Title :
Basestation adaptive antennas for a high-speed FDD/TDMA system
Author :
Ogawa, Yasutaka ; Tanabe, Yasuhiko ; Nishimura, Toshihiko ; Ohgane, Takeo
Author_Institution :
Graduate Sch. of Eng., Hokkaido Univ., Sapporo, Japan
Abstract :
Multipath propagation causes serious performance degradation in a high-speed mobile TDMA system. We have proposed the adaptive antenna which copes with the multipath signals. These considerations have been limited to an uplink channel. We propose the basestation adaptive antennas both for the uplink and downlink channels. We assume an FDD/TDMA system where the frequencies are different between the uplink and downlink channels. The weight vectors proposed in this paper are determined using DOA estimation. The problem of the frequency difference in FDD is removed by this scheme. For the uplink channel, we can realize the path-diversity using the adaptive antenna with several weight vectors. For the downlink channel, we propose a single-beam adaptive antenna and two-beam one. It is shown that the combination of the two-beam basestation adaptive antenna and the mobile terminal with two-input (two antenna) MLSE equalizer shows better performance
Keywords :
access protocols; adaptive antenna arrays; adaptive equalisers; array signal processing; direction-of-arrival estimation; diversity reception; land mobile radio; maximum likelihood sequence estimation; multibeam antennas; multipath channels; multiuser channels; radio links; time division multiple access; DOA estimation; basestation adaptive antennas; downlink channel; frequency difference; high-speed FDD/TDMA system; high-speed mobile TDMA system; mobile terminal; multipath propagation; multipath signals; path-diversity; performance degradation; single-beam adaptive antenna; two-beam adaptive antenna; two-input MLSE equalizer; uplink channel; weight vectors; Adaptive arrays; Antennas and propagation; Degradation; Direction of arrival estimation; Downlink; Equalizers; Frequency; Maximum likelihood estimation; Mobile antennas; Time division multiple access;
Conference_Titel :
Communications, 2001. ICC 2001. IEEE International Conference on
Conference_Location :
Helsinki
Print_ISBN :
0-7803-7097-1
DOI :
10.1109/ICC.2001.936611
