Fading-resistant modulation using several transmitter antennas

Abstract

This paper proposes a bandwidth-e cient fading-resistant transmission scheme which implements transmitter diversity using L antennas at the base station. When the antennas are spaced su ciently far apart, the transmission from each antenna undergoes a di erent degree of fading. These transmissions are coordinated to mitigate the e ects of Rayleigh fading and the mobile receiver can recover the entire L-dimensional transmitted vector signal as long as the signal energy of at least one coordinate is large enough. L-dimensional fading-resistant signal constellations are generated by maximizing a gure of merit for the Rayleigh fading channel. This scheme o ers a signi cant performance improvement over a conventional single-antenna BPSK scheme when coding is ine ective due to slow fading.

Combining Modulation Diversity and Index Assignment to Improve Image VQ for a Rayleigh Fading Channel

“…Many techniques have been proposed to improve the performance of those systems. Among them, one can mention: diversity techniques [9,10] and coded modulation schemes [11].…”

Super-quasi-orthogonal space-time trellis codes for four transmit antennas

“…Therefore, we only consider the case that the fourth symbols are identical. The resulting CGD is calculated by (15) Since , the CGD in (15) is always greater than the one in (12). The structure of our set partitioning is such that the first time that the case of three differences appears it always coincides with the case of only one difference.…”

“…The result is powerful codes with simple pairwise decoding strategies. Some related work in the literature can be found in [12]- [14]. In this paper, first, we study the conditions for which a rotated QOSTBC provides full diversity, and then we combine the constellation rotations of SOSTTCs with that of QOSTBCs to systematically design a new class of space-time codes that provide full-rate, full-diversity, and very high coding gains for four transmit antennas.…”

Diversidade em Modulação Aplicada a Canais de Comunicações Móveis: Efeito dos Erros de Estimação de Canal na Transmissão de Imagens

“…ser citadas técnicas de diversidade [27][28][29][30][31][32], esquemas de modulação codificada [33], e uso da transformada wavelet na codificação [34].…”