adjacent interference

[rasar00]

DEAR friends

i nned your help

i want to ask about adjacent interference in gsm which . as you all know the requirement is C/A>=-9 , my question is why minus ? where in cochannel is positive?

also another question if i have two adjacent channel in the same area and the level for serving channel is -75 and the adjacent channel is -84 can it affect ?

[dsdd]

C/A ≥－9dB is GSM spec, but in real field C/A ≥－6dB could make the signal quality more stable. "A" is all adjacent signal strength .

[RF engineer]

DEAR friends

i nned your help

i want to ask about adjacent interference in gsm which . as you all know the requirement is C/A>=-9 , my question is why minus ? where in cochannel is positive?

also another question if i have two adjacent channel in the same area and the level for serving channel is -75 and the adjacent channel is -84 can it affect ?

The value of minus of Adjacency is come from that as C/A =-9 it mean if the neighbor signal stronger than serving cell is acceptable as Rx level (c)-Rxlevel(A)=-9
BR
RF

[rnpopt]

Your mentioned cell will not get adjacent channel interference. Because,condition is : Serving cell Rxlev - Neighbor(Adjacent channel Rxlev) > -9 db ( adjacent channel has to be atleast 9 dB stronger then the serving cell to create adjacent channel interference). For example,if serving cell is -75 dBm and adjacent channel neighbor cell is -66 dBm then : -75-(-66)= -9 dB; so in that case there will be adjacent channel interference.
But for your case: adjacent channel cell is 9dB wicker then the serving. So there will be no interference.

DEAR friends

i nned your help

i want to ask about adjacent interference in gsm which . as you all know the requirement is C/A>=-9 , my question is why minus ? where in cochannel is positive?

also another question if i have two adjacent channel in the same area and the level for serving channel is -75 and the adjacent channel is -84 can it affect ?