RSSI为什么往往比RSCP小？

如题。
RSSI指示的手机在所在的载频上接收到的全部功率，RSCP指示的是手机接收到的导频信道信号强度，但为什么路测时软件显示的RSSI往往比RSCP小？

RSRP（Reference Signal Receiving Power）是在某个Symbol内承载Reference Signal的所有RE上接收到的信号功率的平均值；
而RSSI（Received Signal Strength Indicator）则是在这个Symbol内接收到的所有信号（包括导频信号和数据信号，邻区干扰信号，噪音信号等）功率的平均值
而RSRQ(Reference Signal Receiving Quality)则是RSRP和RSSI的比值，当然因为两者测量所基于的带宽可能不同，会用一个系数来调整，也就是 RSRQ = N*RSRP/RSSI
从定义来看RSRP相当于WCDMA里CPICH的RSCP，RSRQ相当于CPICH Ec/No.
在小区选择或重选时，通常使用RSRP就可以了，在切换时通常需要综合比较RSRP与RSRQ，如果仅比较RSRP可能导致频繁切换，如果仅比较RSRQ虽然减少切换频率但可能导致掉话，当然在切换时具体如何使用这两个参数是eNB实现问题。

RSSI是系统带宽的总功率(包括噪声)-@7I.a$R1k"e7`%d
RSRP是PDSCH信道的功率bbs.mscbsc.com:V%y6p*o"c+G/E
RSRQ=系统带宽的RB个数*RSRP/RSSImscbsc

LTE Reference Signal Received Power (RSRP)  

Definition

Reference signal received power (RSRP), is defined as the linear average over the power contributions (in [W]) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwidth. For RSRP determination the cell-specific reference signals R0 according TS 36.211 [3] shall be used. If the UE can reliably detect that R1 is available it may use R1 in addition to R0 to determine RSRP.   The reference point for the RSRP shall be the antenna connector of the UE.   If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRP of any of the individual diversity branches.

Applicable for

RRC_IDLE intra-frequency, RRC_IDLE inter-frequency, RRC_CONNECTED intra-frequency, RRC_CONNECTED inter-frequency

 
 
RSSI                      Received Signal Strength Indicator
 
RSSI在每个RAT里边的定义还有一些细小的差别,看看36214协议吧