In this chapter, we present a new hardware test-bed to demonstrate closed-loop precoded communications for interference mitigation in multibeam ultrahigh throughput satellite systems under realistic payload and channel impairments. We build the test-bed to demonstrate a real-time channel aided precoded transmission under realistic conditions such as the power constraints and satellite-payload nonlinearities. We develop a scalable architecture of an SDR platform with the DVB-S2X piloting. The SDR platform consists of two parts: analog-to-digital (ADC) and digital-to-analog (DAC) converters preceded by radio frequency (RF) front end and field-programmable gate array (FPGA) backend. The former introduces realistic impairments in the transmission chain such as carrier frequency and phase misalignments, quantization noise of multichannel ADC and DAC, and nonlinearities of RF components. It allows evaluating the performance of the precoded transmission in a more realistic environment rather than using only numerical simulations. We benchmark the performance of the communication standard in realistic channel scenarios, evaluate received signal SNR, and measure the actual channel throughput using LDPC codes.

Chapter Contents:

• 66.1 Introduction
• 66.2 Hardware demonstrator
• 66.2.1 System model
• 66.2.2 Gateway
• 66.2.3 Channel emulator
• 66.2.4 User terminal
• 66.2.4.1 LLR demapper
• 66.2.4.2 LDPC decoder
• 66.2.5 Resource occupation in FPGAs
• 66.3 Conclusion
• Acknowledgments
• References

Inspec keywords: digital video broadcasting; MIMO communication; software radio; precoding; interference suppression; radio receivers; field programmable gate arrays; parity check codes; wireless channels; analogue-digital conversion; satellite communication

Other keywords: scalable architecture; realistic channel scenarios; field-programmable gate array; hardware precoding demonstration; RF components; real-time channel; multichannel ADC; satellite-payload nonlinearities; interference mitigation; realistic impairments; realistic environment; precoded transmission; closed-loop precoded communications; hardware test-bed; communication standard; DAC; channel impairments; multibeam ultrahigh throughput satellite systems; SDR platform; phase misalignments; DVB-S2X piloting; realistic payload characteristics; transmission chain; actual channel; power constraints; carrier frequency; multibeam UHTS communications; digital-to-analog

Subjects: Codes; Radio and television broadcasting; Electromagnetic compatibility and interference; Other topics in statistics; Logic circuits; Radio links and equipment; Signal processing and detection