CAJ | 학술논문

针对具有固定帧长和固定帧同步序列的单通道高阶调制线性混合信号，当两路信号编码异步时，在已知帧长的条件下提出一种基于最大似然准则的频偏估计算法，并给出了算法的有效频偏估计范围。算法通过求互相关获得目标函数，并利用分级搜索的方法估计频偏。为对算法的性能进行评价，文中同时推导了混合信号频偏估计的克拉美罗界（Cramer-Rao Bound ，CRB ）。仿真结果表明，算法在低 Eb／N0下可获得接近CRB的估计性能。此外，算法还适用于功率非对称的混合信号。
침대구유고정정장화고정정동보서렬적단통도고계조제선성혼합신호，당량로신호편마이보시，재이지정장적조건하제출일충기우최대사연준칙적빈편고계산법，병급출료산법적유효빈편고계범위。산법통과구호상관획득목표함수，병이용분급수색적방법고계빈편。위대산법적성능진행평개，문중동시추도료혼합신호빈편고계적극랍미라계（Cramer-Rao Bound ，CRB ）。방진결과표명，산법재저 Eb／N0하가획득접근CRB적고계성능。차외，산법환괄용우공솔비대칭적혼합신호。
For single-channel linear mixture of high-order modulated signals which have the fixed frame length and sync code ,a frequency offset estimation (FOE ) algorithmbased on the maximum likelihood criterion is proposed when the two signals are coded asynchronously ,and the effective range of FOE is given .FOE is calculated byoptimising the objective function ,which is ob-tained from cross-correlation computation ,and the optimised process is accomplished by utilising hierarchical search .To evaluate the performance of the proposed algorithm ,Cramer-Rao Bound (CRB)of mixed-signal FOE is derived .Simulation results show that ,the estimation performance of the algorithm can come close to CRB performance with low Eb/N0 .The proposed algorithm is also ap-plied to the FOE of a mixed signal whose power is asymmetrical .