Although Orthogonal Frequency Division Multiplexing (OFDM) system with superimposed training sequence is bandwidth-efficient,the effectiveness of the conventional channel estimation method by utilizing the first-order statistic is restricted by the power allocation ratio and noise.

In order to improve the transmission performance of Orthogonal Frequency Division Multiplexing(OFDM) systems in fast time-varying channels,a novel time-domain channel estimation scheme based on the superimposed training sequence is proposed.

A method of iterative channel estimation is proposed for orthogonal frequency division multiplexing (OFDM) sys- tem using superimposed training sequence with iterative receiver.

Sparse channel parameter estimation based on superimposed training;

Joint frequency offset and channel estimation for superimposed training OFDM systems;

Iterative channel estimator using superimposed training

FPGA implementation of frequency synchronization arithmetic in time domain based on training sequence;

An improved OFDM symbol synchronization algorithm based on training sequence;

Algorithm of channel estimation using special training sequence for MIMO-OFDM systems;

Algorithm analysis of timing synchronization for OFDM system based on training sequences;

Large estimation range and precise estimation can be acquired by the new method by twice frequency offset estimation;moreover,date transmission efficiency will be improved without any demand for training sequences.

In this paper,we analyzed the channel estimation base on block-type training sequences for the typical UWB indoor channel model.

11a system,the coarse frame synchronization can be realized with auto-correlation posed by the periodicity of short training sequences,and the fine frame synchronization can be implemented using cross-correlation between local short training sequences and received signals.