دانلود رایگان مقاله گسترش مدل پایه ای برای برآورد کانال در سیستم ارتباطی LTE-R

Abstract

This paper investigates fast time-varying channel estimation in LTE-R communication systems. The Basis Expansion Model (BEM) is adopted to fit the fast time-varying channel in a high-speed railway communication scenario. The channel impulse response is modeled as the sum of basis functions multiplied by different coefficients. The optimal coefficients are obtained by theoretical analysis. Simulation results show that a Generalized Complex-Exponential BEM (GCE-BEM) outperforms a Complex-Exponential BEM (CE-BEM) and a polynomial BEM in terms of Mean Squared Error (MSE). Besides, the MSE of the CE-BEM decreases gradually as the number of basis functions increases. The GCE-BEM has a satisfactory performance with the serious fading channel.

5. Conclusion

In this paper, the fast TV channel estimation algorithms based on the CE-BEM, GCE-BEM, and P-BEM was investigated. The simulation revealed that the performance of the GCE-BEM was the best, the P-BEM was the second, and the CE-BEM was the worst. For the CE-BEM, its performance was improved by increasing the number of basis functions. In addition, the MSE of the GCE-BEM is small even with deep fading channel. For the coefficients of the basis functions, this paper employs the Cramer–Rao Lower BoundVector Parameter theorem to obtain the optimum value. In the further work, other algorithms, such as Least Squares, Minimum Mean Square Error, and Linear Minimum Mean Square Error will be adopted to calculate the coefficients, and compare their performance.