近似精确重构的低复杂度星载信道化器

提出频率响应遮蔽(frequency response masking,FRM)与改进型离散傅里叶变换(modified discrete Fourier transform,MDFT)相结合的近似精确重构的低复杂度星载信道化器。其中,FRM结构可以较低复杂度设计出过渡带陡峭的有限冲激响应滤波器(finite impulse response,FIR)低通原型,MDFT滤波器组结构可以基本消除滤波器组的邻带混叠,将FRM结构中不适合邻带拼接的结构改进为高通、低通滤波器互补结构,降低了拼接抖动。调整MDFT结构中的上采样率,使之适合于奇偶分离的信道化器。继而提出新的结构,更适合应用于非均匀带宽。仿真表明,所提方法具有更低的运算复杂度,更陡峭的过渡带和更窄的保护间隔,更小的重构误差。

Nearly perfect reconstruction onboard channelizer of low complexity

This paper proposes a nearly perfect reconstruction onboard channelizer of low complexity combining frequency response masking (FRM) with modified discrete fourier transform (MDFT). Of the two techniques,the FRM structure can design a low pass finite impulse response (FIR) prototype filter with a steep transition band with low complexity, while the MDFT filter bank structure can mostly eliminate the adjacent band aliasing. Replacing the structure of the FRM that is not suitable for the adjacent band splicing by a high pass and low pass filter complementary structure,the splice jitter can be reduced. The upsampling rate in the MDFT structure is adjusted to make it suitable for the odd even split channelizers. Then a new structure is put forward, which is more suitable for non uniform bandwidth applications. Simulations show that this method has a lower computational complexity, a steeper transition band and narrower guard interval, and a smaller reconstruction error.