Double-directional channel measurements

The spatial mobile radio channel contains delay information and angular information about the multipath components (m.p.c.s.). Signal delay and ensuing intersymbol interference has played an important role since the inception of digital mobile radio systems like GSM. The multipath signals impinging from different directions of arrival (DOAs) at an antenna array received quite some attention in the past few years. We call this a directional channel. The investigation of smart antennas has lead to better understanding of the radio channel itself and to more accurate and realistic spatial channel models. The identification of useful m.p.c.s. and the suppression of undesired co-channel interference has great potential in smart antennas. The paper describes the use of a superresolution method to identify as many m.p.c.s. as possible. We offer also a novel solution to the "pairing problem", i.e. which DODs and DOAs match the underlying physical propagation path connecting them. Though the measurements we describe were made, for practical reasons, in predominantly static environments, we aim at mobile radio applications.