Patent ID: 7864831

Claim:
A distributed space-time coding method in an UWB (ultra-wide band) pulse telecommunication system including a source terminal which transmits a signal to a destination terminal during a transmission interval constituted by K frames, Kâ‰§1, each frame being divided into a first and a second half-frame, the signal transmitted in each first half-frame being received, then retransmitted after amplification during a next second half-frame by a distinct relay terminal among K relay terminals of said system, said method comprising: coding, by said source terminal, 4K data symbols belonging to a PPM (pulse position modulation) modulation alphabet or a composite PPM-PAM (pulse position modulation-pulse amplitude modulation) modulation alphabet including a plurality of time positions, so as to provide a sequence of four transmission symbols per frame, said transmission symbols being obtained from 4K linear combinations of said data symbols using a plurality of coefficients belonging to a real algebraic extension of 2K of a field of rational numbers and, for one of said transmission symbols of predetermined rank in said sequence of each frame, a permutation of its PPM components; and modulating a UWB pulse signal by the transmission symbols thus obtained.