A Software Defined Radio Platform is a self-contained RF product that hosts all the features that your customer wants in a portable, easy to use, reliable, sturdy package with consistent performance. The Software Defined Radio Platform has many advantages over the Software Defined Radio + computer configuration for RF engineering.
QRC's Wide Band Transcorder® (WBT®) was designed to speed your RF software product delivery by giving you a ready to use Software Defined Radio Platform for development and distribution. Two separate tuners are available, each transceiving 40 MHz of RF signal for receive, record, generation, and playback (providing up to 80 MHz total instantaneous bandwidth) in one fully functional and field ready platform.
This series outlines the advantages of using QRC's WBT-200 or WBT-210 instead of a classic software defined radio (SDR) to create and field your solution to market.
If you need an RF solution with an open architecture that supports your proprietary software, the SDR + computer configuration sounds like a good approach to a new product solution. The reality is; however, often far from an easy road. If you start with an SDR and a computer then your custom software solution could be many months or even years away from delivery to a customer. Months to years are a long time to wait for your return on investment! QRC can reduce your risk. We offer a fully integrated and tested Software Defined Radio Platform as the host for you product; and you accelerate your new RF software solutions to market.
With the WBT as a product platform your customers can be using your supplied software capabilities within weeks, or at most a couple months, depending on the complexity of the software application. That is much faster than the SDR and PC combination. We know developers who have struggled with this time to market problem and switched to the WBT.
One of the things that has surprised us most about our WBT Software Defined Radio Platform is that multiple businesses have adopted the WBT as their hardware platform AFTER they had ALREADY tried to build their own hardware platform first.
These business people had already taken on all of the challenges of creating a functioning product using an SDR and computer for their customers. However, upon finding the WBT they have abandoned their own hardware efforts and switched over to adopt the Software Defined Radio Platform WBT.
The WBT reduces time to market to weeks or months because the Software Defined Radio Platform is ready for software development right out of the box. We designed the WBT models for easy use right out of the box. The WBT 200 model has a built in touch screen for mobility, and the WBT 210 model has no touch screen and is easily rack mountable or used on a bench.
This WBT Software Solution App performs basic signal event logging. It was developed in 8 weeks by one developer as his first use of the WBT Application Programmer Interface. Concept demos were touch screen ready for interaction with the sponsor by the fourth week.
QRC enables you to easily add your own software products to the WBT Software Defined Radio Platform. This was the goal from day one. The WBT has an "App Space", similar to any smartphone. We provide all of the source code for a comprehensive "example app", which can control and attach to the I&Q data stream, calculate FFTs, display data, and log those results. The WBP Application Programmer Interface is fully documented, ready to run and easy to use in a portable virtual machine.
We integrated a stable and supported Linux OS with mature off the shelf development tools in the portable virtual machine image. We provide advanced user interface components, File Interface, and other tool building support. Developers may create solutions in C++, QT, Python or the GNU Radio Companion.
Look at the kinds of engineering steps it takes to start with the SDR and PC configuration to make an RF solution product. All the engineering risks of evaluating and integrating a solution remains on you until these items are resolved.
What Are the SDR + Computer Configuration Integration Risks?
You first must select an SDR from a crowded field of vendors. Some SDRs cannot provide a digitized RF data stream in I&Q data format. They can only give an energy measurement. You need the digitized I&Q data stream to do any real demodulation or signal processing.
After selection you will need a configured Development Environment to be able to evaluate the SDR + Computer concept platform.
You then have to deal with many things that impact your leashed system's performance including, for example;
The overhead in the PC,
Controlling the tuning,
Setting the gain values,
Overflow data bits (many SDRs don't even have an overflow bit!), and much more.
Other issues that we've seen in most SDRs (especially the cheaper ones) include;
Problems with IQ imbalance,
The DC component signal that is always present with direct conversion radios that must be managed
Non-linear tuner behavior
Calibration routines,(most SDRs don't come calibrated for power)
Update and upload routines
Some form of useful FFT that minimizes CPU
Timing management interfaces (10 MHz and 1 PPS) as well as software synchronization.
Tagging the collected data with highly accurate time information is also a pretty complex topic that should be accounted for if time and or position of when the data was received is important.
An installation package that takes all the right 'stuff' and puts it on the user's compute
Most manufacturers don't publish the USB chipset controller identifiers, so good luck finding a source of laptop PC's with that chart. Now your product solution would require a specific short list of PC's with the ideal USB chipset.
Also, many chipsets aren't ideal. As you can see in this table below the Ettus SDR they indicate they cannot stream the 25 MHz bandwidth promised in both directions at the same time even on some of the USB chips they recommend for use.
USB 3.0 Can Be a Serious Limitation
Watch out for USB limitations. SDRs employ a USB 3.0 data connection to the computer. If your product needs to transmit and receive with the same tuner you may find that the USB 3.0 data connection cannot support the wide RF bandwidths some SDRs can digitize into I&Q data. That is a serious disadvantage for the SDR + Computer solution.
For example, Ettus has a table on their website that shows three recommended USB 3.0 chipsets for the PC. See the pictures to the left for details.
When the transfer rate is less than 25 MS/s it means 25 MHz bandwidth is not going to work. So in the end analysis, only one chipset remains able to fully support the performance claim.
The Market Advantage Of Wide Band Widths And PCIE Bus Design
Many SDRs are available with smaller bandwidths like 16 or 32 MHz. However, the market advantage of flexibility is with the wider bandwidths like 50 or 80 MHz of simultaneous bandwidth.
Your WBT based product will be more versatile and able to demodulate wider signals with wider bandwidth tuners. For example, the cellular technology, LTE, would be nearly impossible to demodulate with a narrow bandwidth SDR. A wider bandwidth accompanying a wider tunable range also increases flexibility for the analysis of the wireless "Internet of Things" in our communication industry. We designed the WBT with a PCIE bus technology to reliably handle 80 MHz of bandwidth without loss. Also, the WBT keeps over 90% of the system's CPU available to process and make use of that I&Q data stream in your software solution.
If you don't use the WBT, then your next effort for a product would be to build a development environment on the computer so you can explore the real capability of the SDR. Some of the details of this time consuming configuration management exercise are as follows. Many developers will select a Linux operating system, thinking it's a free item to use as an open source OS. However, managing the configuration of an effective development environment can require days or even weeks to get all of the right packages, drivers, and compilation components installed before you really get to begin testing your SDR capability with your code.
Cobbling a development environment together is time consuming! Time is money especially at this stage of your project because you have not yet started developing the software solution. More of your time will be lost in the frustration of learning what you need to know to get up and running with your ad-hoc development system to discover the risks and problems in the SDR you selected. In many cases the SDR vendor has little to no installation or configuration documentation. Frankly, when documentation is present, it is either out of date, or refers to a not yet released "unstable" configuration. This leads to an embarrassingly inordinate amount of time spent wading through technical forums.
That is why we provide a supported development environment that is fully integrated to the WBT and ready to use on day one. It's a virtual machine image that is portable and full of well-known software development tools. We integrated a stable Linux OS with mature off the shelf development tools in a portable virtual machine image. We provide an API, user interface QT components, File Interface, and other tool building support. Developers may create solutions in C++ or Python.
The WBT Waterfall App created with the Development Environment in C++
The basic Spectrum Analysis App created with the Development Environment in C++
We have seen problems in tuner performance like RF signal spurs every 100 MHz.
We have seen problems in the weight of several solutions on the market. For example one solution weighed in at 28 pounds compared with the less than 10 pounds of a WBT. The portability of the WBT is one of the reasons a developer adopted the WBT and abandoned their own solution.
Some developers could not get the dynamic range they needed; the WBT has 130 dBm of dynamic range. Others had issues with the RF noise floor. The WBT can show a -140 dBm noise floor.
Then there are problems like radio tuner firmware upgrade limitations, RF signal stability issues, problems with support, the list goes on and one. After you resolve the integration issues you are likely to be much poorer than you budgeted and have a schedule much longer than you planned.
Will you reinvent the laptop to make the SDR and storage fit inside?
QRC has already resolved all of the issues in our Wide Band Transcorder products. QRC has been integrating RF solutions since 1987. Our success has prepared us to field a world class RF Spectrum Capture and Playback product line.
The removable off-the-shelf SSD storage feature allows continuous recording time because a user is able to swap out the full drives while recording continues without interruption.
Is Your SDR + Laptop an cumbersome solution?
Will you stop at "some assembly required" before use?
Frankly, the WBT's performance is beyond most SDRs capabilities.
The WBT 210 Software Defined Radio Platform
The WBT RF performance is superior to every other SDR we've had the chance to use. Each transceiver in the WBT platform is a high quality, special order Software Defined Radio engine, able to process up to 40 MHz of full duplex data. That is, transmit and receive data simultaneously.
Both WBT-200 and 210 models have two full duplex SDRs. That gives the WBT 80 MHz of bandwidth. The platform can record hours of data to either of the two integrated hot-swappable solid state disks.
The GRC can help define a prototype tool or demonstrate an RF algorithm within minutes when it is used by an experienced engineer. But we also secure the GRC based solution as apps that are portable.
A GRC based app can be compiled into protected executable code, and deployed to the field for an end user who has no GRC experience. This overcomes one of the biggest shortfalls in GNU Radio Companion in our opinion. Use of the GRC usually requires an experienced GRC programmer to setup all those capabilities. With the WBT, a GRC solution is complied, distributed and used. A WBT app solution is LITERALLY as simple as picking the App icon from the App Manager view and running it.
This FFT demo was created with GNU Radio Companion and ready to distribute to WBT users as an engineering solution in minutes.
We will shortly announce an FPGA coprocessor option and it's software support. Also video and sound output will come through the HDMI Interface. More user interface API enhancements are expected regularly.
QRC is committed to providing those who use the WBT with an easy to adopt yet powerful to expand upon platform. We aim for world class support and capabilities, at a price that most can't achieve for themselves. Whether it's to record a signal and just listen to it or to process the I&Q and generate new signals we aim to cover it. For any use case that you can imagine with two independently tunable transceivers, QRC can provide a solution, and a price point, that will be hard to beat. Give us a call, and let's discuss your specific need. I'm sure there's a WBT configuration we can supply you with that will make sense, both economically and satisfy your time to market needs.