LTE信号强度
SignalStrength: 99 0 -73 -75 -120 -160 -1 20 -112 -17 -58 2147483647 0 2147483647 99 255 2147483647 gsm|lte use_rsrp_and_rssnr_for_lte_level [-128, -118, -108, -98] [-115, -105, -95, -85]
信号强度范围，Log中第9位是Rsrp -112, 第11位是Rssnr -58
Rsrp
[-140,-128) 0
[-128,-118) 1
[-118,-108) 2
[-108, -98) 3
[-98,-44] 4
Rssnr
[-200,-30) 0
[-30,10) 1
[10,45) 2
[45,130) 3
[130,300] 4
高通原生使用Rsrp和Rssnr来共同决定，Log中有use_rsrp_and_rssnr_for_lte_level的打印，取两者的最小值显示信号
目前S20项目修改成单独使用Rsrp来决定LTE信号强度
移动3G TDSCDMA
SignalStrength: 99 0 -120 -160 -120 -160 -1 99 2147483647 2147483647 2147483647 2147483647 0 2147483647 3 6 -114 gsm|lte use_only_rsrp_for_lte_level [-128, -118, -108, -98] [-115, -105, -95, -85]
mTdScdmaRscp 在第14位是2147483647
(-25，) | = 2147483647 0
[-110,-97) 1
[-97,-73) 2
[-73,-49) 3
[-49,-25] 4
联通3G WCDMA
SignalStrength: 99 0 -120 -160 -120 -160 -1 99 2147483647 2147483647