SOFTWARE DEFINED RADIO

SOFTWARE DEFINED RADIO [SDR]

[Here is an article on SDR compiled by my students Shijesh, Sibil, Shyju and John by browsing the internet, books and journals]


The rapid growth of technology and changing trends in the Communication techniques has paved way for the introduction of many telecommunication devices, many of which are not feasible to modify cost effectively due to lack of flexibility in their implementation. Software Defined Radio (SDR) technology mitigates this problem by providing the flexibility through software.

Software-Defined Radio (SDR) is a rapidly evolving technology that is receiving enormous recognition and generating widespread interest in the telecommunication industry. Over the last few years, analog radio systems are being replaced by digital radio systems and programmable hardware modules are increasingly being used in digital radio systems at different functional levels. SDR technology aims to take advantage of these programmable hardware modules to build open-architecture based radio system software.

An SDR system is a radio communication system where components that have typically been implemented in hardware are instead implemented using software on embedded computing devices. In other words SDR is a Radio in which some or all of the physical layer functions are software defined.

A Radio is any kind of device that wirelessly transmits or receives signals in the radio frequency (RF) part of the electromagnetic spectrum to facilitate the transfer of information.

In today's world, radios exist in a multitude of items such as cell phones, computers, car door openers, vehicles, and televisions.

While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics are practical enabling many processes that were once only theoretically possible.

In the past, radio systems were designed to communicate using one or two waveforms [waveform here refers to any specific standard like Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA) or it can be as simple as Frequency or Amplitude Modulation (FM or AM)].

As a result, two groups of people with different types of traditional radio were not able to communicate due to incompatibility problems. The need to communicate with people using different types of equipment can only be solved using software programmable radios because of its flexible architecture.

Traditional hardware based radio devices limit cross-functionality and can only be modified through physical intervention. This results in higher production costs and minimal flexibility in supporting multiple waveform standards. By contrast, software defined radio technology provides an efficient and comparatively inexpensive solution to this problem, allowing multi-mode, multi-band and/or multi-functional wireless devices that can be enhanced using software upgrades.

The primary goal of SDR is to replace as many analog components and hardwired digital VLSI devices of the transceiver (radio) as possible with programmable devices.

Some of the advantages of SDR are:

Multifunctionality. The same piece of hardware i.e. the radio set can be used to transmit, receive and process different communication signals that adhere to different air interface standards. This can be done simply by reconfiguring the software.

Global Mobility. The same piece of hardware i.e. the radio set can be used in different parts of the world that endorse different air interface standards. This can again be done simply by reconfiguring the software.

Compactness and power efficient design. Unlike traditional non-SDR systems, which require multiple hardware sets for multi-functional communication, the same piece of SDR hardware can be reduced for such a purpose. This results in compact and power –efficient design, especially as the number of systems increases.

Ease of manufacture. A SDR comprises of fewer hardware parts than a traditional radio since most processing is done in software within a general-purpose microprocessors or special purpose microprocessors like the DSP, or in reconfigurable hardware including FPGAs. This eases the production cycle for the manufacturer with lesser parts to standardize and produce.

Ease of upgrades. Any service upgrade can be easily introduced through the release of new software versions without the expense of recalling or replacing the hardware units. A user can simply download the software off the internet and load it into the SDR.
The most significant asset of SDR is versatility. Wireless systems employ protocols that vary from one service to another. Even in the same type of service, for example wireless fax, the protocol often differs from country to country. A single SDR set with an all-inclusive software repertoire can be used in any mode, anywhere in the world. Changing the service type, the mode, and/or the modulation protocol involves simply selecting and launching the requisite program, and making sure the batteries are adequately charged if portable operation is contemplated.

The ultimate goal of SDR engineers is to provide a single radio transceiver capable of playing the roles of GSM phone, CDMA phone, Wimax terminal, wireless fax, wireless Web browser, Global Positioning System (GPS) unit, and other functions still in the realm of science fiction.


VIKRAM KARVE

http://vikramkarve.sulekha.com/

http://www.linkedin.com/in/karve

vikramkarve@sify.com

Dissertation

Master of Engineering [ME] Post Graduate Dissertations guided by Prof Vikram Waman Karve at IAT [DIAT] Pune for ME [Electronics & Telecommunications Engineering] degree of University of Pune.

[Copies are available in DIAT Deemed University Library and University of Pune]


Year: 1992

1. Application of knowledge based systems in naval command and control / Manoj Bhatt
Author(s) : Bhatt, M. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1992

2. Simulation studies in naval threat scenario / S. Srinivasan
Author(s) : Srinivasan, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1992

3. Strap down inertial navigation system algorithms / C. Dayanand
Author(s) : Dayanand, C. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1992


Year: 1994

4. Application of expert system for data fusion in a multi-sensor environment for target identification / Vipin Thapar
Author(s) : Thapar, V. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1994

5. Performance evaluation of naval weapon systems based on MOE approach incorporating knowledge based systems / Ranjit Singh
Author(s) : Singh, R. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1994

6. Expert system design and application in naval weapon combat system, selection and analysis / Amit Rastogi
Author(s) : Rastogi, A. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1994

7. Naval weapon system design incorporating expert system / G. Jacob Panicker
Author(s) : Panicker, J. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1994


Year: 1995


8. Active sonar target classification using neural networks / Subroto Ghosh
Author(s) : Ghosh, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1995

9. Design of a hierarchy based information security system for multiuser computer systems and networks / P.P. Kulkarni
Author(s) : Kulkarni, P.P. ; Karve , V.W. Guide
Publisher : Pune : DIAT, 1995

10. Expert system application for multi sensor data fusion in robotic systems / P.K. Gupta
Author(s) : Gupta, P.K. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1995

11. Sonar based application of neural network / S. Ghosh
Author(s) : Ghosh, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT - Seminar Paper

12. Fuzzy logic in navy / Subroto Ghosh
Author(s) : Ghosh, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT - Seminar Paper

13. Electromagnetic interference prediction incorporating expert system / V.N. Ramesh
Author(s) : Ramesh, V.N. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1995


Year: 1996


14. Virtual reality applications in naval weapon and combat systems / R.K. Pai
Author(s) : Pai, R.K. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1996

15. Command and control system for modern submarines- A fully integrated fault tolerant (FIFT) cybernetic based design / A. Madhavarao
Author(s) : Madhavarao, A. ; Karve , V.W. Guide
Publisher : Pune : DIAT, 1996

16. Design of a fuzzy logic based decision support system for combat systems operations and engineering / Santosh Nagarajan
Author(s) : Nagarajan, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1996

17. Design and development of optical fibre based hydrophone system for underwater anti-submarine warfare / Debashish Saha
Author(s) : Saha, D. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1996


Year: 1997

18. Design optimization of optical fibre hydrophone system for sonar and underwater warfare applications / S. Shrikumar
Author(s) : Shrikumar, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1997

19. Three dimensional cube model for ship design, weapon selection wvaluation and installation / Manoj Tayal
Author(s) : Tayal, M. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1997

20. Knowledge based systems approach towards threat evaluation & weapon assignment / P. Kapadia
Author(s) : Kapadia, P. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1997

21. Comprehensive study of genetic algorithm as search, optimization and machine learning mechanism / Girish R. Pradhan
Author(s) : Pradhan, G.R. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1997


Year: 1998

22. Systems Approach Based Design and Development of Integrated Ship's signature mangemenent system (DSS) for ship Design and C2W effectiveness / Gautam Naha
Author(s) : Naha, Gautam ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1998

23. System analysis and design for modelling of command and control warfare sysrems for computer aided wargaming / D.K. Murali
Author(s) : Murali, D.K. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1998

24. Cybernetics system design and analysis using soft system dynamics / S.Sriram
Author(s) : Sriram, S. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1998

25. Design and development of an interoperability analysis model and decision support system for interoperability evaluation of maritime communication systems / U.V. Natu
Author(s) : Natu, U.V. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1998

Year: 1999

26. Vulnerability modelling for a warship / M. Ramesh
Author(s) : Ramesh, M. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1999

27. Performance evaluation of computer communication networks / Vijay Singh
Author(s) : Singh, V. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1999

28. Soft systems approach to the design of the naval command & control warfare system in the information operations scenario / Rajesh Debnath
Author(s) : Debnath, R. ; Karve, V.W. Guide
Publisher : Pune : DIAT, 1999


[To be continued…]

Cognitive Radio - The Future of Software Defined Radio

COGNITIVE RADIO

[Here is an article on Cognitive Radio compiled by my students Shijesh, Sibil, Shyju and John by browsing the internet, books and journals]


The Radio Spectrum – that segment of the electromagnetic continuum comprising the radio-frequency range – accommodates myriad communications devices today.

As the Radio Spectrum gets is gets more and more crowded and available frequencies become scarce the evolution of Cognitive Radio may be able to optimally manage the available spectrum.

The use of radio frequency bands has been regulated in most countries through the process of spectrum allocation in which the use of a particular frequency band is restricted to the license holders of the band. Within this framework, spectrum has often been viewed as a scarce resource in high demand. However, various studies carried out have suggested that most licensed spectrums are often under-utilized with large spectral holes at different places at different times.

Cognitive Radio (CR) systems have been proposed as a possible solution to the spectrum crisis. The idea is to detect times when a specific licensed band is not used at a particular place and use that band for transmission without causing any significant interference to the transmissions of the license holder. Built on the foundation of the Software Defined Radio (SDR), Cognitive Radios will learn and autonomously perform “cognitive” functions as a form of intelligence that comes from their ability to be defined and upgraded using software.

To examine the concept of cognitive radio consider the example.

Let’s say you walk into an empty café called Spectrum. Since all of the tables are available, you position yourself at the best one and settle down for a meal. [Let’s assume all tables have four seats and you occupy one seat].

A few minutes later, another person comes in and sits on a seat at another vacant table.

Soon, if all the tables are full [but there are a few vacant seats on some tables], a new patron must negotiate with someone already at a table to be allowed to share the table. [Maybe she may request you to let her occupy the vacant chair at your table, and you may agree].

This process of negotiation is the concept behind a technology called Cognitive Radio, a way to share and optimally utilize unused spectrum. Cognitive Radio is sometimes called Smart Radio because it senses its environment and reacts to it.

The present paucity of radio spectrum is primarily due to the cost and performance limits of legacy hardware established during the past century. Traditionally, radios were hardwired to operate at a particular power and frequency, and once a station was assigned a frequency, no other station could use it. Over the years, as engineers built radios in cheaper and smaller packages, it became possible to build intelligence into them, making the idea of sharing frequencies possible.

Engineers are now working to bring flexible operating intelligence to future radios, cell phones and other wireless communications devices. During the coming decade, cognitive radio technology should enable nearly any wireless system to locate and link to any locally available unused radio spectrum to best serve the consumer. Employing adaptive software, these smart devices could reconfigure their communications functions to meet the demands of the transmission network or the user.

Cognitive Radio will intelligently know, by sensing, adapting and learning, what to do based on prior experiential knowledge, by building an internal database that defines how to best operate in different places and at specific times of day.

As Cognitive Radios send and receive signals, they will nimbly leap and bound in and out of free bands as required, avoiding those that are already in use. This lightning-fast channel jumping will permit cognitive radio systems to transmit voice and data streams at reasonable speeds.

This efficient use of existing Radio Frequency resources will alleviate spectrum-availability traffic jams and wireless communications may become far more dependable, convenient and, perhaps, considerably economical than it is today. Indeed, if Cognitive Radio technology progresses as its developers hope the airwaves will never be the same again.

What Every Telecom Professional Should Know

Book Review by Vikram Waman Karve

TECH TERMS – What every Telecommunications and Digital Media Professional Should Know


Tell me, what is a zombie? No, no! It’s not the witchcraft zombie I’m talking about, nor am I referring to those automaton nerds, lost cases, you see around you. Okay, I’ll give you a hint – this zombie has got something to do with IT. Still clueless?

Did you know that Zombie refers to hackers’ use of other people’s personal computers to either conceal their online activities or to launch attacks on other computers? Once a computer has been turned into a “zombie” it can be used as a repository for illegal software, become a clandestine meeting place for hackers to conduct secret meetings, be used to send pornographic or other undesirable e-mail or spam, serve as the launching point for a denial of service attack, and so on – all without the knowledge of the zombie computer’s owner. So don’t let your PC become a zombie.

Did you know all this? Well, I didn’t – till I read a marvellous book, a splendid Technical Thesaurus, called TECH TERMS. This book is packed with a wealth of knowledge comprising must-know terms and concepts for every Telecom and IT professionals worth her salt. This book encapsulates an essential list of Internet, IT, Telecom, Digital, Broadcasting, and Computing terms one needs to master to remain current through thorough understanding of state-of-the-art technology and concepts – a sine qua non for survival and success in the rapidly advancing world of Telecommunications and Information Technology.

Title: TECH TERMS – What every Telecommunications and Digital Media Professional Should Know

Author: Jeff Rutenbeck

Elsevier (2006) 280 pp

ISBN 13: 978-0-240-80757-7

The “tech terms” are arranged alphabetically and each term is assigned a “level” of 1, 2, or 3 indicating the degree to which a term or concept can be considered fundamental or foundational to a particular technological domain [level 1], those which require some understanding [level 2], and highly specialized or complicated concepts [level 3].

Cyberspace, Blog, Hacker, Byte, Broadband, iPod, Database are level 1 terms; Technobabble, TCP/IP, GPS, GSM, ADSL, ISDN, Cybersquatting, Wiki, Bluetooth, Blu-Ray, Ethernet, URL, Router, Zombie, Honeypot, WYSIWYG, Nanotechnology are level 2 terms, and terms and concepts like CDMA, NICAM, CPDP, XSS, DLL, ColdFusion are level 3 terms.

Hey, do you know the full form of URL? Or USB? Or FIFO? Or ISDN?

Why don’t you just go down to your nearest bookstore or library and get a copy of this book? TECH TERMS is an excellent reference book, a must-have for all IT Pros in today’s techno-centric world.


[Reviewed by VIKRAM WAMAN KARVE]


http://vikramkarve.sulekha.com/

http://www.linkedin.com/in/karve

http://www.ryze.com/go/karve


mailto:vikramkarve@sify.com

mailto:vikramkarve@hotmail.com