CAJ | 학술논문

针对描述通信信道中存在的非高斯、重拖尾脉冲噪声的对称?稳定(S?S)分布模型,其概率密度函数不存在解析表达式,在信号检测和信道迭代译码等应用场合不易分析和处理的问题,提出了一种以3倍散度为界的两段曲线逼近算法.首先,确定两段曲线的分界点;其次,在3倍散度之外,确定了前3项级数来逼近;最后,在3倍散度之内,构造了一个简洁的双参数指数函数,并用泰勒级数展开的方法确定指数函数中的2个参数.所提出的两段曲线逼近法避免了已有级数逼近法中存在的级数项项数的选择问题和级数发散的问题.数值计算结果表明,与传统的柯西高斯混合逼近算法相比,提出的逼近算法更接近真实的 S?S 分布.
침대묘술통신신도중존재적비고사、중타미맥충조성적대칭?은정(S?S)분포모형,기개솔밀도함수불존재해석표체식,재신호검측화신도질대역마등응용장합불역분석화처리적문제,제출료일충이3배산도위계적량단곡선핍근산법.수선,학정량단곡선적분계점;기차,재3배산도지외,학정료전3항급수래핍근;최후,재3배산도지내,구조료일개간길적쌍삼수지수함수,병용태륵급수전개적방법학정지수함수중적2개삼수.소제출적량단곡선핍근법피면료이유급수핍근법중존재적급수항항수적선택문제화급수발산적문제.수치계산결과표명,여전통적가서고사혼합핍근산법상비,제출적핍근산법경접근진실적 S?S 분포.
The symmetric alpha stable (SaS) was used to model a non-Gaussian, heavy tail and impulsive noise of com-munication channels. However, explicit expressions for the probability density functions (PDF) in terms of elementary functions are still unknown except for some special cases, which limits the application of the SaS distribution in practice, which the bi-region separated by the triple divergence was proposed. Specially, within the triple divergence, a simple exponential function with two special parameters was constructed, and the two parameters were determined by using Taylor serial expansion. Compared with conventional algorithms using the series expansion, the proposed algorithm avoids the selecting the number of the series items and the risk of series expansion divergence. Moreover, numerical re-sults verify that the proposed approximation is closer to the actual SaS PDF than the conventional Cauchy-Gaussian mixture approximation.