Si4313-B1
8.6. RSSI and Clear Channel Assessment
Received signal strength indicator (RSSI) is an estimate of the signal strength in the channel to which the receiver
is tuned. The RSSI value can be read from an 8-bit register with 0.5 dB resolution per bit. Figure 12 demonstrates
the relationship between input power level and RSSI value. The absolute value of the RSSI will change slightly
depending on the modem settings. The RSSI may be read at anytime, but an incorrect error may rarely occur. The
RSSI value may be incorrect if read during the update period. The update period is approximately 10 ns every
4 Tb. For 10 kbps, this would result in a 1 in 40,000 probability that the RSSI may be read incorrectly. This
probability is extremely low, but to avoid this, one of the following options is recommended: majority polling,
reading the RSSI value within 1 Tb of the RSSI interrupt, or using the RSSI threshold described in the next
paragraph for Clear Channel Assessment (CCA).
Add R/W
Function/Description
D7
D6
D5
D4
D3
D2
D1
D0
POR Def.
26
27
R
R/W
Received Signal Strength Indicator
RSSI Threshold for Clear Channel Indicator
rssi[7]
rssith[7]
rssi[6]
rssith[6]
rssi[5]
rssith[5]
rssi[4]
rssith[4]
rssi[3]
rssith[3]
rssi[2]
rssith[2]
rssi[1]
rssith[1]
rssi[0]
rssith[0]
00h
For CCA, threshold is programmed into rssith[7:0] in "Register 27h. RSSI Threshold for Clear Channel Indicator."
After the RSSI is evaluated in the preamble, a decision is made if the signal strength on this channel is above or
below the threshold. If the signal strength is above the programmed threshold then the RSSI status bit, irssi, in
"Register 04h. Interrupt/Status 2" will be set to 1. The RSSI status can also be routed to a GPIO line by configuring
the GPIO configuration register to GPIOx[3:0] = 1110.
RSSI vs Input Power
250
200
150
100
50
0
-120
-100
-80
-60
-40
-20
0
20
In Pow [dBm]
Figure 12. RSSI Value vs. Input Power
Rev. 1.0
39
相关PDF资料
SI4320-J1-FT IC RCVR FSK 915MHZ 5.4V 16-TSSOP
SI4322-A0-FT IC RX FSK UNI 868/915MHZ 16TSSOP
SI4324DY-T1-GE3 MOSFET N-CH D-S 30V 8-SOIC
SI4330-B1-FM IC RCVR ISM 960MHZ 3.6V 20-QFN
SI4354DY-T1-GE3 MOSFET N-CH D-S 30V 8-SOIC
SI4355-B1A-FM IC EZRADIO FM RECEIVER SI4355
SI4388DY-T1-GE3 MOSFET DUAL N-CH 30V 8-SOIC
SI4390DY-T1-GE3 MOSFET N-CH 30V 8.5A 8SOIC
相关代理商/技术参数
SI4313-B1-FMR 功能描述:射频接收器 240-960 MHz Receiver RoHS:否 制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel
SI4315-A0-FT 功能描述:射频接收器 Receivers - IA4315 RoHS:否 制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel
SI4320DY 制造商:VISHAY 制造商全称:Vishay Siliconix 功能描述:N-Channel 30-V (D-S) MOSFET
SI4320DY-T1 功能描述:MOSFET 30V 25A 1.6W RoHS:否 制造商:STMicroelectronics 晶体管极性:N-Channel 汲极/源极击穿电压:650 V 闸/源击穿电压:25 V 漏极连续电流:130 A 电阻汲极/源极 RDS(导通):0.014 Ohms 配置:Single 最大工作温度: 安装风格:Through Hole 封装 / 箱体:Max247 封装:Tube
SI4320DY-T1-E3 功能描述:MOSFET 30V 25A 3.5W 3.0mohm @ 10V RoHS:否 制造商:STMicroelectronics 晶体管极性:N-Channel 汲极/源极击穿电压:650 V 闸/源击穿电压:25 V 漏极连续电流:130 A 电阻汲极/源极 RDS(导通):0.014 Ohms 配置:Single 最大工作温度: 安装风格:Through Hole 封装 / 箱体:Max247 封装:Tube
SI4320DY-T1-GE3 功能描述:MOSFET 30V 25A 3.5W 3.0mohm @ 10V RoHS:否 制造商:STMicroelectronics 晶体管极性:N-Channel 汲极/源极击穿电压:650 V 闸/源击穿电压:25 V 漏极连续电流:130 A 电阻汲极/源极 RDS(导通):0.014 Ohms 配置:Single 最大工作温度: 安装风格:Through Hole 封装 / 箱体:Max247 封装:Tube
SI4320-J1-FT 功能描述:射频接收器 Receivers - IA4320 RoHS:否 制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel
SI4320-J1-FTR 功能描述:射频接收器 Receiver (EZRadio) RoHS:否 制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel