叠加导频OFDM系统的EM信道估计算法

为了提高无线通信系统的传输效率,提出一种基于叠加导频,即将导频符号和发送数据符号按比例叠加后形成频域发送数据的期望最大迭代信道估计算法.该算法不需要信道和接收数据的统计特性,没有因发送导频而带来的带宽损失,适用于多载波(正交频分复用)和单载波传输系统,并且可以通过选择迭代次数实现系统性能和计算复杂度之间的折衷.仿真结果表明,在发射功率损失较少的条件下,该算法仍能很快收敛到给定参数的信道,并取得很好的系统性能.

An EM channel estimation algorithm for OFDM system based on added pilot

To improve the transmission rate of wireless communication systems,an expectation maximization(EM) iterative semi-blind channel parameters estimation algorithm is proposed based on the added pilot(AP) pattern,in which the frequency domain transmitted data are obtained by adding the pilot symbols to the transmitted data symbols in proportion.The algorithm doesn’t need the channel statistics and can be applied to single and multiple carriers transmission without band loss.A tradeoff between the system performance and the algorithm complexity can be realized by choosing the iteration number.The simulation results show that the proposed algorithm can converge fast with less loss of the transmitted power and the good performance can be obtained comparing with the interpolation methods for pilot symbols assistant modulation(PSAM) OFDM systems.