  Three dimensional (3D) resource reuse is an important design requirement for
the prospective 6G wireless communication systems. Hence, we propose a
cooperative 3D beamformer for use in 3D space. Explicitly, we harness multiple
base station antennas for joint zero forcing transmit pre-coding for beaming
the transmit signals in specific 3D directions. The technique advocated is
judiciously configured for use in both cell-based and cell-free wireless
architectures. We evaluated the performance of the proposed scheme using the
novel metric of Volumetric Spectral Efficiency (VSE). We also characterized the
performance of the scheme in terms of its spectral efficiency (SE) and Bit
Error Rate (BER) through extensive simulation studies.
