课程名称︰无线网络基础与应用
课程性质︰选修
课程教师︰蔡欣穆
开课学院：电资学院
开课系所︰资工所、网媒所
考试日期（年月日）︰2015.04.17
考试时限（分钟）：
试题 :
Say there exist a 3x2 link, which has a channel
┌ h_11 h_12 ┐
│ │
H_(3x2) = │ h_21 h_22 │
│ │
└ h_31 h_32 ┘
How can a 3-antenna transmitter transmit a signal x, but null its signal at
two antennas of a two-antenna receiver?