宽带数字正交技术及性能分析

讨论了几种宽带数字基于傅里叶变换和离散滤波器的Ｈｉｌｂｅｒｔ变换以及对基带内任意带通信号特殊的正交变换技术，并利用Ｇｒａｍ－Ｓｃｈｉｎｉｄｔ正交化校准原理分析了这几种数字正交技术的性能以及Ｉ、Ｑ通过间的幅度和相位不平衡误差。计算机模拟结果表明，除了Ｈｉｌｂｅｒｔ滤波器的不平衡度较大外，其余两种数字正文技术在较宽的频率范围内都能保持很高的镜像抑制，这为实现宽带实时的数字Ｉ、Ｑ通道提供了工程保证。

Wideband Digital Quadrature Techniques andAnaiysis of Their Performances

in the is paper, several wideband digital quadrature technique are discussed, including FFTtransforming and discrete filter based on Hilbert transforming. A special quadrature sampling technique forarbitrary bandpass signal within bassband sample rate is also presented.Their performances wiTh the quadratureprinciples of Gram-Schmidt are analyzed the errors of I and Q correction are given The computerstimulations show that in wide range of input frequency expect for discrecte filter ,the other methods can obtainvery low image power relative to the primary response.