Performance of the Bi-orthogonal Modulation for Ultra-WideBand Communications with Multiple Access Interference

Special issue on emerging multiple access technologies Abstract This paper investigates the use of bi-orthogonal modulations in multiuser communication systems based on ultra wide band impulse radio (UWB-IR) technology: the communication systems considered herein use Gaussian waveforms in AWGN channel and rely on the utilization of a time-hopping spreading technique. A hybrid pulse modulation is defined, which is obtained by combining pulse amplitude modulation (PAM) and pulse position modulation (PPM) techniques. Particularly, we have compared the bi-orthogonal system performance to the classical orthogonal one, also in the condition of lack of a general synchronism, possibly caused by the presence of interfering users that belong to a separate network. Moreover, we have taken into account the use of an M-ary alphabet, in the case of orthogonal and bi-orthogonal modulation schemes.