CAJ | 학술논문

针对通用的两状态陆地移动卫星(LMS)信道模型中，每一状态的Loo分布包含无限范围内的积分且不存在闭合形式，导致性能估计难以实现的问题，基于两状态信道模型给出等增益合并分集LMS系统中断概率的闭式解。利用Taylor级数展开法将包络的概率密度函数(PDF)近似为Rice分布PDF的加权和，利用Beaulieu序列法推导独立信道随机变量和的累积分布函数和二阶矩，得出系统中断概率的闭式解。仿真结果表明，近似中断概率与理论值十分一致，具有精确性、灵活性、复杂度低的优点。
침대통용적량상태륙지이동위성(LMS)신도모형중，매일상태적Loo분포포함무한범위내적적분차불존재폐합형식，도치성능고계난이실현적문제，기우량상태신도모형급출등증익합병분집LMS계통중단개솔적폐식해。이용Taylor급수전개법장포락적개솔밀도함수(PDF)근사위Rice분포PDF적가권화，이용Beaulieu서렬법추도독립신도수궤변량화적루적분포함수화이계구，득출계통중단개솔적폐식해。방진결과표명，근사중단개솔여이론치십분일치，구유정학성、령활성、복잡도저적우점。
The Loo distribution includes an infinite-range integral and is unclosed-form within each state for versatile two-state land mobile satellite (LMS) channel model, which makes the performance estimation difficult. The closed-form expression of outage probability for equal gain combining diversity LMS systems is presented based on two-state channel model. Firstly, the envelope probability density function (PDF) for each state is approximated as a sum of weighted Rice’s PDFs by using Taylor series expansion algorithm. At a second stage, the cumulative distribution function and second moment of the sum of independent channel random variables are derived by applying Beaulieu series method. Finally, the closed-form of outage performance is obtained. Simulation results show that the approximated outage probability not only agrees very well with exact results over two-state LMS channel model, but also has superiority in significant accuracy, flexibility, and moderate computational complexity.