Performance Improvement in OFDM using Combination of Signal Scrambling and DCT

Nowadays lot of enormous requirement for multimedia services which are data and text in nature and their demand is increasing to large extent. Considering more demand into picture a MC system called as OFDM which forms basis for all 4G communication which is wireless in nature is used. The high popularity OFDM has gained more importance because of its larger capacity which allows the increased count of subcarriers, capacity to carry huge amount of data and larger footprint and also more coverage region with high mobility. Unfortunately the PAPR problem is affecting the system to great extent. The amplifier which requires high power starts operating in the zone which is nonlinear of their characteristic curve because of its high range showing Peak to Avg. of power in an OFDM signal thereby degrading the condition of the principle related to the orthogonality among the subcarriers. This tends to the addition of ISI in the signal which is being transmitted. Here we implemented the techniques to lower PAPR value.