Spatial-frequency-scanning data transmission for mmW multi-user wireless communication systems

An E-band point-to-multipoint wireless data transmission adopting a spatial-frequency-scanning diversity concept is demonstrated. A 7-channel multi-carrier QPSK modulated signal is generated and transmitted on a link realized by a wideband Tx-Rx frontend in combination with a frequency scanning substrate-integrated slotted waveguide antenna. The antenna transmits each sub-carrier, i.e. channel, with a different angle of departure and with a gain variation in the range of 1.6 to 10.5 dBi in the frequency range of 72.8 to 78.8 GHz. The sub-carrier frequency spacing of 1 GHz and modulation bandwidth of 100 and 200 MBd per channel are optimized for high unwanted channel leakage suppression according to the antenna's radiation pattern. Data rates of 200 and 400 Mbps are transmitted at each of the 7 channels, which are received at different locations of a 4 m link with an angular spacing of 12.5°. The error vector magnitude of the transmitted channel at each angle of departure is determined and analyzed, obtaining values in the range of 8.1 and 19.6 %. The power channel suppression for the unwanted channels transmitted at each angle of departure is measured with values from 5.3 to 30.1 dB.