在無線通訊系統下，多重路徑衰落是最常見的干擾並且嚴重地影響通訊品質。因為中上衰落模型具有較好的模擬彈性而且能夠精確地與實驗數據相符合，所以中分衰落模型是最能夠全方位適用於各種通道的模型。分集結合技術是最常用來降低多路徑衰落的效應，並且期望能夠增加系統的效能。為了量化分集結合系統的效能，水平跨越比例和平均衰落期間通常是用來評估在多重路徑衰落下的分集結合系統效能。如果接收天線沒有間隔足夠的距離，通道之間所產生相關性將會降低分集結合系統的效能，所以具有相關性的分集結合系統效能通常都是劣於獨立性的分集結合系統。因此，對於在實驗室中產生相關性中上衰落通道是非常重要的，因為它兼顧了理論與實用的價值；而且對於分析相關性中上衰落通道的統計特性是有其助益的。 In wireless communication systems, multipath fading is commonly encountered and adversely affects the quality of communication. The Nakagami-m fading model is one of the most versatile models, because it has superior flexibility and accurately matches experimental data. Diversity combining techniques are commonly used to reduce multipath fading effects, and they are thus expected to enhance system performance. In order to quantify the performance of diversity combining systems, the level crossing rate and the average fade duration are usually used to evaluate the performance of diversity combining systems in multipath fading channels. However, if the receiver antennas are not sufficiently separated, the diversity combining techniques are diminished over correlated channel branches, whereas the performance in a correlated diversity system is worse than that for independent multipath fading channels. Hence, the generation of correlated Nakagami-m fading channels in a laboratory environment is of theoretical and practical importance, and it is useful to study the statistics of such channels.
