A method in a network device of adjusting a channel precoding matrix for one or more users operating in a virtualized Massive Multi-Input Multi-Output, M-MIMO, wireless network managed by a neutral host, NH, wherein: - virtualization means that i) resources owned by infrastructure providers are split into slices consisting of virtualized core networks and virtualized access networks corresponding to wired slice and the wireless slice, respectively, and that ii) physical resources behind the slices are hidden to one or more service providers, SPs, and a logical representation of the entire system is created, - the NH is an entity that i) plans, installs and runs a radio access network but does not have its own subscribers and does not own its own radio spectrum license and that ii) leases its network to the one or more SPs; - each of the users receives wireless services from the one or more SPs operating on the virtualized M-MIMO wireless network, and - the method comprises: selecting (S1105) for each service provider, N antennas from all available antennas managed by the neutral host; obtaining (S1110) from each service provider corresponding channel state information, CSI, parameters for each of their respective user; receiving (S1110) from each service provider a precoding matrix calculated according to the obtained CSI parameters; determining (S1115) if all CSI parameters are known; and if the CSI parameters are all known (S1120), a final precoding matrix based on the known CSI parameters is derived (S1125), whereas if only a subset of CSI parameters are known (S1130), a final precoding matrix based on the known subset of CSI parameters is derived (S1135), wherein the final precoding matrix is adjusted to reduce transmission power to minimize inter-SP interference if only a subset of CSI parameters are known. - virtualization means that i) resources owned by infrastructure providers are split into slices consisting of virtualized core networks and virtualized access networks corresponding to wired slice and the wireless slice, respectively, and that ii) physical resources behind the slices are hidden to one or more service providers, SPs, and a logical representation of the entire system is created, - the NH is an entity that i) plans, installs and runs a radio access network but does not have its own subscribers and does not own its own radio spectrum license and that ii) leases its network to the one or more SPs; - each of the users receives wireless services from the one or more SPs operating on the virtualized M-MIMO wireless network, and - the method comprises: selecting (S1105) for each service provider, N antennas from all available antennas managed by the neutral host; obtaining (S1110) from each service provider corresponding channel state information, CSI, parameters for each of their respective user; receiving (S1110) from each service provider a precoding matrix calculated according to the obtained CSI parameters; determining (S1115) if all CSI parameters are known; and selecting (S1105) for each service provider, N antennas from all available antennas managed by the neutral host; obtaining (S1110) from each service provider corresponding channel state information, CSI, parameters for each of their respective user; receiving (S1110) from each service provider a precoding matrix calculated according to the obtained CSI parameters; determining (S1115) if all CSI parameters are known; and if the CSI parameters are all known (S1120), a final precoding matrix based on the known CSI parameters is derived (S1125), whereas if only a subset of CSI parameters are known (S1130), a final precoding matrix based on the known subset of CSI parameters is derived (S1135), wherein the final precoding matrix is adjusted to reduce transmission power to minimize inter-SP interference if only a subset of CSI parameters are known. <EOS>