The innovative spirit sweeping the National University of Lesotho (NUL) rolls on unabated. Molefi Makuebu and Letapata Shoaepane, recent NUL B. Eng Computer Systems and Networks graduates are happy to introduce their latest design, a software Defined Radio (SDR) that catches all radios in Lesotho and some abroad, and can even track airplane traffic above you.
The smart graduates, supervised by Mr Khobatha Setetemela, achieved the feat as students at the NUL!
These guys do not only identify and catch radio stations. They are able to track in real-time, airplane movements. Displaying the plane’s flight number, altitude, speed, and location coordinates on the web portal of their radio system, all at once. As you take off in one of those overseas trips, they know you are gone.
And that is not all! They are working on including in their smart system, a transmission and reception of HDTV recorder functionality. This will soon enhance easy film making in Lesotho with good quality high definition videos over our own Digital Migration Network.
The product by the two fellows is not your normal hardwired radio that one can create after a bid of fiddling along with a few wires—No! It is a result of intense thinking, programming and grasping of fundamental scientific facts.
There is something intriguing about SDRs as compared to normal hardware radios; their versatility. That is, they lend themselves to being manipulated, changed and even improved on by their users, long after they are made. Like chameleons, they can change colour depending on the new environment. That alone, separates SDRs from much of what you thought you knew about radio.
In his preferred jargon, Mr Makuebu would define SDR this way. “It is a collection of hardware and software technologies that enable reconfigurable system architectures for wireless networks and user terminals.”
As if that jargon is not enough, his companion, Mr Shoepane, is more than willing to drive the point home. “The main goal of software radio development is to execute most of the radio functions through software over a stable architecture. That allows for easy and economic updates and improvements of a radio’s capabilities.”
Devoid of scientific verbosity, SDRs are what you were told they were; chameleons! That is, when a layman’s language is a preferred mode of communication. If an average colour-changing chameleon has a skin with cells (hardware) that can manipulate wavelengths and change colour (software), “…in SDRs, both hardware and software components are used and it becomes easy to reconfigure the software part of the SDR,” Shoaepane revealed.
The two gentlemen laid down their vision as working towards removal of impediments often encountered with the use of hardware radios, chief of which is cost of these conventional radios.
In their own words, “It is also expensive to put in place standard radios because a transceiver is entirely an integrated circuit.” That means if you want to modify conventional radios, you will have to start everything from the beginning! Thus equipment vendors incur high costs of producing new hardware upgrades.
Yet another importance of SRDs’ brilliance is also anchored along the dimension of cost. “For a hardware radio, separate devices are used for separate functions while for a software defined radio one device is used for many functions,” Makuebu showed. That, again is a big cost-saving attribute.
The problem is, the use of conventional radios is a ritual in many places. So what has the duo achieved in contributing to the change? A big deal! They have, in their hands, a full functioning FM Radio software receiver they developed. As shown, the FM radio will catch any radio station in Lesotho. Plus they feel at home as they monitor traffic at the Moshoeshoe I International airport.
As with all good things, working on this project was no smooth sailing. Of course, it was easier in the case of FM Radio band because they depended on the NUL Department of Physics and Electronics radio (DOPE FM) as their test platform which was on a close range. But yet, it was not easy with airline signals during testing.
They experienced some challenges with their equipment transmit/receive range. In this case, Moshoeshoe 1 airport was far to be used as test platform so they normally had to get closer to do so. Also, their equipment had a limited frequency range of 2 – 2000 Mhz and an antenna of length 1.52 cm. Due to these limitations, the numbers of radio stations received and airline traffic detected were limited depending on the geographical location.
Looking into the future, the young innovators switched to their scientific verbosity, perhaps aiming exclusively at their science peers, “better operating SDR systems could be implemented using a transceiver which would satisfy the transmit/receive range and the antenna size. For example, a HackRF one which covers a frequency range from 1 to 6000 MHz, and covers many licensed and unlicensed as well as ham radio bands.” There you go!
This blog post was originally written by NUL Research and Innovations