ABSTRACT

Wireless communication is the transfer of information over a distance without the use of electrical conductors or wires "[1 the distance involved may be short (a few metre as in television remote control) or long (thousands or millions of kilometers for radio communication). When the context is clear. The term is often shortened to "wireless". Wireless communication is a branch of telecommunications and thus, involve modulation. Frequency modulation is a process in which the amplitude of the modulated carrier is kept constant while its frequency and rate of change are varied by the modulating signal. Frequency modulation transmitter has an oscillator that generates a carrier signal on a desired frequency. A voltage controlled oscillator is used so that the oscillatory frequency can be changed by modulating signal. The oscillator runs at its assigned frequency (called the Centre frequency) the frequency of the signal is caused to vary above and below its assigned Centre frequency in a way that is directly proportional to the modulating signal. It is stifled above and below its assigned centre at a rate proportional to the frequency of the modulating signal. This take up a bit of what is called bandwidth on the electromagnetic spectrum. The modulated frequency signal appears as a "group" of frequency around the centre frequency with the sub group of frequencies above the centre being called the upper and the sub group of frequency below the central frequency is called lower sidebands. This RE signal is then amplified by a high power RF amplifier, and the (now) high powered FM signal is then sent via a transmission line to an antenna from where the signal radi-3tes into space. [8]