Software-Defined Radio#
Software-Defined Radio (SDR) is a new approach for mobile communication architectures. The general idea is to replace special analog hardware components by FPGAs, DSPs and 'general purpose processors' (GPPs), and therefore allow fast-prototyping on a flexible platform. SDR is the enabling technology for Green IT, supporting multiple radio standards in a flexible and energy efficient manner. SDR based systems are reconfigurable and reduce developing time and costs in comparison with special purpose processors. Most of our SDR assets are based on Ettus Research and National Instruments https://www.ettus.com.
The RF front-haul is based on software-defined radio (SDR) components. Different off-the shelf commercial SDRs can be used from Ettus Research/National Instru- ment such as Universal Software Radio Peripheral (USRP) or space-ready SDR from GomSpace. Some of the RF units that can be deployed within the testbed may utilize the following models:
- Ettus Research based SDRs
(USRP N310, USRP B210, USRP X310) - GomSpace based Space ready SDR
(Nanocom SDR)
Hardware Specifications#
The requirements of each radio can be utilized according to use-case, hardware function, and application as previously mentioned. Accordingly, we can choose our radio frontend with respect to the maximum used bandwidth, number of available RF channels, and the on-board FPGA. In the table shown below, we summarize some of the tested SDRs specifications and their compatibility with the 3GPP standards such as 4G and 5G-NR.
| Specifications | USRP N310 | USRP B210 | USRP X310 |
|---|---|---|---|
| Vendor | Ettus Research | Ettus Research | Ettus Research |
| Driver | UHD - USRP Hardware Driver | UHD - USRP Hardware Driver | UHD - USRP Hardware Driver |
| RF Frequenct Range | 10 MHz – 6GHz | 70 MHz – 6GHz | DC – 6GHz *depends on daughterboard |
| Duplexing | FDD or TDD | FDD or TDD | FDD or TDD |
| MIMO | 4x4 MIMO | 2x1 MIMO 2x2 MIMO | 2x2 MIMO |
| Interfaces | USB Type A host port micro-USB port (serial console, JTAG) RJ45 - 1 GbE SFP+ | USB 3.0 | USB Type A host port micro-USB port (serial console, JTAG) RJ45 - 1 GbE SFP+ PCIe Express |
| Communication | SFP+ | USB 3.0 | RJ45/SFP+/PCIe |
| Compatibility | 4G/5G (up to 100MHz) | 4G/5G (40MHz with ¾ sampling) | 4G/5G (40MHz with ¾ sampling) |