ABSTRACT: This is the world of VLSI . Presently all most all the people are using technology in various forms like mobiles, i-pods, i-phones etc., Every one enjoys technology but only a few know about VLSI design in world design and its working. Coming to VLSI it is the process of creating integrated circuits by combing 1000`s of transistor based circuits in to a single chip. It began 1970`s when complex semi conductors and communication technologies were being developed, But now it has become key to many sophisticated electronic devices. As the subject is a big ocean we laid our emphasis on VLSI chip coupled with SDR technology used in mobiles. VLSI technology makes the mobile affordable and SDR technology make its flexible. Coming to the role of soft ware define radio abbreviated as SDR, it helps one to access different net works like CDMA, GSM, WILL etc. Basically SDR is radio communication system which can potentially tune to any frequency band and received any modulation across a large frequency spectrum by means of little hard ware as possible and process it signals through soft ware.
This paper introduces the basic design of SDR, use of VLSI chips in mobiles and their working principles.
1. VLSI - Very large scale integration
2. SDR - Soft ware defined Radio
3. R.F - Radio Frequency
4. I.F -intermediate frequency
Tele communication industry is one of the highly developed segment which is dependent on VLSI technology. SDR also plays a prominent role in the mobile communication VLSI helps in reducing the size and price of the mobile where as SDR increases the flexibility of the mobile.
Existing networks in telecommunication can be classified into two major types -
a) GSM (Global System for Mobile communication)
b) CDMA (Code Division Multiple Access)
These networks differ in their accessing frequencies. The problem encountered while using these network is, both these networks can not be accessed from the same hand set. Now a days dual SIM card phones have been developed using SDR. Soft ware radio provides solution by using super heterodyne radio frequency front end. Soft ware defined radios have significant utility for the military and cell phone services both of which must serve a wide variety of changing radio protocols in real time.
The following segments introduce the use of VLSI and SDR, their working principles, advantages and disadvantages
VLSI technology :- Most of the student are exposed to ICs at a very basic level involving SSI and MSI circuits like multiplexers, encoders, decoders etc. VLSI is the next stage of SSI and MSI. This field involves packing more and more logic devices into smaller and smaller areas. Particularly in this era of Nano technology simplicity plays a very prominent role for any device. This is possible by using VLSI design. But this design involves a lot of expertise in many fronts like system architecture, logic and circuit design way for fabrication etc. A lot of knowledge is required for the actual implementation and design of VLSI. Digital VLSI circuits are predominantly CMOS based. The way normal blocks like latches and gates are implemented is different from what students have seen so far, but the behaviour remains the same. All the miniaturization involves new things to consider. A lot of thought has to go into actual implementations as well as design. Let us look at some of the factors involved. 1. Circuit Delays. Large complicated circuits running at very high frequencies have one big problem to tackle - the problem of delays in propagation of signals through gates and wires ... even for areas a few micrometers across! The operation speed is so large that as the delays add up, they can actually become comparable to the clock speeds. 2. Power. Another effect of high operation frequencies is increased consumption of...
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