科技通报
科技通報
과기통보
BULLETIN OF SCIENCE AND TECHNOLOGY
2014年
5期
110-113,144
,共5页
正交频分复用%信道估计%离散傅里叶变换%聚类分析
正交頻分複用%信道估計%離散傅裏葉變換%聚類分析
정교빈분복용%신도고계%리산부리협변환%취류분석
orthogonal frequency division multiplexing(OFDM)%channel estimation%discrete fourier transform(DFT)%cluster analysis
在正交频分复用系统中，传统的DFT信道估计算法计算复杂度比MMSE算法低，性能比LS算法好，但是它只消除了信道冲激响应中循环前缀长度之外的噪声，而循环前缀长度以内的噪声并没有进行抑制，说明性能存在提高的空间。一般，通过引入判决门限，进一步消除信道噪声的影响，提高系统性能。本文，利用聚类分析技术对循环前缀长度内的噪声进行识别，进一步消除噪声的干扰。仿真证明，本文的改进信道估计算法性能优于原算法。
在正交頻分複用繫統中，傳統的DFT信道估計算法計算複雜度比MMSE算法低，性能比LS算法好，但是它隻消除瞭信道遲激響應中循環前綴長度之外的譟聲，而循環前綴長度以內的譟聲併沒有進行抑製，說明性能存在提高的空間。一般，通過引入判決門限，進一步消除信道譟聲的影響，提高繫統性能。本文，利用聚類分析技術對循環前綴長度內的譟聲進行識彆，進一步消除譟聲的榦擾。倣真證明，本文的改進信道估計算法性能優于原算法。
재정교빈분복용계통중，전통적DFT신도고계산법계산복잡도비MMSE산법저，성능비LS산법호，단시타지소제료신도충격향응중순배전철장도지외적조성，이순배전철장도이내적조성병몰유진행억제，설명성능존재제고적공간。일반，통과인입판결문한，진일보소제신도조성적영향，제고계통성능。본문，이용취류분석기술대순배전철장도내적조성진행식별，진일보소제조성적간우。방진증명，본문적개진신도고계산법성능우우원산법。
In Orthogonal Frequency Division Multiplexing(OFDM)systems,the traditional DFT-based channel estimator for OFDM systems has lower computational complexity than the MMSE algorithm ,and better performance than the LS channel estimators. However,the traditional DFT-based channel estimator removes only the noise in the channel impulse response beyond the length of the cyclic prefix (CP),while the noise within the length of CP is not suppressed,indicating that there is certain space to improve performance. Usually,the impact of channel noise was eliminated through the introduction of the decision threshold,and system performance improved. In this paper,we propose the cluster analysis techniques is used to distinguish channel taps from the noise. Simulation results show that our improved channel estimator performs better than the original one.
