A Performance study for Average LCR and AFD of Dual MRC and SC Diversity over Correlated Nakagami Environment

• Main Authors: Yu Kuang Chu, 朱有光
• Other Authors: Chung Ping Liu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/76480206905403901967

碩士 === 元智大學 === 電機工程學系 === 91 === The signal fading phenomena caused by multi-path propagation in wireless system will significantly degrade the performance of communication systems. Due to the signal envelope fluctuations, there are a lot of criteria for evaluating performance of wireless communication systems. The level crossing rate (LCR) and average fading duration(AFD) are two of the most important parameters. Both of them characterize some aspects of the second-order statistical behavior of envelopes fluctuations. Although there exist a lot of distributions that well characterized the statistics of the mobile radio signal; however, empirical results as well as physical reasoning have shown the fact that the Nakagami-m distribution is a more versatile model for variety of fading environment such as urban, suburban radio multi-path channels and even for indoor propagation. In this thesis , Nakagami fading channel were utilized to study the correlated signals and its related mathematical expressions are derived with LCR and AFD. In this study , a dual-branch receiver with maximal ratio combining (MRC) and selection combining (SC) techniques over Nakagami-m fading channel was analyzed with numerical calculations. Signals in the two diversity branches are assumed to be correlated with Nakagami-m fading. The Results indicate that average level crossing rate(LCR) and average fade duration (AFD) are significant affected by the correlation between branches with MRC and SC schemes.