SCM-OFDM系统中一种新型的盲频偏估计方法

A Novel Bind Carrier Frequency Offset Estimation Method in SCM-OFDM Systems

该文提出了一种用于重叠码调制-正交频分复用(SCM-OFDM)系统中基于信号检测的频偏估计方法。这种估计方法首先利用SCM迭代检测器输出的判决符号重构接收信号,再利用最小均方误差准则对频偏进行估计。该方法不需要额外的训练序列或导频符号,是一种高效的盲频偏估计方法。此外,该文还提出了一种改进的频偏估计方法。在改进的方法中,接收机将频偏估计与信号检测进行联合迭代;这样在每一次迭代过程中,信号检测和频偏估计都需要执行一次,并且接收机在信号检测时可以利用上一次得到的频偏估计值进行频偏补偿。仿真结果表明,该文提出的基于信号检测的频偏估计方法能够高效并准确地估计出SCM-OFDM系统的频偏。

A Carrier Frequency Offset （CFO） estimation method is proposed based on signal detection in Superposition Coded Modulation （SCM）-OFDM systems. This method reconstructs first the received signal by decision symbols from the SCM iterative detector, and then estimates the CFO by employing the Minimum Mean Squared Error （MMSE） criterion. It is an efficient blind CFO estimation method without the aid of extra training sequences or pilot symbols. ~rtherrnore, an improved method is proposed to estimate CFO in this paper. In the improved method, a joint CFO estimation and signal detection receiver is realized by an iterative process. Thus data detection and CFO estimation need to be implemented in each iteration process. And the receiver can compensate the CFO by the last estimated value during signal detection. Simulation results show that the proposed CFO estimation methods can significantly and accurately estimate the CFO for SCM-OFDM systems.