Comparison of low complexity demapper algorithms applied to rotated constellation in DVB-T2

Signal Space Diversity (SSD) technique was adopted in Digital Video Broadcasting-Terrestrial, second generation (DVB-T2) standard ten years ago in order to increase system performance over fading channels. This technique consists in rotated and cyclic Q-delayed M-Quadrature Amplitude Modulation (QAM) and has been proposed without taking into account the complexity induced by the demapper. Due to the complexity of the hardware implementation, the features of this technique have not been effectively exploited for network deployment. Therefore, several low complexity algorithms have been proposed during the last decade in the scientific literature in order to reduce the number of metrics and operators used in the demapping process. This paper proposes an exhaustive overview of all the nine DVB-T2 demapping algorithms existing up to now in the literature by comparing them in terms of parameters, performance and percentage of reduction obtained.