Some of you may have read my earlier posts on stealing spectrum via Femtocells and using Femtocells abroad illegally. This presentation tries to answer one such problem on how do you find the location where GPS cannot be used. This could also be used in case of Cognitive Radios. See my old blog entry here.
Showing posts with label Cognitive radio. Show all posts
Showing posts with label Cognitive radio. Show all posts
Thursday, October 7, 2010
Wednesday, September 1, 2010
Wednesday, August 11, 2010
Thursday, November 27, 2008
SDR: Today and Future
I also got an opportunity to attend the SDR briefing in LTE World Summit. There were many interesting presentations including one titled "SDR in Mobile Devices" by Thierry Dubois, SDR Market Analyst, IMEC, Belgium. Infact last year I blogged about SDR from Imec presentation as well. The following is an extract from Thierry's presentation:
The key benefits of SDR are as follows:
There are three main areas where SDR's are required but some problems exist as can be seen from the diagram above. 
The next step after SDR is cognitive radio (CR). The main advantage for using CR would be because spectrum is over-allocated but under-utilised. There are lots of white spaces in the spectrum that could be utilised by devices intelligently of their own.
Cognitive Radios are defines as: A radio that can autonomously change its parameters based on interaction with, and possibly learning of, the environment in which it operates. Through appropriate radio resource management, such a cognitive radio should make flexible and efficient use of network/spectrum resources.
The key benefits of SDR are as follows:- Reducing the Bill Of Materials (BOM)
- Lower development costs
- Facilitate better reuse of intellectual property (IPR)
- Possibility to upgrade products already in the field
- Enabler of the Cognitive Radio vision
There are three main areas where SDR's are required but some problems exist as can be seen from the diagram above. - Flexibility is the key for baseband. Some of the common signal processing blocks may not be reusable. This means that though some protocols can easily be defined for a particular baseband, others may not be possible for that baseband. Good progress is still being made though on this front.
- Reconfigurable RF is some way away, further down the road.
- The biggest challenge is the antenna interface for which no proper solution exists. Some solutions being worked on right now include MEMS based solution, Carbon nanotubes, Special ceramic materials, etc.
The next step after SDR is cognitive radio (CR). The main advantage for using CR would be because spectrum is over-allocated but under-utilised. There are lots of white spaces in the spectrum that could be utilised by devices intelligently of their own.Cognitive Radios are defines as: A radio that can autonomously change its parameters based on interaction with, and possibly learning of, the environment in which it operates. Through appropriate radio resource management, such a cognitive radio should make flexible and efficient use of network/spectrum resources.
CR would consist of Intelligent Sensing hardware and Intelligent Sensing Algorithms. There are two types of CR being considered:
- Opportunistic Radio: A radio that co-exists with other systems using the same spectrum. E.g., White Space Devices
- Smart Reconfigurable Radio Systems: A radio that makes flexible and efficient use of network/spectrum resources across heterogeneous environments. Seamlessly roaming possible on different networks, countries, frequencies, etc. It requires true paradigm shift i.e., spectrum liberalization
An Introductory paper on SDR is available on Bitwave Semiconuctor website.
Monday, June 18, 2007
Cognitive radio
Cognitive radio (CR) is a newly emerging technology, which has been recently proposed to implement some kind of intelligence to allow a radio terminal to automatically sense, recognize, and make wise use of any available radio frequency spectrum at a given time. The use of the available frequency spectrum is purely on an opportunity driven basis. In other words, it can utilize any idle spectrum sector for the exchange of information and stop using it the instant the primary user of the spectrum sector needs to use it. Thus, cognitive radio is also sometimes called smart radio, frequency agile radio, police radio, or adaptive software radio,1 and so on. For the same reason, the cognitive radio techniques can, in many cases, exempt licensed use of the spectrum that is otherwise not in use or is lightly used; this is done without infringing upon the rights of licensed users or causing harmful interference to licensed operations.
The only difference with SDR (Software Defined Radio) is that a cognitive radio needs to scan a wide range of frequency spectra before deciding which band to use, instead of a predefined one, as an SDR terminal does. One of the most important characteristic features of an SDR terminal is that its signal is processed almost completely in the digital domain, needing very little analogue circuit. This brings a tremendous benefit to make the terminal very flexible (for a multimode terminal) and ultrasmall size with the help of state-of-the-art microelectronics technology.
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