"Although software defined radio (SDR) is not a new concept for a long time, the answers to these questions, such as what SDR is, what it can do, and what are the physical objects based on SDR technology, do not seem to be so obvious and well-known. Recently, we visited two experts from national instruments (Ni) who introduced Ni's SDR platform products to us, giving us a clearer understanding of SDR technology.
Mr. Manuel uhm is the marketing director of ettus research, a subsidiary of Ni, and the chief marketing officer of the wireless Innovation Forum (formerly known as the SDR Forum). The wireless innovation forum is responsible for the software communication architecture standard of U.S. military radio and CBRS commercial broadband service for spectrum sharing between naval radar and Marines. Mr. Tu Fangze is a marketing engineer of Ni technology, responsible for RF and wireless business. He has participated in many RF related projects, including 128 antenna large-scale MIMO system, millimeter wave system and wireless mobile phone test system.
Mr. uhm said that the broad definition of SDR is to define part or all of the communication physical layer through software. According to this definition, all commercial base stations are SDR devices: they have a general FPGA and can make relevant changes to the physical layer. In addition to the base station, the terminal we use can also be understood as a software defined radio device.
Specifically, the SDR products of Ni are basically some instruments and equipment, which are usually used for communication product R & D, military equipment and product testing. They cover from portable applications to extremely strong RF performance, as shown in the figure below.
We note that these devices fall into two categories. One is various USRP platforms, and the other is RF instrument platforms such as VST, VSA and mmwave. The radio platform defined by Ni software can cover the needs of users in different industries, including commercial users, communication industry equipment, research institutions and colleges.
From the perspective of software, customers of USRP platform attach great importance to the open source attribute of products. They need underlying code, so such products usually run GNU radio open source development tools. In contrast, products under the Ni brand usually run LabVIEW, which makes development easier. Mr. Tu Fangze said that Ni is a platform manufacturer, so it will choose different software tools according to customers' needs. Because ettus research brand has a high recognition in the open source circle, the brand remains after the merger.
Spectrum sharing
Mr. uhm said that cognitive radio is an important field of software radio, and its typical application is spectrum sharing. There is a CBRS project in the United States, which is the abbreviation of citizens broadband radio service. CBRS allows anyone to share the vast spectrum currently used by the U.S. Navy. The US warship radar occupies some spectrum, but these spectrum are idle in most cases, and its utilization rate is very low, because naval warships do not appear on the coastline at any time. In February this year, Nokia, alphabet and Qualcomm used these spectrums to test LTE technology and broadcast HD video of a rally in Las Vegas.
The premise of spectrum sharing is that the base station must be able to identify the military radar signal and avoid it by adjusting the frequency when the signal appears, which is cognitive radio technology. Mr. uhm said that the future radio platform will become more and more intelligent, and realize independent radio transmission by combining artificial intelligence chips and solutions. On the other hand, system testing will pay more and more attention to artificial intelligence. In the future of five or ten years, LTE, Bluetooth and WiFi currently transmitting in the fixed frequency band will constantly change the frequency band it needs through artificial intelligence, so the test scheme will become more and more intelligent.
The latest n310 in the USRP platform has the function of spectrum sharing (such as CBRS). It can be distributed in a wide area. It can troubleshoot remotely without local operation. It has the characteristics of high reliability and fault tolerance.
USRP n310 is said to be one of the SDR products with the highest channel number density at present. It provides four transmitting and four receiving channels at a height of 0.5u. Each channel provides an instantaneous bandwidth of up to 100MHz and covers the extended frequency range of 10MHz to 6GHz. USRP n310 adopts zynq-7100 of Xilinx company SOC performs baseband processing, and programmable FPGA meets the requirements of real-time processing and low delay.
5g prototype and test
The previously mentioned Ni SDR instrument with large bandwidth and high performance can be used for the research and test of 5g mobile communication, including Ni VST, VSA, mmwave and other platforms. In terms of software, LabVIEW is the main development platform. Mr. Tu Fangze said that many 5g research projects use LabVIEW because customers need a complete tool chain, and Ni has built this system platform to enable users to quickly verify their algorithms, which is what LabVIEW is best at.
He said that after the arrival of 5g, there are more and more communication protocols, which poses new challenges to the testing work. The first is the increase of test cases. The second is that the demand for bandwidth will become larger. The third is that the test time is very high, so products should enter the market quickly. Ni closely follows up the 3GPP agreement to make the products quickly meet the 3GPP standards. The application of SDR technology makes all this possible.
Mr. Tu Fangze said that Ni has invested in 5g technology for a long time. In 2010, it established the RF leading plan to carry out large-scale MIMO and millimeter wave system research projects with many users at home and abroad. These partners include foreign Nokia, Intel and Facebook, as well as domestic institutions such as Southeast University and Beijing University of Posts and telecommunications. In terms of large-scale MIMO, Ni cooperates with Lund University, Intel, Southeast University, etc. In terms of millimeter wave, Ni cooperates with Nokia, Beijing University of Posts and telecommunications and some leading communication manufacturers in China to carry out relevant research.
Recently, Ni has cooperated with key chip manufacturers, research institutions and terminal manufacturers at home and abroad to carry out 5g chip R & D, chip testing and terminal testing. For example, Ni has just cooperated with Samsung to conduct interoperability test, and with qorvo to demonstrate the test of RF front-end module. Qorvo, the industry's first 5g RF front-end module qm19000, has an operating frequency range of 3.3 ~ 4.2ghz and a bandwidth of 400MHz. It integrates transmitting PA and receiving LNA. Ni's PXI test system includes pxie-5840 6.6 GHz VST, pxie-4139 ± 60V / 3A SMU and pxie-6570 digital mode instruments. The successful test of this module makes 5g mobile communication technology another step towards commercial application.
Original address: https://www.eeboard.com/news/5g-71/
Search aiban.com and pay more attention. You can master the latest development board, intelligent hardware, open source hardware, activities and other information every day. Recommend attention!
[wechat scanning can be followed directly]“
Our other product:
