Investigations on spectral efficiency of multi-cell networks using hybrid beamforming

Millimeter wave communication systems with antenna beamforming facilitates practical solutions to the capacity crunch issues in the upcoming 5G wireless networks. Multi-cell dense networks are prone to three major interferences-inter-cell, intra-cell and Inter layer interference-the most dominating being the inter-cell interference. This paper focuses to alleviate inter-cell interference using hybrid beamforming (HBF) approach, leveraging coordinated multipoint (CoMP) technique, thereby improving the SE of 5G networks. Simulation results show HBF peforms in par with optimal weights, making it a suitable candidate for 5G networks. As the number of data streams is increased from Ns=1 to 4 for 0 dB signal to noise ratio (SNR) with Nt=64 and Nr=16, the SE increases from 9.5557 bits/s/Hz to 26.423 bits/s/Hz for optimal weights and from 9.1885 bits/s/Hz to 19.763 bits/s/Hz and hybrid weights, respectively. The second set of experiments are conducted to study the effect of number of transmit antennas on spectral efficiency (SE). The results show that as the number of transmit antennas is increased from Nt=16 to 64 for 0 dB SNR, with Nr=16 and Ns=4, the SE increases from 17.735 bits/s/Hz to 26.423 bits/s/Hz and 13.750 bits/s/Hz to 19.763 bits/s/Hz for optimal weights and hybrid weights, respectively.