Energy Efficiency Improvement in Mobile Communication System by Reducing the PAPR

Abstract

Peak to average power ratio (PAPR) is a great issue in multicarrier systems especially in the LTE/LTEA communication system, so there is still a wide range that handles the PAPR problem. Orthogonal frequency division multiple access (OFDMA) technique is used in the downlink LTE system as it has many advantages over multipath propagation system. On the other side it suffers from a high PAPR that will affect the energy efficiency. In this paper, a new hybrid scheme is proposed in the downlink mobile communication system to overcome this issue. Besides reducing the PAPR, the proposed scheme did not have a significant increase in the system complexity but also it had nearly the same bit error rate (BER) system performance as OFDM system. Also we introduce a combination of different pre-coding techniques in OFDM system that improve the BER such as (Discrete Hartley Transform, Discrete Cosine Transform and Discrete Sine Transform) with the companding techniques that have a good ability in reducing the PAPR with a little increase in system complexity such as (Absolute exponential, Tangent rooting and Logarithmic) companding techniques. We tested the system performance for different techniques combination, and according to the analysis and the simulations done, it was found that the hybrid technique that is composed from the Discrete Hartley transform pre-coding technique and the Logarithmic companding technique in the downlink system outperforms all other hybrid techniques combinations.