Utilization of Sc-fdma and Ofdma Based Uplink and Downlink Resources in Lte-a Network Assisted Device to Device Communication for Effective Spectrum Management

Increasing data traffic demands high data rates. Device to device communication (D2D) underlying cellular network improves the spectrum utilisation, hence increases the overall cell throughput if we take proper care on two aspects. First one is physical resource block (PRB) allocation between D2Ds and cellular network users (CEs) and the second one is interference avoiding between PRB sharing CE and D2D with controlled transmission power. An efficient allocation of both uplink (UL) and downlink (DL) PRBs simultaneously at a time for D2D underlying LTE-A cellular network along with an efficient power control mechanism is proposed in this paper. To efficiently use the spectrum, which accommodates more number of D2D, we share SC-FDMA based UL and OFDMA based DL, LTE – A PRBs simultaneously. During PRB allocation high priority is given to the UL PRBs for D2D communication and there after DL PRBs are allocated, if no UL PRBs are free or signal to interference and noise ratio (SINR) is high on UL PRB, as peak to average power ratio (PAPR) is low for UL when compared to DL. The propose method uses proportional fair (PF) scheduling algorithm for PRB allocation to guarantee at least cellular or D2D communication to be continued with accepted fairness in worst case scenario. Proposed power control mechanism avoids the interference caused by PRB sharing pairs effectively. Simulation results shows that the proposed PRB allocation and power control techniques improves the overall cell site throughput.