Per Vices Product Development

Introduction

In this article we will discuss how Per Vices Corporation works with clients to integrate high performance software defined radios (SDR) into customer systems for various mission critical applications. An SDR is a radio system where RF communication is done using software/firmware, instead of hardware that traditional radios are based on. An SDR’s radio front-end (RFE) contains the transmit (Tx) and the receive (Rx) functions to transmit and receive signals over a wide operating bandwidth and tuning frequency range. Our SDRs are very computationally powerful, and capable, due to our SDR’s digital backend containing Field Programmable Gate Arrays (FPGAs), with on-board Digital Signal Processing (DSP) capabilities for various tasks such as modulation, demodulation, upconverting, downconverting, filtering, etc. as well as all the data packet handling.

Who is Per Vices?

Per Vices is a company which specializes in building and integrating the best commercial-off-the-shelf (COTS) software defined radio (SDR) products used for mission critical applications. Founded in 2006 and with the first commercial products available in 2012, founders Victor Wollesen and Brandon Malatest are proud to have been included as one of the early hardware and integration companies to go through Y Combinator; a start-up accelerator which has helped startups including Reddit, Airbnb, Dropbox, and Twitch. From there, Per Vices has been designing, developing, building, and integrating high performance systems used for mission, life, and safety critical applications such as radar, MRI, low latency links, spectrum monitoring, GPS/GNSS, and test and measurement.

While we ensure confidentiality with our clients, we can say that we work with some of the top radar manufacturers, HFT firms, MRI manufacturers and government organizations. Some notable achievements include having our SDRs power the the lowest latency transatlantic link, being incorporated into high end radar systems, and being utilized for the highest performing spectrum monitoring and recording solutions.

Per Vices Products

Our flagship products are the Crimson TNG and Cyan high performance SDRs.

The Crimson TNG stock product consists of five modular boards: power board, digital/FPGA/DSP board, time board, Rx board, and Tx board. The RFE consists of 4 Rx/ 4 Tx independently controlled channels each offering 16-bit converters, and each offering 325 MHz of RF bandwidth giving a total of over 1200 MHz of RF bandwidth, and a tuning range of near DC to 6 GHz. The digital back end has an Altera Arria V FPGA SoC and dual 10GBASE-R SFP+ ports for networking to the host system at a rate of 20 Gbps. Right out of the box, our SDRs have a web UI for controlling the RFE and is also UHD compatible. Figure 1 shows an overview of our Crimson TNG SDR architecture.

Cyan is a higher performance SDR system and offers the best performance of any COTS SDR. It also has a modular board design consisting of separate time, power, digital, back plane, Rx and Tx boards. The radio boasts 16 radio boards where each board can be either Rx or Tx, with a tuning range of DC- 16 GHz with the ability to upgrade to higher frequencies as needed. Each radio board also offers 1 GSPS or 3 GSPS converters offering 1 or 3 GHz of RF bandwidth per radio chain. The digital back-end contains an Intel Stratix 10 FPGA SoC with 4x 40 Gbps qSFP+ ports, and upgradeable to 4x 100Gbps.

In addition to offering multiple high end SDR platforms, we also specialize in integration and custom developments. Per Vices take a customer focused approach when working with clients; establishing a strong working relationship, while coordinating timelines and goals to solve problems and challenges the customer faces. We provide all of the following for our clients where as most companies do not:

• Everything from the design, development and manufacturing of our SDR products
• Full integration support
• COTS stock products or custom SKU platforms
• Combination of hardware, firmware, and software design skills
• Licenses to our source code
• Interfacing equipment; such as host and recording systems
• Site visits to setup, integrate, and demonstrate our products
• Custom developments for customers requiring changes to the number of radio chains, tuning range, bandwidth, channel isolation, phase noise, wideband SFDR, noise figure, Tx output power, temperature range, latency, etc.

Benefits for using SDR are numerous. For starters, the FPGA is (re)configurable, and therefore a radio can be completely changed or repurposed by software changes (i.e. IP cores). This includes DSP such as modulation/demodulation schemes, encryption/decryption, other types of DSP analysis, and much more. Moreover, FPGAs make SDRs highly interoperable thus easily integrated into new or legacy systems for service life extension programs (SLEPs). Our SDRs are also UHD compatible out-of-the-box and can be used for common open source radio tool kits such as GNU Radio. Also possible is to create custom programs and applications in Python, C++, etc. All of these capabilities mean that one SDR will be able to perform multiple functions while maintaining utility over a long life span when compared to traditional hardware defined radios.

Case Studies: Per Vices SDR and Integration Efforts in Various Applications

Case study 1: Radar System Integration

For this project, we were tasked with modifying our Crimson TNG SDR platform to meet the radio, waveform storage, waveform generation, and interface requirements associated with replacing legacy equipment in a primary surveillance radar. The challenge with the project is that we needed to solve a combination of RF and digital performance requirements, size, weight and power (SWaP), and cost requirements such that careful considerations needed to be made when balancing the performance against the costs and the SWaP.

The final solution consisted of a combination of existing and new hardware to meet all of the requirements in a cost effective manner. By re-using our existing design and IP, we were able to save a tremendous amount of development time and costs. The final solution resulted in the modification of two parts of our stock Crimson TNG product; hardware and firmware.

From a hardware perspective we needed to undertake activities for designing a new circuit board to interface with our existing receive and transmit radio boards (Figure 2). The additional hardware was necessary to meet the performance figures the customer required associated with noise figure, sensitivity, attenuation, dynamic range, isolation, gain flatness, IIP3, out of band signal rejection and phase and amplitude stability.

As part of the project, we also needed to modify our stock firmware to include the external triggering, storage of waveform data, and custom messaging. Additionally, modifications to the firmware were necessary to ensure fully integration with interfacing equipment, which consisted of both new and legacy systems requiring flexibility in both data formats and protocols used.

To accomplish this task, we entered into a proof-of-concept contract to make minor changes to our clocking architecture to demonstrate our ability to meet customer requirements in a timely manner and within budget. Following the evaluation contract we entered into a full integration contract in which we designed the new circuit board, new mechanical enclosure, and performed the necessary changes to the firmware to meet the interface requirements with a legacy system. On delivery of the new system we worked closely with the end customer to ensure successful integration.

Case study 2: GPS/GNSS simulation

This project involved developing a custom SDR platform to meet the strict RF performance requirements associated with the simulation of different environments for testing GPS effectiveness. The requirements called for a combination of high performance RF and digital requirements for testing of both high and low power signals across multiple GPS bands.

The result was for Per Vices to come up with a new, performance focused, hardware design to meet the customer requirements in delivering a high channel count transmitter with aggressive channel masking and very high dynamic range for use across the L1 and L2 GPS bands. Our solution consisted of a new hardware design which enabled up to 16 transmit radio channels to be used with custom filtering and provide combined high power and low power signal outputs to be transmitted over the same radio port (SMA).

In order to achieve this, the customer first worked with our stock Crimson TNG platform to validate the performance of a 4 channel system. The next step was working with us to optimize some of the RF performance on the Crimson TNG platform to ensure we could meet the project’s objectives, and the final step was for us to design a new system to meet all of the objectives. In the end, the performance of the system exceeded the customer’s requirements while reaching near the theoretical maximums. We then worked with the customer on the integration of the new SDR within their existing system setup.

Case study 3: Spectrum monitoring & recording

The goal of this project was to use our stock Cyan platform combined with our host storage solution to capture a large amount of spectrum across multiple channels and store the raw data.

Spectrum monitoring & recording have unique challenges that require the equipment being used to provide advanced capabilities with respect to very high data rates; both on the capture and on the storage. For this project, the challenge was in capturing, transferring, handling, and storing a very large amount of data at very high data rates, on the order of 154 Gbps of data.

Our final solution consisted of a combination of our Cyan 8 Rx 1GSPS SDR along with a custom built storage solution which included a combination of high performance FPGA accelerated NICs, NVMe drives, SATA drives, and enough RAM to support the data flow. By using our stock Cyan platform, we were able to save the customer a significant amount of time and costs and allowed us to focus on the design and integration of a suitable storage system architecture. The final solution resulted in the two units being delivered to the customer, fully configured for their application, and with an example program to demonstrate performance.

To achieve the goals associated with this project, we discussed options with the customer and determined that the stock Cyan platform (Figure 3) would be a good fit for their project and also save them considerable non-recurring engineering (NRE) costs and time. Following the discussions concerning the radio resources, we continued the discussions around a suitable host and storage system that would meet all of their needs. We built a solution that met both their technical requirements and budgetary requirements and performed all the necessary actions required for an easy integration and operation of the two devices (i.e. the Cyan platform and the storage solution).

Why was Per Vices Selected for these projects?

Per Vices was selected as the preferred designer and manufacturer of these projects for several major factors:

• Extensive integration experience: we are able to adapt our products and solutions to ensure a smooth integration with customer’s equipment
• Availability: COTS products could already meet 80-85% of the system requirements
• Competitiveness: low cost of development and unit costs to ensure the customer end solution would be very competitive
• Complexity: reduction in supply chain complexity by having only one supplier as opposed to hundreds
• Performance: we demonstrated our ability to meet the very aggressive RF and digital performance requirements
• Risk Management: the availability of a COTS product allowed the customer to have the project proceed with each stage incrementally while validating performance
• Communication: fast and effective communication between both parties’ engineering teams
• Flexibility: our ability to customize the entire SDR, from form factor, to the individual components on the boards along with providing interfacing equipment

Conclusion

SDR is a highly capable and complex system that is becoming an integral part of various mission critical RF-based systems. Here we briefly discussed our experience in integrating our state-of-the-art SDRs into radar, GPS/GNSS, spectrum monitoring and recording, and low latency links. Each of these industries required Per Vices to work closely with the client to ensure they were receiving the right SDR system while going above and beyond the performance metrics required.

If you have an upcoming project requiring SDR for radar, MRI/RF medical devices, low latency links, spectrum monitoring & recording, GPS/GNSS, test and measurement, interoperability or any other RF communications, we’d love to help you out. Contact us and we can arrange a time to speak with our team of experts.

By Brandon Malatest and Brendon McHugh