Cdma downlink SNR clarification

Hello

Ive done it in the past (3-4years ago) but focusing on green perspectives + an 'old' mind trying to remember lead me to request some clarification on the types i am going to use.

Trying to calculate SIR in cdma network for downlink, using BS omnidirectional antennas, a simply scenario for voice service.

According to selected type of service we choose, p.e. voice, data rate, video etc we set the requested eb/no vaue (in dB). For voice we can set it to 5dB.

Proceesing gain: for voice acceptable data rate is around 12-13kbps so PG~=25dB.

Thermal noise Pn ~=-103dBm

Orthogonal factor a= 0.1-1.

Interferences: Icochannel: a*Pbs/pathloss, for every new user coming to our sector (BS antenna coverage)

Adjacent channel: Iadjacent: Pbs - pathloss(user,bs), for every new user coming to our cluster

First user gets only Themal noise so: ebn0 = PG + Pbs -pathloss - Pn

Second till end user: ebno = PG + Pbs - pathloss(user,bs) - (Pn + I)
where I = Ico-channel + Iadjacent

I am assuming something wrong? Do i forget something?

Thank you in advance.