OFDM 시스템에서 주파수 오차와 위상 잡음에 의한 ICI를 제거하기 위한 효율적인 자가상쇄 기법

국문 초록 (Abstract)

OFDM 시스템은 스펙트럼 효율 때문에 각광받고 있지만, ICI의 원인인 주파수 오차와 위상 잡음에 민감하다는 단점을 가지고 있다. ICI 자가상쇄 방법은 주파수 오차나 위상 잡음을 없애는데 좋은 성능을 가지고 있다. 이 논문에서는 N/2 간격의 conjugate 데이터 방법을 이용하여 주파수 오차와 위상잡음이 많이 존재하는 상황 (주파수오차=0.2~0.4, 위상잡음=10도 정도)에서 성능이 좋은 ICI 자가 상쇄 방식을 제안한다. 또한, 파일럿을 이용하여 좀 더 효율적인 ICI 자가상쇄 방법을 제안한다. 모의실험 결과는 이러한 제안된 방식의 성능이 기존의 방식보다 우수하다는 것을 확인할 수 있었다.

다국어 초록 (Multilingual Abstract)

OFDM System is a promising transmission technique due to its spectral efficiency. But, a major disadvantage of the OFDM system is its sensitivity to frequency offset and phase noise that makes intercarrier interference (ICI), which degrades the system performance severely. The ICI self-cancellation method has a good performance with frequency offset or phase noise. This paper proposed the N/2 spacing data-conjugate method that works well in large frequency offset and phase noise (normalized frequency offset=0.2-0.4, phase noise standard deviation=about 10deg). Also, an efficiency ICI cancellation method using pilot was proposed. Simulation results confirm that performance of the proposed scheme is better than conventional schemes.

목차 (Table of Contents)

• 요약
• ABSTRACT
• Ⅰ. 서론
• Ⅱ. 시스템 모델
• Ⅲ. N/2 간격의 data-conjugate 방법
• Ⅳ. 파일럿을 이용한 효율적인 자가상쇄 방법
• Ⅴ. 모의 실험 및 고찰
• Ⅵ. 결론
• 참고문헌

참고문헌 (Reference)

1 "http://grouper.ieee.org/groups/802/11/"

2 B. Stantchev, "Time-variant distortions in OFDM" 2000

3 Y Fu, "Theoretical BER Analysis of OFDM Systems with ICI self-cancellation" 2002

4 S. Tang, "Self-Cancellation of Intercarrier- Interference in OFDM Systems with Phase Noise" 2006

5 P. Tan, "Reduced ICI in OFDM Systems Using the "Better Than" Raised-Cosine Pulse" 2004

6 D. D. Lin, "OFDM phase noise cancellation via approximate probabilistic inference" 2005

7 Y. Zhao, "Intercarrier Interference Sefl-cancellation scheme for OFDM Mobile Communication Systems" 2001

8 T. Zhao, "Intercarrier Interference Compression in OFDM Communication Systems by using Correlative Coding" 1998

9 T. Shigang, "Intercarrer Interference cancellation with frequency diversity for OFDM systems" 2007

10 K. Sathananthan, "Cancellation technique to redued intercarrier interference in OFDM" 2000

11 H. Kang, "BER Performance of the OFDM System with the Polynomial Cancellation Coding under the Frequency Offset" 1999

12 L. Piazzo, "Analysis of phase noise effects in OFDM modems" 2003

13 Z. Jianhua, "Analysis of ICI cancellation scheme in OFDM systems with phase noise" 2004

14 L. J. Cimini, Jr., "Analysis and simulation of a digital mobile channel using orthogonal frequency division multiplexing scheme" 1985

15 R. heung-Gyoon, "An improved ICI reduction method n OFDM communication system" 2004

16 W. G. Jeon, "An equalization technique for orthogonal frequency-division multiplexing system in time-variant multipath channel" 1999

17 K. Sathananthan, "A novel ICI cancellation scheme to reduce both frequency offset and IC imbalance effects in OFDM" 2004