**8. Conclusions**

In this chapter, we have looked at the feasibility of the multi-user MIMO for future wireless systems which are characterized by low-level quantization of CSIT. We have shown that multi-user MIMO can deliver its promised gains if the UEs resort to intelligent detection rather than the sub-optimal single-user detection. To this end, we have proposed a low-complexity interference-aware receiver structure which is characterized by the exploitation of the structure of residual interference. We have further investigated the impact of low-level fixed rate feedback on the performance of multi-user MIMO in LTE systems. We have analyzed two important characteristics of the LTE precoders, i.e. low resolution and EGT. We have shown that the performance loss of the LTE precoders in the multi-user MIMO mode is attributed to their characteristic of EGT rather than their low resolution. We have proposed a feedback and precoding design and have shown that the performance in multi-user MIMO significantly improves once strategy of more levels of transmission is resorted to as compared to the case of increased angular resolution. The work presented in this chapter is not merely confined to the framework of LTE, rather it gives the receiver structure and precoding design guidelines for modern wireless systems.
