The effects of I/Q imbalance on reconfigurable intelligent surface-asissted spatial modulation systems

The demand of wireless communication technology is increasing day by day, and this needs improving the transmission and channel capacity of communication signals. As a solution for this problem multiple-input multiple-output (MIMO) communication models offered in the improvement research. Nevertheless it has been observed that there are restrictions in data transmission because of the problems such as inter-channel interference in MIMO communication models. Improvement of spectrum and energy efficiency is tried to ensure with new generation spatial modulation (SM) and similar communication models, which are offered as a solution to this data limitation, but system performance is negatively affected from hardware errors that occur during the application of these models. In-phase (I)/quadrature-phase (Q) (I/Q) imbalance, which is a hardware error that seriously reduces performance, also reduces system quality. Reconfigurable intelligent surface (RIS) technology, which has recently become a very popular idea in the field of wireless communication, is thought that will become widespread in new generation communication systems. During the integration of RISs into future communication systems, the effects of I/Q imbalance should not be ignored and the disruptive effects caused by I/Q imbalance in RIS-assisted systems should be eliminated. Considering all these situations, in this study; the effects of I/Q imbalance caused by hardware impairments are examined on RIS-assisted SM and SSK communication models in various scenarios. These scenarios has been created on the simulation by considering the miscellaneousness situations such as determining the detection algorithms according to the I/Q imbalance parameters and estimating the reflection phases of RIS technology. The results show that the negative effects of I/Q imbalance should be considered in the design of communication models that use the SM/SSK technique. It has been observed that the use of RIS reduces the IQ imbalance effect in SM/SSK communication models, but error performance still needs to be improved.