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Fundamental to all wireless communications is modulation, the process of superimposing the carrier signal on the modulation signal. Most of the wireless transmissions today are digital with the limited spectrum available, the type of modulation is more critical than it has ever been. The main purpose of modulation is to squeeze them as much data into the least amount of spectrum possible. The term known as spectral efficiency measures how quickly data can be transmitted in an assigned bandwidth. Multiple techniques have popped to achieve and improve spectral efficiency. Thus ‘4- dimensional QFSK’ will help in reducing the required bandwidth for transmission compared to existing techniques to a greater extent without increasing the Probability of Error (P e ).

The requirements for Wireless Personal Area Network are less band-width, high speed, low probability of error and reduced multipath interference. In M-ary Phase Shift Keying, M-ary Amplitude Shift Keying and M-ary Quadrature Amplitude Shift Keying, as N increases, the probability of error increases, even though bandwidth decreases. In M-ary Frequency shift keying as N increases, the probability of error decreases but bandwidth increases. In general, while working with the wireless systems using these techniques, various problems encountered are: multi-path fading, single carrier fading, time dispersion which leads to inter symbol interference, lower bit rate capacity, less power efficiency and less spectral efficiency. Hence there is a need to design a new modulation technique which fulfills all the requirements of Wireless Personal Area Network. We have implemented a spectrally and power efficient modulator of 3-Dimensional Polar Frequency Shift Keying modulation.

While working with the wireless communication systems(especially Personal Data Network) using existing modulation techniques, various problems encountered are: multipath fading, time dispersion which leads to ISI, lower bit rate capacity, requirement of larger transmit power for high bit rate and less spectral efficiency. To overcome above problems, this paper proposes a new digital modulation technique: N-Dimensional polar FSK. The proposed technique is based on multi-carrier system which helps in reducing frequency selective fading. To reduce multipath interference, symbol duration should be increased by increasing number of bits/symbol. This new technique works excellent by resulting in a constant bandwidth and Euclidean distance as the number of bits/symbol increases, thus providing high spectral and power efficiency.