一种抵抗零中频接收机正交失配特性的FM解调算法

为了解决零中频接收机中射频链路正交下变频两路本振信号固有的相位不完全正交、幅度不完全一致特性对接收机解调性能的影响，本文提出了一种针对FM信号特点的解调算法。该算法具有天然的抗正交失配及完全实时跟踪特性，不需要建模、训练和参数解算等复杂数学运算，也不需要额外的硬件开销，简单易行。仿真实验表明本文提出的解调算法在任何正交失配条件下，都具备与理想正交下变频时相同的解调性能，并在实际工程应用中验证了有效性与可靠性。

A Novel FM Discriminator for Quadrature Demodulation Compensation of Zero-IF Receiver

In Zero-IF receiver, the radio quadrature demodulator has inherent I/Q gain and phase imbalance. In order to reduce its impact on the demodulation performance, a novel FM discriminator is proposed. The algorithm can track and compensate the I/Q imbalance correctly without modeling, training and parameter-calculating. Without additional hardware cost, the proposed discriminator can be easily implemented. Simulation proves that the proposed discriminator can get same demodulation performance both with I/Q imbalance and ideal quadrature demodulator. Besides, hardware experiments are achieved to demonstrate its effectiveness and reliability.