Multi-user Massive MIMO for Cross-Tiers Interference Mitigation in Heterogeneous 5G Next Generation Network

3GPP standard is exploring the enhancement of 5G development. As a result, a more durable network must be created to enable huge access to networks and intelligent communication systems beyond 5G and 6G. In this paper, a cross-tier interference is addressed in the two-tier 5G architecture. A massive MIMO is used at the Base stations (BSs) which served micro user equipment (MUEs)., and small cells (SBSs) are equipped with lesser antennas are served to small cell user equipment (SUEs). A synchronized co-channel TDD is used to communicate over the available bandwidth. The advantage of the synchronized co-channel TDD mode is utilized to estimate the channel. A correlation matrix of a received signal is estimated from the uplink (UL) pilot signal. Hence we modified the correlation matrix and therefore even though the precise knowledge of the interfering channel is not available the channel can be estimated. A modified heuristic optimal resource allocation (HORA) algorithm is used for scheduling. The simulation demonstrates considerable throughput improvement at the user end in two-tier cellular architecture and robust conditions.