A Deterministic Ultra Wideband Channel Modeling


Bernard Uguen , Eric Plouhinec , Yves Lostanlen , Gérard Chassay , (1) LCST/IETR INSA Rennes - 20 av des Buttes de Coësmes - CS 14315 - 35043 RENNES Cedex - France (2) SIRADEL S.A. - 3 allée Adolphe Bobière - CS 24343 - 35043 RENNES Cedex - France

Abstract In this work we study the realisation of a deterministic channel modeling which allows the construction of a realistic received waveform from a wireless Spread Spectrum Multiple-Access (SSMA) using Time Hopping (TH) modulation. The goal is to reach the symbol decision from a simulated waveform. This paper explains how to use the Uniform Theory of Diffraction (UTD) method combined with a ray tracing to obtain the received TH modulation waveform in indoor or outdoor environment.

1 Introduction

This paper presents the various steps allowing the realisation of a deterministic UWB simulator. It provides details about the structural aspects and the simulator timing management.

2

The emitted and received waveforms formulation

2.1 Time Hopping format impulses A typical format of multiusers PPM sequence is the following [2] [3]:           "!#%$  '&  )(+*-, . '0/ & 2 143      (1) Where : 567 8 is the impulse waveform at the generator output. 7 8 :9;  ( 9; 8 is the second derivative of 7  [3],

Spread spectrum Multiple-Access (MA) communications using Time Hopping (TH) and binary Pulse Position Modulation (PPM) has recently been proposed in [1], [2], [3] . The signal contains baseband impulses of very short duration (about the nanosecond). Owing to the pulses brevity, the energy of the radio signal is practically spread out from D.C. to a few GHz. [5]) if we choose to not take into account the spatial The advantage is that while reaching a multipath resolufiltering antennas effect. tion close to the nanosecond (roughly 30 cm of resolution) it 5%< is the index of the source. is theoretically possible to partly eliminate fading related to multipath. Therefore the power of emission can be reduced 5%=?> is the number of pulses per symbol. considerably. Because of its very broad band, the radio op5%=?@A 0