Distortion components in MIMO transmission
• 9.3.1 Nonlinear distortion
• 9.3.2 Linear distortion
• 9.4 Digital predistortion techniques for multichannel transmission
• 9.4.1 Digital predistortion techniques for multiband transmission
• 9.4.1.1 Dual-band DPD models
• 9.4.1.2 Tri-band and higher order DPD models
• 9.4.1.3 Multiband DPD for harmonic distortion dual-band DPD models
• 9.4.2 Digital predistortion techniques for multiple-channel transmission
• 9.4.2.1 Cross-over memory polynomial
• 9.4.2.2 Parallel Hammerstein (PH) model
• 9.5 Digital predistortion techniques for multiband/multichannel transmission in the presence of modulator imperfections
• 9.6 Application considerations of DPD models for multiband/multichannel transmission
• References

Inspec keywords: electromagnetic interference; MIMO systems; 5G mobile communication; nonlinear distortion; linearisation techniques; quadrature amplitude modulation; radiofrequency amplifiers; multifrequency antennas; wideband amplifiers; modulators; 4G mobile communication

Other keywords: digital predistortion system; DPD; digital level algorithms; cross-modulation interference; level description; multichannel power amplifier linearization; multiple-input transmission schemes; output transmission schemes; cross-over interference; multiband power amplifier linearization; 4G/5G communication; modulator imperfection; power amplifier nonlinearity; PA nonlinearity; signal distortions; hardware imperfections

Subjects: Mobile radio systems; Electromagnetic compatibility and interference; Amplifiers; Single antennas; Modulators, demodulators, discriminators and mixers