Introduction to Small Scale Multipath Propagation
Some Notion
coherence time:在一段时间内,信道的增益不变,是常数
coherence bandwidth:在一定频率范围内,,信道的增益不变,是常数
Multipath Channel Effect: Time Invariant and Time Variant
Time Variant:实际信道
Doppler shift:多普勒频移;公式:计算多普勒频率
Parameters of Mobile Multipath Channels
Multipath
Time Dispersion Parameters
Mean excess delay:平均附加时延公式
RMS delay spread:传播时延均方根公式
Types of small-scale fading
Based on multipath time delay spread
Flat Fading平坦衰落:信号带宽<相干带宽
Frequency Selective Fading频率选择性衰落:信号带宽》相干带宽
Rayleigh and Ricean Distributions
Overview of Equalization and Diversity
Diversity:分级合并;多分级技术可以大大降低中断概率公式