Static and Stationary Space–Time Domains

2012 ◽  
pp. 277-349
Author(s):  
Anadijiban Das ◽  
Andrew DeBenedictis
Keyword(s):  
Space Time ◽  
Time Domains

Joint Angular and Time Diversity of Multi-Antenna CDMA Systems in Wireless Fading Channels

2011 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Feng She ◽  
Hsiao Hwa Chen ◽  
Hongyang Li
Keyword(s):  
Fading Channels ◽  
Performance Improvement ◽  
Multipath Fading ◽  
Antenna System ◽  
Space Time ◽  
Diversity Gain ◽  
Multipath Fading Channel ◽  
Time Diversity ◽  
Time Domains ◽  
Code Division Multiple

In this paper, a multi-antenna based receiver structure for direct sequence code division multiple access (DS/CDMA) system is proposed. The proposed scheme exploits the excellent time resolution of a CDMA RAKE receiver and uses an antenna array beamforming structure to resolve multipath returns in both angular and time domains. A much higher diversity gain than that based only on the time domain diversity can be achieved. This work suggests a new space-time diversity paradigm, namely angular-time diversity, which differs from traditional Alamouti-type space-time coded schemes. The impairments caused by multipath and multiuser interference are analyzed. The performance of the proposed receiver in multipath fading channel is explicitly evaluated. An expression for uncoded system bit error probability is derived. Simulation results show the performance improvement in terms of BER due to the use of multi-antenna in the receiver, and the results illustrate that the multi-antenna based receiver works effectively in resolving multipaths in both angular and time domains to achieve performance improvement due to angular and time diversity gain provided by the multi-antenna system.

scholarly journals Space-Time Adaptive Cancellation in Passive Radar Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Tamás Pető ◽  
Rudolf Seller
Keyword(s):  
Interference Cancellation ◽  
Field Measurements ◽  
Critical Issue ◽  
Space Time ◽  
Passive Radar ◽  
Space Domain ◽  
Radar Systems ◽  
Time Domains ◽  
Adaptive Cancellation ◽  
Preprocessing Technique

A critical issue in the realization of passive radar systems is the effective suppression of the zero Doppler interference (ZDI). The performance of the clutter cancellation relies much on the used algorithms. Several state-of-the-art approaches consist in the independent use of spatial and temporal algorithms for ZDI suppression. In this paper, a novel interference cancellation algorithm is proposed, which jointly exploits the available information from both space and time domains. We call this novel method Space-Time Adaptive Cancellation (STAC), and it differs from previous schemes included among the tools of Space-Time Adaptive Processing (STAP). The STAC algorithm is able to cancel out the high power direct and multipath signals on all the surveillance antenna channels prior to the beamforming and other space domain processing methods. The proposed preprocessing technique facilitates the detection of targets even in the direction of the illuminator or large static scatterers. Moreover, the interference rejection capability is also enhanced in the space domain. The performance of the presented algorithm is verified through simulations and field measurements. The experiments show improvement over the currently available filtering techniques.

Joint Multi-Mode Dispersion Extraction in Frequency-Wavenumber and Space-Time Domains

2015 ◽  
Vol 63 (15) ◽  
pp. 4115-4128
Author(s):  
Shuchin Aeron ◽  
Sandip Bose ◽  
Henri-Pierre Valero
Keyword(s):  
Space Time ◽  
Mode Dispersion ◽  
Time Domains ◽  
Multi Mode
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