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

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 the 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. A series of field tests was then conducted using the 5 GHz frequency band to evaluate the transmission performance of the proposed system. The results show that the proposed S/T-equalizer can reduce inter-symbol interference effects while maintaining reasonable signal strength, thereby improving the BER performance.