Sorry,
I should have look first in wiki, before asking this question as the answer is there:
It is now a well known fact that it is possible to cancel the interference at the mobile handset side by changing the baseband software without changing anything in the network side. SAIC-enabled mobiles can work in high interference levels. SAIC-enabled mobiles need even less transmit power from the network which in turn reduces the interference for non-SAIC mobiles. studies shows that with 100% SAIC mobile penetration a capacity gain of 60 to 80% is achievable. There are various approaches possible to have a SAIC-enabled phone:
1. Prefilter based baseband algorithms (2X complex than conventional receiver but gives 12-15 dB gain)
2. Constant Modulus based SAIC (simple but less gain and also it is not very robust)
3. Joint Detection (JD)