单音干扰下OFDM系统中频域迭代干扰消除算法

针对正交频分复用（OFDM，Orthogonal Frequency Division Multiplexing）系统受单音干扰问题，提出了一种有效的频域迭代干扰消除算法。所提算法首先在频域对干扰进行准确估计和重构，然后进行干扰消除。为实现更准确的干扰频率粗估计，提出了新的结合补零内插的频谱波峰搜索方法，有效地避免了干扰位于两子载波之间时频谱泄露导致的谱峰错判。干扰频率精确估计综合采用频率转化、低通滤波、加权相位平均算法迭代实现，估计误差在每一次迭代中减小。仿真结果表明:对于-20dB以上的干信比，所提算法能保证干扰参数的精确估计，使系统达到没有干扰时的误码率性能。 

A Frequency-Domain Iterative Cancellation Algorithm for Single-Tone Interference in OFDM systems

To solve the single-tone interference problem in orthogonal frequency division multi- plexing(OFDM) systems, an efficient frequency domain iterative interference cancellation algorithm was proposed. Firstly, the proposed algorithm made accurate estimates and reconstruction for the interference in frequency domain, and then the interference was subtracted from the raw data. To achieve a more accurate estimation of coarse interference frequency, a new method of spectrum peak search which combined with zero padding interpolation was proposed. The method effectively avoided the misjudgment of spectral peak position which was caused by spectrum leakage when interference located between the subcarriers. The accurate estimation of interference frequency was implemented by iteratively adopted a combination of frequency conversion, low pass filtering, weighted phase average(WPA) algorithm, the estimation error decreased at each iteration. The simulation results show that for the jamming to signal ratio(JSR) of -20dB above , the proposed algorithm can ensure the accurate estimation of interference parameters, make the system to achieve the bit error rate(BER) performance without interference.