Gidel FPGA boards used for next-generation wireless communications research
Real-time processing used by a German research team in an experimental wireless communication base station.
March 28, 2022 — As 5G, the fifth generation of wireless communication standards, is being rolled out, scientists continue to search for ways to improve the bandwidth efficiency of wireless communication networks. With the rise of connected objects (IoT) such as autonomous vehicles, future communication networks must be able to exchange data in real time with more and more terminals within a cell.
One promising technology to achieve this is Massive MIMO (Multiple Input, Multiple Output) base stations. Massive MIMO base stations consist of an array of dozens or hundreds of antennas that communicate simultaneously with a large number of terminals within the cell. The signal received from each terminal in the cell has specific characteristics due to its relative position with respect to the base station. SDMA (Space Division Multiple Access) is a method that analyzes these characteristics to optimize the downlink transmission accordingly. This ensures that the capacity of all antennas in the network is utilized to its maximum, providing the best possible bandwidth to all endpoints in the cell.
The main challenge in the development of Massive MIMO antennas is the processing of all these signals in real time. Since all cell terminals are connected to all base station antennas, complex encoding and decoding must take place to put together the puzzle pieces of each uplink and downlink signal. And this processing must be as fast as possible, because the mobile terminals constantly change position within the cell.
Pushing the boundaries of wireless communication
A research team from the Department of Electrical Engineering and Computer Science (EECS) at the Technical University (TU) Berlin, Germany, led by Professor Giuseppe Caire, is working to address these challenges. Professor Caire is a globally recognized and distinguished scientist in the field of communication research. The goal of research is to increase the capability, functionality, and reliability of wireless devices and systems by investigating new concepts and optimizing them to determine their fundamental limitations. The team built experimental massive MIMO antennas to prove the validity of their concept. The results of this research and its proof of concept will be used by the industry to develop the fifth and sixth generation mobile communication systems.
Real-time processing with Gidel FPGA technology
Looking for a solution to process incoming signals, the TU Berlin team turned to Israel-based FPGA processing expert Gidel. The experimental massive MIMO base station is capable of communicating with eight user terminals, simultaneously, with less than the radio resources a conventional base station needs to communicate with a single user terminal.
All antenna signals and communication streams are handled on a single high performance FPGA board which is connected to the radio front ends as well as the network infrastructure via multi-gigabit transceivers and the PCI Express interface. This solution ensures high throughput and extremely low latency, which is critical in wireless communication. To achieve this, Gidel implemented Intel’s Arria10 FPGA due to its high floating point processing power and data communication performance.
Massive MIMO base stations with SDMA use beamforming to target radio transmissions to each terminal. This reduces the radiation power required for transmission and thus the risk of interference. Adding antennas to the array improves beamforming accuracy and therefore base station efficiency.
The experimental setup of TU Berlin, which was developed by Dr.-Ing. Andreas Benzin, has an array of 64 antennas for a single Gidel FPGA board for signal processing. In a practical implementation, the Gidel board could handle up to 192 antennas at a time. Larger base stations could easily be implemented by adding FPGA boards to the system.
Easy upgrades with consistent hardware and software
Gidel has been with the research team for many years. “It all started in 2005,” recalls Dr. Ing. Andreas Kortke. “At that time, Gidel’s ProcStar II boards offered a large number of high-speed, general-purpose FPGA signals and the ProcWizzard programming tool made programming easy.” The team could focus on implementing its signal processing algorithms on the FPGA early on. They didn’t have to waste time developing the peripheral-to-host interface, drivers, etc., since these were provided by Gidel.
Over the years, the team has built new experimental systems with next-generation FPGA hardware. “Migrating to the latest Gidel platform was extremely easy as the hardware concept remained the same and the same API suite was maintained across platforms,” says Kortke.
The collaboration between Gidel and the research team of the TU Berlin has lasted for more than 15 years. The technical capabilities of Gidel’s FPGA boards are not the only reason for this success, however. “The quality of the technical documentation for hardware and software has also been very helpful for our work,” says Andreas Kortke. “And we could always count on Gidel’s customer support in case of problems”. With technologies such as the Internet of Things (IoT), edge computing, autonomous vehicles, and more, the need for fast and reliable wireless internet will only grow in the years to come. With high-speed processing and low latency, Gidel’s FPGA technology is helping to create the infrastructures of tomorrow’s connected world. Reuven Weintraub, CEO of Gidel, said, “This application demonstrates the potential of our FPGA technology wherever high throughput and real-time processing is required.”