Group waveform-coded biorthogonal pulse position modulation with level cutting for ultra-wideband impulse radio communications

A new modulation scheme termed as group waveform-coded biorthogonal pulse position modulation (GWC-BPPM) is proposed for an ultrawideband (UWB) impulse radio communication system. The group waveform-coded signal, generated using several orthogonal waveform codes to transmit data simultaneously, is converted to pulse position and polarity to improve data rate and obtain processing gain in reception. In addition, the authors also suggest greatly boosting the data rate of the proposed scheme by introducing the level cutting concept. By restricting the maximum level of the group waveform-coded signal, the authors can boost the data rate without any degradation in error performance. To guarantee the benefit and the validity of the proposed scheme, the authors focus on the achievable data rate as a performance measure and analyse it theoretically. Simulations show that the achievable data rate of the proposed systems can be increased by GWC-BPPM and can be boosted via level cutting compared with other schemes such as M-ary BPPM and MBOK.