Closed-Loop Antenna System for Improved Satellite Signal Reception

Project in Nutshell:
We were commissioned by a major manufacturer of mobile satellite antennas to develop algorithms for an Artix 7 FPGA by Xilinx/AMD to improve the final signal for a vehicle-mounted antenna. We achieved a speed of 12 microseconds to generate corrections to the antenna performance — 3 microseconds faster than the target value.
As a result, our client can remotely tune the antenna and provide a high-quality satellite signal in near real-time.

Client & Challenge

A world leader in the design and manufacturing of mobile antennas turned to us for FPGA design for the solution based on AMD/Xilinx Artix 7. The challenge was to transfer the signal analysis and correction factor generation process to the FPGA to improve the final quality of the signal that is delivered to the antenna.

Before the FPGA implementation, signal analysis and correction factor generation were done on a CPU and its response speed was insufficient: it took more than 15 microseconds from the command receipt to recalculate the factor to the output of the new data to the antenna.

Solution

We worked with the client on the time and materials pricing model, involving an FPGA tech lead and an FPGA developer in the project. The work took several stages:

Our engineers implemented basic functions according to the technical specifications and handed them over for laboratory and field testing on the client's side.
After the testing, our client requested the implementation of some additional features.

The debugging process took place on the client's side, and our team provided advice and support to the client's engineering team when necessary. Our engineers reproduced and fixed the detected errors.

1. Concept Development

Our engineers described the algorithms to be implemented in the FPGA to calculate the main parameters of the phased array antenna in a fixed-point format.

_{Schematic diagram of the signal reception system and correction factor formation}

Our solution operates in the following way: the antenna receives a signal evaluated by algorithms. These algorithms generate data for the FPGA that generates a correction factor to improve the communication quality and sends it to the antenna, which applies the signal changes. The computer monitors the status, selects a new correction factor, and sends it to the board.

2. Hardware Design & Firmware Development

We developed the hardware platform based on the AMD/Xilinx Artix-7 FPGA. The firmware, based on the data received via the SPI interface, calculates the main parameters for the antenna phased array. All calculations are done in fixed-point format. After this analysis, the obtained values are transmitted via output lines in the SPI format. The PC receives the signal, evaluates it and outputs four signal parameters sent to the board. Based on this information, we recalculate the correction factors in the FPGA: phase, amplitude, phase correction, and amplitude correction. This data is sent to the RF part via the SPI interface. According to the task, we have 15 microseconds to start issuing the calculated data after the four parameters come. After entering the first estimated data into the RF part, it must come out no later than 15 microseconds (actually, it is 12).

Business Value

As a result of the project, the client can reduce the time spent calculating parameters for setting up a phased array antenna to 12 microseconds. This affects the speed at which the antenna is adjusted during movement, increasing the connection quality to a satellite.

Also, the client can remotely tune the phased antenna array mounted on moving vehicles and significantly improve communication, emergency response, and transportation.

More of What We Do for Satellite Communications:
Broadband Software-Defined Radio Satellite Modem: we designed the device in a compact 1U form factor by dividing it into digital and analogue boards.
High-Speed Large Data Transfer with SPDK and DPDK Solutions: how we implement high-performance data processing – 10х faster than the Linux kernel network stack.
Software Modules for the HTS Satellite Communication System: we developed TCP PEP and QoS modules using DPDK for an HTS satellite communication system.

Tell us about your project!

All submitted information will be kept confidential.