This contribution provides a very high data rate UWB system design based on direct sequence spreading. In order to attain > 500Mbps for short range communication, two classical solutions are feasible: either use very short spreading sequences or very large bandwidth. These classical strategies increase intersymbol interference. In contrast, our approach consists in allocating multiple long codes to each user. Long codes allow to cope with channel impairments while the use of multiple codes maintains very high bit rates. With such high data rates the receiver obviously has to be simple by requiring a low complexity digital processing. This paper shows that the proposed strategy is compatible with simple receivers. In fact, even if the amount of interference increases, joint usage of very long codes and simple linear receiver can result in high data rate, high performance UWB system. This assertion is substantiated through comparisons with existing UWB solutions.

Direct sequence ultra wide band (DS-UWB) is a strong candidate for high data rate (HDR) wireless personal area networks (WPAN) IEEE 802.15.3a standard for achieving up to 480 Mbps. This paper presents a new system design methodology based on a multicode approach where the spreading sequences have a duration longer than the channel impulse response (CIR) with the goal of achieving higher data rates up to 1.6 Gbps. Multiple codes are allocated to one user and transmitted synchronously in a TDMA access scheme. All codes are modulated by the same QAM constellation, the best combination of number of codes and QAM order for achieving the largest range of coverage is illustrated for 4 target rates: 10, 110, 480 and 1600 Mbps. The selection methodology is based on a theoretical SNIR derivation at the output of a linear minimum mean square error equalizer using classical WPAN channels as specified by IEEE 802.15.3a. Compared to the DS-UWB proposal for IEEE 802.15.3a, the proposed system grants around 3 times range increase

In this paper the capacity of a specific PPM (pulse position modulation) ultra wide band (UWB) system using a semi-digital demodulator architecture is evaluated. Then the impact of time desynchronization between the local pulse templates and the received signal on the capacity of the link is assessed, the goal being to quantify the jitter effect and delay estimation error on this capacity and issue design recommendations for real system construction.