Dear all,
I am printing out my interference helper outcome using
LogComponentEnable ("InterferenceHelper", LOG_LEVEL_ALL) together with LOgCOmponentEnable("YansWifiPhy ", LOG_LEVEL_ALL)
Sometimes I see no interference at all denoted by "interference (W)= 0" , sometimes I see positive value such as interference(W) = 6.17e-13 .
However, what appears weird for me is that sometimes the interference(W) value is negative such as the following (look at the third interference(W) value is negative :
==============================output of interest======
receiving plcp payload
YansWifiPhy:StartReceivePacket(0x263cee0, 0x25d9480, OfdmRate6MbpsBW10MHz, 0, 0)
bandwidth(MHz)=10, signal(W)= 4.30941e-11, noise(W)=4.00287e-14, interference(W)=0, snr(linear)=1076.58
InterferenceHelper:CalculatePlcpHeaderPer(0x263cf00)
previous= +147683923.0ns, current=+147685258.0ns
previous= +147685258.0ns, current=+148315923.0ns
bandwidth(MHz)=10, signal(W)= 4.30941e-11, noise(W)=4.00287e-14, interference(W)=1.14475e-12, snr(linear)=36.373
Case 5a - previous is in the preamble and current is after payload start: mode=OfdmRate3MbpsBW10MHz, psr=1
snr(dB)=30.3205, per=0
receiving plcp payload
YansWifiPhy:StartReceivePacket(0x24fd8d0, 0x2938d80, OfdmRate6MbpsBW10MHz, 0, 0)
bandwidth(MHz)=10, signal(W)= 1.59013e-11, noise(W)=4.00287e-14,
interference(W)=-3.23117e-27, snr(linear)=397.248
InterferenceHelper:CalculatePlcpHeaderPer(0x24fd8f0)
previous= +147684223.0ns, current=+147685558.0ns
previous= +147685558.0ns, current=+148316223.0ns
bandwidth(MHz)=10, signal(W)= 1.59013e-11, noise(W)=4.00287e-14, interference(W)=6.1731e-13, snr(linear)=24.1904
Case 5a - previous is in the preamble and current is after payload start: mode=OfdmRate3MbpsBW10MHz, psr=1
snr(dB)=25.9906, per=0
receiving plcp payload
=============================end of output =====================
What causes such negative value ?
When I check in the code interference(W) value is from th variable "noiseinterferenceW" and in the code there is this expression
noiseInterferenceW += (*j).GetDelta ();
WHAt does this expression do ? Is this one cause the negative value ? Why is the interference power negative ?
Thank you.