The Impact of Adjacent Channel Leakage Power Ratio in LTE System and WCDMA System

Abstract

Transmission power must have a suitable level, because high power level leads to mobile battery consumption and interference problem while low power level produces poor signal strength. Due to the leakage power in adjacent channel the performancedegrades, Leakage power affect the system capacity as it interferes with the transmission in adjacent channels and power consumption because time between battery charges for mobile phones is required to be as long as possible.The aim of this study is to evaluate the impact of adjacent channel leakage power ratio (ACLR) in LTE and WCDMA for the first and second adjacent channels. This study evaluates the power for the three channels (main ,first and second channels) by calculating the ACLR, and minimizing the leakage power ratio by using root-raised-cosine filter for WCDMA system, and square measurement filter for LTE system . The resultshow that the middle reference measurement channel (R) = 6, the power is equal to -6.52 dBm in the main channel , the power in the first adjacent channel is equal to -42.36 dBm and the power in the second adjacent channel is equal to -85.73 dBm. The percentage of leakage power between main channel and first adjacent channel is 0.026 % and percentage of leakage power between main channel and second adjacent channel is (1.2×10^-6) % for LTE system (E-UTRA).For WCDMA (UTRA) power is equal to -1.34 dBm in the main channel, the power in the first adjacent channel is equal to -34.74 dBm and the power in the second adjacent channel is equal to -70.78 dBm .The Percentage of leakage power between main channel and first adjacent channel is equal to .045 % and percentage of leakage power between main and second adjacent channel equal is (1.14 ×10^-5) %. The obtained results explore that LTE is better than WCDMA in term of leakage power. This study recommends to investigate the effect of ACLR in the fifth generation.