Average spectral efficiency of multi-modulation cellular systems

Fourth generation systems are proposed to create extended wireless networks by applying frequency reuse techniques based on a cellular scheme. However, the total bandwidth needed depends on the channel bandwidth and the signal-to-interference protection ratio. The procedure to compute the performance of such interference-limited cellular systems is introduced in this study for systems with various modulation schemes (quadrature phase shift keying, 16 and 64 quadrature amplitude modulation), founding the percentage of the cell area that could be managed with each modulation, considering full load sectors. The conditions to share the same subcarriers between two users in next to base stations are also presented. The total bandwidth required to deploy a network with three sectored cells with 10 MHz channel results to be 360 MHz. This is a big issue since the size of the bands is generally 200 MHz, and it could limit the expected performance of these systems.