Mm-wave Wideband Mimo Channel Sounding

The use of wideband 60 GHz radio propagation channel will allow high data rates in future communication systems [1]. E.g., the 57...64 GHz frequency band will allow Gbit data rates for short-range wireless access. Indeed this frequency range offers huge bandwidths and, due to the oxygen absorption, improves frequency reuse in cellular networks compared to lower frequencies. Furthermore, array signal processing is a promising approach to enhance the link performance. Fortunately enough, antenna arrays are small at mm-wave frequencies so that large MIMO (Multiple Input Multiple Output) systems with high capacity could be realized in a small volume like the corner of a laptop, PDA or mobile phone. The adaptive antenna array gain can be used to enhance the link gain and to reduce interference. Missing line-of-sight can be mitigated by directing beams towards the strongest available multipaths or by submitting a variety of links toward widely distributed infrastructure antennas. The achievable capacity of MIMO systems is defined by the availability of parallel propagation channels in multipath environment. Therefore, the performance prediction of mm-wave mobile radio links requires thorough investigation of the time-varying and directional propagation characteristics Most of the solutions for characterizing the radio channel in the 60 GHz band with adequate bandwidth are based on vector network analyzers, where the characterization of the channel is slow, limiting the possibilities to perform multi-channel measurements required for MIMO. Most real-time measurement results reported in the literature suffer from a too small bandwidth. E.g., a bandwidth of 400 MHz corresponds to spatial resolution of only 0.75 m, which is not enough to resolve propagation occurring in a typical indoor environment. In section, II we introduce the measurement setup. The measurement campaign and the results are presented in section III and IV respectively. Section V concludes this paper.