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Follow on Google News | Developing Software Radio Based System for Interoperability Solution to the First Response TIt is enough to recall the great tragedy of the Sept 11, 2001 when a message sent by police to the fire teams operating in the World Center never was received. It resulted to a great tragedy of loosing several hundred firemen.
By: Author program, Dr. Oleg Panfilov Software Radio (SR) products are at the verge of revolutionizing the communication industry as we know it. The present fragmented communication environment is responsible for the severe incompatibility problems and cost overruns in providing communication services in different frequency bands and/or operating standards. The SR systems by providing all signal processing in software asymptotically approaching the ultimate software definable radio (SDR) systems goal of seamless system operation in multiterminal/ The SDR Forum stipulates that ideal SDR products must possess two fundamental features – flexibility towards operational standards and independence from carrier frequencies. The path to that goal lies through direct down conversion from RF to baseband immediately after antennae. Like any ultimate goal, it can be approached asymptotically while each generation of new semiconductor processes will bring the elusive SDR goal of multiterminal/ SDR in a nut shell reflects the convergence of two very dynamic technologies: There are good historical reasons of having different flavors of SDRs depending upon where the signal processing starts in microprocessors. In a true software defined radio (TSR) the ADCs are placed as close as possible to an antenna, putting a premium on the quality of ADCs. The technology seems poised to penetrate large-scale standards-driven commercial wireless products and networks such as broadband wireless access systems, wireless local area networks (WLAN), third-generation (3G) networks and beyond exemplified by the long term evolution (LTE) systems. SDR systems are potentially capable to solve system interoperability problem by providing seamless system operation in highly fragmented, multi-terminal/ There are good historical reasons for different types of SDRs depending upon where the signal processing starts in microprocessors. In the software assisted SDR products, which are hybrid in nature, the signal processing is done in analogue as well as in digital form. Such systems are independent from protocols used but depend on frequency bands. In a true software defined radio systems they are protocol and frequency independent. It is achieved by making signal and data processing in digital form. All subsequent signal processing of the digitized antenna output is done by fast logic circuits and fast microprocessors using downloadable signal processing SW selected according to a system operational environment. It puts great demand on the performance of analog-to-digital converters (ADCs) placed as close as possible to the antenna. This is essence of the True Software Radio (TSR) approach. The great promise of the SDR technology to revolutionize the communication industry by making systems independent of communication protocols and carrier frequencies invariably generate a lot of hype around of it. A lot of companies are trying to jump into the SDR’s bandwagon claiming that they have product based on it. A close examination of these claims more often than not finds at the best only a remote resemblance of these claims possess validity. To differentiate a broad range of SDR related products we have to rely on some kind of criteria. The SDR forum defines SDRs as “radios that provide software control of a variety of modulation techniques, wide and narrow band operation, communication security functions, and waveform requirements of current and evolving standards over a broad frequency range”. In essence it stipulates that the real SDR products have to possess two fundamental features – flexibility towards operational standards and independence from carrier frequencies. So, with such definition in mind we are capable to redress the entire issue of Software Radio and separate the Software Assisted Radio (SAR) systems from True Software Radio (TSR) ones. According to that definition, the TSR systems possess both above mentioned features. While the most numerous first group embraces hybrid systems where only a portion of signal processing is done in SW, and a sizable portion done by analog components, only the TSR systems corresponds to the spirit and expectations associated with SDR. SAR systems can be viewed as intermediate stages on the evolutionary path towards TSR. The path to that goal lies through direct down conversion from RF to baseband immediately after the antennae. Like any ideal it can be approached asymptotically, when each iteration of new processes in microelectronics brings closer and closer towards multiterminal/ SDR in a nut shell reflects the convergence of two very dynamic technologies: High precision quantization of radio signals at the antenna output enables fast reconfiguration of the air interface parameters of communication terminals. The dynamic switching of frequencies and communication protocols in the user's terminals enable the remote reconfiguration of a terminal by adding or removing system software components resulting in great system flexibility. # # # International Foundation Apollo-Union is a multi-function development corporation working for the advanced development of programs and researches in various areas. The primary objective of corporation: Support for scientific innovative research. http://www.apollounion.info/ We are proposing to solve the incompatibility problem by developing Software Definable Radio (SDR) based transceiver. Such transceiver will be capable to receive signals in one frequency band and in one standard and retransmit it in another frequency band and another standard to be received on another side of communication link. End
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