Mbsfn Channel Estimation Methods

Refer to the LTE-A standards, the E-MBMS, whose physical layer structure is to transmit MBMS through SFN, is adoptive to solve problems on broadcast television business. This SFN transmission will probably make multiple delays, while the LTE-A also makes a definition on its special pilot structure, and this article is going to focus on the various channel estimation methods of the structure.In this paper, least squares algorithm, two dimensions wiener filter algorithm, ALMMSE algorithm and transform domain filtering channel estimation algorithm are introduced, and the transform domain filter cutoff frequency selection criterion is optimized. Both complexity and estimation accuracy should be taken into account to solve the problem of channel estimation in MBSFN frame structure. This paper presents the complexity analysis of the four algorithms above, and then the simulation results and comparison of these channel estimation algorithms are given with ideal channel parameters.In the practical application, transform domain filtering algorithm needs to use the information of the signal to noise ratio, two dimensions Wiener filtering and ALMMSE algorithm also need to use the root mean square delay and the maximum Doppler frequency shift information. These channel characteristics in a complex real-world environment is unknown and always constantly changing, so in the later part of this article,analysis emphasizes on the three most important parameters of the wireless channel estimation: SNR, RMS delay, the maximum Doppler frequency shift. In the SNR estimation, this paper describes several existing algorithms: ML algorithm, Boumard algorithm, XU algorithm, and then introduces a wonderful robust SNR estimation algorithm in transform domain, and the impact caused by either the delay or the environmental movement is quite small. Dealing with the root mean square delay estimation, this paper introduces a mapping transform domain estimation algorithm, which can get an accurate result of the RMS delay within a single frame estimation. About the Maximum Doppler frequency shift estimation, you can also learn something from this paper, and you will find out that the introduced CP-based estimation method can provide really good performance.In the last part of this paper, the parameter estimation is added into MBSFN simulation platform to compare the above four channel estimation algorithms in case of non-ideal performance parameters, and some evaluation is given.