Hybrid Modulation Schemes for UWB Wireless Systems

This paper presents two novel hybrid modulation schemes for ultra-wideband (UWB) communication systems using time-hopping spread spectrum (TH-SS) techniques. These schemes are namely: biphase N-ary PPM and biphase M-ary PAM. In the biphase N-ary PPM, a combination of pulse position modulation (PPM) and binary phase shift keying (BPSK) to provide better system performance with low computational complexity, while the biphase M-ary PAM combines the pulse amplitude modulation (PAM) and binary phase shift keying (BPSK) to give enhanced system performance and the same complexity is pronounced. This spread spectrum technique permits to predict the system performance with high accuracy and reasonable complexity in the presence of line of sight (LOS) in indoor channel and AWGN channel, where a correlation receiver is used to extract the information sequence modulated on the monocycle train from the distorted and corrupted receiving waveforms with a high accuracy. MATLAB simulation results show significant improvement in the performance (modulation gain) of hybrid modulation schemes compared with other published classical modulation schemes