Method and apparatus for providing generic hierarchical precoding codebooks

A base band unit, BBU, in a wireless cellular heterogeneous network is provided in a transmission node cluster, TNC, of transmission nodes, TNs, of neighbouring cells of the wireless cellular heterogeneous network, wherein the BBU comprises generic hierarchical precoding codebooks, CBs, each CB comprising cluster precoding matrices, CPMs, and each CPM is provided for a possible combination of active TNs within the TNC.