CAJ | 학술논문

针对双选择衰落信道下OFDM系统中基于复指数基扩展模型（CE-BEM）的信道估计算法存在的不足，提出了一种基于加窗的基扩展模型信道估计算法。该算法通过时域加窗和去窗处理来减少CE-BEM存在的频谱泄露，并抑制多普勒频移对估计性能的影响；利用设计的导频方案，简化数学模型；再通过正交映射对估计的基扩展模型系数进行转换，从而进一步提高信道估计的精确度。同时采用归一化均方误差和误码率来衡量信道的估计性能，实验仿真表明，提出的算法在高速的移动环境下能有效提高估计性能。
침대쌍선택쇠락신도하OFDM계통중기우복지수기확전모형（CE-BEM）적신도고계산법존재적불족，제출료일충기우가창적기확전모형신도고계산법。해산법통과시역가창화거창처리래감소CE-BEM존재적빈보설로，병억제다보륵빈이대고계성능적영향；이용설계적도빈방안，간화수학모형；재통과정교영사대고계적기확전모형계수진행전환，종이진일보제고신도고계적정학도。동시채용귀일화균방오차화오마솔래형량신도적고계성능，실험방진표명，제출적산법재고속적이동배경하능유효제고고계성능。
In terms of the deficiencies of channel estimation algorithm based on the Complex Exponential Basis Expansion Model(CE-BEM)in Orthogonal Frequency Division Multiplexing(OFDM)systems under doubly-selective fading chan-nels, this paper proposes a new channel estimation algorithm based on windowed basis expansion model. The algorithm can be applied to reduce spectrum leakage which exists in CE-BEM through the time domain windowing and de-windowing processing, and suppress the influence of doppler shift to estimation performance. The mathematical model is simplified by using the designed pilot scheme;and then the estimated coefficients of CE-BEM are converted by orthogonal projection, and further improve the channel estimation accuracy. Besides, the Normalized Mean Square Error(NMSE)and Bit Error Rate(BER)are used to measure the channel estimation performance. Experimental simulation results demonstrate that the proposed algorithm can effectively improve the channel estimation performance in mobile environment with high speed.