CDMA (Code Division Multiple Access), namely Multiple Access techniques that separate communications in the domain code. CDMA is a digital technology without cable (Digital Wirless Technology), which first made by United States companies - Qualcomm CDMA is a some use of different frequency spectrum without any double-talk.

This causes the CDMA more resistant to interference and noise. To mark users that use the same frequency spectrum, CDMA use The unique code that is PRCS (Pseudo - Random Code Sequence) In contrast with FDMA (frequency Division Multiple Access) and TDMA (Time Division Multiple Access), then use the CDMA and Frequency in the same access for each user.

The use of frequency and time of the same cause CDMA is vulnerable to interference. The greater the interference that occurs CDMA is a small capacity. CDMA bring great benefits that are above and similar technology another at this time. CDMA network offers the largest capacity for to serve more customers with the cost of the same infra-structure.

CDMA offer data transmission speeds higher among others. Every user / assign the user with the number of binary code, called Direct Sequence (DCS) when the call occurred. DCS is a signal raised by Linear modulation with wideband Pseudorandom Noise (PN) Sequence, so the Direct Sequence CDMA wider use signal from the FDMA and TDMA.

Wideband signal to reduce the work interesting and can make frequency reuse between cell progress. All the users are together in the range the radio frequency spectrum. These codes are divided on MS and BS called Psendorandom Noise (PN)



















Institutions that work with agencies worldwide industry standards and determine the needs of technical allocated for the program through the 3G system IMT-2000 (International Mobile Telecommunication-2000) is a 3G telecommunications standard.

The need for network IMT-2000 is a number of improvements and capacity efficiency through a system of 2G spectrum and support data services on speed 144 kbps transmission minimum condition for moving (outdoor) and 2 Mbps in the a silent (indoor).