The VLSI technology is the widely used technology but hardly anyone knows about it in depth. VLSI is mainly about the technology of combining the number of transistors based circuits into a single chip. Currently VLSI is combined with SDR technology to make the ease of use. This technology is used in mobiles phones. SDR is software defined radio. It is widely used in CDMA and CSMA technology. SDR in a technology which helps the device to tune to any bandwidth by using less hard ware.

In this documentation we will got through the basics about the VLSI and SDR technology. VLSI and SDR have been very helpful for the mobile companies to provide better service with combination of both as VLSI reduces size and price of the mobile and SDR increases the flexibility of the module. The technology used in day to day can be classified in two main types GSM (Global System For Mobile Communication) and CDMA (Code Division Multiple Access).  These networks helps us in accessing various bandwidth but the problem with them is both simultaneously cannot be accessed from the same handset or same mobile phone at one time.


VLSI is the previous stage of SSI and MSI. This include combining more and more logical device in smaller area. Particularly in this age of nano technology ease and simplicity plays important role. This can be done using VLSI and this requires more efficiency in areas like system architecture, logic and circuit design. A lot of study is required for implementation of VLSI.

Digital VLSI circuits are most CMOS based. The normal blocks like latches and gateways are mostly used but in different way. Lets go through some factors involved in this implementation.


Since this technology is combination of number of circuits in a small area it may cause delay in transfer of signals through this circuits.

b.)    POWER:

Since the number of circuits, latches and gateways are used it requires a lot of power consumption and this may cause the device to get heated at the surface.

c.)     LAYOUT:

As we all know that we have to fit 1000’s of circuits in a very smaller area there can be number of arrangements for this. The important thing here is how efficiently this 1000’s of circuits are arranged.

Applications of VLSI in communication system

The widely used VLSI today is classified into three main categories:

ANALOG:  It main consist of amplifier, data convertor and sensors.

APPLICATION OF  SPECIFIC INTEGRATED CIRCUITS: Due to many upcoming technologies manufacturing of IC’s has enabled to integrate number of circuits in small area.

SYSTEM ON CHIP: As we all know that VLSI is all about combining number of circuits so it is somewhere similar to a system on one chip.

SDR: SDR was been introduced to over some the problem of accessing the two technologies of GSM and CDMA on one handset. SDR works in two ways IDEAL and PRACTICAL CONCEPT. In IDEAL CONCEPT the digital processor reads the converter and its software and transforms the data to the required form.  And the PRACTICAL CONCET use the super heterodyne method to overcome this problem.  Its uses the mixer which lower the received frequency. This lowered frequency is then treated by ADC and then GSM and CDM can be used on same handset.

Hence, uses of this technology gives us advantages like lowering the package count, low board space, less board level connections, high performance and more reliability and lower the cost.

But this also has some disadvantages like this project can led to high risks, long fabrication time, lengthy designs, spiking problem, and leakage of Power

CONCLUSION: This documents helps us to conclude that VLSI can be used for communication as this would provide is use of two technologies on one handset.

Download VLSI In Communication System Seminar Report.