一种双选择性信道中OFDM系统的IQ不平衡补偿方法

IQ imbalance compensation scheme for OFDM systems in doubly-selective channels

针对正交频分复用(orthogonal frequency division multiplexing,OFDM)系统在时间—频率双选择性信道环境中由同相正交(in-phase and quadrature-phase,IQ)支路不平衡耦合多径时变信道导致的复杂子载波间干扰问题,提出了一种基于球形译码算法和并行干扰消除算法的IQ不平衡补偿方法。该方法通过对系统模型进行简化与分块处理,采用球形译码算法消除块内的子载波间干扰,采用并行干扰消除算法抑制块间干扰,并进行交替迭代运算。仿真结果表明,提出的算法在时间—频率双选择性信道环境下具有良好的IQ不平衡补偿性能。

Considering the inter-carrier interferences （ICI） caused by in-phase and quadrature-phase （IQ） imbalances and multipath time-varying channels in orthogonal frequency division multiplexing （OFDM） systems through time-frequency doubly-selective channels, an IQ imbalances compensation scheme is proposed based on sphere decoding （SD） and parallel interference cancellation （PIC）. By simplifying the system model and dividing it into several blocks, the SD algorithm is used to compensate the intra-block interference, while the PIC algorithm is used to mitigate the inter-block interference. These two algorithms are combined with several iterations. Simulation results show a good system performance of the proposed IQ imbalance compensation scheme.