aaron_do
|
Hi,
thanks for the reply. I understand that it is a spectrum mask. However, when we do a frequency domain plot I think we usually either use PSD, or power at a single frequency. The spectrum mask usually covers a band. So for 802.15.4 the adjacent and alternate channel interference requirements are +0 dB and +30 dB.
So taking the +0dB case, assume we receive -85 dBm. Is the interferer:
1) -85 dBm at 5 MHz offset 2) -85 dBm/Hz from 5 MHz onwards (very unlikely) 3) -85 dBm spread over a frequency band (for example 2 MHz) leading to -148 dBm/Hz.
I guess (1) and (3) don't lead to very different receiver specs. However, the second part of my question is, can we assume that to meet standard requirements, the total interference power is -85 dBm + -55 dBm?
thanks, Aaron
|