Frequency smoothing gains in preamble-based channel estimation for multicarrier systems
Frequency smoothing gains in preamble-based channel estimation for multicarrier systems
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DOI：
10.1016/j.sigpro.2013.01.010
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
Dimitrios Katselis;C. Rojas;M. Bengtsson;H. Hjalmarsson
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文献类型：
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作者：
Dimitrios Katselis;C. Rojas;M. Bengtsson;H. Hjalmarsson
在确定性信道假设下，研究了多载波系统中基于最小二乘前导的信道估计问题。对滤波器组多载波偏置正交幅度调制(FBMC/OQAM)系统进行了分析，但对循环前缀正交频分复用(CP-OFDM)系统的分析结果也保持不变。假设每个子载波的噪声干扰是独立的，我们证明了频域平滑技术可以用来改善均方误差(MSE)性能。根据子载波数的不同，平滑的选择可能不同。我们还给出了频域平滑的时间域公式。基于这个公式，我们证明了频域平滑技术可以最小化LS信道估计器的方差，而它们可以通过以偏差换取方差来进一步降低其均方误差。仿真结果验证了所得结果的正确性。
In this paper, the problem of least-squares (LS) preamble-based channel estimation in multicarrier systems under a deterministic channel assumption is revisited. The analysis is presented for the filterbank multicarrier offset quadrature amplitude modulation (FBMC/OQAM) system, although the derived results hold unchanged for the cyclic prefixed orthogonal frequency division multiplexing (CP-OFDM) system, as well. Assuming independent noise disturbances per subcarrier, we show that frequency-domain smoothing techniques can be used to improve the mean square error (MSE) performance. Depending on the number of subcarriers, the choice of smoothing may be different. We also present the time-domain formulation of the frequency-domain smoothing. Based on this formulation, we show that frequency-domain smoothing techniques can minimize the variance of the LS channel estimator, while they can further reduce its MSE by trading bias for variance. Simulations are given to support the derived results.