不精确帧同步对幅值相位线性插值影响的分析

在正交频分复用系统中，常见的频域线性插值方法为I 路Q路信道分别进行线性插值(I-Q 插值). 幅值相位线性插值（A-P 插值）由于性能略差且硬件实现复杂度高而很少被采用. 该文在不精确帧同步系统中循环前缀（cyclic prefix, CP）提前截去的情况下，研究了A-P 插值方法受CP提前截去量的影响，并与I-Q 插值进行比较，给出了I-Q 插值和A-P 插值的均方误差通用表达式. 研究结果表明，A-P 插值方法的性能受CP提前截去量的影响很小，仅取决于频域信道相关特性，而I-Q 插值会受CP提前截去量及频域信道相关特性两方面的影响. 因此，当同步算法性能较差而引起较大定时偏差时，也可选择A-P 插值作为频域插值算法.

Effect of Imperfect Frame Synchronization on Linear Interpolation of Amplititude and Phase

In orthogonal frequency division multiplexing (OFDM) systems, a common interpolation method is the linear interpolation in in-phase and quadrature components (I-Q interpolation). Linear interpolation of amplitude and phase (A-P interpolation) is rarely used in practice since it is inferior to I-Q interpolation in terms of performance and computational complexity. For imperfect frame synchronization, the effect of cyclic prefix (CP) removal prior to the A-P interpolation is studied and compared with I-Q interpolation. A universal expression of mean square error in A-P and I-Q interpolations is given. Analyses show that A-P interpolation mainly depends on frequency correlation of the channels, and is less affected by preact of CP removal, while I-Q interpolation is affected by both frequency correlation of the channels and preact of CP removal. Thus, A-P interpolation can also be used when the synchronization performance is poor.