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http://dx.doi.org/10.5515/KJKIEES.2009.20.8.701

Adaptive Multi-Tap Equalization for Removing ICI Caused by Transmitter Power Transient in LTE Uplink System  

Chae, Hyuk-Jin (Department of Electrical and Electronic Engineering, Yonsei University)
Cho, Il-Nam (LG Electronics)
Kim, Dong-Ku (Department of Electrical and Electronic Engineering, Yonsei University)
Publication Information
The Journal of Korean Institute of Electromagnetic Engineering and Science / v.20, no.8, 2009 , pp. 701-713 More about this Journal
Abstract
This paper studies a method for reducing performance degradation due to losing sub-carrier orthogonality caused by power transient between physical channels in LTE uplink transmission. The pattern of inter-carrier interference(ICI) caused by power transient is different from what has been studied for doppler shift, in that its pattern occurs at front and rear sides of channels in each period of power transient. The reason of ICI's occurrence results from power difference between channels, power transient duration, multi-path channel delay spread, and numbers of sub-carrier. New criterion is proposed to find out number of taps of multi-tap equalizer enough to improve the ICI. The scheme is to determine the number of taps of multi-tap equalizer when a normalized interference or a normalized ICI is greater than a normalized noise. Simulation results show that the number of taps is flexibly adjusted according to SNR(Signal to Noise Ratio) of a received signal to improve Bit Error Rate(BER), while the complexity of the proposed scheme is reduced down to 88 percentage of the classical method.
Keywords
LTE; ICI; Equalization; Power Transient;
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