OFDM空时发射分集系统信道盲估计

本文研究了OFDM空时发射分集系统的子空间信道盲估计方法。该方法仅利用空时编码及OFDM调制引入的冗余,在接收天线小于发射天线时,也可以对信道进行盲估计。对盲估计方法所共有的估计模糊性问题进行了详细的论述,证明估计仅存在两个标量不确定因子。这种方法不需要对信号进行冗余预编码,系统将有更高的速率;同时也不需要对系统输出进行过采样或采用多天线接收。由于不需要确切知道信道的阶数,算法对信道阶数过估计有较好的鲁棒性。

Blind Channel Estimation for Space Time Block Coded OFDM System

This paper deals with a subspace-based blind channel estimation method for space-time coded OFDM system.Using only the redundant information inherent in space-time block coding(STBC)and OFDM modulation,channel state information(CSI) can be blindly estimated up to two scalar ambiguities,even when the receiving antennae are less than transmitting antennae.The estima- tion ambiguity,which is common to all blind method,is discussed in detail and we prove that there only exists two scalar indetermina- cies.This method needs neither redundant pre-coding nor over-sampling or multiple receive antennae,thus has higher data rate.Besides, it is robust to channel order overestimation,for only the upper bounds of channel orders are needed.