Hi,
Its about far-near problem (05.05 p.5.1), i.e.
blocking by near mobile with
high signal at only 600kHz offset.
Therefore, calculated that LO noise at 600kHz offset should be around
-140dBc/Hz to keep nominal Rx sencitivity for wanted far mobile.
Mmm, interesting, I had never thought about this.
Can you confirm my computation is the right one :
Minimum Ec/No of 8 dB, thernal noise of GSM ~ -120 dBm, so the weakest
mobile would be a -112 dBm.
The interference I see specified in 05.05 is a -26 dBm sine, so with
-140 dBc/Hz you'd get a -166 dBm 'leak' of the interference in the
signal of interest at any given position, which you need to integrate
over the entire useful bandwidth of the GSM signal ( 271 kHz -> 10 *
log10(271e3) = 54 dB ), which would give a -112 dBm noise.
Cheers,
Sylvain