Field test results for a beam and null simultaneous steering S/T-equalizer in broadband mobile communication environments

This paper proposes a beam and null simultaneous steering Space-Time Equalizer (S/T-Equalizer). The proposed S/T-Equalizer performs separated S/T-signal processing in order to reduce computational complexity to a practical level. For spatial signal processing, a new Adaptive Array Antenna algorithm is used that combines the beam and null steering concepts. For temporal signal processing, a conventional delayed decision feedback sequence estimation equalizer may be used. The proposed S/T-Equalizer was prototyped, and a series of field tests was conducted using a 5 GHz frequency band to evaluate transmission performances of the proposed system. Results show that the proposed S/T-Equalizer can reduce inter-symbol interference effects while maintaining reasonable signal strength, thereby improving BER performance.