Multi-tone frequency shift keying for ultrawideband wireless communications

This study explores the performance of multi-tone frequency shift keying (MT-FSK) in ultrawideband (UWB) wireless communications as an alternative to the standard modulation techniques. Its advantage is its ability to provide multiple user access even within the recently tightened regulations on UWB communications. Unlike previous works that discussed MT-FSK from the information theory perspective, here the possibility of practical implementation is explored. The basic system parameters such as tone bandwidth, number of frequencies and duty cycle are studied in terms of propagation characteristics, optimum data rate and system complexity. With optimum parameters, the authors show that a system using MT-FSK is capable of data transmission at a data rate of 250 Mbps with bit-error-rate below 10^-5 whereas the receiver complexity is lower than for standard methods utilising the UWB spectrum by means of impulse radio or multi-band orthogonal frequency division multiplexing (OFDM).