- 卫星链路效率计算
- 卫星功放功率换算
上行链路和下行链路的 modcod 不同,分开计算。
计算公式:
公式(1)通过 datarate 和 modcod 计算 symbolrate、bandwidth、efficiency
symbolrate = datarate / ( mod_fact * viterbi_fec * rs_code )
bandwidth = symbolrate * ( 1 + roll_off )
efficiency = datarate / bandwidth
公式(2)通过 symbolrate 和 modcod 计算 datarate、bandwith、efficiency
datarate = symbolrate * ( mod_fact * viterbi_fec * rs_code )
bandwidth = symbolrate * ( 1 + roll_off )
efficiency = datarate / bandwidth
计算单位:
datarate: kbps
symbolrate: ksps
bandwith: kHz
efficiency: bps/Hz
常数定义:
rs_code = 188/204(约为 0.9216,可在程序中计算得出,小数保留 4 位有效数字)
roll_off = 0.05(滚降因子)
调制因子:
mod_fact = { "BPSK": 1, "QPSK": 2, "8PSK": 3, "16APSK": 4, "32APSK": 5, "64APSK": 6, "128APSK": 7, "256APSK": 8 }
调制因子取值方式:比如,当 modcod 为 QPSK 3/4 时,viterbi_fec = 3/4,以此类推,所以 viterbi_fec 是根据所选的 modcod 来取值的。
下行 modcod:
downlink_modcods:
[ "BPSK 1/5", "BPSK 11/45", "BPSK 4/15", "BPSK 1/3", "QPSK 2/9", "QPSK 11/45", "QPSK 1/4", "QPSK 4/15", "QPSK 13/45", "QPSK 14/45", "QPSK 1/3", "QPSK 2/5", "QPSK 9/20", "QPSK 7/15", "QPSK 1/2", "QPSK 11/20", "QPSK 8/15", "QPSK 3/5", "QPSK 2/3", "QPSK 32/45", "QPSK 3/4", "QPSK 4/5", "QPSK 5/6", "QPSK 8/9", "QPSK 9/10", "8PSK 7/15", "8PSK 8/15", "8PSK 3/5", "8PSK 26/45", "8PSK 23/36", "8PSK 2/3", "8PSK 25/36", "8PSK 13/18", "8PSK 32/45", "8PSK 3/4", "8PSK 5/6", "8PSK 8/9", "8PSK 9/10", "16APSK 1/2-L", "16APSK 7/15", "16APSK 8/15-L", "16APSK 5/9-L", "16APSK 8/15", "16APSK 3/5-L", "16APSK 26/45", "16APSK 3/5", "16APSK 28/45", "16APSK 23/36", "16APSK 2/3-L", "16APSK 2/3", "16APSK 25/36", "16APSK 13/18", "16APSK 32/45", "16APSK 3/4", "16APSK 7/9", "16APSK 4/5", "16APSK 5/6", "16APSK 77/90", "16APSK 8/9", "16APSK 9/10", "32APSK 2/3-L", "32APSK 2/3", "32APSK 32/45", "32APSK 11/15", "32APSK 3/4", "32APSK 7/9", "32APSK 4/5", "32APSK 5/6", "32APSK 8/9", "32APSK 9/10", "64APSK 32/45-L", "64APSK 11/15", "64APSK 7/9", "64APSK 4/5", "64APSK 5/6", "128APSK 3/4", "128APSK 7/9", "256APSK 29/45-L", "256APSK 2/3-L", "256APSK 31/45-L", "256APSK 32/45", "256APSK 11/15-L", "256APSK 3/4" ]
上行 modcod:
uplink_modcods:
[ "QPSK-7/20", "QPSK-2/5", "QPSK-9/20", "QPSK-1/2", "QPSK-11/20", "QPSK-3/5", "QPSK-13/20", "QPSK-7/10", "QPSK-3/4", "QPSK-4/5", "QPSK-17/20", "8PSK-7/15", "8PSK-1/2", "8PSK-8/15", "8PSK-17/30", "8PSK-3/5", "8PSK-19/30", "8PSK-2/3", "8PSK-7/10", "8PSK-11/15", "16APSK-2/5", "16APSK-17/40", "16APSK-9/20", "16APSK-19/40", "16APSK-1/2", "16APSK-21/40", "16APSK-11/20", "16APSK-23/40", "16APSK-3/5", "16APSK-5/8", "16APSK-13/20", "16APSK-27/40", "16APSK-7/10", "16APSK-29/40", "16APSK-3/4", "16APSK-31/40", "16APSK-4/5", "64APSK-31/60", "64APSK-8/15", "64APSK-11/20", "64APSK-17/30", "64APSK-7/12", "64APSK-3/5", "64APSK-37/60", "64APSK-19/30", "64APSK-13/20", "64APSK-2/3", "64APSK-41/60", "64APSK-7/10", "64APSK-43/60", "64APSK-11/15", "64APSK-3/4", "64APSK-23/30", "64APSK-47/60", "64APSK-4/5", "64APSK-49/60", "64APSK-5/6", "64APSK-17/20", "64APSK-13/15", "64APSK-53/6" ]
上行链路或下行链路都具备以下功能:
用户输入datarate,选择 modcod ,根据公式(1)计算:
数据速率(datarate):直接从用户输入读取
符号速率(symbolrate):计算后填入
占用带宽(bandwith):计算后填入
利用效率(efficiency):计算后填入
例如:
modcod 选 QPSK 3/4,datarate 输入 1000,那么:
数据速率(datarate):1000 kbps
符号速率(symbolrate):723.066 ksps (-3%)
占用带宽(bandwith):759.219 kHz (-3%)
利用效率(efficiency):1.317 bps/Hz
用户输入symbolrate,选择 modcod ,根据公式(2)计算:
符号速率(symbolrate):直接从用户输入读取
数据速率(datarate):计算后填入
占用带宽(bandwith):计算后填入
利用效率(efficiency):计算后填入
例如:
modcod 选 QPSK 3/4,symbolrate 输入 1000,那么:
符号速率(symbolrate):1000 ksps (-3%)
数据速率(datarate):1383.000 kbps
占用带宽(bandwith):1050.000 kHz (-3%)
利用效率(efficiency):1.317 bps/Hz
卫星功放的功率值通常有两种表示方式,一种是以 Watts 为单位表示,一种是以 dBm 为单位表示,所以程序具备两种单位互相换算的功能。
(1)用户输入单位为 Watts 的功率值,程序根据以下公式计算出 dBm 的功率值:
P(dBm) = 10 * Log10(P(W)) + 10 * Log(10)(1000(mW))
例如:
如果用户输入 BUC 输出功率为:8 W
那么:
BUC 的输出功率为:39.03 dBm
(1)用户输入单位为 dBm 的功率值,程序根据以下公式计算出 Watts 的功率值:
P(W) = 10^((P(W)/10)-3)
例如:
如果用户输入 BUC 输出功率为:38 dBm
那么:
BUC 的输出功率为:6.30957344480193 W