Development of a DVB-S2X signal generator for modem equipment testing
Автор: Zharinov V.F., Komarov V.A.
Журнал: Siberian Aerospace Journal @vestnik-sibsau-en
Рубрика: Informatics, computer technology and management
Статья в выпуске: 1 vol.27, 2026 года.
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This paper examines the specifics of ground-based experimental testing of modem equipment for satellite communication systems operating in highly elliptical orbit (HEO). We formulate the problem of lacking specialized test equipment for this testing process. Using software-defined radio technology, we develop a generalized block diagram of a DVB-S2X standard test signal generator that additionally implements simulation of signal retransmission by satellites operating in HEO. We develop a suite for application and specialized software of the signal generator, implementing traffic preparation, encapsulation, and synthesis of complex baseband signal samples on an FPGA in accordance with the DVB-S2X standard. We propose a generalized digital signal processing architecture that simulates distortions characteristic of signal propagation through a satellite transponder in a highly elliptical orbit. We implement a prototype signal generator based on the USRP X410 software-defined radio platform, operating across symbol rates ranging from less than 0.1 to 122.88 Msym/s. We present a generalized block diagram of the test bench used for experimental studies. We show practical results of FPGA resource utilization in the X410 radio device for implementing the developed specialized software, verification results of the generated signal-code structure, and performance test results of the prototype signal generator using a reference demodulator. The obtained results fully confirm the correct operation of the developed prototype signal generator. The developed prototype can be used as part of the test and verification equipment for modem hardware within the ground communication complex of the Express-RV system.
Tests, modem equipment, satellite, software-defined radio
Короткий адрес: https://sciup.org/148333270
IDR: 148333270 | УДК: 621.376 | DOI: 10.31772/2712-8970-2026-27-1-72-81
Текст научной статьи Development of a DVB-S2X signal generator for modem equipment testing
The need to ensure guaranteed Internet access throughout Russia and, in particular, in the waters of the Arctic Ocean led to the creation of a satellite communication system with spacecraft in a highly elliptical orbit “Express-RV” [1]. In this communication system, data transmission via the on-board spacecraft relay system between the satellite communications center and subscriber terminals (direct channel) is implemented on the basis of modem equipment using the DVB-S2X data transmission standard [2; 3]. The key features of the propagation of signals transmitted through spacecraft in a highly elliptical orbit (HEO) are their variable propagation delay and Doppler shift in the operational area of the orbit. A synchronization system operating in modem equipment provides compensation for these distortions when receiving signals [4–8]. In turn, the stability of the communication channel and the data transfer rate depend on the correctness of the synchronization system in the future.
Thus, providing the possibility of debugging, configuring and subsequent testing of modem equipment in laboratory conditions as close as possible to real conditions necessitates the creation of a specialized signal generator that generates DVB-S2X standard signals with distortions characteristic of signal transmission through spacecraft to the HEO [9].
Solution description
A generalized block diagram of the DVB-S2X shaper, developed on the basis of software-defined radio technology, is shown in Fig. 1 [10].
Software-defined radio
Fig. 1. Generalized block diagram of the DVB-S2X signal generator
Рис. 1. Обобщенная структурная схема формирователя сигналов DVB-S2X
A software-defined radio device is connected to the control computer. The control computer hosts a control software package that implements the functions of traffic generation, management of special FPGA software, as well as the configuration of the analog output path of the radio device. The FPGA software includes a DVB-S2X standard modulator subprogram based on Creonic's IP core, as well as a radio channel model subprogram.
Figure 2 shows the graphical interface for controlling the shaper on the computer side, implemented in the LabVIEW graphical programming environment.
Encapsulator control
Filling packets
Valid FIFO
377042,
PDU counter 3740!
Loop counter 1
PDU data | Random data B
BBFRAME counter
Data
GSE packets counter
Loop counter 2 [2147483647
Empty Elements FIFO
Modulator control
Samples iO
-149
Dummy frame counter
Samples i1 [581
Samples i2
-881
Samples 1133.
Samples q1 642
Samples q2 -779
BBFRAME counter
Modulator settings
Scrambler sequence
Interpolation Cluster Interpolation input sample rate
Transceiver configurate
TX LO Frequency
Last counter 137403
Samples i3 992
Status 1855822866
Samples q3 369
Bytes counter
FIFO ready counter [3591530992
DBs state control
Dummy frames enable
Clear frag
Fig. 2. Graphical interface for controlling the generator (signal generation tab).
Encapsulator settings
BBFRAME CRC-32
