电子学报 ›› 2016, Vol. 44 ›› Issue (5): 1156-1161.DOI: 10.3969/j.issn.0372-2112.2016.05.020

• 学术论文 • 上一篇    下一篇

NC-OFDM系统旁瓣抑制中的可变干扰抵消基函数设计

代光发1,2, 王勤2, 王高峰1, 陈少平2   

  1. 1. 武汉大学电子信息学院, 湖北武汉 430074;
    2. 中南民族大学智能无线通信湖北省重点实验室, 湖北武汉 430074
  • 收稿日期:2014-10-10 修回日期:2015-09-06 出版日期:2016-05-25 发布日期:2016-05-25
  • 作者简介:代光发 男,1979年出生于湖北洪湖,武汉大学电子信息学院在读博士.现任职于中南民族大学,讲师.主要研究方向为OFDM、认知无线电.E-mail:daiguangfa@scuec.edu.cn;陈少平 男,1965年出生于湖北公安,博士.中南民族大学智能无线通信湖北省重点实验室,教授.研究方向为通信理论与通信技术.E-mail:spchen@scuec.edu.cn;王高峰 男,1965年出生于湖北英山.留美双博士,武汉大学电子信息学院教授.主要研究领域包括微纳集成电路设计、电子设计自动化(EDA)软件、微机电系统器件研究、微纳光电集成电路研究、电磁场理论和通讯工程、信号处理和人工智能、小波分析等.
  • 基金资助:

    国家自然科学基金(No.61302117,No.61201267,No.61179007)

Variable Cancellation Basis for Side-Lobe Suppression in Non-contiguous OFDM Systems

DAI Guang-fa1,2, WANG Qin2, WANG Gao-feng1, CHEN Shao-ping2   

  1. 1. College of Electronics and Information, Wuhan University, Wuhan, Hubei 430074, China;
    2. Hubei Key Laboratory of Intelligent Wireless Communications, South Central University for Nationalities, Wuhan, Hubei 430074, China
  • Received:2014-10-10 Revised:2015-09-06 Online:2016-05-25 Published:2016-05-25

摘要:

在抑制非连续载波正交频分复用(Non-contiguous Orthogonal Frequency-Division Multiplexing,NC-OFDM)系统旁瓣的方法中,使用固定长度和矩形形状干扰抵消子载波的主动干扰抵消方法(Active Interference Cancellation,AIC)抑制深度不够,而其改进方法扩展AIC (Extended AIC)对数据子载波干扰又太大.本文发现插入在不同频段的干扰抵消子载波对旁瓣抑制的效果不同,并在此基础上提出对干扰抵消子载波按频率分组,不同组的干扰抵消子载波使用不同的长度与波形,从而提高对NC-OFDM信号旁瓣的抑制效果,同时减小了所引入的载波间干扰.仿真结果表明:采用本文提出的可变基函数方案,在达到-60dB的旁瓣抑制深度时,即使采用高阶的64-QAM符号映射(实验条件是误符号率为10-5),干扰抵消信号对数据子载波造成的载波间干扰也几乎可以忽略.

关键词: 认知无线电, 非连续载波正交频分复用, 旁瓣抑制, 主动干扰抵消

Abstract:

In non-contiguous orthogonal frequency-division multiplexing (NC-OFDM) based cognitive radio systems, conventional active interference cancellation (AIC) and extended AIC (EAIC) schemes use the same rectangular waveform of the same length for all canceling carriers (CCs), leading to the limitation of performance improvement of side-lobe suppression or inter-carrier interference (ICI) reduction.In this paper, a novel variable cancellation basis was proposed for side-lobe suppression in NC-OFDM cognitive radio systems based on the observation that CCs in different frequency have non-uniform attribution for sidelobe suppression.So, CCs are grouped by frequency locations and shaped with different waveforms of different lengths to satisfy good side-lobe suppression performance while reducing ICI at the same time.Numerical results show that, with the proposed CC scheme, NC-OFDM signal's side-lobe can be suppressed to -60 dB with negligible signal-to-noise ratio loss at a symbol error rate of 10-5 with 64 quadratic-amplitude modulation symbol.

Key words: cognitive radio, non-contiguous orthogonal frequency-division multiplexing, side-lobe suppression, active interference cancellation

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