짧은 버스트 MPSK전송을 위한 데이터 도움방식의 위상 및 주파수 편이 결합추정기

Abstract

In this paper, a new data-aided joint phase and frequency estimator is proposed and its variances of phase and frequency estimates are derived. To estimate the phase and frequency offset, first of all, the overall observation interval is divided into same length sub-intervals, and then phase estimates are independently computed based on symbols of the each sub-intervals. To be continue the sequence of computed phase estimates, proper integer multiples of $2\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\pi$ are added to (or subtracted from) the computed phase estimates, which is called linearized phase estimate, because the result of $arg(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\cdot)$ function used to get phase estimates is confined within $[-\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\pi, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\pi)$. The phase offset of the proposed joint estimator is estimated by averaging the linearized phase estimates and the frequency offset by averaging the differences between consecutive linearized phase estimates. The variance of the proposed phase offset estimate is same to MCRB of phase if there is no frequency offset, but it is smaller than MCRB of phase if there is frequency offset. However, the variance of the proposed frequency offset estimate is requires more than 0.5 dB symbol energy to get the same MCRB of frequency with the same observation interval.