改进的多通道系统频域信道均衡算法

An Improved Frequency-Domain Equalization Algorithm in Multi-Channel System

在多通道系统中,通道之间的幅相不一致性往往会使系统的性能恶化。在基于阵列天线波束形成过程中,各通道之间的幅相不一致性会使阵列波束方向图发生畸变;在基于阵列的测向系统中,通道之间的不一致性会使测向伪谱噪底抬高,分辨率降低,因此进行信道均衡就显得特别重要。针对宽带多通道系统,在常规频域均衡算法的基础上提出了改进的频域均衡算法。本算法利用频域采样抽取的思想,并充分利用快速傅里叶变换(FFT)和快速傅里叶逆变换(IFFT)避免了矩阵乘法和求逆运算,大大降低了计算量,利于实际工程实现。仿真分析了该均衡算法的性能,验证了其有效性。

The inconsistency between the channels will generally degrade the performance of multi-chan-nel system.In the beam forming process based on array antennas,the channel inconsistency will lead to the beam distortion.When doing direction of arrival estimation based on array antennas,it will also raise the noise floor of the pseudo-spectrum and reduce the spectrum-resolution.Therefore it is necessary to equalize the mismatch between the channels.This paper proposes an improved equalization algorithm based on the conventional frequency-domain equalization method.It takes advantage of the frequency-sampling technique and makes full use of fast Fourier transform（FFT）and inverse fast Fourier transform（IFFT）to reduce the computational burden,avoiding the complex computation of multiplication and inversion with matrices.The simulation results show the performance and the effectiveness of the improved algorithm.