Meningkatnya permintaan pada pelayanan komunikasi mobile memberikan
dampak perkembangan yang cepat pada metode akses jamak. Teknologi UMTS yang
mengunakan W-CDMA yang dikembangkan dari teknologi akses jamak CDMA saat
ini dipertimbangkan sebagai suatu teknik yang memberi harapan untuk mendapatkan
kapasitas yang tinggi dalam system.
dari sitem komunikasi seluler yang mampu menyediakan layanan data kecepatan
tinggi ( multimedia )
Increasing request communication mobile service give impact to fast
development at multiple access method. UMTS technology that use wideband CDMA
that form developed from CDMA multiple access method. CDMA multiple access
method give more high capacity in UMTS system. UMTS technology is three generation
from mobile communication system that capable to ready multimedia service.
In W-CDMA system , all station use same frequency so the major noise
contributed is interference one carrier to another carrier. Something that cause
interference inter user because difference power receive signal level at base station (
Node B ) from everyone user.
In order to guard interference level in UMTS system be needed power control
existence. By power control , receive power signal level at base station ( Node B ) from
all user in cell that user have far distance from base station and near distance from base
station have same power signal level. So near – far interference can be decrease and
cause system capacity to be high.
In the simulation final project result that maximum cell capacity with power
control mechanism for voice service is 84 channel per cell at 1dB step size. While for 2
dB and 3 dB step size result that maximum cell capacity is 77 channel and 67 channel.
So can be conclusion that more step size in the power control caused decrease cell
capacity.
Keyword: UMTS , WCDMA , Multiple Access , Power Control