NR系统中下行物理信号有哪些()
A. 辅同步信号(Secondary synchronization si gnal, SSS)
B. 信道状态信息参考信号(Channel -state information reference signal, CSI -RS)
C. 解调参考信号(Demodulation reference signals, DM-RS)
D. 相位跟踪参考信号(Phase-tracking reference signals, PT-RS)
E. 主同步信号(Primary synchronization signal, PSS)