What is usrp radio and Why Do We Use Them?

27 Nov.,2024

 

Software Services - NI - National Instruments

Single-Seat License Program

For more information, please visit our website.

The Single-Seat License Program provides access to an NI software service agreement with benefits like new and previous version downloads, technical support, and online training. These benefits are included in subscription licenses and for the first year of perpetual licenses. After the first year, software service is renewable on an annual basis.

How Does NI USRP Hardware Work? - National Instruments

3a. Host-Only USRP

Figure 2: NI USRP-

Following a common SDR architecture, USRP hardware implements a direct conversion analog front end with high-speed analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) featuring a fixed-personality FPGA for the digital downconversion (DDC) and digital upconversion (DUC) steps. The receiver chain begins with a highly sensitive analog front end that can receive very small signals and digitize them using direct downconversion to in-phase (I) and quadrature (Q) baseband signals. Downconversion is followed by high-speed analog-to-digital conversion and a DDC that reduces the sampling rate and packetizes I and Q for transmission to a host computer using Gigabit Ethernet for further processing. The transmitter chain starts with the host computer where I and Q are generated and transferred over the Ethernet cable to the USRP hardware. A DUC prepares the signals for the DAC after which I-Q mixing occurs to directly upconvert the signals to produce an RF frequency signal, which is then amplified and transmitted.

 

Figure 3: USRP- System-Level Diagram

 

3b. USRP Devices with Programmable FPGAs

Figure 4: NI USRP-

The NI USRP-294x/295x devices combine two full-duplex transmit and receive channels with up to 160 MHz/channel of real-time bandwidth and a large DSP-oriented Kintex-7 FPGA in a half-1U rack-mountable form factor. The analog RF front end interfaces with the large Kintex-7 410T FPGA through dual ADCs and DACs clocked at 120 MS/s. 

Highmesh Product Page

Each RF channel includes a switch allowing for time division duplex (TDD) operation on a single antenna using the TX 1 RX1 port, or frequency division duplex (FDD) operation using two ports, TX1 and RX2. 

The NI USRP-294x/295x devices cover from 10 MHz to 6 GHz frequency range with user-programmable digital IO lines for controlling external devices. The Kintex-7 FPGA is a reconfigurable LabVIEW FPGA target that incorporates DSP48 coprocessing for high-rate, low-latency applications. The PCI Express x4 connection back to the system controller allows up to 800 MB/s of streaming data transfer back to your desktop or PXI chassis, and 200 MB/s to your laptop. This connection allows up to 17 USRP devices to be cabled back to a single PXI Express chassis, which can then be daisy chained together for high-bandwidth, high-channel-count applications.

Figure 5: USRP- System-Level Diagram

 

3c. NI USRP- Stand-Alone Device

Figure 6: NI USRP-

The stand-alone NI USRP- includes an onboard processor, FPGA, and RF all in one form factor. The USRP- is built on a heterogeneous processing architecture with an onboard Intel Core i7 processor running the NI Linux Real-Time OS. It is a 2x2 radio that covers frequencies between 10 MHz and 6 GHz with the 160 MHz bandwidth and adds an x86 processor to form stand-alone system operation, which can be targeted to deterministically perform processing and program the Xilinx Kintex 470 FPGA all from a single design environment. The USRP- is also equipped with a GPS-disciplined 10 MHz oven-controlled crystal oscillator (OCXO) Reference Clock.

 

Figure 7: USRP- System-Level Diagram

Want more information on usrp radio? Feel free to contact us.