Pilot-less channel estimation and evaluation for LOS-MIMO microwave radio links

Abstract

A computer-implemented method, performed in a network node, for estimating one or more relative channel gains and one or more channel phases associated with a wireless propagation channel (H) between N transmit antennas (220) and M receive antennas (230) in a line-of-sight, LOS, multiple-input multiple-output, MIMO, communication system (200), the method comprising configuring a channel equalizer to compensate for differences in complex gain over the wireless propagation channel (H) between the N transmit antennas (220) and the M receive antennas (230), configuring a phase tracker to compensate for differences in phase between a set of transmit side oscillators (240) at the N transmit antennas (220) and a set of receive side oscillators (250) at the M receive antennas (230), obtaining a set of equalizer coefficients (W) from the channel equalizer indicative of relative complex gain differences of propagation paths between the N transmit antennas (220) and the M receive antennas (230), obtaining a set of phase compensation values (E) from the phase tracker representing estimated phases of the set of transmit side oscillators and the set of differences of propagation paths between the N transmit antennas (220) and the M receive antennas (230), obtaining a set of phase compensation values (E) from the phase tracker representing estimated phases of the set of transmit side oscillators and the set of receive side oscillators, and upon the channel equalizer meeting a convergence criterion, estimating the one or more relative channel gains and the one or more channel phases based on an inverse function of the set of equalizer coefficients (W) and the set of phase compensation values (E).

Dependencies are inferred from the claim text.