Comparative analysis of iterative and non-iterative equalization methods for small cells in the LTE uplink

The performance of iterative and non-iterative equalization methods for single carrier frequency domain multiple access (SC-FDMA) receiver are studied in this thesis. SC-FDMA is the multiple access scheme adopted in the uplink of LTE, the first 4G system for mobile radio communications. Frequency domain equalization (FDE) is required to combat the frequency selectivity effect caused by multipath propagation. The equalization process at base station represents a key point that is not defined in 3GPP (3rd Generation Partnership Project) standard specifications. As a consequence the development of reduced complexity and high performance equalization methods that can be applied to FDE in the uplink LTE is an interesting issue. The comparative analysis of linear equalization (LE), decision feedback equalization and iterative block equalization schemes is provided. A physical layer uplink simulator focused on signal processing has been developed to evaluate the performance of such schemes. New solutions based on dual DFE scheme for SC-FDMA and soft decision variants of iterative block equalizer are proposed to increase the effectiveness of iterative and non-iterative equalization methods. The considered schemes are integrated into the base station signal processing part of the uplink layer simulator and are tested considering both static channel models and 3GPP multipath fading channel models for broadband transmission in Small Cells scenario. Simulation results show that the considered methods offer better performance than the basic equalization schemes and become attractive to real implementation for their reduced computational complexity reached by the exploitation of the Fast Fourier Transformation kernel speed.