非理想发射机情况下的QPSK性能分析

Performance of QPSK in the presence of nonideal transmitters

调制器的不均衡以及放大器的非线性对接收机的性能具有非常大的影响。由于不均衡对载波跟踪环路的稳态锁定点的影响,使得平均误比特率(BEP)的性能受到了的决定性影响。通过对调制器不均衡的模型讨论,深刻分析了调制器不均衡对载波跟踪环路稳态锁定点和平均BEP的影响。

The modulator imbalance and amplifier nonlinearity have a deleterious effect on the receiver performance. With regard to modulator imbalances, the primary source of degradation comes about because of the effect of the imbalance on the steady-state lock point of the carrier tracking loop, which has a direct impact on the detemination of accurate average BEP performance. We begin our discussion with a description of an imbalance model, then analyse its effect on carrier tracking loop steady-state lock point and its effect on average BEP.