Energy Efficiency Techniques in Ultra-Dense Wireless Heterogeneous 5G networks cellular wireless networks are envisioned to overcome the fundamental challenges of existing cellular networks, higher data rates, excellent end to-end performance and user-coverage in hot-spots and crowded areas with lower latency, energy consumption and cost per information transfer. To address these challenges, IoT-5G systems will adopt a multi-tier architecture consisting of macro cells, different types of licensed small cells, relays, and device-to-device (D2D) networks to serve users with different quality-of-service (QoS) requirements in a spectrum and energy-efficient manner. Starting with the visions and requirements of 5G multi-tier networks, this thesis outlines the challenges of interference management (power control, cell association) in these networks with shared spectrum access (when the different network tiers share the same licensed spectrum In this context, a qualitative comparison of the existing cell association and power control schemes is provided to our thesis for interference management in IoT-5G networks. Open challenges are highlighted and guidelines are provided to schemes in order to overcome these and make them suitable for the emerging IoT-5G systems. The multi carrier code division multiple access (MC-CDMA) systems and analyze the performance by examining the MC-CDMA system model in time domain. to reduce the cross correlation between the time domain MC-CDMA waveforms and the impulsive noise. From Computer simulation results it is cleared that to support our analysis the proposed MC-SI-CDMA system in impulsive noise can gives a performance improvement of 2.5 dB at a bit error rate (BER) level of 10−3 and it is compared with the DS-CDMA system. The mean theoretical SINR is compared to the mean SINR measured via Monte Carlo simulations for BRAN a channel model. It is then used to compare the sensitivities of MC-CDMA and MC-DS-CDMA systems to carrier offset in a frequency selective channel with a zero forcing (ZF) or a minimum mean square error (MMSE) equalizer. The data rate and spectrum efficiency of wireless mobile communications have been significantly improved terrestrial digital TV broadcasting have been developed using OFDM and CDMA technology. Most of the mobile communication systems transmit bits of information to the receiver through radio space. In wireless heterogeneous networks (HetNets), the spatial densification through small cells and the application of massive MIMO antenna arrays are key enablers for high data throughput, wider coverage, and improved energy efficiency (EE). However, ultra-dense deployment of small cells.