Wiener's Loop Filter for PLL-Based Carrier Recovery ofOQPSK and MSK-Type Modulations

[摘要] This letter considers carrier recovery for offsetquadrature phase shift keying (OQPSK) and minimum shiftkeying-type (MSK-type) modulations based on phase-lock loop(PLL). The concern of the letter is the optimization of the loopfilter of the PLL. The optimization is worked out in the light ofWiener's theory taking into account the phase noise affecting theincoming carrier, the additive white Gaussian noise that is presenton the channel, and the self-noise produced by the phase detector.Delay in the loop, which may affect the numerical implementationof the PLL, is also considered. Closed-form expressions for theloop filter and for the mean-square error are given for the casewhere the phase noise is characterized as a first-order process.

[学科分类] 电子、光学、磁材料