Spatial channel characteristics in the outdoor hotspot environment based on wideband MIMO measurements

Wideband multiple-input multiple-output （MIMO） channel measurements were performed at 5.25GHz in the hotspot environment in Beijing. The propagation mechanism was line-of-sight and obstructed-line-of-sight （LOS/OLOS） in the outdoor scenario. Using a large amount of estimated angle of departure （AoD） and angle of arrival （AoA） results, the cumulative distribution functions （CDFs） of directional spread （DS） are extracted, which illustrate that the spatial dispersion is quite significant at both ends due to the low antenna height of base station and rich scatterers. The average power azimuth spectrum （PAS） is found to be well fitted with a Laplacian function. In addition, the non-isotropic property of spatial correlation is investigated, and the average envelop correlation over arbitrary antenna spacing provides the correlation distance to facilitate the MIMO optimization and deployment in the outdoor hotspot environment.     

基于新型距离度量的多级编码在MQAM调制中的应用

基于在MLC／PDL系统中提出的一种新型距离度量，研究其在Rayleigh衰落信道下采用MQAM高效调制时的应用；提出了两种新的映射方法：BP-BP与UP-UP，并采用平衡距离准则作为最佳多级码的设计准则，得到了一种高性能、短时延、低复杂度的高效多级编码系统设计方案．