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Beamforming is critical to enable initiatives by the U.S. Federal Communications Commission (FCC) to increase spectrum capacity and provide additional cellular service and coverage through satellite and terrestrial systems. The key technology for this application is beamforming, which electronically steers data streams to and from a satellite via a combination of an array of antennas on the satellite and very sophisticated, ground-based computational engines.

Figure 1. The two major components of the beamforming system include the Analog Conversion Unit (ACU) and Beamformer Computational Unit (BCU).

Mercury Computer Systems secured an $8.6 million contract to develop a ground-based satellite beamforming platform where the much of the computational burden is accomplished on the ground and communicated to the satellite. In order to provide these services, upwards of 15 TeraOPs of computational performance is required to support the steering of hundreds of beams in the satellite. The standards-based communications platform is designed to include multiple carrier-grade field-programmable gate arrays, or FPGA-based, compute blades in an AdvancedTCA (ATCA) chassis. In its full configuration, the system interconnects more than 100 latestgeneration FPGAs with one-half terabit of streaming I/O, delivering one of the highest performing, signal-processing platforms in existence.

ATCA Capabilities

Mercury's customer, who is developing the ground-based beamformer, wanted to leverage the high-performance capabilities of ATCA technology. A series of industry-standard specifications for next-generation carrier-grade communications equipment, ATCA enabled the customer to take advantage of a broad and growing ecosystem, with processor blades and chassis, for example, available from a number of vendors, and FPGA compute blades available from Mercury. While a proprietary system could have handled the computing requirements, designers would not have been able to select from a variety of suppliers for the chassis, host processors, hard drives, and other support functions. Although some COTS system architectures could have handled the requirements, they would not have been suitable for a variety of reasons, including: scalability, modularity, and economics. Mercury would have had to customize the other infrastructures substantially, which would not have been feasible from a cost perspective.

Modularity is another reason ATCA made sense for a solution that needs to expand as system requirements grow. Rear-transition modules route the antenna data streams into and out of the system. AdvancedMCs (AMCs) serve as host processors and hard drives. The system also uses custom-built ATCA blades for the FPGAs performing the computing. ATCA is designed with small modules called AMCs that are hot-swappable from the front panel. Rear Transition Modules also can be plugged into the back to bring traffic into the chassis, giving system designers a number of ways to expand the system and making the system more cost effective.